GNU Linux-libre 4.9-gnu1

[releases.git] / drivers / char / ipmi / ipmi_si_intf.c

/*
 * ipmi_si.c
 *
 * The interface to the IPMI driver for the system interfaces (KCS, SMIC,
 * BT).
 *
 * Author: MontaVista Software, Inc.
 *         Corey Minyard <minyard@mvista.com>
 *         source@mvista.com
 *
 * Copyright 2002 MontaVista Software Inc.
 * Copyright 2006 IBM Corp., Christian Krafft <krafft@de.ibm.com>
 *
 *  This program is free software; you can redistribute it and/or modify it
 *  under the terms of the GNU General Public License as published by the
 *  Free Software Foundation; either version 2 of the License, or (at your
 *  option) any later version.
 *
 *
 *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
 *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 *  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 *  BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 *  OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 *  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
 *  TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
 *  USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  675 Mass Ave, Cambridge, MA 02139, USA.
 */

/*
 * This file holds the "policy" for the interface to the SMI state
 * machine.  It does the configuration, handles timers and interrupts,
 * and drives the real SMI state machine.
 */

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/sched.h>
#include <linux/seq_file.h>
#include <linux/timer.h>
#include <linux/errno.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/list.h>
#include <linux/pci.h>
#include <linux/ioport.h>
#include <linux/notifier.h>
#include <linux/mutex.h>
#include <linux/kthread.h>
#include <asm/irq.h>
#include <linux/interrupt.h>
#include <linux/rcupdate.h>
#include <linux/ipmi.h>
#include <linux/ipmi_smi.h>
#include <asm/io.h>
#include "ipmi_si_sm.h"
#include <linux/dmi.h>
#include <linux/string.h>
#include <linux/ctype.h>
#include <linux/of_device.h>
#include <linux/of_platform.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/acpi.h>

#ifdef CONFIG_PARISC
#include <asm/hardware.h>       /* for register_parisc_driver() stuff */
#include <asm/parisc-device.h>
#endif

#define PFX "ipmi_si: "

/* Measure times between events in the driver. */
#undef DEBUG_TIMING

/* Call every 10 ms. */
#define SI_TIMEOUT_TIME_USEC    10000
#define SI_USEC_PER_JIFFY       (1000000/HZ)
#define SI_TIMEOUT_JIFFIES      (SI_TIMEOUT_TIME_USEC/SI_USEC_PER_JIFFY)
#define SI_SHORT_TIMEOUT_USEC  250 /* .25ms when the SM request a
                                      short timeout */

enum si_intf_state {
        SI_NORMAL,
        SI_GETTING_FLAGS,
        SI_GETTING_EVENTS,
        SI_CLEARING_FLAGS,
        SI_GETTING_MESSAGES,
        SI_CHECKING_ENABLES,
        SI_SETTING_ENABLES
        /* FIXME - add watchdog stuff. */
};

/* Some BT-specific defines we need here. */
#define IPMI_BT_INTMASK_REG             2
#define IPMI_BT_INTMASK_CLEAR_IRQ_BIT   2
#define IPMI_BT_INTMASK_ENABLE_IRQ_BIT  1

enum si_type {
        SI_KCS, SI_SMIC, SI_BT
};

static const char * const si_to_str[] = { "kcs", "smic", "bt" };

#define DEVICE_NAME "ipmi_si"

static struct platform_driver ipmi_driver;

/*
 * Indexes into stats[] in smi_info below.
 */
enum si_stat_indexes {
        /*
         * Number of times the driver requested a timer while an operation
         * was in progress.
         */
        SI_STAT_short_timeouts = 0,

        /*
         * Number of times the driver requested a timer while nothing was in
         * progress.
         */
        SI_STAT_long_timeouts,

        /* Number of times the interface was idle while being polled. */
        SI_STAT_idles,

        /* Number of interrupts the driver handled. */
        SI_STAT_interrupts,

        /* Number of time the driver got an ATTN from the hardware. */
        SI_STAT_attentions,

        /* Number of times the driver requested flags from the hardware. */
        SI_STAT_flag_fetches,

        /* Number of times the hardware didn't follow the state machine. */
        SI_STAT_hosed_count,

        /* Number of completed messages. */
        SI_STAT_complete_transactions,

        /* Number of IPMI events received from the hardware. */
        SI_STAT_events,

        /* Number of watchdog pretimeouts. */
        SI_STAT_watchdog_pretimeouts,

        /* Number of asynchronous messages received. */
        SI_STAT_incoming_messages,


        /* This *must* remain last, add new values above this. */
        SI_NUM_STATS
};

struct smi_info {
        int                    intf_num;
        ipmi_smi_t             intf;
        struct si_sm_data      *si_sm;
        const struct si_sm_handlers *handlers;
        enum si_type           si_type;
        spinlock_t             si_lock;
        struct ipmi_smi_msg    *waiting_msg;
        struct ipmi_smi_msg    *curr_msg;
        enum si_intf_state     si_state;

        /*
         * Used to handle the various types of I/O that can occur with
         * IPMI
         */
        struct si_sm_io io;
        int (*io_setup)(struct smi_info *info);
        void (*io_cleanup)(struct smi_info *info);
        int (*irq_setup)(struct smi_info *info);
        void (*irq_cleanup)(struct smi_info *info);
        unsigned int io_size;
        enum ipmi_addr_src addr_source; /* ACPI, PCI, SMBIOS, hardcode, etc. */
        void (*addr_source_cleanup)(struct smi_info *info);
        void *addr_source_data;

        /*
         * Per-OEM handler, called from handle_flags().  Returns 1
         * when handle_flags() needs to be re-run or 0 indicating it
         * set si_state itself.
         */
        int (*oem_data_avail_handler)(struct smi_info *smi_info);

        /*
         * Flags from the last GET_MSG_FLAGS command, used when an ATTN
         * is set to hold the flags until we are done handling everything
         * from the flags.
         */
#define RECEIVE_MSG_AVAIL       0x01
#define EVENT_MSG_BUFFER_FULL   0x02
#define WDT_PRE_TIMEOUT_INT     0x08
#define OEM0_DATA_AVAIL     0x20
#define OEM1_DATA_AVAIL     0x40
#define OEM2_DATA_AVAIL     0x80
#define OEM_DATA_AVAIL      (OEM0_DATA_AVAIL | \
                             OEM1_DATA_AVAIL | \
                             OEM2_DATA_AVAIL)
        unsigned char       msg_flags;

        /* Does the BMC have an event buffer? */
        bool                has_event_buffer;

        /*
         * If set to true, this will request events the next time the
         * state machine is idle.
         */
        atomic_t            req_events;

        /*
         * If true, run the state machine to completion on every send
         * call.  Generally used after a panic to make sure stuff goes
         * out.
         */
        bool                run_to_completion;

        /* The I/O port of an SI interface. */
        int                 port;

        /*
         * The space between start addresses of the two ports.  For
         * instance, if the first port is 0xca2 and the spacing is 4, then
         * the second port is 0xca6.
         */
        unsigned int        spacing;

        /* zero if no irq; */
        int                 irq;

        /* The timer for this si. */
        struct timer_list   si_timer;

        /* This flag is set, if the timer is running (timer_pending() isn't enough) */
        bool                timer_running;

        /* The time (in jiffies) the last timeout occurred at. */
        unsigned long       last_timeout_jiffies;

        /* Are we waiting for the events, pretimeouts, received msgs? */
        atomic_t            need_watch;

        /*
         * The driver will disable interrupts when it gets into a
         * situation where it cannot handle messages due to lack of
         * memory.  Once that situation clears up, it will re-enable
         * interrupts.
         */
        bool interrupt_disabled;

        /*
         * Does the BMC support events?
         */
        bool supports_event_msg_buff;

        /*
         * Can we disable interrupts the global enables receive irq
         * bit?  There are currently two forms of brokenness, some
         * systems cannot disable the bit (which is technically within
         * the spec but a bad idea) and some systems have the bit
         * forced to zero even though interrupts work (which is
         * clearly outside the spec).  The next bool tells which form
         * of brokenness is present.
         */
        bool cannot_disable_irq;

        /*
         * Some systems are broken and cannot set the irq enable
         * bit, even if they support interrupts.
         */
        bool irq_enable_broken;

        /*
         * Did we get an attention that we did not handle?
         */
        bool got_attn;

        /* From the get device id response... */
        struct ipmi_device_id device_id;

        /* Driver model stuff. */
        struct device *dev;
        struct platform_device *pdev;

        /*
         * True if we allocated the device, false if it came from
         * someplace else (like PCI).
         */
        bool dev_registered;

        /* Slave address, could be reported from DMI. */
        unsigned char slave_addr;

        /* Counters and things for the proc filesystem. */
        atomic_t stats[SI_NUM_STATS];

        struct task_struct *thread;

        struct list_head link;
        union ipmi_smi_info_union addr_info;
};

#define smi_inc_stat(smi, stat) \
        atomic_inc(&(smi)->stats[SI_STAT_ ## stat])
#define smi_get_stat(smi, stat) \
        ((unsigned int) atomic_read(&(smi)->stats[SI_STAT_ ## stat]))

#define SI_MAX_PARMS 4

static int force_kipmid[SI_MAX_PARMS];
static int num_force_kipmid;
#ifdef CONFIG_PCI
static bool pci_registered;
#endif
#ifdef CONFIG_PARISC
static bool parisc_registered;
#endif

static unsigned int kipmid_max_busy_us[SI_MAX_PARMS];
static int num_max_busy_us;

static bool unload_when_empty = true;

static int add_smi(struct smi_info *smi);
static int try_smi_init(struct smi_info *smi);
static void cleanup_one_si(struct smi_info *to_clean);
static void cleanup_ipmi_si(void);

#ifdef DEBUG_TIMING
void debug_timestamp(char *msg)
{
        struct timespec64 t;

        getnstimeofday64(&t);
        pr_debug("**%s: %lld.%9.9ld\n", msg, (long long) t.tv_sec, t.tv_nsec);
}
#else
#define debug_timestamp(x)
#endif

static ATOMIC_NOTIFIER_HEAD(xaction_notifier_list);
static int register_xaction_notifier(struct notifier_block *nb)
{
        return atomic_notifier_chain_register(&xaction_notifier_list, nb);
}

static void deliver_recv_msg(struct smi_info *smi_info,
                             struct ipmi_smi_msg *msg)
{
        /* Deliver the message to the upper layer. */
        if (smi_info->intf)
                ipmi_smi_msg_received(smi_info->intf, msg);
        else
                ipmi_free_smi_msg(msg);
}

static void return_hosed_msg(struct smi_info *smi_info, int cCode)
{
        struct ipmi_smi_msg *msg = smi_info->curr_msg;

        if (cCode < 0 || cCode > IPMI_ERR_UNSPECIFIED)
                cCode = IPMI_ERR_UNSPECIFIED;
        /* else use it as is */

        /* Make it a response */
        msg->rsp[0] = msg->data[0] | 4;
        msg->rsp[1] = msg->data[1];
        msg->rsp[2] = cCode;
        msg->rsp_size = 3;

        smi_info->curr_msg = NULL;
        deliver_recv_msg(smi_info, msg);
}

static enum si_sm_result start_next_msg(struct smi_info *smi_info)
{
        int              rv;

        if (!smi_info->waiting_msg) {
                smi_info->curr_msg = NULL;
                rv = SI_SM_IDLE;
        } else {
                int err;

                smi_info->curr_msg = smi_info->waiting_msg;
                smi_info->waiting_msg = NULL;
                debug_timestamp("Start2");
                err = atomic_notifier_call_chain(&xaction_notifier_list,
                                0, smi_info);
                if (err & NOTIFY_STOP_MASK) {
                        rv = SI_SM_CALL_WITHOUT_DELAY;
                        goto out;
                }
                err = smi_info->handlers->start_transaction(
                        smi_info->si_sm,
                        smi_info->curr_msg->data,
                        smi_info->curr_msg->data_size);
                if (err)
                        return_hosed_msg(smi_info, err);

                rv = SI_SM_CALL_WITHOUT_DELAY;
        }
out:
        return rv;
}

static void smi_mod_timer(struct smi_info *smi_info, unsigned long new_val)
{
        smi_info->last_timeout_jiffies = jiffies;
        mod_timer(&smi_info->si_timer, new_val);
        smi_info->timer_running = true;
}

/*
 * Start a new message and (re)start the timer and thread.
 */
static void start_new_msg(struct smi_info *smi_info, unsigned char *msg,
                          unsigned int size)
{
        smi_mod_timer(smi_info, jiffies + SI_TIMEOUT_JIFFIES);

        if (smi_info->thread)
                wake_up_process(smi_info->thread);

        smi_info->handlers->start_transaction(smi_info->si_sm, msg, size);
}

static void start_check_enables(struct smi_info *smi_info, bool start_timer)
{
        unsigned char msg[2];

        msg[0] = (IPMI_NETFN_APP_REQUEST << 2);
        msg[1] = IPMI_GET_BMC_GLOBAL_ENABLES_CMD;

        if (start_timer)
                start_new_msg(smi_info, msg, 2);
        else
                smi_info->handlers->start_transaction(smi_info->si_sm, msg, 2);
        smi_info->si_state = SI_CHECKING_ENABLES;
}

static void start_clear_flags(struct smi_info *smi_info, bool start_timer)
{
        unsigned char msg[3];

        /* Make sure the watchdog pre-timeout flag is not set at startup. */
        msg[0] = (IPMI_NETFN_APP_REQUEST << 2);
        msg[1] = IPMI_CLEAR_MSG_FLAGS_CMD;
        msg[2] = WDT_PRE_TIMEOUT_INT;

        if (start_timer)
                start_new_msg(smi_info, msg, 3);
        else
                smi_info->handlers->start_transaction(smi_info->si_sm, msg, 3);
        smi_info->si_state = SI_CLEARING_FLAGS;
}

static void start_getting_msg_queue(struct smi_info *smi_info)
{
        smi_info->curr_msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
        smi_info->curr_msg->data[1] = IPMI_GET_MSG_CMD;
        smi_info->curr_msg->data_size = 2;

        start_new_msg(smi_info, smi_info->curr_msg->data,
                      smi_info->curr_msg->data_size);
        smi_info->si_state = SI_GETTING_MESSAGES;
}

static void start_getting_events(struct smi_info *smi_info)
{
        smi_info->curr_msg->data[0] = (IPMI_NETFN_APP_REQUEST << 2);
        smi_info->curr_msg->data[1] = IPMI_READ_EVENT_MSG_BUFFER_CMD;
        smi_info->curr_msg->data_size = 2;

        start_new_msg(smi_info, smi_info->curr_msg->data,
                      smi_info->curr_msg->data_size);
        smi_info->si_state = SI_GETTING_EVENTS;
}

/*
 * When we have a situtaion where we run out of memory and cannot
 * allocate messages, we just leave them in the BMC and run the system
 * polled until we can allocate some memory.  Once we have some
 * memory, we will re-enable the interrupt.
 *
 * Note that we cannot just use disable_irq(), since the interrupt may
 * be shared.
 */
static inline bool disable_si_irq(struct smi_info *smi_info, bool start_timer)
{
        if ((smi_info->irq) && (!smi_info->interrupt_disabled)) {
                smi_info->interrupt_disabled = true;
                start_check_enables(smi_info, start_timer);
                return true;
        }
        return false;
}

static inline bool enable_si_irq(struct smi_info *smi_info)
{
        if ((smi_info->irq) && (smi_info->interrupt_disabled)) {
                smi_info->interrupt_disabled = false;
                start_check_enables(smi_info, true);
                return true;
        }
        return false;
}

