linux/arch/x86/kernel/apic/htirq.c
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   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
  24static struct irq_domain *htirq_domain;
  25
  26/*
  27 * Hypertransport interrupt support
  28 */
  29static int
  30ht_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
  53static 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
  63static 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
 105static 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
 115static 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
 137static 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
 146static 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
 153void 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
 165int 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
 183void arch_teardown_ht_irq(unsigned int irq)
 184{
 185        irq_domain_free_irqs(irq, 1);
 186}
 187