arch/x86/kernel/apic/htirq.c

   1 /*
   2  * Support Hypertransport IRQ
   3  *
   4  * Copyright (C) 1997, 1998, 1999, 2000, 2009 Ingo Molnar, Hajnalka Szabo
   5  *      Moved from arch/x86/kernel/apic/io_apic.c.
   6  * Jiang Liu <jiang.liu@linux.intel.com>
   7  *      Add support of hierarchical irqdomain
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  */
  13 #include <linux/mm.h>
  14 #include <linux/interrupt.h>
  15 #include <linux/init.h>
  16 #include <linux/device.h>
  17 #include <linux/pci.h>
  18 #include <linux/htirq.h>
  19 #include <linux/irq.h>
  20
  21 #include <asm/irqdomain.h>
  22 #include <asm/hw_irq.h>
  23 #include <asm/apic.h>
  24 #include <asm/hypertransport.h>
  25
  26 static struct irq_domain *htirq_domain;
  27
  28 /*
  29  * Hypertransport interrupt support
  30  */
  31 static int
  32 ht_set_affinity(struct irq_data *data, const struct cpumask *mask, bool force)
  33 {
  34         struct irq_data *parent = data->parent_data;
  35         int ret;
  36
  37         ret = parent->chip->irq_set_affinity(parent, mask, force);
  38         if (ret >= 0) {
  39                 struct ht_irq_msg msg;
  40                 struct irq_cfg *cfg = irqd_cfg(data);
  41
  42                 fetch_ht_irq_msg(data->irq, &msg);
  43                 msg.address_lo &= ~(HT_IRQ_LOW_VECTOR_MASK |
  44                                     HT_IRQ_LOW_DEST_ID_MASK);
  45                 msg.address_lo |= HT_IRQ_LOW_VECTOR(cfg->vector) |
  46                                   HT_IRQ_LOW_DEST_ID(cfg->dest_apicid);
  47                 msg.address_hi &= ~(HT_IRQ_HIGH_DEST_ID_MASK);
  48                 msg.address_hi |= HT_IRQ_HIGH_DEST_ID(cfg->dest_apicid);
  49                 write_ht_irq_msg(data->irq, &msg);
  50         }
  51
  52         return ret;
  53 }
  54
  55 static struct irq_chip ht_irq_chip = {
  56         .name                   = "PCI-HT",
  57         .irq_mask               = mask_ht_irq,
  58         .irq_unmask             = unmask_ht_irq,
  59         .irq_ack                = irq_chip_ack_parent,
  60         .irq_set_affinity       = ht_set_affinity,
  61         .irq_retrigger          = irq_chip_retrigger_hierarchy,
  62         .flags                  = IRQCHIP_SKIP_SET_WAKE,
  63 };
  64
  65 static int htirq_domain_alloc(struct irq_domain *domain, unsigned int virq,
  66                               unsigned int nr_irqs, void *arg)
  67 {
  68         struct ht_irq_cfg *ht_cfg;
  69         struct irq_alloc_info *info = arg;
  70         struct pci_dev *dev;
  71         irq_hw_number_t hwirq;
  72         int ret;
  73
  74         if (nr_irqs > 1 || !info)
  75                 return -EINVAL;
  76
  77         dev = info->ht_dev;
  78         hwirq = (info->ht_idx & 0xFF) |
  79                 PCI_DEVID(dev->bus->number, dev->devfn) << 8 |
  80                 (pci_domain_nr(dev->bus) & 0xFFFFFFFF) << 24;
  81         if (irq_find_mapping(domain, hwirq) > 0)
  82                 return -EEXIST;
  83
  84         ht_cfg = kmalloc(sizeof(*ht_cfg), GFP_KERNEL);
  85         if (!ht_cfg)
  86                 return -ENOMEM;
  87
  88         ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, info);
  89         if (ret < 0) {
  90                 kfree(ht_cfg);
  91                 return ret;
  92         }
  93
  94         /* Initialize msg to a value that will never match the first write. */
  95         ht_cfg->msg.address_lo = 0xffffffff;
  96         ht_cfg->msg.address_hi = 0xffffffff;
  97         ht_cfg->dev = info->ht_dev;