/*
 * Allocate a message.  If unable to allocate, start the interrupt
 * disable process and return NULL.  If able to allocate but
 * interrupts are disabled, free the message and return NULL after
 * starting the interrupt enable process.
 */
static struct ipmi_smi_msg *alloc_msg_handle_irq(struct smi_info *smi_info)
{
        struct ipmi_smi_msg *msg;

        msg = ipmi_alloc_smi_msg();
        if (!msg) {
                if (!disable_si_irq(smi_info, true))
                        smi_info->si_state = SI_NORMAL;
        } else if (enable_si_irq(smi_info)) {
                ipmi_free_smi_msg(msg);
                msg = NULL;
        }
        return msg;
}

static void handle_flags(struct smi_info *smi_info)
{
retry:
        if (smi_info->msg_flags & WDT_PRE_TIMEOUT_INT) {
                /* Watchdog pre-timeout */
                smi_inc_stat(smi_info, watchdog_pretimeouts);

                start_clear_flags(smi_info, true);
                smi_info->msg_flags &= ~WDT_PRE_TIMEOUT_INT;
                if (smi_info->intf)
                        ipmi_smi_watchdog_pretimeout(smi_info->intf);
        } else if (smi_info->msg_flags & RECEIVE_MSG_AVAIL) {
                /* Messages available. */
                smi_info->curr_msg = alloc_msg_handle_irq(smi_info);
                if (!smi_info->curr_msg)
                        return;

                start_getting_msg_queue(smi_info);
        } else if (smi_info->msg_flags & EVENT_MSG_BUFFER_FULL) {
                /* Events available. */
                smi_info->curr_msg = alloc_msg_handle_irq(smi_info);
                if (!smi_info->curr_msg)
                        return;

                start_getting_events(smi_info);
        } else if (smi_info->msg_flags & OEM_DATA_AVAIL &&
                   smi_info->oem_data_avail_handler) {
                if (smi_info->oem_data_avail_handler(smi_info))
                        goto retry;
        } else
                smi_info->si_state = SI_NORMAL;
}

/*
 * Global enables we care about.
 */
#define GLOBAL_ENABLES_MASK (IPMI_BMC_EVT_MSG_BUFF | IPMI_BMC_RCV_MSG_INTR | \
                             IPMI_BMC_EVT_MSG_INTR)

static u8 current_global_enables(struct smi_info *smi_info, u8 base,
                                 bool *irq_on)
{
        u8 enables = 0;

        if (smi_info->supports_event_msg_buff)
                enables |= IPMI_BMC_EVT_MSG_BUFF;

        if (((smi_info->irq && !smi_info->interrupt_disabled) ||
             smi_info->cannot_disable_irq) &&
            !smi_info->irq_enable_broken)
                enables |= IPMI_BMC_RCV_MSG_INTR;

        if (smi_info->supports_event_msg_buff &&
            smi_info->irq && !smi_info->interrupt_disabled &&
            !smi_info->irq_enable_broken)
                enables |= IPMI_BMC_EVT_MSG_INTR;

        *irq_on = enables & (IPMI_BMC_EVT_MSG_INTR | IPMI_BMC_RCV_MSG_INTR);

        return enables;
}

static void check_bt_irq(struct smi_info *smi_info, bool irq_on)
{
        u8 irqstate = smi_info->io.inputb(&smi_info->io, IPMI_BT_INTMASK_REG);

        irqstate &= IPMI_BT_INTMASK_ENABLE_IRQ_BIT;

        if ((bool)irqstate == irq_on)
                return;

        if (irq_on)
                smi_info->io.outputb(&smi_info->io, IPMI_BT_INTMASK_REG,
                                     IPMI_BT_INTMASK_ENABLE_IRQ_BIT);
        else
                smi_info->io.outputb(&smi_info->io, IPMI_BT_INTMASK_REG, 0);
}

static void handle_transaction_done(struct smi_info *smi_info)
{
        struct ipmi_smi_msg *msg;

        debug_timestamp("Done");
        switch (smi_info->si_state) {
        case SI_NORMAL:
                if (!smi_info->curr_msg)
                        break;

                smi_info->curr_msg->rsp_size
                        = smi_info->handlers->get_result(
                                smi_info->si_sm,
                                smi_info->curr_msg->rsp,
                                IPMI_MAX_MSG_LENGTH);

                /*
                 * Do this here becase deliver_recv_msg() releases the
                 * lock, and a new message can be put in during the
                 * time the lock is released.
                 */
                msg = smi_info->curr_msg;
                smi_info->curr_msg = NULL;
                deliver_recv_msg(smi_info, msg);
                break;

        case SI_GETTING_FLAGS:
        {
                unsigned char msg[4];
                unsigned int  len;

                /* We got the flags from the SMI, now handle them. */
                len = smi_info->handlers->get_result(smi_info->si_sm, msg, 4);
                if (msg[2] != 0) {
                        /* Error fetching flags, just give up for now. */
                        smi_info->si_state = SI_NORMAL;
                } else if (len < 4) {
                        /*
                         * Hmm, no flags.  That's technically illegal, but
                         * don't use uninitialized data.
                         */
                        smi_info->si_state = SI_NORMAL;
                } else {
                        smi_info->msg_flags = msg[3];
                        handle_flags(smi_info);
                }
                break;
        }

        case SI_CLEARING_FLAGS:
        {
                unsigned char msg[3];

                /* We cleared the flags. */
                smi_info->handlers->get_result(smi_info->si_sm, msg, 3);
                if (msg[2] != 0) {
                        /* Error clearing flags */
                        dev_warn(smi_info->dev,
                                 "Error clearing flags: %2.2x\n", msg[2]);
                }
                smi_info->si_state = SI_NORMAL;
                break;
        }

        case SI_GETTING_EVENTS:
        {
                smi_info->curr_msg->rsp_size
                        = smi_info->handlers->get_result(
                                smi_info->si_sm,
                                smi_info->curr_msg->rsp,
                                IPMI_MAX_MSG_LENGTH);

                /*
                 * Do this here becase deliver_recv_msg() releases the
                 * lock, and a new message can be put in during the
                 * time the lock is released.
                 */
                msg = smi_info->curr_msg;
                smi_info->curr_msg = NULL;
                if (msg->rsp[2] != 0) {
                        /* Error getting event, probably done. */
                        msg->done(msg);

                        /* Take off the event flag. */
                        smi_info->msg_flags &= ~EVENT_MSG_BUFFER_FULL;
                        handle_flags(smi_info);
                } else {
                        smi_inc_stat(smi_info, events);

                        /*
                         * Do this before we deliver the message
                         * because delivering the message releases the
                         * lock and something else can mess with the
                         * state.
                         */
                        handle_flags(smi_info);

                        deliver_recv_msg(smi_info, msg);
                }
                break;
        }

        case SI_GETTING_MESSAGES:
        {
                smi_info->curr_msg->rsp_size
                        = smi_info->handlers->get_result(
                                smi_info->si_sm,
                                smi_info->curr_msg->rsp,
                                IPMI_MAX_MSG_LENGTH);

                /*
                 * Do this here becase deliver_recv_msg() releases the
                 * lock, and a new message can be put in during the
                 * time the lock is released.
                 */
                msg = smi_info->curr_msg;
                smi_info->curr_msg = NULL;
                if (msg->rsp[2] != 0) {
                        /* Error getting event, probably done. */
                        msg->done(msg);

                        /* Take off the msg flag. */
                        smi_info->msg_flags &= ~RECEIVE_MSG_AVAIL;
                        handle_flags(smi_info);
                } else {
                        smi_inc_stat(smi_info, incoming_messages);

                        /*
                         * Do this before we deliver the message
                         * because delivering the message releases the
                         * lock and something else can mess with the
                         * state.
                         */
                        handle_flags(smi_info);

                        deliver_recv_msg(smi_info, msg);
                }
                break;
        }

        case SI_CHECKING_ENABLES:
        {
                unsigned char msg[4];
                u8 enables;
                bool irq_on;

                /* We got the flags from the SMI, now handle them. */
                smi_info->handlers->get_result(smi_info->si_sm, msg, 4);
                if (msg[2] != 0) {
                        dev_warn(smi_info->dev,
                                 "Couldn't get irq info: %x.\n", msg[2]);
                        dev_warn(smi_info->dev,
                                 "Maybe ok, but ipmi might run very slowly.\n");
                        smi_info->si_state = SI_NORMAL;
                        break;
                }
                enables = current_global_enables(smi_info, 0, &irq_on);
                if (smi_info->si_type == SI_BT)
                        /* BT has its own interrupt enable bit. */
                        check_bt_irq(smi_info, irq_on);
                if (enables != (msg[3] & GLOBAL_ENABLES_MASK)) {
                        /* Enables are not correct, fix them. */
                        msg[0] = (IPMI_NETFN_APP_REQUEST << 2);
                        msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
                        msg[2] = enables | (msg[3] & ~GLOBAL_ENABLES_MASK);
                        smi_info->handlers->start_transaction(
                                smi_info->si_sm, msg, 3);
                        smi_info->si_state = SI_SETTING_ENABLES;
                } else if (smi_info->supports_event_msg_buff) {
                        smi_info->curr_msg = ipmi_alloc_smi_msg();
                        if (!smi_info->curr_msg) {
                                smi_info->si_state = SI_NORMAL;
                                break;
                        }
                        start_getting_msg_queue(smi_info);
                } else {
                        smi_info->si_state = SI_NORMAL;
                }
                break;
        }

        case SI_SETTING_ENABLES:
        {
                unsigned char msg[4];

                smi_info->handlers->get_result(smi_info->si_sm, msg, 4);
                if (msg[2] != 0)
                        dev_warn(smi_info->dev,
                                 "Could not set the global enables: 0x%x.\n",
                                 msg[2]);

                if (smi_info->supports_event_msg_buff) {
                        smi_info->curr_msg = ipmi_alloc_smi_msg();
                        if (!smi_info->curr_msg) {
                                smi_info->si_state = SI_NORMAL;
                                break;
                        }
                        start_getting_msg_queue(smi_info);
                } else {
                        smi_info->si_state = SI_NORMAL;
                }
                break;
        }
        }
}

/*
 * Called on timeouts and events.  Timeouts should pass the elapsed
 * time, interrupts should pass in zero.  Must be called with
 * si_lock held and interrupts disabled.
 */
static enum si_sm_result smi_event_handler(struct smi_info *smi_info,
                                           int time)
{
        enum si_sm_result si_sm_result;

restart:
        /*
         * There used to be a loop here that waited a little while
         * (around 25us) before giving up.  That turned out to be
         * pointless, the minimum delays I was seeing were in the 300us
         * range, which is far too long to wait in an interrupt.  So
         * we just run until the state machine tells us something
         * happened or it needs a delay.
         */
        si_sm_result = smi_info->handlers->event(smi_info->si_sm, time);
        time = 0;
        while (si_sm_result == SI_SM_CALL_WITHOUT_DELAY)
                si_sm_result = smi_info->handlers->event(smi_info->si_sm, 0);

        if (si_sm_result == SI_SM_TRANSACTION_COMPLETE) {
                smi_inc_stat(smi_info, complete_transactions);

                handle_transaction_done(smi_info);
                goto restart;
        } else if (si_sm_result == SI_SM_HOSED) {
                smi_inc_stat(smi_info, hosed_count);

                /*
                 * Do the before return_hosed_msg, because that
                 * releases the lock.
                 */
                smi_info->si_state = SI_NORMAL;
                if (smi_info->curr_msg != NULL) {
                        /*
                         * If we were handling a user message, format
                         * a response to send to the upper layer to
                         * tell it about the error.
                         */
                        return_hosed_msg(smi_info, IPMI_ERR_UNSPECIFIED);
                }
                goto restart;
        }

        /*
         * We prefer handling attn over new messages.  But don't do
         * this if there is not yet an upper layer to handle anything.
         */
        if (likely(smi_info->intf) &&
            (si_sm_result == SI_SM_ATTN || smi_info->got_attn)) {
                unsigned char msg[2];

                if (smi_info->si_state != SI_NORMAL) {
                        /*
                         * We got an ATTN, but we are doing something else.
                         * Handle the ATTN later.
                         */
                        smi_info->got_attn = true;
                } else {
                        smi_info->got_attn = false;
                        smi_inc_stat(smi_info, attentions);

                        /*
                         * Got a attn, send down a get message flags to see
                         * what's causing it.  It would be better to handle
                         * this in the upper layer, but due to the way
                         * interrupts work with the SMI, that's not really
                         * possible.
                         */
                        msg[0] = (IPMI_NETFN_APP_REQUEST << 2);
                        msg[1] = IPMI_GET_MSG_FLAGS_CMD;

                        start_new_msg(smi_info, msg, 2);
                        smi_info->si_state = SI_GETTING_FLAGS;
                        goto restart;
                }
        }

        /* If we are currently idle, try to start the next message. */
        if (si_sm_result == SI_SM_IDLE) {
                smi_inc_stat(smi_info, idles);

                si_sm_result = start_next_msg(smi_info);
                if (si_sm_result != SI_SM_IDLE)
                        goto restart;
        }

        if ((si_sm_result == SI_SM_IDLE)
            && (atomic_read(&smi_info->req_events))) {
                /*
                 * We are idle and the upper layer requested that I fetch
                 * events, so do so.
                 */
                atomic_set(&smi_info->req_events, 0);

                /*
                 * Take this opportunity to check the interrupt and
                 * message enable state for the BMC.  The BMC can be
                 * asynchronously reset, and may thus get interrupts
                 * disable and messages disabled.
                 */
                if (smi_info->supports_event_msg_buff || smi_info->irq) {
                        start_check_enables(smi_info, true);
                } else {
                        smi_info->curr_msg = alloc_msg_handle_irq(smi_info);
                        if (!smi_info->curr_msg)
                                goto out;

                        start_getting_events(smi_info);
                }
                goto restart;
        }

        if (si_sm_result == SI_SM_IDLE && smi_info->timer_running) {
                /* Ok it if fails, the timer will just go off. */
                if (del_timer(&smi_info->si_timer))
                        smi_info->timer_running = false;
        }

out:
        return si_sm_result;
}

static void check_start_timer_thread(struct smi_info *smi_info)
{
        if (smi_info->si_state == SI_NORMAL && smi_info->curr_msg == NULL) {
                smi_mod_timer(smi_info, jiffies + SI_TIMEOUT_JIFFIES);

                if (smi_info->thread)
                        wake_up_process(smi_info->thread);

                start_next_msg(smi_info);
                smi_event_handler(smi_info, 0);
        }
}

static void flush_messages(void *send_info)
{
        struct smi_info *smi_info = send_info;
        enum si_sm_result result;

