drivers/hv/hv.c

   1 /*
   2  * Copyright (c) 2009, Microsoft Corporation.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms and conditions of the GNU General Public License,
   6  * version 2, as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  15  * Place - Suite 330, Boston, MA 02111-1307 USA.
  16  *
  17  * Authors:
  18  *   Haiyang Zhang <haiyangz@microsoft.com>
  19  *   Hank Janssen  <hjanssen@microsoft.com>
  20  *
  21  */
  22 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  23
  24 #include <linux/kernel.h>
  25 #include <linux/mm.h>
  26 #include <linux/slab.h>
  27 #include <linux/vmalloc.h>
  28 #include <linux/hyperv.h>
  29 #include <linux/version.h>
  30 #include <linux/interrupt.h>
  31 #include <linux/clockchips.h>
  32 #include <asm/hyperv.h>
  33 #include <asm/mshyperv.h>
  34 #include "hyperv_vmbus.h"
  35
  36 /* The one and only */
  37 struct hv_context hv_context = {
  38         .synic_initialized      = false,
  39 };
  40
  41 #define HV_TIMER_FREQUENCY (10 * 1000 * 1000) /* 100ns period */
  42 #define HV_MAX_MAX_DELTA_TICKS 0xffffffff
  43 #define HV_MIN_DELTA_TICKS 1
  44
  45 /*
  46  * hv_init - Main initialization routine.
  47  *
  48  * This routine must be called before any other routines in here are called
  49  */
  50 int hv_init(void)
  51 {
  52         if (!hv_is_hypercall_page_setup())
  53                 return -ENOTSUPP;
  54
  55         hv_context.cpu_context = alloc_percpu(struct hv_per_cpu_context);
  56         if (!hv_context.cpu_context)
  57                 return -ENOMEM;
  58
  59         return 0;
  60 }
  61
  62 /*
  63  * hv_post_message - Post a message using the hypervisor message IPC.
  64  *
  65  * This involves a hypercall.
  66  */
  67 int hv_post_message(union hv_connection_id connection_id,
  68                   enum hv_message_type message_type,
  69                   void *payload, size_t payload_size)
  70 {
  71         struct hv_input_post_message *aligned_msg;
  72         struct hv_per_cpu_context *hv_cpu;
  73         u64 status;
  74
  75         if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT)
  76                 return -EMSGSIZE;
  77
  78         hv_cpu = get_cpu_ptr(hv_context.cpu_context);
  79         aligned_msg = hv_cpu->post_msg_page;
  80         aligned_msg->connectionid = connection_id;
  81         aligned_msg->reserved = 0;
  82         aligned_msg->message_type = message_type;
  83         aligned_msg->payload_size = payload_size;
  84         memcpy((void *)aligned_msg->payload, payload, payload_size);
  85
  86         status = hv_do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL);
  87
  88         /* Preemption must remain disabled until after the hypercall
  89          * so some other thread can't get scheduled onto this cpu and
  90          * corrupt the per-cpu post_msg_page
  91          */
  92         put_cpu_ptr(hv_cpu);
  93
  94         return status & 0xFFFF;
  95 }
  96
  97 static int hv_ce_set_next_event(unsigned long delta,
  98                                 struct clock_event_device *evt)
  99 {
 100         u64 current_tick;
 101
 102         WARN_ON(!clockevent_state_oneshot(evt));
 103
 104         current_tick = hyperv_cs->read(NULL);
 105         current_tick += delta;
 106         hv_init_timer(HV_X64_MSR_STIMER0_COUNT, current_tick);
 107         return 0;
 108 }
 109
 110 static int hv_ce_shutdown(struct clock_event_device *evt)
 111 {
 112         hv_init_timer(HV_X64_MSR_STIMER0_COUNT, 0);
 113         hv_init_timer_config(HV_X64_MSR_STIMER0_CONFIG, 0);
 114
 115         return 0;
 116 }
 117
 118 static int hv_ce_set_oneshot(struct clock_event_device *evt)
 119 {
 120         union hv_timer_config timer_cfg;
 121
 122         timer_cfg.enable = 1;
 123         timer_cfg.auto_enable = 1;
 124         timer_cfg.sintx = VMBUS_MESSAGE_SINT;
 125         hv_init_timer_config(HV_X64_MSR_STIMER0_CONFIG, timer_cfg.as_uint64);
 126
 127         return 0;
 128 }
 129
 130 static void hv_init_clockevent_device(struct clock_event_device *dev, int cpu)
 131 {
 132         dev->name = "Hyper-V clockevent";
 133         dev->features = CLOCK_EVT_FEAT_ONESHOT;
 134         dev->cpumask = cpumask_of(cpu);
 135         dev->rating = 1000;
 136         /*
 137          * Avoid settint dev->owner = THIS_MODULE deliberately as doing so will
 138          * result in clockevents_config_and_register() taking additional
 139          * references to the hv_vmbus module making it impossible to unload.
