kernel/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 <asm/irqdomain.h>
  20 #include <asm/hw_irq.h>
  21 #include <asm/apic.h>
  22 #include <asm/hypertransport.h>
  23
  24 static struct irq_domain *htirq_domain;
  25
  26 /*
  27  * Hypertransport interrupt support
  28  */
  29 static int
  30 ht_set_affinity(struct irq_data *data, const struct cpumask *mask, bool force)
  31 {
  32         struct irq_data *parent = data->parent_data;
  33         int ret;
  34
  35         ret = parent->chip->irq_set_affinity(parent, mask, force);
  36         if (ret >= 0) {
  37                 struct ht_irq_msg msg;
  38                 struct irq_cfg *cfg = irqd_cfg(data);
  39
  40                 fetch_ht_irq_msg(data->irq, &msg);
  41                 msg.address_lo &= ~(HT_IRQ_LOW_VECTOR_MASK |
  42                                     HT_IRQ_LOW_DEST_ID_MASK);
  43                 msg.address_lo |= HT_IRQ_LOW_VECTOR(cfg->vector) |
  44                                   HT_IRQ_LOW_DEST_ID(cfg->dest_apicid);
  45                 msg.address_hi &= ~(HT_IRQ_HIGH_DEST_ID_MASK);
  46                 msg.address_hi |= HT_IRQ_HIGH_DEST_ID(cfg->dest_apicid);
  47                 write_ht_irq_msg(data->irq, &msg);
  48         }
  49
  50         return ret;
  51 }
  52
  53 static struct irq_chip ht_irq_chip = {
  54         .name                   = "PCI-HT",
  55         .irq_mask               = mask_ht_irq,
  56         .irq_unmask             = unmask_ht_irq,
  57         .irq_ack                = irq_chip_ack_parent,
  58         .irq_set_affinity       = ht_set_affinity,
  59         .irq_retrigger          = irq_chip_retrigger_hierarchy,
  60         .flags                  = IRQCHIP_SKIP_SET_WAKE,
  61 };
  62
  63 static int htirq_domain_alloc(struct irq_domain *domain, unsigned int virq,
  64                               unsigned int nr_irqs, void *arg)
  65 {
  66         struct ht_irq_cfg *ht_cfg;
  67         struct irq_alloc_info *info = arg;
  68         struct pci_dev *dev;
  69         irq_hw_number_t hwirq;
  70         int ret;
  71
  72         if (nr_irqs > 1 || !info)
  73                 return -EINVAL;
  74
  75         dev = info->ht_dev;
  76         hwirq = (info->ht_idx & 0xFF) |
  77                 PCI_DEVID(dev->bus->number, dev->devfn) << 8 |
  78                 (pci_domain_nr(dev->bus) & 0xFFFFFFFF) << 24;
  79         if (irq_find_mapping(domain, hwirq) > 0)
  80                 return -EEXIST;
  81
  82         ht_cfg = kmalloc(sizeof(*ht_cfg), GFP_KERNEL);
  83         if (!ht_cfg)
  84                 return -ENOMEM;
  85
  86         ret = irq_domain_alloc_irqs_parent(domain, virq, nr_irqs, info);
  87         if (ret < 0) {
  88                 kfree(ht_cfg);
  89                 return ret;
  90         }
  91
  92         /* Initialize msg to a value that will never match the first write. */
  93         ht_cfg->msg.address_lo = 0xffffffff;
  94         ht_cfg->msg.address_hi = 0xffffffff;
  95         ht_cfg->dev = info->ht_dev;
  96         ht_cfg->update = info->ht_update;
  97         ht_cfg->pos = info->ht_pos;
  98         ht_cfg->idx = 0x10 + (info->ht_idx * 2);
  99         irq_domain_set_info(domain, virq, hwirq, &ht_irq_chip, ht_cfg,
 100                             handle_edge_irq, ht_cfg, "edge");
 101
 102         return 0;
 103 }
 104
 105 static void htirq_domain_free(struct irq_domain *domain, unsigned int virq,
 106                               unsigned int nr_irqs)
 107 {
 108         struct irq_data *irq_data = irq_domain_get_irq_data(domain, virq);
 109
 110         BUG_ON(nr_irqs != 1);
 111         kfree(irq_data->chip_data);
 112         irq_domain_free_irqs_top(domain, virq, nr_irqs);
 113 }
 114
 115 static void htirq_domain_activate(struct irq_domain *domain,
 116                                   struct irq_data *irq_data)
 117 {
 118         struct ht_irq_msg msg;
 119         struct irq_cfg *cfg = irqd_cfg(irq_data);
 120
 121         msg.address_hi = HT_IRQ_HIGH_DEST_ID(cfg->dest_apicid);
 122         msg.address_lo =
 123                 HT_IRQ_LOW_BASE |
 124                 HT_IRQ_LOW_DEST_ID(cfg->dest_apicid) |
 125                 HT_IRQ_LOW_VECTOR(cfg->vector) |
 126                 ((apic->irq_dest_mode == 0) ?
 127                         HT_IRQ_LOW_DM_PHYSICAL :
 128                         HT_IRQ_LOW_DM_LOGICAL) |
 129                 HT_IRQ_LOW_RQEOI_EDGE |
 130                 ((apic->irq_delivery_mode != dest_LowestPrio) ?
 131                         HT_IRQ_LOW_MT_FIXED :
 132                         HT_IRQ_LOW_MT_ARBITRATED) |
 133                 HT_IRQ_LOW_IRQ_MASKED;
 134         write_ht_irq_msg(irq_data->irq, &msg);
 135 }
 136
 137 static void htirq_domain_deactivate(struct irq_domain *domain,
 138                                     struct irq_data *irq_data)
 139 {
 140         struct ht_irq_msg msg;
 141
 142         memset(&msg, 0, sizeof(msg));
 143         write_ht_irq_msg(irq_data->irq, &msg);
 144 }
 145
 146 static const struct irq_domain_ops htirq_domain_ops = {
 147         .alloc          = htirq_domain_alloc,
 148         .free           = htirq_domain_free,
 149         .activate       = htirq_domain_activate,
 150         .deactivate     = htirq_domain_deactivate,
 151 };
 152
 153 void arch_init_htirq_domain(struct irq_domain *parent)
 154 {
 155         if (disable_apic)
 156                 return;
 157
 158         htirq_domain = irq_domain_add_tree(NULL, &htirq_domain_ops, NULL);
 159         if (!htirq_domain)
 160                 pr_warn("failed to initialize irqdomain for HTIRQ.\n");
 161         else
 162                 htirq_domain->parent = parent;
 163 }
 164
 165 int arch_setup_ht_irq(int idx, int pos, struct pci_dev *dev,
 166                       ht_irq_update_t *update)
 167 {
 168         struct irq_alloc_info info;
 169
 170         if (!htirq_domain)
 171                 return -ENOSYS;
 172
 173         init_irq_alloc_info(&info, NULL);
 174         info.ht_idx = idx;
 175         info.ht_pos = pos;
 176         info.ht_dev = dev;
 177         info.ht_update = update;
 178
 179         return irq_domain_alloc_irqs(htirq_domain, 1, dev_to_node(&dev->dev),
 180                                      &info);
 181 }
 182
 183 void arch_teardown_ht_irq(unsigned int irq)
 184 {
 185         irq_domain_free_irqs(irq, 1);
 186 }