        /*
         * Currently, this function is called only in run-to-completion
         * mode.  This means we are single-threaded, no need for locks.
         */
        result = smi_event_handler(smi_info, 0);
        while (result != SI_SM_IDLE) {
                udelay(SI_SHORT_TIMEOUT_USEC);
                result = smi_event_handler(smi_info, SI_SHORT_TIMEOUT_USEC);
        }
}

static void sender(void                *send_info,
                   struct ipmi_smi_msg *msg)
{
        struct smi_info   *smi_info = send_info;
        unsigned long     flags;

        debug_timestamp("Enqueue");

        if (smi_info->run_to_completion) {
                /*
                 * If we are running to completion, start it.  Upper
                 * layer will call flush_messages to clear it out.
                 */
                smi_info->waiting_msg = msg;
                return;
        }

        spin_lock_irqsave(&smi_info->si_lock, flags);
        /*
         * The following two lines don't need to be under the lock for
         * the lock's sake, but they do need SMP memory barriers to
         * avoid getting things out of order.  We are already claiming
         * the lock, anyway, so just do it under the lock to avoid the
         * ordering problem.
         */
        BUG_ON(smi_info->waiting_msg);
        smi_info->waiting_msg = msg;
        check_start_timer_thread(smi_info);
        spin_unlock_irqrestore(&smi_info->si_lock, flags);
}

static void set_run_to_completion(void *send_info, bool i_run_to_completion)
{
        struct smi_info   *smi_info = send_info;

        smi_info->run_to_completion = i_run_to_completion;
        if (i_run_to_completion)
                flush_messages(smi_info);
}

/*
 * Use -1 in the nsec value of the busy waiting timespec to tell that
 * we are spinning in kipmid looking for something and not delaying
 * between checks
 */
static inline void ipmi_si_set_not_busy(struct timespec64 *ts)
{
        ts->tv_nsec = -1;
}
static inline int ipmi_si_is_busy(struct timespec64 *ts)
{
        return ts->tv_nsec != -1;
}

static inline int ipmi_thread_busy_wait(enum si_sm_result smi_result,
                                        const struct smi_info *smi_info,
                                        struct timespec64 *busy_until)
{
        unsigned int max_busy_us = 0;

        if (smi_info->intf_num < num_max_busy_us)
                max_busy_us = kipmid_max_busy_us[smi_info->intf_num];
        if (max_busy_us == 0 || smi_result != SI_SM_CALL_WITH_DELAY)
                ipmi_si_set_not_busy(busy_until);
        else if (!ipmi_si_is_busy(busy_until)) {
                getnstimeofday64(busy_until);
                timespec64_add_ns(busy_until, max_busy_us*NSEC_PER_USEC);
        } else {
                struct timespec64 now;

                getnstimeofday64(&now);
                if (unlikely(timespec64_compare(&now, busy_until) > 0)) {
                        ipmi_si_set_not_busy(busy_until);
                        return 0;
                }
        }
        return 1;
}


/*
 * A busy-waiting loop for speeding up IPMI operation.
 *
 * Lousy hardware makes this hard.  This is only enabled for systems
 * that are not BT and do not have interrupts.  It starts spinning
 * when an operation is complete or until max_busy tells it to stop
 * (if that is enabled).  See the paragraph on kimid_max_busy_us in
 * Documentation/IPMI.txt for details.
 */
static int ipmi_thread(void *data)
{
        struct smi_info *smi_info = data;
        unsigned long flags;
        enum si_sm_result smi_result;
        struct timespec64 busy_until;

        ipmi_si_set_not_busy(&busy_until);
        set_user_nice(current, MAX_NICE);
        while (!kthread_should_stop()) {
                int busy_wait;

                spin_lock_irqsave(&(smi_info->si_lock), flags);
                smi_result = smi_event_handler(smi_info, 0);

                /*
                 * If the driver is doing something, there is a possible
                 * race with the timer.  If the timer handler see idle,
                 * and the thread here sees something else, the timer
                 * handler won't restart the timer even though it is
                 * required.  So start it here if necessary.
                 */
                if (smi_result != SI_SM_IDLE && !smi_info->timer_running)
                        smi_mod_timer(smi_info, jiffies + SI_TIMEOUT_JIFFIES);

                spin_unlock_irqrestore(&(smi_info->si_lock), flags);
                busy_wait = ipmi_thread_busy_wait(smi_result, smi_info,
                                                  &busy_until);
                if (smi_result == SI_SM_CALL_WITHOUT_DELAY)
                        ; /* do nothing */
                else if (smi_result == SI_SM_CALL_WITH_DELAY && busy_wait)
                        schedule();
                else if (smi_result == SI_SM_IDLE) {
                        if (atomic_read(&smi_info->need_watch)) {
                                schedule_timeout_interruptible(100);
                        } else {
                                /* Wait to be woken up when we are needed. */
                                __set_current_state(TASK_INTERRUPTIBLE);
                                schedule();
                        }
                } else
                        schedule_timeout_interruptible(1);
        }
        return 0;
}


static void poll(void *send_info)
{
        struct smi_info *smi_info = send_info;
        unsigned long flags = 0;
        bool run_to_completion = smi_info->run_to_completion;

        /*
         * Make sure there is some delay in the poll loop so we can
         * drive time forward and timeout things.
         */
        udelay(10);
        if (!run_to_completion)
                spin_lock_irqsave(&smi_info->si_lock, flags);
        smi_event_handler(smi_info, 10);
        if (!run_to_completion)
                spin_unlock_irqrestore(&smi_info->si_lock, flags);
}

static void request_events(void *send_info)
{
        struct smi_info *smi_info = send_info;

        if (!smi_info->has_event_buffer)
                return;

        atomic_set(&smi_info->req_events, 1);
}

static void set_need_watch(void *send_info, bool enable)
{
        struct smi_info *smi_info = send_info;
        unsigned long flags;

        atomic_set(&smi_info->need_watch, enable);
        spin_lock_irqsave(&smi_info->si_lock, flags);
        check_start_timer_thread(smi_info);
        spin_unlock_irqrestore(&smi_info->si_lock, flags);
}

static int initialized;

static void smi_timeout(unsigned long data)
{
        struct smi_info   *smi_info = (struct smi_info *) data;
        enum si_sm_result smi_result;
        unsigned long     flags;
        unsigned long     jiffies_now;
        long              time_diff;
        long              timeout;

        spin_lock_irqsave(&(smi_info->si_lock), flags);
        debug_timestamp("Timer");

        jiffies_now = jiffies;
        time_diff = (((long)jiffies_now - (long)smi_info->last_timeout_jiffies)
                     * SI_USEC_PER_JIFFY);
        smi_result = smi_event_handler(smi_info, time_diff);

        if ((smi_info->irq) && (!smi_info->interrupt_disabled)) {
                /* Running with interrupts, only do long timeouts. */
                timeout = jiffies + SI_TIMEOUT_JIFFIES;
                smi_inc_stat(smi_info, long_timeouts);
                goto do_mod_timer;
        }

        /*
         * If the state machine asks for a short delay, then shorten
         * the timer timeout.
         */
        if (smi_result == SI_SM_CALL_WITH_DELAY) {
                smi_inc_stat(smi_info, short_timeouts);
                timeout = jiffies + 1;
        } else {
                smi_inc_stat(smi_info, long_timeouts);
                timeout = jiffies + SI_TIMEOUT_JIFFIES;
        }

do_mod_timer:
        if (smi_result != SI_SM_IDLE)
                smi_mod_timer(smi_info, timeout);
        else
                smi_info->timer_running = false;
        spin_unlock_irqrestore(&(smi_info->si_lock), flags);
}

static irqreturn_t si_irq_handler(int irq, void *data)
{
        struct smi_info *smi_info = data;
        unsigned long   flags;

        spin_lock_irqsave(&(smi_info->si_lock), flags);

        smi_inc_stat(smi_info, interrupts);

        debug_timestamp("Interrupt");

        smi_event_handler(smi_info, 0);
        spin_unlock_irqrestore(&(smi_info->si_lock), flags);
        return IRQ_HANDLED;
}

static irqreturn_t si_bt_irq_handler(int irq, void *data)
{
        struct smi_info *smi_info = data;
        /* We need to clear the IRQ flag for the BT interface. */
        smi_info->io.outputb(&smi_info->io, IPMI_BT_INTMASK_REG,
                             IPMI_BT_INTMASK_CLEAR_IRQ_BIT
                             | IPMI_BT_INTMASK_ENABLE_IRQ_BIT);
        return si_irq_handler(irq, data);
}

static int smi_start_processing(void       *send_info,
                                ipmi_smi_t intf)
{
        struct smi_info *new_smi = send_info;
        int             enable = 0;

        new_smi->intf = intf;

        /* Set up the timer that drives the interface. */
        setup_timer(&new_smi->si_timer, smi_timeout, (long)new_smi);
        smi_mod_timer(new_smi, jiffies + SI_TIMEOUT_JIFFIES);

        /* Try to claim any interrupts. */
        if (new_smi->irq_setup)
                new_smi->irq_setup(new_smi);

        /*
         * Check if the user forcefully enabled the daemon.
         */
        if (new_smi->intf_num < num_force_kipmid)
                enable = force_kipmid[new_smi->intf_num];
        /*
         * The BT interface is efficient enough to not need a thread,
         * and there is no need for a thread if we have interrupts.
         */
        else if ((new_smi->si_type != SI_BT) && (!new_smi->irq))
                enable = 1;

        if (enable) {
                new_smi->thread = kthread_run(ipmi_thread, new_smi,
                                              "kipmi%d", new_smi->intf_num);
                if (IS_ERR(new_smi->thread)) {
                        dev_notice(new_smi->dev, "Could not start"
                                   " kernel thread due to error %ld, only using"
                                   " timers to drive the interface\n",
                                   PTR_ERR(new_smi->thread));
                        new_smi->thread = NULL;
                }
        }

        return 0;
}

static int get_smi_info(void *send_info, struct ipmi_smi_info *data)
{
        struct smi_info *smi = send_info;

        data->addr_src = smi->addr_source;
        data->dev = smi->dev;
        data->addr_info = smi->addr_info;
        get_device(smi->dev);

        return 0;
}

static void set_maintenance_mode(void *send_info, bool enable)
{
        struct smi_info   *smi_info = send_info;

        if (!enable)
                atomic_set(&smi_info->req_events, 0);
}

static const struct ipmi_smi_handlers handlers = {
        .owner                  = THIS_MODULE,
        .start_processing       = smi_start_processing,
        .get_smi_info           = get_smi_info,
        .sender                 = sender,
        .request_events         = request_events,
        .set_need_watch         = set_need_watch,
        .set_maintenance_mode   = set_maintenance_mode,
        .set_run_to_completion  = set_run_to_completion,
        .flush_messages         = flush_messages,
        .poll                   = poll,
};

/*
 * There can be 4 IO ports passed in (with or without IRQs), 4 addresses,
 * a default IO port, and 1 ACPI/SPMI address.  That sets SI_MAX_DRIVERS.
 */

static LIST_HEAD(smi_infos);
static DEFINE_MUTEX(smi_infos_lock);
static int smi_num; /* Used to sequence the SMIs */

#define DEFAULT_REGSPACING      1
#define DEFAULT_REGSIZE         1

#ifdef CONFIG_ACPI
static bool          si_tryacpi = true;
#endif
#ifdef CONFIG_DMI
static bool          si_trydmi = true;
#endif
static bool          si_tryplatform = true;
#ifdef CONFIG_PCI
static bool          si_trypci = true;
#endif
static char          *si_type[SI_MAX_PARMS];
#define MAX_SI_TYPE_STR 30
static char          si_type_str[MAX_SI_TYPE_STR];
static unsigned long addrs[SI_MAX_PARMS];
static unsigned int num_addrs;
static unsigned int  ports[SI_MAX_PARMS];
static unsigned int num_ports;
static int           irqs[SI_MAX_PARMS];
static unsigned int num_irqs;
static int           regspacings[SI_MAX_PARMS];
static unsigned int num_regspacings;
static int           regsizes[SI_MAX_PARMS];
static unsigned int num_regsizes;
static int           regshifts[SI_MAX_PARMS];
static unsigned int num_regshifts;
static int slave_addrs[SI_MAX_PARMS]; /* Leaving 0 chooses the default value */
static unsigned int num_slave_addrs;

#define IPMI_IO_ADDR_SPACE  0
#define IPMI_MEM_ADDR_SPACE 1
static const char * const addr_space_to_str[] = { "i/o", "mem" };

static int hotmod_handler(const char *val, struct kernel_param *kp);

module_param_call(hotmod, hotmod_handler, NULL, NULL, 0200);
MODULE_PARM_DESC(hotmod, "Add and remove interfaces.  See"
                 " Documentation/IPMI.txt in the kernel sources for the"
                 " gory details.");

#ifdef CONFIG_ACPI
module_param_named(tryacpi, si_tryacpi, bool, 0);
MODULE_PARM_DESC(tryacpi, "Setting this to zero will disable the"
                 " default scan of the interfaces identified via ACPI");
#endif
#ifdef CONFIG_DMI
module_param_named(trydmi, si_trydmi, bool, 0);
MODULE_PARM_DESC(trydmi, "Setting this to zero will disable the"
                 " default scan of the interfaces identified via DMI");
#endif
module_param_named(tryplatform, si_tryplatform, bool, 0);
MODULE_PARM_DESC(tryplatform, "Setting this to zero will disable the"
                 " default scan of the interfaces identified via platform"
                 " interfaces like openfirmware");
#ifdef CONFIG_PCI
module_param_named(trypci, si_trypci, bool, 0);
MODULE_PARM_DESC(trypci, "Setting this to zero will disable the"
                 " default scan of the interfaces identified via pci");
#endif
module_param_string(type, si_type_str, MAX_SI_TYPE_STR, 0);
MODULE_PARM_DESC(type, "Defines the type of each interface, each"
                 " interface separated by commas.  The types are 'kcs',"
                 " 'smic', and 'bt'.  For example si_type=kcs,bt will set"
                 " the first interface to kcs and the second to bt");
module_param_array(addrs, ulong, &num_addrs, 0);
MODULE_PARM_DESC(addrs, "Sets the memory address of each interface, the"
                 " addresses separated by commas.  Only use if an interface"
                 " is in memory.  Otherwise, set it to zero or leave"
                 " it blank.");
module_param_array(ports, uint, &num_ports, 0);
MODULE_PARM_DESC(ports, "Sets the port address of each interface, the"
                 " addresses separated by commas.  Only use if an interface"
                 " is a port.  Otherwise, set it to zero or leave"
                 " it blank.");
module_param_array(irqs, int, &num_irqs, 0);
MODULE_PARM_DESC(irqs, "Sets the interrupt of each interface, the"
                 " addresses separated by commas.  Only use if an interface"
                 " has an interrupt.  Otherwise, set it to zero or leave"
                 " it blank.");
module_param_array(regspacings, int, &num_regspacings, 0);
MODULE_PARM_DESC(regspacings, "The number of bytes between the start address"
                 " and each successive register used by the interface.  For"
                 " instance, if the start address is 0xca2 and the spacing"
                 " is 2, then the second address is at 0xca4.  Defaults"
                 " to 1.");
module_param_array(regsizes, int, &num_regsizes, 0);
MODULE_PARM_DESC(regsizes, "The size of the specific IPMI register in bytes."
                 " This should generally be 1, 2, 4, or 8 for an 8-bit,"
                 " 16-bit, 32-bit, or 64-bit register.  Use this if you"
                 " the 8-bit IPMI register has to be read from a larger"
                 " register.");
module_param_array(regshifts, int, &num_regshifts, 0);
MODULE_PARM_DESC(regshifts, "The amount to shift the data read from the."
                 " IPMI register, in bits.  For instance, if the data"
                 " is read from a 32-bit word and the IPMI data is in"
                 " bit 8-15, then the shift would be 8");
module_param_array(slave_addrs, int, &num_slave_addrs, 0);
MODULE_PARM_DESC(slave_addrs, "Set the default IPMB slave address for"
                 " the controller.  Normally this is 0x20, but can be"
                 " overridden by this parm.  This is an array indexed"
                 " by interface number.");
module_param_array(force_kipmid, int, &num_force_kipmid, 0);
MODULE_PARM_DESC(force_kipmid, "Force the kipmi daemon to be enabled (1) or"
                 " disabled(0).  Normally the IPMI driver auto-detects"
                 " this, but the value may be overridden by this parm.");
module_param(unload_when_empty, bool, 0);
MODULE_PARM_DESC(unload_when_empty, "Unload the module if no interfaces are"
                 " specified or found, default is 1.  Setting to 0"
                 " is useful for hot add of devices using hotmod.");
module_param_array(kipmid_max_busy_us, uint, &num_max_busy_us, 0644);
MODULE_PARM_DESC(kipmid_max_busy_us,
                 "Max time (in microseconds) to busy-wait for IPMI data before"
                 " sleeping. 0 (default) means to wait forever. Set to 100-500"
                 " if kipmid is using up a lot of CPU time.");