 140          */
 141
 142         dev->set_state_shutdown = hv_ce_shutdown;
 143         dev->set_state_oneshot = hv_ce_set_oneshot;
 144         dev->set_next_event = hv_ce_set_next_event;
 145 }
 146
 147
 148 int hv_synic_alloc(void)
 149 {
 150         int cpu;
 151         struct hv_per_cpu_context *hv_cpu;
 152
 153         /*
 154          * First, zero all per-cpu memory areas so hv_synic_free() can
 155          * detect what memory has been allocated and cleanup properly
 156          * after any failures.
 157          */
 158         for_each_present_cpu(cpu) {
 159                 hv_cpu = per_cpu_ptr(hv_context.cpu_context, cpu);
 160                 memset(hv_cpu, 0, sizeof(*hv_cpu));
 161         }
 162
 163         hv_context.hv_numa_map = kzalloc(sizeof(struct cpumask) * nr_node_ids,
 164                                          GFP_ATOMIC);
 165         if (hv_context.hv_numa_map == NULL) {
 166                 pr_err("Unable to allocate NUMA map\n");
 167                 goto err;
 168         }
 169
 170         for_each_present_cpu(cpu) {
 171                 hv_cpu = per_cpu_ptr(hv_context.cpu_context, cpu);
 172
 173                 tasklet_init(&hv_cpu->msg_dpc,
 174                              vmbus_on_msg_dpc, (unsigned long) hv_cpu);
 175
 176                 hv_cpu->clk_evt = kzalloc(sizeof(struct clock_event_device),
 177                                           GFP_KERNEL);
 178                 if (hv_cpu->clk_evt == NULL) {
 179                         pr_err("Unable to allocate clock event device\n");
 180                         goto err;
 181                 }
 182                 hv_init_clockevent_device(hv_cpu->clk_evt, cpu);
 183
 184                 hv_cpu->synic_message_page =
 185                         (void *)get_zeroed_page(GFP_ATOMIC);
 186                 if (hv_cpu->synic_message_page == NULL) {
 187                         pr_err("Unable to allocate SYNIC message page\n");
 188                         goto err;
 189                 }
 190
 191                 hv_cpu->synic_event_page = (void *)get_zeroed_page(GFP_ATOMIC);
 192                 if (hv_cpu->synic_event_page == NULL) {
 193                         pr_err("Unable to allocate SYNIC event page\n");
 194                         goto err;
 195                 }
 196
 197                 hv_cpu->post_msg_page = (void *)get_zeroed_page(GFP_ATOMIC);
 198                 if (hv_cpu->post_msg_page == NULL) {
 199                         pr_err("Unable to allocate post msg page\n");
 200                         goto err;
 201                 }
 202
 203                 INIT_LIST_HEAD(&hv_cpu->chan_list);
 204         }
 205
 206         return 0;
 207 err:
 208         /*
 209          * Any memory allocations that succeeded will be freed when
 210          * the caller cleans up by calling hv_synic_free()
 211          */
 212         return -ENOMEM;
 213 }
 214
 215
 216 void hv_synic_free(void)
 217 {
 218         int cpu;
 219
 220         for_each_present_cpu(cpu) {
 221                 struct hv_per_cpu_context *hv_cpu
 222                         = per_cpu_ptr(hv_context.cpu_context, cpu);
 223
 224                 kfree(hv_cpu->clk_evt);
 225                 free_page((unsigned long)hv_cpu->synic_event_page);
 226                 free_page((unsigned long)hv_cpu->synic_message_page);
 227                 free_page((unsigned long)hv_cpu->post_msg_page);
 228         }
 229
 230         kfree(hv_context.hv_numa_map);
 231 }
 232
 233 /*
 234  * hv_synic_init - Initialize the Synthethic Interrupt Controller.
 235  *
 236  * If it is already initialized by another entity (ie x2v shim), we need to
 237  * retrieve the initialized message and event pages.  Otherwise, we create and
 238  * initialize the message and event pages.
 239  */
 240 int hv_synic_init(unsigned int cpu)
 241 {
 242         struct hv_per_cpu_context *hv_cpu
 243                 = per_cpu_ptr(hv_context.cpu_context, cpu);
 244         union hv_synic_simp simp;
 245         union hv_synic_siefp siefp;
 246         union hv_synic_sint shared_sint;
 247         union hv_synic_scontrol sctrl;
 248
 249         /* Setup the Synic's message page */
 250         hv_get_simp(simp.as_uint64);
 251         simp.simp_enabled = 1;
 252         simp.base_simp_gpa = virt_to_phys(hv_cpu->synic_message_page)
 253                 >> PAGE_SHIFT;
 254
 255         hv_set_simp(simp.as_uint64);
 256
 257         /* Setup the Synic's event page */
 258         hv_get_siefp(siefp.as_uint64);
 259         siefp.siefp_enabled = 1;
 260         siefp.base_siefp_gpa = virt_to_phys(hv_cpu->synic_event_page)
 261                 >> PAGE_SHIFT;
 262
 263         hv_set_siefp(siefp.as_uint64);
 264
 265         /* Setup the shared SINT. */
 266         hv_get_synint_state(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT,
 267                             shared_sint.as_uint64);
 268
 269         shared_sint.as_uint64 = 0;
 270         shared_sint.vector = HYPERVISOR_CALLBACK_VECTOR;
 271         shared_sint.masked = false;
 272         if (ms_hyperv.hints & HV_X64_DEPRECATING_AEOI_RECOMMENDED)
 273                 shared_sint.auto_eoi = false;
 274         else
 275                 shared_sint.auto_eoi = true;
 276
 277         hv_set_synint_state(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT,
 278                             shared_sint.as_uint64);
 279
 280         /* Enable the global synic bit */
 281         hv_get_synic_state(sctrl.as_uint64);
 282         sctrl.enable = 1;
 283
 284         hv_set_synic_state(sctrl.as_uint64);
 285
 286         hv_context.synic_initialized = true;
 287
 288         /*
 289          * Register the per-cpu clockevent source.