  98         ht_cfg->update = info->ht_update;
  99         ht_cfg->pos = info->ht_pos;
 100         ht_cfg->idx = 0x10 + (info->ht_idx * 2);
 101         irq_domain_set_info(domain, virq, hwirq, &ht_irq_chip, ht_cfg,
 102                             handle_edge_irq, ht_cfg, "edge");
 103
 104         return 0;
 105 }
 106
 107 static void htirq_domain_free(struct irq_domain *domain, unsigned int virq,
 108                               unsigned int nr_irqs)
 109 {
 110         struct irq_data *irq_data = irq_domain_get_irq_data(domain, virq);
 111
 112         BUG_ON(nr_irqs != 1);
 113         kfree(irq_data->chip_data);
 114         irq_domain_free_irqs_top(domain, virq, nr_irqs);
 115 }
 116
 117 static void htirq_domain_activate(struct irq_domain *domain,
 118                                   struct irq_data *irq_data)
 119 {
 120         struct ht_irq_msg msg;
 121         struct irq_cfg *cfg = irqd_cfg(irq_data);
 122
 123         msg.address_hi = HT_IRQ_HIGH_DEST_ID(cfg->dest_apicid);
 124         msg.address_lo =
 125                 HT_IRQ_LOW_BASE |
 126                 HT_IRQ_LOW_DEST_ID(cfg->dest_apicid) |
 127                 HT_IRQ_LOW_VECTOR(cfg->vector) |
 128                 ((apic->irq_dest_mode == 0) ?
 129                         HT_IRQ_LOW_DM_PHYSICAL :
 130                         HT_IRQ_LOW_DM_LOGICAL) |
 131                 HT_IRQ_LOW_RQEOI_EDGE |
 132                 ((apic->irq_delivery_mode != dest_LowestPrio) ?
 133                         HT_IRQ_LOW_MT_FIXED :
 134                         HT_IRQ_LOW_MT_ARBITRATED) |
 135                 HT_IRQ_LOW_IRQ_MASKED;
 136         write_ht_irq_msg(irq_data->irq, &msg);
 137 }
 138
 139 static void htirq_domain_deactivate(struct irq_domain *domain,
 140                                     struct irq_data *irq_data)
 141 {
 142         struct ht_irq_msg msg;
 143
 144         memset(&msg, 0, sizeof(msg));
 145         write_ht_irq_msg(irq_data->irq, &msg);
 146 }
 147
 148 static const struct irq_domain_ops htirq_domain_ops = {
 149         .alloc          = htirq_domain_alloc,
 150         .free           = htirq_domain_free,
 151         .activate       = htirq_domain_activate,
 152         .deactivate     = htirq_domain_deactivate,
 153 };
 154
 155 void __init arch_init_htirq_domain(struct irq_domain *parent)
 156 {
 157         struct fwnode_handle *fn;
 158
 159         if (disable_apic)
 160                 return;
 161
 162         fn = irq_domain_alloc_named_fwnode("PCI-HT");
 163         if (!fn)
 164                 goto warn;
 165
 166         htirq_domain = irq_domain_create_tree(fn, &htirq_domain_ops, NULL);
 167         irq_domain_free_fwnode(fn);
 168         if (!htirq_domain)
 169                 goto warn;
 170
 171         htirq_domain->parent = parent;
 172         return;
 173
 174 warn:
 175         pr_warn("Failed to initialize irqdomain for HTIRQ.\n");
 176 }
 177
 178 int arch_setup_ht_irq(int idx, int pos, struct pci_dev *dev,
 179                       ht_irq_update_t *update)
 180 {
 181         struct irq_alloc_info info;
 182
 183         if (!htirq_domain)
 184                 return -ENOSYS;
 185
 186         init_irq_alloc_info(&info, NULL);
 187         info.ht_idx = idx;
 188         info.ht_pos = pos;
 189         info.ht_dev = dev;
 190         info.ht_update = update;
 191
 192         return irq_domain_alloc_irqs(htirq_domain, 1, dev_to_node(&dev->dev),
 193                                      &info);
 194 }
 195
 196 void arch_teardown_ht_irq(unsigned int irq)
 197 {
 198         irq_domain_free_irqs(irq, 1);
 199 }