static void std_irq_cleanup(struct smi_info *info)
{
        if (info->si_type == SI_BT)
                /* Disable the interrupt in the BT interface. */
                info->io.outputb(&info->io, IPMI_BT_INTMASK_REG, 0);
        free_irq(info->irq, info);
}

static int std_irq_setup(struct smi_info *info)
{
        int rv;

        if (!info->irq)
                return 0;

        if (info->si_type == SI_BT) {
                rv = request_irq(info->irq,
                                 si_bt_irq_handler,
                                 IRQF_SHARED,
                                 DEVICE_NAME,
                                 info);
                if (!rv)
                        /* Enable the interrupt in the BT interface. */
                        info->io.outputb(&info->io, IPMI_BT_INTMASK_REG,
                                         IPMI_BT_INTMASK_ENABLE_IRQ_BIT);
        } else
                rv = request_irq(info->irq,
                                 si_irq_handler,
                                 IRQF_SHARED,
                                 DEVICE_NAME,
                                 info);
        if (rv) {
                dev_warn(info->dev, "%s unable to claim interrupt %d,"
                         " running polled\n",
                         DEVICE_NAME, info->irq);
                info->irq = 0;
        } else {
                info->irq_cleanup = std_irq_cleanup;
                dev_info(info->dev, "Using irq %d\n", info->irq);
        }

        return rv;
}

static unsigned char port_inb(const struct si_sm_io *io, unsigned int offset)
{
        unsigned int addr = io->addr_data;

        return inb(addr + (offset * io->regspacing));
}

static void port_outb(const struct si_sm_io *io, unsigned int offset,
                      unsigned char b)
{
        unsigned int addr = io->addr_data;

        outb(b, addr + (offset * io->regspacing));
}

static unsigned char port_inw(const struct si_sm_io *io, unsigned int offset)
{
        unsigned int addr = io->addr_data;

        return (inw(addr + (offset * io->regspacing)) >> io->regshift) & 0xff;
}

static void port_outw(const struct si_sm_io *io, unsigned int offset,
                      unsigned char b)
{
        unsigned int addr = io->addr_data;

        outw(b << io->regshift, addr + (offset * io->regspacing));
}

static unsigned char port_inl(const struct si_sm_io *io, unsigned int offset)
{
        unsigned int addr = io->addr_data;

        return (inl(addr + (offset * io->regspacing)) >> io->regshift) & 0xff;
}

static void port_outl(const struct si_sm_io *io, unsigned int offset,
                      unsigned char b)
{
        unsigned int addr = io->addr_data;

        outl(b << io->regshift, addr+(offset * io->regspacing));
}

static void port_cleanup(struct smi_info *info)
{
        unsigned int addr = info->io.addr_data;
        int          idx;

        if (addr) {
                for (idx = 0; idx < info->io_size; idx++)
                        release_region(addr + idx * info->io.regspacing,
                                       info->io.regsize);
        }
}

static int port_setup(struct smi_info *info)
{
        unsigned int addr = info->io.addr_data;
        int          idx;

        if (!addr)
                return -ENODEV;

        info->io_cleanup = port_cleanup;

        /*
         * Figure out the actual inb/inw/inl/etc routine to use based
         * upon the register size.
         */
        switch (info->io.regsize) {
        case 1:
                info->io.inputb = port_inb;
                info->io.outputb = port_outb;
                break;
        case 2:
                info->io.inputb = port_inw;
                info->io.outputb = port_outw;
                break;
        case 4:
                info->io.inputb = port_inl;
                info->io.outputb = port_outl;
                break;
        default:
                dev_warn(info->dev, "Invalid register size: %d\n",
                         info->io.regsize);
                return -EINVAL;
        }

        /*
         * Some BIOSes reserve disjoint I/O regions in their ACPI
         * tables.  This causes problems when trying to register the
         * entire I/O region.  Therefore we must register each I/O
         * port separately.
         */
        for (idx = 0; idx < info->io_size; idx++) {
                if (request_region(addr + idx * info->io.regspacing,
                                   info->io.regsize, DEVICE_NAME) == NULL) {
                        /* Undo allocations */
                        while (idx--)
                                release_region(addr + idx * info->io.regspacing,
                                               info->io.regsize);
                        return -EIO;
                }
        }
        return 0;
}

static unsigned char intf_mem_inb(const struct si_sm_io *io,
                                  unsigned int offset)
{
        return readb((io->addr)+(offset * io->regspacing));
}

static void intf_mem_outb(const struct si_sm_io *io, unsigned int offset,
                          unsigned char b)
{
        writeb(b, (io->addr)+(offset * io->regspacing));
}

static unsigned char intf_mem_inw(const struct si_sm_io *io,
                                  unsigned int offset)
{
        return (readw((io->addr)+(offset * io->regspacing)) >> io->regshift)
                & 0xff;
}

static void intf_mem_outw(const struct si_sm_io *io, unsigned int offset,
                          unsigned char b)
{
        writeb(b << io->regshift, (io->addr)+(offset * io->regspacing));
}

static unsigned char intf_mem_inl(const struct si_sm_io *io,
                                  unsigned int offset)
{
        return (readl((io->addr)+(offset * io->regspacing)) >> io->regshift)
                & 0xff;
}

static void intf_mem_outl(const struct si_sm_io *io, unsigned int offset,
                          unsigned char b)
{
        writel(b << io->regshift, (io->addr)+(offset * io->regspacing));
}

#ifdef readq
static unsigned char mem_inq(const struct si_sm_io *io, unsigned int offset)
{
        return (readq((io->addr)+(offset * io->regspacing)) >> io->regshift)
                & 0xff;
}

static void mem_outq(const struct si_sm_io *io, unsigned int offset,
                     unsigned char b)
{
        writeq(b << io->regshift, (io->addr)+(offset * io->regspacing));
}
#endif

static void mem_region_cleanup(struct smi_info *info, int num)
{
        unsigned long addr = info->io.addr_data;
        int idx;

        for (idx = 0; idx < num; idx++)
                release_mem_region(addr + idx * info->io.regspacing,
                                   info->io.regsize);
}

static void mem_cleanup(struct smi_info *info)
{
        if (info->io.addr) {
                iounmap(info->io.addr);
                mem_region_cleanup(info, info->io_size);
        }
}

static int mem_setup(struct smi_info *info)
{
        unsigned long addr = info->io.addr_data;
        int           mapsize, idx;

        if (!addr)
                return -ENODEV;

        info->io_cleanup = mem_cleanup;

        /*
         * Figure out the actual readb/readw/readl/etc routine to use based
         * upon the register size.
         */
        switch (info->io.regsize) {
        case 1:
                info->io.inputb = intf_mem_inb;
                info->io.outputb = intf_mem_outb;
                break;
        case 2:
                info->io.inputb = intf_mem_inw;
                info->io.outputb = intf_mem_outw;
                break;
        case 4:
                info->io.inputb = intf_mem_inl;
                info->io.outputb = intf_mem_outl;
                break;
#ifdef readq
        case 8:
                info->io.inputb = mem_inq;
                info->io.outputb = mem_outq;
                break;
#endif
        default:
                dev_warn(info->dev, "Invalid register size: %d\n",
                         info->io.regsize);
                return -EINVAL;
        }

        /*
         * Some BIOSes reserve disjoint memory regions in their ACPI
         * tables.  This causes problems when trying to request the
         * entire region.  Therefore we must request each register
         * separately.
         */
        for (idx = 0; idx < info->io_size; idx++) {
                if (request_mem_region(addr + idx * info->io.regspacing,
                                       info->io.regsize, DEVICE_NAME) == NULL) {
                        /* Undo allocations */
                        mem_region_cleanup(info, idx);
                        return -EIO;
                }
        }

        /*
         * Calculate the total amount of memory to claim.  This is an
         * unusual looking calculation, but it avoids claiming any
         * more memory than it has to.  It will claim everything
         * between the first address to the end of the last full
         * register.
         */
        mapsize = ((info->io_size * info->io.regspacing)
                   - (info->io.regspacing - info->io.regsize));
        info->io.addr = ioremap(addr, mapsize);
        if (info->io.addr == NULL) {
                mem_region_cleanup(info, info->io_size);
                return -EIO;
        }
        return 0;
}

/*
 * Parms come in as <op1>[:op2[:op3...]].  ops are:
 *   add|remove,kcs|bt|smic,mem|i/o,<address>[,<opt1>[,<opt2>[,...]]]
 * Options are:
 *   rsp=<regspacing>
 *   rsi=<regsize>
 *   rsh=<regshift>
 *   irq=<irq>
 *   ipmb=<ipmb addr>
 */
enum hotmod_op { HM_ADD, HM_REMOVE };
struct hotmod_vals {
        const char *name;
        const int  val;
};

static const struct hotmod_vals hotmod_ops[] = {
        { "add",        HM_ADD },
        { "remove",     HM_REMOVE },
        { NULL }
};

static const struct hotmod_vals hotmod_si[] = {
        { "kcs",        SI_KCS },
        { "smic",       SI_SMIC },
        { "bt",         SI_BT },
        { NULL }
};

static const struct hotmod_vals hotmod_as[] = {
        { "mem",        IPMI_MEM_ADDR_SPACE },
        { "i/o",        IPMI_IO_ADDR_SPACE },
        { NULL }
};

static int parse_str(const struct hotmod_vals *v, int *val, char *name,
                     char **curr)
{
        char *s;
        int  i;

        s = strchr(*curr, ',');
        if (!s) {
                printk(KERN_WARNING PFX "No hotmod %s given.\n", name);
                return -EINVAL;
        }
        *s = '\0';
        s++;
        for (i = 0; v[i].name; i++) {
                if (strcmp(*curr, v[i].name) == 0) {
                        *val = v[i].val;
                        *curr = s;
                        return 0;
                }
        }

        printk(KERN_WARNING PFX "Invalid hotmod %s '%s'\n", name, *curr);
        return -EINVAL;
}

static int check_hotmod_int_op(const char *curr, const char *option,
                               const char *name, int *val)
{
        char *n;

        if (strcmp(curr, name) == 0) {
                if (!option) {
                        printk(KERN_WARNING PFX
                               "No option given for '%s'\n",
                               curr);
                        return -EINVAL;
                }
                *val = simple_strtoul(option, &n, 0);
                if ((*n != '\0') || (*option == '\0')) {
                        printk(KERN_WARNING PFX
                               "Bad option given for '%s'\n",
                               curr);
                        return -EINVAL;
                }
                return 1;
        }
        return 0;
}

static struct smi_info *smi_info_alloc(void)
{
        struct smi_info *info = kzalloc(sizeof(*info), GFP_KERNEL);

        if (info)
                spin_lock_init(&info->si_lock);
        return info;
}

static int hotmod_handler(const char *val, struct kernel_param *kp)
{
        char *str = kstrdup(val, GFP_KERNEL);
        int  rv;
        char *next, *curr, *s, *n, *o;
        enum hotmod_op op;
        enum si_type si_type;
        int  addr_space;
        unsigned long addr;
        int regspacing;
        int regsize;
        int regshift;
        int irq;
        int ipmb;
        int ival;
        int len;
        struct smi_info *info;

        if (!str)
                return -ENOMEM;

        /* Kill any trailing spaces, as we can get a "\n" from echo. */
        len = strlen(str);
        ival = len - 1;
        while ((ival >= 0) && isspace(str[ival])) {
                str[ival] = '\0';
                ival--;
        }

        for (curr = str; curr; curr = next) {
                regspacing = 1;
                regsize = 1;
                regshift = 0;
                irq = 0;
                ipmb = 0; /* Choose the default if not specified */

                next = strchr(curr, ':');
                if (next) {
                        *next = '\0';
                        next++;
                }

                rv = parse_str(hotmod_ops, &ival, "operation", &curr);
                if (rv)
                        break;
                op = ival;

                rv = parse_str(hotmod_si, &ival, "interface type", &curr);
                if (rv)
                        break;
                si_type = ival;

                rv = parse_str(hotmod_as, &addr_space, "address space", &curr);
                if (rv)
                        break;

                s = strchr(curr, ',');
                if (s) {
                        *s = '\0';
                        s++;
                }
                addr = simple_strtoul(curr, &n, 0);
                if ((*n != '\0') || (*curr == '\0')) {
                        printk(KERN_WARNING PFX "Invalid hotmod address"
                               " '%s'\n", curr);
                        break;
                }

                while (s) {
                        curr = s;
                        s = strchr(curr, ',');
                        if (s) {
                                *s = '\0';
                                s++;
                        }
                        o = strchr(curr, '=');
                        if (o) {
                                *o = '\0';
                                o++;
                        }
                        rv = check_hotmod_int_op(curr, o, "rsp", &regspacing);
                        if (rv < 0)
                                goto out;
                        else if (rv)
                                continue;
                        rv = check_hotmod_int_op(curr, o, "rsi", &regsize);
                        if (rv < 0)
                                goto out;
                        else if (rv)
                                continue;
                        rv = check_hotmod_int_op(curr, o, "rsh", &regshift);
                        if (rv < 0)
                                goto out;
                        else if (rv)
                                continue;
                        rv = check_hotmod_int_op(curr, o, "irq", &irq);
                        if (rv < 0)
                                goto out;
                        else if (rv)
                                continue;
                        rv = check_hotmod_int_op(curr, o, "ipmb", &ipmb);
                        if (rv < 0)
                                goto out;
                        else if (rv)
                                continue;

                        rv = -EINVAL;
                        printk(KERN_WARNING PFX
                               "Invalid hotmod option '%s'\n",
                               curr);
                        goto out;
                }

                if (op == HM_ADD) {
                        info = smi_info_alloc();
                        if (!info) {
                                rv = -ENOMEM;
                                goto out;
                        }