 290          */
 291         if (ms_hyperv.features & HV_X64_MSR_SYNTIMER_AVAILABLE)
 292                 clockevents_config_and_register(hv_cpu->clk_evt,
 293                                                 HV_TIMER_FREQUENCY,
 294                                                 HV_MIN_DELTA_TICKS,
 295                                                 HV_MAX_MAX_DELTA_TICKS);
 296         return 0;
 297 }
 298
 299 /*
 300  * hv_synic_clockevents_cleanup - Cleanup clockevent devices
 301  */
 302 void hv_synic_clockevents_cleanup(void)
 303 {
 304         int cpu;
 305
 306         if (!(ms_hyperv.features & HV_X64_MSR_SYNTIMER_AVAILABLE))
 307                 return;
 308
 309         for_each_present_cpu(cpu) {
 310                 struct hv_per_cpu_context *hv_cpu
 311                         = per_cpu_ptr(hv_context.cpu_context, cpu);
 312
 313                 clockevents_unbind_device(hv_cpu->clk_evt, cpu);
 314         }
 315 }
 316
 317 /*
 318  * hv_synic_cleanup - Cleanup routine for hv_synic_init().
 319  */
 320 int hv_synic_cleanup(unsigned int cpu)
 321 {
 322         union hv_synic_sint shared_sint;
 323         union hv_synic_simp simp;
 324         union hv_synic_siefp siefp;
 325         union hv_synic_scontrol sctrl;
 326         struct vmbus_channel *channel, *sc;
 327         bool channel_found = false;
 328         unsigned long flags;
 329
 330         if (!hv_context.synic_initialized)
 331                 return -EFAULT;
 332
 333         /*
 334          * Search for channels which are bound to the CPU we're about to
 335          * cleanup. In case we find one and vmbus is still connected we need to
 336          * fail, this will effectively prevent CPU offlining. There is no way
 337          * we can re-bind channels to different CPUs for now.
 338          */
 339         mutex_lock(&vmbus_connection.channel_mutex);
 340         list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
 341                 if (channel->target_cpu == cpu) {
 342                         channel_found = true;
 343                         break;
 344                 }
 345                 spin_lock_irqsave(&channel->lock, flags);
 346                 list_for_each_entry(sc, &channel->sc_list, sc_list) {
 347                         if (sc->target_cpu == cpu) {
 348                                 channel_found = true;
 349                                 break;
 350                         }
 351                 }
 352                 spin_unlock_irqrestore(&channel->lock, flags);
 353                 if (channel_found)
 354                         break;
 355         }
 356         mutex_unlock(&vmbus_connection.channel_mutex);
 357
 358         if (channel_found && vmbus_connection.conn_state == CONNECTED)
 359                 return -EBUSY;
 360
 361         /* Turn off clockevent device */
 362         if (ms_hyperv.features & HV_X64_MSR_SYNTIMER_AVAILABLE) {
 363                 struct hv_per_cpu_context *hv_cpu
 364                         = this_cpu_ptr(hv_context.cpu_context);
 365
 366                 clockevents_unbind_device(hv_cpu->clk_evt, cpu);
 367                 hv_ce_shutdown(hv_cpu->clk_evt);
 368         }
 369
 370         hv_get_synint_state(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT,
 371                             shared_sint.as_uint64);
 372
 373         shared_sint.masked = 1;
 374
 375         /* Need to correctly cleanup in the case of SMP!!! */
 376         /* Disable the interrupt */
 377         hv_set_synint_state(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT,
 378                             shared_sint.as_uint64);
 379
 380         hv_get_simp(simp.as_uint64);
 381         simp.simp_enabled = 0;
 382         simp.base_simp_gpa = 0;
 383
 384         hv_set_simp(simp.as_uint64);
 385
 386         hv_get_siefp(siefp.as_uint64);
 387         siefp.siefp_enabled = 0;
 388         siefp.base_siefp_gpa = 0;
 389
 390         hv_set_siefp(siefp.as_uint64);
 391
 392         /* Disable the global synic bit */
 393         hv_get_synic_state(sctrl.as_uint64);
 394         sctrl.enable = 0;
 395         hv_set_synic_state(sctrl.as_uint64);
 396
 397         return 0;
 398 }