                        info->addr_source = SI_HOTMOD;
                        info->si_type = si_type;
                        info->io.addr_data = addr;
                        info->io.addr_type = addr_space;
                        if (addr_space == IPMI_MEM_ADDR_SPACE)
                                info->io_setup = mem_setup;
                        else
                                info->io_setup = port_setup;

                        info->io.addr = NULL;
                        info->io.regspacing = regspacing;
                        if (!info->io.regspacing)
                                info->io.regspacing = DEFAULT_REGSPACING;
                        info->io.regsize = regsize;
                        if (!info->io.regsize)
                                info->io.regsize = DEFAULT_REGSPACING;
                        info->io.regshift = regshift;
                        info->irq = irq;
                        if (info->irq)
                                info->irq_setup = std_irq_setup;
                        info->slave_addr = ipmb;

                        rv = add_smi(info);
                        if (rv) {
                                kfree(info);
                                goto out;
                        }
                        rv = try_smi_init(info);
                        if (rv) {
                                cleanup_one_si(info);
                                goto out;
                        }
                } else {
                        /* remove */
                        struct smi_info *e, *tmp_e;

                        mutex_lock(&smi_infos_lock);
                        list_for_each_entry_safe(e, tmp_e, &smi_infos, link) {
                                if (e->io.addr_type != addr_space)
                                        continue;
                                if (e->si_type != si_type)
                                        continue;
                                if (e->io.addr_data == addr)
                                        cleanup_one_si(e);
                        }
                        mutex_unlock(&smi_infos_lock);
                }
        }
        rv = len;
out:
        kfree(str);
        return rv;
}

static int hardcode_find_bmc(void)
{
        int ret = -ENODEV;
        int             i;
        struct smi_info *info;

        for (i = 0; i < SI_MAX_PARMS; i++) {
                if (!ports[i] && !addrs[i])
                        continue;

                info = smi_info_alloc();
                if (!info)
                        return -ENOMEM;

                info->addr_source = SI_HARDCODED;
                printk(KERN_INFO PFX "probing via hardcoded address\n");

                if (!si_type[i] || strcmp(si_type[i], "kcs") == 0) {
                        info->si_type = SI_KCS;
                } else if (strcmp(si_type[i], "smic") == 0) {
                        info->si_type = SI_SMIC;
                } else if (strcmp(si_type[i], "bt") == 0) {
                        info->si_type = SI_BT;
                } else {
                        printk(KERN_WARNING PFX "Interface type specified "
                               "for interface %d, was invalid: %s\n",
                               i, si_type[i]);
                        kfree(info);
                        continue;
                }

                if (ports[i]) {
                        /* An I/O port */
                        info->io_setup = port_setup;
                        info->io.addr_data = ports[i];
                        info->io.addr_type = IPMI_IO_ADDR_SPACE;
                } else if (addrs[i]) {
                        /* A memory port */
                        info->io_setup = mem_setup;
                        info->io.addr_data = addrs[i];
                        info->io.addr_type = IPMI_MEM_ADDR_SPACE;
                } else {
                        printk(KERN_WARNING PFX "Interface type specified "
                               "for interface %d, but port and address were "
                               "not set or set to zero.\n", i);
                        kfree(info);
                        continue;
                }

                info->io.addr = NULL;
                info->io.regspacing = regspacings[i];
                if (!info->io.regspacing)
                        info->io.regspacing = DEFAULT_REGSPACING;
                info->io.regsize = regsizes[i];
                if (!info->io.regsize)
                        info->io.regsize = DEFAULT_REGSPACING;
                info->io.regshift = regshifts[i];
                info->irq = irqs[i];
                if (info->irq)
                        info->irq_setup = std_irq_setup;
                info->slave_addr = slave_addrs[i];

                if (!add_smi(info)) {
                        if (try_smi_init(info))
                                cleanup_one_si(info);
                        ret = 0;
                } else {
                        kfree(info);
                }
        }
        return ret;
}

#ifdef CONFIG_ACPI

/*
 * Once we get an ACPI failure, we don't try any more, because we go
 * through the tables sequentially.  Once we don't find a table, there
 * are no more.
 */
static int acpi_failure;

/* For GPE-type interrupts. */
static u32 ipmi_acpi_gpe(acpi_handle gpe_device,
        u32 gpe_number, void *context)
{
        struct smi_info *smi_info = context;
        unsigned long   flags;

        spin_lock_irqsave(&(smi_info->si_lock), flags);

        smi_inc_stat(smi_info, interrupts);

        debug_timestamp("ACPI_GPE");

        smi_event_handler(smi_info, 0);
        spin_unlock_irqrestore(&(smi_info->si_lock), flags);

        return ACPI_INTERRUPT_HANDLED;
}

static void acpi_gpe_irq_cleanup(struct smi_info *info)
{
        if (!info->irq)
                return;

        acpi_remove_gpe_handler(NULL, info->irq, &ipmi_acpi_gpe);
}

static int acpi_gpe_irq_setup(struct smi_info *info)
{
        acpi_status status;

        if (!info->irq)
                return 0;

        status = acpi_install_gpe_handler(NULL,
                                          info->irq,
                                          ACPI_GPE_LEVEL_TRIGGERED,
                                          &ipmi_acpi_gpe,
                                          info);
        if (status != AE_OK) {
                dev_warn(info->dev, "%s unable to claim ACPI GPE %d,"
                         " running polled\n", DEVICE_NAME, info->irq);
                info->irq = 0;
                return -EINVAL;
        } else {
                info->irq_cleanup = acpi_gpe_irq_cleanup;
                dev_info(info->dev, "Using ACPI GPE %d\n", info->irq);
                return 0;
        }
}

/*
 * Defined at
 * http://h21007.www2.hp.com/portal/download/files/unprot/hpspmi.pdf
 */
struct SPMITable {
        s8      Signature[4];
        u32     Length;
        u8      Revision;
        u8      Checksum;
        s8      OEMID[6];
        s8      OEMTableID[8];
        s8      OEMRevision[4];
        s8      CreatorID[4];
        s8      CreatorRevision[4];
        u8      InterfaceType;
        u8      IPMIlegacy;
        s16     SpecificationRevision;

        /*
         * Bit 0 - SCI interrupt supported
         * Bit 1 - I/O APIC/SAPIC
         */
        u8      InterruptType;

        /*
         * If bit 0 of InterruptType is set, then this is the SCI
         * interrupt in the GPEx_STS register.
         */
        u8      GPE;

        s16     Reserved;

        /*
         * If bit 1 of InterruptType is set, then this is the I/O
         * APIC/SAPIC interrupt.
         */
        u32     GlobalSystemInterrupt;

        /* The actual register address. */
        struct acpi_generic_address addr;

        u8      UID[4];

        s8      spmi_id[1]; /* A '\0' terminated array starts here. */
};

static int try_init_spmi(struct SPMITable *spmi)
{
        struct smi_info  *info;
        int rv;

        if (spmi->IPMIlegacy != 1) {
                printk(KERN_INFO PFX "Bad SPMI legacy %d\n", spmi->IPMIlegacy);
                return -ENODEV;
        }

        info = smi_info_alloc();
        if (!info) {
                printk(KERN_ERR PFX "Could not allocate SI data (3)\n");
                return -ENOMEM;
        }

        info->addr_source = SI_SPMI;
        printk(KERN_INFO PFX "probing via SPMI\n");

        /* Figure out the interface type. */
        switch (spmi->InterfaceType) {
        case 1: /* KCS */
                info->si_type = SI_KCS;
                break;
        case 2: /* SMIC */
                info->si_type = SI_SMIC;
                break;
        case 3: /* BT */
                info->si_type = SI_BT;
                break;
        case 4: /* SSIF, just ignore */
                kfree(info);
                return -EIO;
        default:
                printk(KERN_INFO PFX "Unknown ACPI/SPMI SI type %d\n",
                       spmi->InterfaceType);
                kfree(info);
                return -EIO;
        }

        if (spmi->InterruptType & 1) {
                /* We've got a GPE interrupt. */
                info->irq = spmi->GPE;
                info->irq_setup = acpi_gpe_irq_setup;
        } else if (spmi->InterruptType & 2) {
                /* We've got an APIC/SAPIC interrupt. */
                info->irq = spmi->GlobalSystemInterrupt;
                info->irq_setup = std_irq_setup;
        } else {
                /* Use the default interrupt setting. */
                info->irq = 0;
                info->irq_setup = NULL;
        }

        if (spmi->addr.bit_width) {
                /* A (hopefully) properly formed register bit width. */
                info->io.regspacing = spmi->addr.bit_width / 8;
        } else {
                info->io.regspacing = DEFAULT_REGSPACING;
        }
        info->io.regsize = info->io.regspacing;
        info->io.regshift = spmi->addr.bit_offset;

        if (spmi->addr.space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
                info->io_setup = mem_setup;
                info->io.addr_type = IPMI_MEM_ADDR_SPACE;
        } else if (spmi->addr.space_id == ACPI_ADR_SPACE_SYSTEM_IO) {
                info->io_setup = port_setup;
                info->io.addr_type = IPMI_IO_ADDR_SPACE;
        } else {
                kfree(info);
                printk(KERN_WARNING PFX "Unknown ACPI I/O Address type\n");
                return -EIO;
        }
        info->io.addr_data = spmi->addr.address;

        pr_info("ipmi_si: SPMI: %s %#lx regsize %d spacing %d irq %d\n",
                 (info->io.addr_type == IPMI_IO_ADDR_SPACE) ? "io" : "mem",
                 info->io.addr_data, info->io.regsize, info->io.regspacing,
                 info->irq);

        rv = add_smi(info);
        if (rv)
                kfree(info);

        return rv;
}

static void spmi_find_bmc(void)
{
        acpi_status      status;
        struct SPMITable *spmi;
        int              i;

        if (acpi_disabled)
                return;

        if (acpi_failure)
                return;

        for (i = 0; ; i++) {
                status = acpi_get_table(ACPI_SIG_SPMI, i+1,
                                        (struct acpi_table_header **)&spmi);
                if (status != AE_OK)
                        return;

                try_init_spmi(spmi);
        }
}
#endif

#ifdef CONFIG_DMI
struct dmi_ipmi_data {
        u8              type;
        u8              addr_space;
        unsigned long   base_addr;
        u8              irq;
        u8              offset;
        u8              slave_addr;
};

static int decode_dmi(const struct dmi_header *dm,
                                struct dmi_ipmi_data *dmi)
{
        const u8        *data = (const u8 *)dm;
        unsigned long   base_addr;
        u8              reg_spacing;
        u8              len = dm->length;

        dmi->type = data[4];

        memcpy(&base_addr, data+8, sizeof(unsigned long));
        if (len >= 0x11) {
                if (base_addr & 1) {
                        /* I/O */
                        base_addr &= 0xFFFE;
                        dmi->addr_space = IPMI_IO_ADDR_SPACE;
                } else
                        /* Memory */
                        dmi->addr_space = IPMI_MEM_ADDR_SPACE;

                /* If bit 4 of byte 0x10 is set, then the lsb for the address
                   is odd. */
                dmi->base_addr = base_addr | ((data[0x10] & 0x10) >> 4);

                dmi->irq = data[0x11];

                /* The top two bits of byte 0x10 hold the register spacing. */
                reg_spacing = (data[0x10] & 0xC0) >> 6;
                switch (reg_spacing) {
                case 0x00: /* Byte boundaries */
                    dmi->offset = 1;
                    break;
                case 0x01: /* 32-bit boundaries */
                    dmi->offset = 4;
                    break;
                case 0x02: /* 16-byte boundaries */
                    dmi->offset = 16;
                    break;
                default:
                    /* Some other interface, just ignore it. */
                    return -EIO;
                }
        } else {
                /* Old DMI spec. */
                /*
                 * Note that technically, the lower bit of the base
                 * address should be 1 if the address is I/O and 0 if
                 * the address is in memory.  So many systems get that
                 * wrong (and all that I have seen are I/O) so we just
                 * ignore that bit and assume I/O.  Systems that use
                 * memory should use the newer spec, anyway.
                 */
                dmi->base_addr = base_addr & 0xfffe;
                dmi->addr_space = IPMI_IO_ADDR_SPACE;
                dmi->offset = 1;
        }

        dmi->slave_addr = data[6];

        return 0;
}

static void try_init_dmi(struct dmi_ipmi_data *ipmi_data)
{
        struct smi_info *info;

        info = smi_info_alloc();
        if (!info) {
                printk(KERN_ERR PFX "Could not allocate SI data\n");
                return;
        }

        info->addr_source = SI_SMBIOS;
        printk(KERN_INFO PFX "probing via SMBIOS\n");

        switch (ipmi_data->type) {
        case 0x01: /* KCS */
                info->si_type = SI_KCS;
                break;
        case 0x02: /* SMIC */
                info->si_type = SI_SMIC;
                break;
        case 0x03: /* BT */
                info->si_type = SI_BT;
                break;
        default:
                kfree(info);
                return;
        }

        switch (ipmi_data->addr_space) {
        case IPMI_MEM_ADDR_SPACE:
                info->io_setup = mem_setup;
                info->io.addr_type = IPMI_MEM_ADDR_SPACE;
                break;

        case IPMI_IO_ADDR_SPACE:
                info->io_setup = port_setup;
                info->io.addr_type = IPMI_IO_ADDR_SPACE;
                break;

        default:
                kfree(info);
                printk(KERN_WARNING PFX "Unknown SMBIOS I/O Address type: %d\n",
                       ipmi_data->addr_space);
                return;
        }
        info->io.addr_data = ipmi_data->base_addr;

        info->io.regspacing = ipmi_data->offset;
        if (!info->io.regspacing)
                info->io.regspacing = DEFAULT_REGSPACING;
        info->io.regsize = DEFAULT_REGSPACING;
        info->io.regshift = 0;

        info->slave_addr = ipmi_data->slave_addr;

        info->irq = ipmi_data->irq;
        if (info->irq)
                info->irq_setup = std_irq_setup;

        pr_info("ipmi_si: SMBIOS: %s %#lx regsize %d spacing %d irq %d\n",
                 (info->io.addr_type == IPMI_IO_ADDR_SPACE) ? "io" : "mem",
                 info->io.addr_data, info->io.regsize, info->io.regspacing,
                 info->irq);

        if (add_smi(info))
                kfree(info);
}

static void dmi_find_bmc(void)
{
        const struct dmi_device *dev = NULL;
        struct dmi_ipmi_data data;
        int                  rv;

        while ((dev = dmi_find_device(DMI_DEV_TYPE_IPMI, NULL, dev))) {
                memset(&data, 0, sizeof(data));
                rv = decode_dmi((const struct dmi_header *) dev->device_data,
                                &data);
                if (!rv)
                        try_init_dmi(&data);
        }
}
#endif /* CONFIG_DMI */

#ifdef CONFIG_PCI

#define PCI_ERMC_CLASSCODE              0x0C0700
#define PCI_ERMC_CLASSCODE_MASK         0xffffff00
#define PCI_ERMC_CLASSCODE_TYPE_MASK    0xff
#define PCI_ERMC_CLASSCODE_TYPE_SMIC    0x00
#define PCI_ERMC_CLASSCODE_TYPE_KCS     0x01
#define PCI_ERMC_CLASSCODE_TYPE_BT      0x02

#define PCI_HP_VENDOR_ID    0x103C
#define PCI_MMC_DEVICE_ID   0x121A
#define PCI_MMC_ADDR_CW     0x10

static void ipmi_pci_cleanup(struct smi_info *info)
{
        struct pci_dev *pdev = info->addr_source_data;

        pci_disable_device(pdev);
}

static int ipmi_pci_probe_regspacing(struct smi_info *info)
{
        if (info->si_type == SI_KCS) {
                unsigned char   status;
                int             regspacing;

                info->io.regsize = DEFAULT_REGSIZE;
                info->io.regshift = 0;
                info->io_size = 2;
                info->handlers = &kcs_smi_handlers;

                /* detect 1, 4, 16byte spacing */
                for (regspacing = DEFAULT_REGSPACING; regspacing <= 16;) {
                        info->io.regspacing = regspacing;
                        if (info->io_setup(info)) {
                                dev_err(info->dev,
                                        "Could not setup I/O space\n");
                                return DEFAULT_REGSPACING;
                        }
                        /* write invalid cmd */
                        info->io.outputb(&info->io, 1, 0x10);
                        /* read status back */
                        status = info->io.inputb(&info->io, 1);
                        info->io_cleanup(info);
                        if (status)
                                return regspacing;
                        regspacing *= 4;
                }
        }
        return DEFAULT_REGSPACING;
}

static int ipmi_pci_probe(struct pci_dev *pdev,
                                    const struct pci_device_id *ent)
{
        int rv;
        int class_type = pdev->class & PCI_ERMC_CLASSCODE_TYPE_MASK;
        struct smi_info *info;

        info = smi_info_alloc();
        if (!info)
                return -ENOMEM;

        info->addr_source = SI_PCI;
        dev_info(&pdev->dev, "probing via PCI");

        switch (class_type) {
        case PCI_ERMC_CLASSCODE_TYPE_SMIC:
                info->si_type = SI_SMIC;
                break;

        case PCI_ERMC_CLASSCODE_TYPE_KCS:
                info->si_type = SI_KCS;
                break;

        case PCI_ERMC_CLASSCODE_TYPE_BT:
                info->si_type = SI_BT;
                break;

        default:
                kfree(info);
                dev_info(&pdev->dev, "Unknown IPMI type: %d\n", class_type);
                return -ENOMEM;
        }

        rv = pci_enable_device(pdev);
        if (rv) {
                dev_err(&pdev->dev, "couldn't enable PCI device\n");
                kfree(info);
                return rv;
        }

        info->addr_source_cleanup = ipmi_pci_cleanup;
        info->addr_source_data = pdev;

        if (pci_resource_flags(pdev, 0) & IORESOURCE_IO) {
                info->io_setup = port_setup;
                info->io.addr_type = IPMI_IO_ADDR_SPACE;
        } else {
                info->io_setup = mem_setup;
                info->io.addr_type = IPMI_MEM_ADDR_SPACE;
        }
        info->io.addr_data = pci_resource_start(pdev, 0);

        info->io.regspacing = ipmi_pci_probe_regspacing(info);
        info->io.regsize = DEFAULT_REGSIZE;
        info->io.regshift = 0;

        info->irq = pdev->irq;
        if (info->irq)
                info->irq_setup = std_irq_setup;

        info->dev = &pdev->dev;
        pci_set_drvdata(pdev, info);

        dev_info(&pdev->dev, "%pR regsize %d spacing %d irq %d\n",
                &pdev->resource[0], info->io.regsize, info->io.regspacing,
                info->irq);

        rv = add_smi(info);
        if (rv) {
                kfree(info);
                pci_disable_device(pdev);
        }

        return rv;
}

static void ipmi_pci_remove(struct pci_dev *pdev)
{
        struct smi_info *info = pci_get_drvdata(pdev);
        cleanup_one_si(info);
}

static const struct pci_device_id ipmi_pci_devices[] = {
        { PCI_DEVICE(PCI_HP_VENDOR_ID, PCI_MMC_DEVICE_ID) },
        { PCI_DEVICE_CLASS(PCI_ERMC_CLASSCODE, PCI_ERMC_CLASSCODE_MASK) },
        { 0, }
};
MODULE_DEVICE_TABLE(pci, ipmi_pci_devices);

static struct pci_driver ipmi_pci_driver = {
        .name =         DEVICE_NAME,
        .id_table =     ipmi_pci_devices,
        .probe =        ipmi_pci_probe,
        .remove =       ipmi_pci_remove,
};
#endif /* CONFIG_PCI */

#ifdef CONFIG_OF
static const struct of_device_id of_ipmi_match[] = {
        { .type = "ipmi", .compatible = "ipmi-kcs",
          .data = (void *)(unsigned long) SI_KCS },
        { .type = "ipmi", .compatible = "ipmi-smic",
          .data = (void *)(unsigned long) SI_SMIC },
        { .type = "ipmi", .compatible = "ipmi-bt",
          .data = (void *)(unsigned long) SI_BT },
        {},
};
MODULE_DEVICE_TABLE(of, of_ipmi_match);

static int of_ipmi_probe(struct platform_device *dev)
{
        const struct of_device_id *match;
        struct smi_info *info;
        struct resource resource;
        const __be32 *regsize, *regspacing, *regshift;
        struct device_node *np = dev->dev.of_node;
        int ret;
        int proplen;

        dev_info(&dev->dev, "probing via device tree\n");

        match = of_match_device(of_ipmi_match, &dev->dev);
        if (!match)
                return -ENODEV;

        if (!of_device_is_available(np))
                return -EINVAL;

        ret = of_address_to_resource(np, 0, &resource);
        if (ret) {
                dev_warn(&dev->dev, PFX "invalid address from OF\n");
                return ret;
        }

        regsize = of_get_property(np, "reg-size", &proplen);
        if (regsize && proplen != 4) {
                dev_warn(&dev->dev, PFX "invalid regsize from OF\n");
                return -EINVAL;
        }

        regspacing = of_get_property(np, "reg-spacing", &proplen);
        if (regspacing && proplen != 4) {
                dev_warn(&dev->dev, PFX "invalid regspacing from OF\n");
                return -EINVAL;
        }

        regshift = of_get_property(np, "reg-shift", &proplen);
        if (regshift && proplen != 4) {
                dev_warn(&dev->dev, PFX "invalid regshift from OF\n");
                return -EINVAL;
        }

        info = smi_info_alloc();

        if (!info) {
                dev_err(&dev->dev,
                        "could not allocate memory for OF probe\n");
                return -ENOMEM;
        }

        info->si_type           = (enum si_type) match->data;
        info->addr_source       = SI_DEVICETREE;
        info->irq_setup         = std_irq_setup;

        if (resource.flags & IORESOURCE_IO) {
                info->io_setup          = port_setup;
                info->io.addr_type      = IPMI_IO_ADDR_SPACE;
        } else {
                info->io_setup          = mem_setup;
                info->io.addr_type      = IPMI_MEM_ADDR_SPACE;
        }

        info->io.addr_data      = resource.start;

        info->io.regsize        = regsize ? be32_to_cpup(regsize) : DEFAULT_REGSIZE;
        info->io.regspacing     = regspacing ? be32_to_cpup(regspacing) : DEFAULT_REGSPACING;
        info->io.regshift       = regshift ? be32_to_cpup(regshift) : 0;

        info->irq               = irq_of_parse_and_map(dev->dev.of_node, 0);
        info->dev               = &dev->dev;

        dev_dbg(&dev->dev, "addr 0x%lx regsize %d spacing %d irq %d\n",
                info->io.addr_data, info->io.regsize, info->io.regspacing,
                info->irq);

        dev_set_drvdata(&dev->dev, info);

        ret = add_smi(info);
        if (ret) {
                kfree(info);
                return ret;
        }
        return 0;
}
#else
#define of_ipmi_match NULL
static int of_ipmi_probe(struct platform_device *dev)
{
        return -ENODEV;
}
#endif

#ifdef CONFIG_ACPI
static int acpi_ipmi_probe(struct platform_device *dev)
{
        struct smi_info *info;
        struct resource *res, *res_second;
        acpi_handle handle;
        acpi_status status;
        unsigned long long tmp;
        int rv = -EINVAL;

        if (!si_tryacpi)
               return 0;

        handle = ACPI_HANDLE(&dev->dev);
        if (!handle)
                return -ENODEV;

        info = smi_info_alloc();
        if (!info)
                return -ENOMEM;

        info->addr_source = SI_ACPI;
        dev_info(&dev->dev, PFX "probing via ACPI\n");

        info->addr_info.acpi_info.acpi_handle = handle;

        /* _IFT tells us the interface type: KCS, BT, etc */
        status = acpi_evaluate_integer(handle, "_IFT", NULL, &tmp);
        if (ACPI_FAILURE(status)) {
                dev_err(&dev->dev, "Could not find ACPI IPMI interface type\n");
                goto err_free;
        }

        switch (tmp) {
        case 1:
                info->si_type = SI_KCS;
                break;
        case 2:
                info->si_type = SI_SMIC;
                break;
        case 3:
                info->si_type = SI_BT;
                break;
        case 4: /* SSIF, just ignore */
                rv = -ENODEV;
                goto err_free;
        default:
                dev_info(&dev->dev, "unknown IPMI type %lld\n", tmp);
                goto err_free;
        }

        res = platform_get_resource(dev, IORESOURCE_IO, 0);
        if (res) {
                info->io_setup = port_setup;
                info->io.addr_type = IPMI_IO_ADDR_SPACE;
        } else {
                res = platform_get_resource(dev, IORESOURCE_MEM, 0);
                if (res) {
                        info->io_setup = mem_setup;
                        info->io.addr_type = IPMI_MEM_ADDR_SPACE;
                }
        }
        if (!res) {
                dev_err(&dev->dev, "no I/O or memory address\n");
                goto err_free;
        }
        info->io.addr_data = res->start;

        info->io.regspacing = DEFAULT_REGSPACING;
        res_second = platform_get_resource(dev,
                               (info->io.addr_type == IPMI_IO_ADDR_SPACE) ?
                                        IORESOURCE_IO : IORESOURCE_MEM,
                               1);
        if (res_second) {
                if (res_second->start > info->io.addr_data)
                        info->io.regspacing =
                                res_second->start - info->io.addr_data;
        }
        info->io.regsize = DEFAULT_REGSPACING;
        info->io.regshift = 0;

        /* If _GPE exists, use it; otherwise use standard interrupts */
        status = acpi_evaluate_integer(handle, "_GPE", NULL, &tmp);
        if (ACPI_SUCCESS(status)) {
                info->irq = tmp;
                info->irq_setup = acpi_gpe_irq_setup;
        } else {
                int irq = platform_get_irq(dev, 0);

                if (irq > 0) {
                        info->irq = irq;
                        info->irq_setup = std_irq_setup;
                }
        }

        info->dev = &dev->dev;
        platform_set_drvdata(dev, info);

        dev_info(info->dev, "%pR regsize %d spacing %d irq %d\n",
                 res, info->io.regsize, info->io.regspacing,
                 info->irq);

        rv = add_smi(info);
        if (rv)
                kfree(info);

        return rv;

err_free:
        kfree(info);
        return rv;
}

static const struct acpi_device_id acpi_ipmi_match[] = {
        { "IPI0001", 0 },
        { },
};
MODULE_DEVICE_TABLE(acpi, acpi_ipmi_match);
#else
static int acpi_ipmi_probe(struct platform_device *dev)
{
        return -ENODEV;
}
#endif

static int ipmi_probe(struct platform_device *dev)
{
        if (of_ipmi_probe(dev) == 0)
                return 0;

        return acpi_ipmi_probe(dev);
}

static int ipmi_remove(struct platform_device *dev)
{
        struct smi_info *info = dev_get_drvdata(&dev->dev);

        cleanup_one_si(info);
        return 0;
}

static struct platform_driver ipmi_driver = {
        .driver = {
                .name = DEVICE_NAME,
                .of_match_table = of_ipmi_match,
                .acpi_match_table = ACPI_PTR(acpi_ipmi_match),
        },
        .probe          = ipmi_probe,
        .remove         = ipmi_remove,
};

#ifdef CONFIG_PARISC
static int ipmi_parisc_probe(struct parisc_device *dev)
{
        struct smi_info *info;
        int rv;

        info = smi_info_alloc();

        if (!info) {
                dev_err(&dev->dev,
                        "could not allocate memory for PARISC probe\n");
                return -ENOMEM;
        }

        info->si_type           = SI_KCS;
        info->addr_source       = SI_DEVICETREE;
        info->io_setup          = mem_setup;
        info->io.addr_type      = IPMI_MEM_ADDR_SPACE;
        info->io.addr_data      = dev->hpa.start;
        info->io.regsize        = 1;
        info->io.regspacing     = 1;
        info->io.regshift       = 0;
        info->irq               = 0; /* no interrupt */
        info->irq_setup         = NULL;
        info->dev               = &dev->dev;

        dev_dbg(&dev->dev, "addr 0x%lx\n", info->io.addr_data);

        dev_set_drvdata(&dev->dev, info);

        rv = add_smi(info);
        if (rv) {
                kfree(info);
                return rv;
        }

        return 0;
}

static int ipmi_parisc_remove(struct parisc_device *dev)
{
        cleanup_one_si(dev_get_drvdata(&dev->dev));
        return 0;
}

static const struct parisc_device_id ipmi_parisc_tbl[] = {
        { HPHW_MC, HVERSION_REV_ANY_ID, 0x004, 0xC0 },
        { 0, }
};

static struct parisc_driver ipmi_parisc_driver = {
        .name =         "ipmi",
        .id_table =     ipmi_parisc_tbl,
        .probe =        ipmi_parisc_probe,
        .remove =       ipmi_parisc_remove,
};
#endif /* CONFIG_PARISC */

static int wait_for_msg_done(struct smi_info *smi_info)
{
        enum si_sm_result     smi_result;

        smi_result = smi_info->handlers->event(smi_info->si_sm, 0);
        for (;;) {
                if (smi_result == SI_SM_CALL_WITH_DELAY ||
                    smi_result == SI_SM_CALL_WITH_TICK_DELAY) {
                        schedule_timeout_uninterruptible(1);
                        smi_result = smi_info->handlers->event(
                                smi_info->si_sm, jiffies_to_usecs(1));
                } else if (smi_result == SI_SM_CALL_WITHOUT_DELAY) {
                        smi_result = smi_info->handlers->event(
                                smi_info->si_sm, 0);
                } else
                        break;
        }
        if (smi_result == SI_SM_HOSED)
                /*
                 * We couldn't get the state machine to run, so whatever's at
                 * the port is probably not an IPMI SMI interface.
                 */
                return -ENODEV;

        return 0;
}

static int try_get_dev_id(struct smi_info *smi_info)
{
        unsigned char         msg[2];
        unsigned char         *resp;
        unsigned long         resp_len;
        int                   rv = 0;

        resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
        if (!resp)
                return -ENOMEM;

        /*
         * Do a Get Device ID command, since it comes back with some
         * useful info.
         */
        msg[0] = IPMI_NETFN_APP_REQUEST << 2;
        msg[1] = IPMI_GET_DEVICE_ID_CMD;
        smi_info->handlers->start_transaction(smi_info->si_sm, msg, 2);

        rv = wait_for_msg_done(smi_info);
        if (rv)
                goto out;

        resp_len = smi_info->handlers->get_result(smi_info->si_sm,
                                                  resp, IPMI_MAX_MSG_LENGTH);

        /* Check and record info from the get device id, in case we need it. */
        rv = ipmi_demangle_device_id(resp, resp_len, &smi_info->device_id);

out:
        kfree(resp);
        return rv;
}

static int get_global_enables(struct smi_info *smi_info, u8 *enables)
{
        unsigned char         msg[3];
        unsigned char         *resp;
        unsigned long         resp_len;
        int                   rv;

        resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
        if (!resp)
                return -ENOMEM;

        msg[0] = IPMI_NETFN_APP_REQUEST << 2;
        msg[1] = IPMI_GET_BMC_GLOBAL_ENABLES_CMD;
        smi_info->handlers->start_transaction(smi_info->si_sm, msg, 2);

        rv = wait_for_msg_done(smi_info);
        if (rv) {
                dev_warn(smi_info->dev,
                         "Error getting response from get global enables command: %d\n",
                         rv);
                goto out;
        }

        resp_len = smi_info->handlers->get_result(smi_info->si_sm,
                                                  resp, IPMI_MAX_MSG_LENGTH);

        if (resp_len < 4 ||
                        resp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2 ||
                        resp[1] != IPMI_GET_BMC_GLOBAL_ENABLES_CMD   ||
                        resp[2] != 0) {
                dev_warn(smi_info->dev,
                         "Invalid return from get global enables command: %ld %x %x %x\n",
                         resp_len, resp[0], resp[1], resp[2]);
                rv = -EINVAL;
                goto out;
        } else {
                *enables = resp[3];
        }

out:
        kfree(resp);
        return rv;
}

/*
 * Returns 1 if it gets an error from the command.
 */
static int set_global_enables(struct smi_info *smi_info, u8 enables)
{
        unsigned char         msg[3];
        unsigned char         *resp;
        unsigned long         resp_len;
        int                   rv;

        resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
        if (!resp)
                return -ENOMEM;

        msg[0] = IPMI_NETFN_APP_REQUEST << 2;
        msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
        msg[2] = enables;
        smi_info->handlers->start_transaction(smi_info->si_sm, msg, 3);

        rv = wait_for_msg_done(smi_info);
        if (rv) {
                dev_warn(smi_info->dev,
                         "Error getting response from set global enables command: %d\n",
                         rv);
                goto out;
        }

        resp_len = smi_info->handlers->get_result(smi_info->si_sm,
                                                  resp, IPMI_MAX_MSG_LENGTH);

        if (resp_len < 3 ||
                        resp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2 ||
                        resp[1] != IPMI_SET_BMC_GLOBAL_ENABLES_CMD) {
                dev_warn(smi_info->dev,
                         "Invalid return from set global enables command: %ld %x %x\n",
                         resp_len, resp[0], resp[1]);
                rv = -EINVAL;
                goto out;
        }

        if (resp[2] != 0)
                rv = 1;

out:
        kfree(resp);
        return rv;
}

/*
 * Some BMCs do not support clearing the receive irq bit in the global
 * enables (even if they don't support interrupts on the BMC).  Check
 * for this and handle it properly.
 */
static void check_clr_rcv_irq(struct smi_info *smi_info)
{
        u8 enables = 0;
        int rv;

        rv = get_global_enables(smi_info, &enables);
        if (!rv) {
                if ((enables & IPMI_BMC_RCV_MSG_INTR) == 0)
                        /* Already clear, should work ok. */
                        return;

                enables &= ~IPMI_BMC_RCV_MSG_INTR;
                rv = set_global_enables(smi_info, enables);
        }

        if (rv < 0) {
                dev_err(smi_info->dev,
                        "Cannot check clearing the rcv irq: %d\n", rv);
                return;
        }

        if (rv) {
                /*
                 * An error when setting the event buffer bit means
                 * clearing the bit is not supported.
                 */
                dev_warn(smi_info->dev,
                         "The BMC does not support clearing the recv irq bit, compensating, but the BMC needs to be fixed.\n");
                smi_info->cannot_disable_irq = true;
        }
}

/*
 * Some BMCs do not support setting the interrupt bits in the global
 * enables even if they support interrupts.  Clearly bad, but we can
 * compensate.
 */
static void check_set_rcv_irq(struct smi_info *smi_info)
{
        u8 enables = 0;
        int rv;

        if (!smi_info->irq)
                return;

        rv = get_global_enables(smi_info, &enables);
        if (!rv) {
                enables |= IPMI_BMC_RCV_MSG_INTR;
                rv = set_global_enables(smi_info, enables);
        }

        if (rv < 0) {
                dev_err(smi_info->dev,
                        "Cannot check setting the rcv irq: %d\n", rv);
                return;
        }

        if (rv) {
                /*
                 * An error when setting the event buffer bit means
                 * setting the bit is not supported.
                 */
                dev_warn(smi_info->dev,
                         "The BMC does not support setting the recv irq bit, compensating, but the BMC needs to be fixed.\n");
                smi_info->cannot_disable_irq = true;
                smi_info->irq_enable_broken = true;
        }
}

static int try_enable_event_buffer(struct smi_info *smi_info)
{
        unsigned char         msg[3];
        unsigned char         *resp;
        unsigned long         resp_len;
        int                   rv = 0;

        resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
        if (!resp)
                return -ENOMEM;

        msg[0] = IPMI_NETFN_APP_REQUEST << 2;
        msg[1] = IPMI_GET_BMC_GLOBAL_ENABLES_CMD;
        smi_info->handlers->start_transaction(smi_info->si_sm, msg, 2);

        rv = wait_for_msg_done(smi_info);
        if (rv) {
                printk(KERN_WARNING PFX "Error getting response from get"
                       " global enables command, the event buffer is not"
                       " enabled.\n");
                goto out;
        }

        resp_len = smi_info->handlers->get_result(smi_info->si_sm,
                                                  resp, IPMI_MAX_MSG_LENGTH);

        if (resp_len < 4 ||
                        resp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2 ||
                        resp[1] != IPMI_GET_BMC_GLOBAL_ENABLES_CMD   ||
                        resp[2] != 0) {
                printk(KERN_WARNING PFX "Invalid return from get global"
                       " enables command, cannot enable the event buffer.\n");
                rv = -EINVAL;
                goto out;
        }

        if (resp[3] & IPMI_BMC_EVT_MSG_BUFF) {
                /* buffer is already enabled, nothing to do. */
                smi_info->supports_event_msg_buff = true;
                goto out;
        }

        msg[0] = IPMI_NETFN_APP_REQUEST << 2;
        msg[1] = IPMI_SET_BMC_GLOBAL_ENABLES_CMD;
        msg[2] = resp[3] | IPMI_BMC_EVT_MSG_BUFF;
        smi_info->handlers->start_transaction(smi_info->si_sm, msg, 3);

        rv = wait_for_msg_done(smi_info);
        if (rv) {
                printk(KERN_WARNING PFX "Error getting response from set"
                       " global, enables command, the event buffer is not"
                       " enabled.\n");
                goto out;
        }

        resp_len = smi_info->handlers->get_result(smi_info->si_sm,
                                                  resp, IPMI_MAX_MSG_LENGTH);

        if (resp_len < 3 ||
                        resp[0] != (IPMI_NETFN_APP_REQUEST | 1) << 2 ||
                        resp[1] != IPMI_SET_BMC_GLOBAL_ENABLES_CMD) {
                printk(KERN_WARNING PFX "Invalid return from get global,"
                       "enables command, not enable the event buffer.\n");
                rv = -EINVAL;
                goto out;
        }

        if (resp[2] != 0)
                /*
                 * An error when setting the event buffer bit means
                 * that the event buffer is not supported.
                 */
                rv = -ENOENT;
        else
                smi_info->supports_event_msg_buff = true;

out:
        kfree(resp);
        return rv;
}

static int smi_type_proc_show(struct seq_file *m, void *v)
{
        struct smi_info *smi = m->private;

        seq_printf(m, "%s\n", si_to_str[smi->si_type]);

        return 0;
}

static int smi_type_proc_open(struct inode *inode, struct file *file)
{
        return single_open(file, smi_type_proc_show, PDE_DATA(inode));
}

static const struct file_operations smi_type_proc_ops = {
        .open           = smi_type_proc_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
};

static int smi_si_stats_proc_show(struct seq_file *m, void *v)
{
        struct smi_info *smi = m->private;

        seq_printf(m, "interrupts_enabled:    %d\n",
                       smi->irq && !smi->interrupt_disabled);
        seq_printf(m, "short_timeouts:        %u\n",
                       smi_get_stat(smi, short_timeouts));
        seq_printf(m, "long_timeouts:         %u\n",
                       smi_get_stat(smi, long_timeouts));
        seq_printf(m, "idles:                 %u\n",
                       smi_get_stat(smi, idles));
        seq_printf(m, "interrupts:            %u\n",
                       smi_get_stat(smi, interrupts));
        seq_printf(m, "attentions:            %u\n",
                       smi_get_stat(smi, attentions));
        seq_printf(m, "flag_fetches:          %u\n",
                       smi_get_stat(smi, flag_fetches));
        seq_printf(m, "hosed_count:           %u\n",
                       smi_get_stat(smi, hosed_count));
        seq_printf(m, "complete_transactions: %u\n",
                       smi_get_stat(smi, complete_transactions));
        seq_printf(m, "events:                %u\n",
                       smi_get_stat(smi, events));
        seq_printf(m, "watchdog_pretimeouts:  %u\n",
                       smi_get_stat(smi, watchdog_pretimeouts));
        seq_printf(m, "incoming_messages:     %u\n",
                       smi_get_stat(smi, incoming_messages));
        return 0;
}

static int smi_si_stats_proc_open(struct inode *inode, struct file *file)
{
        return single_open(file, smi_si_stats_proc_show, PDE_DATA(inode));
}

static const struct file_operations smi_si_stats_proc_ops = {
        .open           = smi_si_stats_proc_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
};

static int smi_params_proc_show(struct seq_file *m, void *v)
{
        struct smi_info *smi = m->private;

        seq_printf(m,
                   "%s,%s,0x%lx,rsp=%d,rsi=%d,rsh=%d,irq=%d,ipmb=%d\n",
                   si_to_str[smi->si_type],
                   addr_space_to_str[smi->io.addr_type],
                   smi->io.addr_data,
                   smi->io.regspacing,
                   smi->io.regsize,
                   smi->io.regshift,
                   smi->irq,
                   smi->slave_addr);

        return 0;
}

static int smi_params_proc_open(struct inode *inode, struct file *file)
{
        return single_open(file, smi_params_proc_show, PDE_DATA(inode));
}

static const struct file_operations smi_params_proc_ops = {
        .open           = smi_params_proc_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
};

/*
 * oem_data_avail_to_receive_msg_avail
 * @info - smi_info structure with msg_flags set
 *
 * Converts flags from OEM_DATA_AVAIL to RECEIVE_MSG_AVAIL
 * Returns 1 indicating need to re-run handle_flags().
 */
static int oem_data_avail_to_receive_msg_avail(struct smi_info *smi_info)
{
        smi_info->msg_flags = ((smi_info->msg_flags & ~OEM_DATA_AVAIL) |
                               RECEIVE_MSG_AVAIL);
        return 1;
}

/*
 * setup_dell_poweredge_oem_data_handler
 * @info - smi_info.device_id must be populated
 *
 * Systems that match, but have firmware version < 1.40 may assert
 * OEM0_DATA_AVAIL on their own, without being told via Set Flags that
 * it's safe to do so.  Such systems will de-assert OEM1_DATA_AVAIL
 * upon receipt of IPMI_GET_MSG_CMD, so we should treat these flags
 * as RECEIVE_MSG_AVAIL instead.
 *
 * As Dell has no plans to release IPMI 1.5 firmware that *ever*
 * assert the OEM[012] bits, and if it did, the driver would have to
 * change to handle that properly, we don't actually check for the
 * firmware version.
 * Device ID = 0x20                BMC on PowerEdge 8G servers
 * Device Revision = 0x80
 * Firmware Revision1 = 0x01       BMC version 1.40
 * Firmware Revision2 = 0x40       BCD encoded
 * IPMI Version = 0x51             IPMI 1.5
 * Manufacturer ID = A2 02 00      Dell IANA
 *
 * Additionally, PowerEdge systems with IPMI < 1.5 may also assert
 * OEM0_DATA_AVAIL and needs to be treated as RECEIVE_MSG_AVAIL.
 *
 */
#define DELL_POWEREDGE_8G_BMC_DEVICE_ID  0x20
#define DELL_POWEREDGE_8G_BMC_DEVICE_REV 0x80
#define DELL_POWEREDGE_8G_BMC_IPMI_VERSION 0x51
#define DELL_IANA_MFR_ID 0x0002a2
static void setup_dell_poweredge_oem_data_handler(struct smi_info *smi_info)
{
        struct ipmi_device_id *id = &smi_info->device_id;
        if (id->manufacturer_id == DELL_IANA_MFR_ID) {
                if (id->device_id       == DELL_POWEREDGE_8G_BMC_DEVICE_ID  &&
                    id->device_revision == DELL_POWEREDGE_8G_BMC_DEVICE_REV &&
                    id->ipmi_version   == DELL_POWEREDGE_8G_BMC_IPMI_VERSION) {
                        smi_info->oem_data_avail_handler =
                                oem_data_avail_to_receive_msg_avail;
                } else if (ipmi_version_major(id) < 1 ||
                           (ipmi_version_major(id) == 1 &&
                            ipmi_version_minor(id) < 5)) {
                        smi_info->oem_data_avail_handler =
                                oem_data_avail_to_receive_msg_avail;
                }
        }
}

#define CANNOT_RETURN_REQUESTED_LENGTH 0xCA
static void return_hosed_msg_badsize(struct smi_info *smi_info)
{
        struct ipmi_smi_msg *msg = smi_info->curr_msg;

        /* Make it a response */
        msg->rsp[0] = msg->data[0] | 4;
        msg->rsp[1] = msg->data[1];
        msg->rsp[2] = CANNOT_RETURN_REQUESTED_LENGTH;
        msg->rsp_size = 3;
        smi_info->curr_msg = NULL;
        deliver_recv_msg(smi_info, msg);
}

/*
 * dell_poweredge_bt_xaction_handler
 * @info - smi_info.device_id must be populated
 *
 * Dell PowerEdge servers with the BT interface (x6xx and 1750) will
 * not respond to a Get SDR command if the length of the data
 * requested is exactly 0x3A, which leads to command timeouts and no
 * data returned.  This intercepts such commands, and causes userspace
 * callers to try again with a different-sized buffer, which succeeds.
 */

#define STORAGE_NETFN 0x0A
#define STORAGE_CMD_GET_SDR 0x23
static int dell_poweredge_bt_xaction_handler(struct notifier_block *self,
                                             unsigned long unused,
                                             void *in)
{
        struct smi_info *smi_info = in;
        unsigned char *data = smi_info->curr_msg->data;
        unsigned int size   = smi_info->curr_msg->data_size;
        if (size >= 8 &&
            (data[0]>>2) == STORAGE_NETFN &&
            data[1] == STORAGE_CMD_GET_SDR &&
            data[7] == 0x3A) {
                return_hosed_msg_badsize(smi_info);
                return NOTIFY_STOP;
        }
        return NOTIFY_DONE;
}

static struct notifier_block dell_poweredge_bt_xaction_notifier = {
        .notifier_call  = dell_poweredge_bt_xaction_handler,
};

/*
 * setup_dell_poweredge_bt_xaction_handler
 * @info - smi_info.device_id must be filled in already
 *
 * Fills in smi_info.device_id.start_transaction_pre_hook
 * when we know what function to use there.
 */
static void
setup_dell_poweredge_bt_xaction_handler(struct smi_info *smi_info)
{
        struct ipmi_device_id *id = &smi_info->device_id;
        if (id->manufacturer_id == DELL_IANA_MFR_ID &&
            smi_info->si_type == SI_BT)
                register_xaction_notifier(&dell_poweredge_bt_xaction_notifier);
}

/*
 * setup_oem_data_handler
 * @info - smi_info.device_id must be filled in already
 *
 * Fills in smi_info.device_id.oem_data_available_handler
 * when we know what function to use there.
 */

static void setup_oem_data_handler(struct smi_info *smi_info)
{
        setup_dell_poweredge_oem_data_handler(smi_info);
}

static void setup_xaction_handlers(struct smi_info *smi_info)
{
        setup_dell_poweredge_bt_xaction_handler(smi_info);
}

static void check_for_broken_irqs(struct smi_info *smi_info)
{
        check_clr_rcv_irq(smi_info);
        check_set_rcv_irq(smi_info);
}

static inline void wait_for_timer_and_thread(struct smi_info *smi_info)
{
        if (smi_info->thread != NULL)
                kthread_stop(smi_info->thread);
        if (smi_info->timer_running)
                del_timer_sync(&smi_info->si_timer);
}

static int is_new_interface(struct smi_info *info)
{
        struct smi_info *e;

        list_for_each_entry(e, &smi_infos, link) {
                if (e->io.addr_type != info->io.addr_type)
                        continue;
                if (e->io.addr_data == info->io.addr_data)
                        return 0;
        }

        return 1;
}

static int add_smi(struct smi_info *new_smi)
{
        int rv = 0;

        printk(KERN_INFO PFX "Adding %s-specified %s state machine",
               ipmi_addr_src_to_str(new_smi->addr_source),
               si_to_str[new_smi->si_type]);
        mutex_lock(&smi_infos_lock);
        if (!is_new_interface(new_smi)) {
                printk(KERN_CONT " duplicate interface\n");
                rv = -EBUSY;
                goto out_err;
        }

        printk(KERN_CONT "\n");

        /* So we know not to free it unless we have allocated one. */
        new_smi->intf = NULL;
        new_smi->si_sm = NULL;
        new_smi->handlers = NULL;

        list_add_tail(&new_smi->link, &smi_infos);

out_err:
        mutex_unlock(&smi_infos_lock);
        return rv;
}

static int try_smi_init(struct smi_info *new_smi)
{
        int rv = 0;
        int i;

        printk(KERN_INFO PFX "Trying %s-specified %s state"
               " machine at %s address 0x%lx, slave address 0x%x,"
               " irq %d\n",
               ipmi_addr_src_to_str(new_smi->addr_source),
               si_to_str[new_smi->si_type],
               addr_space_to_str[new_smi->io.addr_type],
               new_smi->io.addr_data,
               new_smi->slave_addr, new_smi->irq);

        switch (new_smi->si_type) {
        case SI_KCS:
                new_smi->handlers = &kcs_smi_handlers;
                break;

        case SI_SMIC:
                new_smi->handlers = &smic_smi_handlers;
                break;

        case SI_BT:
                new_smi->handlers = &bt_smi_handlers;
                break;

        default:
                /* No support for anything else yet. */
                rv = -EIO;
                goto out_err;
        }

        /* Allocate the state machine's data and initialize it. */
        new_smi->si_sm = kmalloc(new_smi->handlers->size(), GFP_KERNEL);
        if (!new_smi->si_sm) {
                printk(KERN_ERR PFX
                       "Could not allocate state machine memory\n");
                rv = -ENOMEM;
                goto out_err;
        }
        new_smi->io_size = new_smi->handlers->init_data(new_smi->si_sm,
                                                        &new_smi->io);

        /* Now that we know the I/O size, we can set up the I/O. */
        rv = new_smi->io_setup(new_smi);
        if (rv) {
                printk(KERN_ERR PFX "Could not set up I/O space\n");
                goto out_err;
        }

        /* Do low-level detection first. */
        if (new_smi->handlers->detect(new_smi->si_sm)) {
                if (new_smi->addr_source)
                        printk(KERN_INFO PFX "Interface detection failed\n");
                rv = -ENODEV;
                goto out_err;
        }

        /*
         * Attempt a get device id command.  If it fails, we probably
         * don't have a BMC here.
         */
        rv = try_get_dev_id(new_smi);
        if (rv) {
                if (new_smi->addr_source)
                        printk(KERN_INFO PFX "There appears to be no BMC"
                               " at this location\n");
                goto out_err;
        }

        setup_oem_data_handler(new_smi);
        setup_xaction_handlers(new_smi);
        check_for_broken_irqs(new_smi);

        new_smi->waiting_msg = NULL;
        new_smi->curr_msg = NULL;
        atomic_set(&new_smi->req_events, 0);
        new_smi->run_to_completion = false;
        for (i = 0; i < SI_NUM_STATS; i++)
                atomic_set(&new_smi->stats[i], 0);

        new_smi->interrupt_disabled = true;
        atomic_set(&new_smi->need_watch, 0);
        new_smi->intf_num = smi_num;
        smi_num++;

        rv = try_enable_event_buffer(new_smi);
        if (rv == 0)
                new_smi->has_event_buffer = true;

        /*
         * Start clearing the flags before we enable interrupts or the
         * timer to avoid racing with the timer.
         */
        start_clear_flags(new_smi, false);

        /*
         * IRQ is defined to be set when non-zero.  req_events will
         * cause a global flags check that will enable interrupts.
         */
        if (new_smi->irq) {
                new_smi->interrupt_disabled = false;
                atomic_set(&new_smi->req_events, 1);
        }

        if (!new_smi->dev) {
                /*
                 * If we don't already have a device from something
                 * else (like PCI), then register a new one.
                 */
                new_smi->pdev = platform_device_alloc("ipmi_si",
                                                      new_smi->intf_num);
                if (!new_smi->pdev) {
                        printk(KERN_ERR PFX
                               "Unable to allocate platform device\n");
                        goto out_err;
                }
                new_smi->dev = &new_smi->pdev->dev;
                new_smi->dev->driver = &ipmi_driver.driver;

                rv = platform_device_add(new_smi->pdev);
                if (rv) {
                        printk(KERN_ERR PFX
                               "Unable to register system interface device:"
                               " %d\n",
                               rv);
                        goto out_err;
                }
                new_smi->dev_registered = true;
        }

        rv = ipmi_register_smi(&handlers,
                               new_smi,
                               &new_smi->device_id,
                               new_smi->dev,
                               new_smi->slave_addr);
        if (rv) {
                dev_err(new_smi->dev, "Unable to register device: error %d\n",
                        rv);
                goto out_err_stop_timer;
        }

        rv = ipmi_smi_add_proc_entry(new_smi->intf, "type",
                                     &smi_type_proc_ops,
                                     new_smi);
        if (rv) {
                dev_err(new_smi->dev, "Unable to create proc entry: %d\n", rv);
                goto out_err_stop_timer;
        }

        rv = ipmi_smi_add_proc_entry(new_smi->intf, "si_stats",
                                     &smi_si_stats_proc_ops,
                                     new_smi);
        if (rv) {
                dev_err(new_smi->dev, "Unable to create proc entry: %d\n", rv);
                goto out_err_stop_timer;
        }

        rv = ipmi_smi_add_proc_entry(new_smi->intf, "params",
                                     &smi_params_proc_ops,
                                     new_smi);
        if (rv) {
                dev_err(new_smi->dev, "Unable to create proc entry: %d\n", rv);
                goto out_err_stop_timer;
        }

        dev_info(new_smi->dev, "IPMI %s interface initialized\n",
                 si_to_str[new_smi->si_type]);

        return 0;

out_err_stop_timer:
        wait_for_timer_and_thread(new_smi);

out_err:
        new_smi->interrupt_disabled = true;

        if (new_smi->intf) {
                ipmi_smi_t intf = new_smi->intf;
                new_smi->intf = NULL;
                ipmi_unregister_smi(intf);
        }

        if (new_smi->irq_cleanup) {
                new_smi->irq_cleanup(new_smi);
                new_smi->irq_cleanup = NULL;
        }

        /*
         * Wait until we know that we are out of any interrupt
         * handlers might have been running before we freed the
         * interrupt.
         */
        synchronize_sched();

        if (new_smi->si_sm) {
                if (new_smi->handlers)
                        new_smi->handlers->cleanup(new_smi->si_sm);
                kfree(new_smi->si_sm);
                new_smi->si_sm = NULL;
        }
        if (new_smi->addr_source_cleanup) {
                new_smi->addr_source_cleanup(new_smi);
                new_smi->addr_source_cleanup = NULL;
        }
        if (new_smi->io_cleanup) {
                new_smi->io_cleanup(new_smi);
                new_smi->io_cleanup = NULL;
        }

        if (new_smi->dev_registered) {
                platform_device_unregister(new_smi->pdev);
                new_smi->dev_registered = false;
        }

        return rv;
}

static int init_ipmi_si(void)
{
        int  i;
        char *str;
        int  rv;
        struct smi_info *e;
        enum ipmi_addr_src type = SI_INVALID;

        if (initialized)
                return 0;
        initialized = 1;

        if (si_tryplatform) {
                rv = platform_driver_register(&ipmi_driver);
                if (rv) {
                        printk(KERN_ERR PFX "Unable to register "
                               "driver: %d\n", rv);
                        return rv;
                }
        }

        /* Parse out the si_type string into its components. */
        str = si_type_str;
        if (*str != '\0') {
                for (i = 0; (i < SI_MAX_PARMS) && (*str != '\0'); i++) {
                        si_type[i] = str;
                        str = strchr(str, ',');
                        if (str) {
                                *str = '\0';
                                str++;
                        } else {
                                break;
                        }
                }
        }

        printk(KERN_INFO "IPMI System Interface driver.\n");

        /* If the user gave us a device, they presumably want us to use it */
        if (!hardcode_find_bmc())
                return 0;

#ifdef CONFIG_PCI
        if (si_trypci) {
                rv = pci_register_driver(&ipmi_pci_driver);
                if (rv)
                        printk(KERN_ERR PFX "Unable to register "
                               "PCI driver: %d\n", rv);
                else
                        pci_registered = true;
        }
#endif

#ifdef CONFIG_DMI
        if (si_trydmi)
                dmi_find_bmc();
#endif

#ifdef CONFIG_ACPI
        if (si_tryacpi)
                spmi_find_bmc();
#endif

#ifdef CONFIG_PARISC
        register_parisc_driver(&ipmi_parisc_driver);
        parisc_registered = true;
#endif

        /* We prefer devices with interrupts, but in the case of a machine
           with multiple BMCs we assume that there will be several instances
           of a given type so if we succeed in registering a type then also
           try to register everything else of the same type */

        mutex_lock(&smi_infos_lock);
        list_for_each_entry(e, &smi_infos, link) {
                /* Try to register a device if it has an IRQ and we either
                   haven't successfully registered a device yet or this
                   device has the same type as one we successfully registered */
                if (e->irq && (!type || e->addr_source == type)) {
                        if (!try_smi_init(e)) {
                                type = e->addr_source;
                        }
                }
        }

        /* type will only have been set if we successfully registered an si */
        if (type) {
                mutex_unlock(&smi_infos_lock);
                return 0;
        }

        /* Fall back to the preferred device */

        list_for_each_entry(e, &smi_infos, link) {
                if (!e->irq && (!type || e->addr_source == type)) {
                        if (!try_smi_init(e)) {
                                type = e->addr_source;
                        }
                }
        }
        mutex_unlock(&smi_infos_lock);

        if (type)
                return 0;

        mutex_lock(&smi_infos_lock);
        if (unload_when_empty && list_empty(&smi_infos)) {
                mutex_unlock(&smi_infos_lock);
                cleanup_ipmi_si();
                printk(KERN_WARNING PFX
                       "Unable to find any System Interface(s)\n");
                return -ENODEV;
        } else {
                mutex_unlock(&smi_infos_lock);
                return 0;
        }
}
module_init(init_ipmi_si);

static void cleanup_one_si(struct smi_info *to_clean)
{
        int           rv = 0;

        if (!to_clean)
                return;

        if (to_clean->intf) {
                ipmi_smi_t intf = to_clean->intf;

                to_clean->intf = NULL;
                rv = ipmi_unregister_smi(intf);
                if (rv) {
                        pr_err(PFX "Unable to unregister device: errno=%d\n",
                               rv);
                }
        }

        if (to_clean->dev)
                dev_set_drvdata(to_clean->dev, NULL);

        list_del(&to_clean->link);

        /*
         * Make sure that interrupts, the timer and the thread are
         * stopped and will not run again.
         */
        if (to_clean->irq_cleanup)
                to_clean->irq_cleanup(to_clean);
        wait_for_timer_and_thread(to_clean);

        /*
         * Timeouts are stopped, now make sure the interrupts are off
         * in the BMC.  Note that timers and CPU interrupts are off,
         * so no need for locks.
         */
        while (to_clean->curr_msg || (to_clean->si_state != SI_NORMAL)) {
                poll(to_clean);
                schedule_timeout_uninterruptible(1);
        }
        disable_si_irq(to_clean, false);
        while (to_clean->curr_msg || (to_clean->si_state != SI_NORMAL)) {
                poll(to_clean);
                schedule_timeout_uninterruptible(1);
        }

        if (to_clean->handlers)
                to_clean->handlers->cleanup(to_clean->si_sm);

        kfree(to_clean->si_sm);

        if (to_clean->addr_source_cleanup)
                to_clean->addr_source_cleanup(to_clean);
        if (to_clean->io_cleanup)
                to_clean->io_cleanup(to_clean);

        if (to_clean->dev_registered)
                platform_device_unregister(to_clean->pdev);

        kfree(to_clean);
}

static void cleanup_ipmi_si(void)
{
        struct smi_info *e, *tmp_e;

        if (!initialized)
                return;

#ifdef CONFIG_PCI
        if (pci_registered)
                pci_unregister_driver(&ipmi_pci_driver);
#endif
#ifdef CONFIG_PARISC
        if (parisc_registered)
                unregister_parisc_driver(&ipmi_parisc_driver);
#endif

        platform_driver_unregister(&ipmi_driver);

        mutex_lock(&smi_infos_lock);
        list_for_each_entry_safe(e, tmp_e, &smi_infos, link)
                cleanup_one_si(e);
        mutex_unlock(&smi_infos_lock);
}
module_exit(cleanup_ipmi_si);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Corey Minyard <minyard@mvista.com>");
MODULE_DESCRIPTION("Interface to the IPMI driver for the KCS, SMIC, and BT"
                   " system interfaces.");