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  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11 #include <linux/mm.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/init.h>
  14 #include <linux/device.h>
  15 #include <linux/pci.h>
  16 #include <linux/htirq.h>
  17 #include <asm/hw_irq.h>
  18 #include <asm/apic.h>
  19 #include <asm/hypertransport.h>
  20
  21 /*
  22  * Hypertransport interrupt support
  23  */
  24 static void target_ht_irq(unsigned int irq, unsigned int dest, u8 vector)
  25 {
  26         struct ht_irq_msg msg;
  27
  28         fetch_ht_irq_msg(irq, &msg);
  29
  30         msg.address_lo &= ~(HT_IRQ_LOW_VECTOR_MASK | HT_IRQ_LOW_DEST_ID_MASK);
  31         msg.address_hi &= ~(HT_IRQ_HIGH_DEST_ID_MASK);
  32
  33         msg.address_lo |= HT_IRQ_LOW_VECTOR(vector) | HT_IRQ_LOW_DEST_ID(dest);
  34         msg.address_hi |= HT_IRQ_HIGH_DEST_ID(dest);
  35
  36         write_ht_irq_msg(irq, &msg);
  37 }
  38
  39 static int
  40 ht_set_affinity(struct irq_data *data, const struct cpumask *mask, bool force)
  41 {
  42         struct irq_cfg *cfg = irqd_cfg(data);
  43         unsigned int dest;
  44         int ret;
  45
  46         ret = apic_set_affinity(data, mask, &dest);
  47         if (ret)
  48                 return ret;
  49
  50         target_ht_irq(data->irq, dest, cfg->vector);
  51         return IRQ_SET_MASK_OK_NOCOPY;
  52 }
  53
  54 static struct irq_chip ht_irq_chip = {
  55         .name                   = "PCI-HT",
  56         .irq_mask               = mask_ht_irq,
  57         .irq_unmask             = unmask_ht_irq,
  58         .irq_ack                = apic_ack_edge,
  59         .irq_set_affinity       = ht_set_affinity,
  60         .irq_retrigger          = apic_retrigger_irq,
  61         .flags                  = IRQCHIP_SKIP_SET_WAKE,
  62 };
  63
  64 int arch_setup_ht_irq(unsigned int irq, struct pci_dev *dev)
  65 {
  66         struct irq_cfg *cfg;
  67         struct ht_irq_msg msg;
  68         unsigned dest;
  69         int err;
  70
  71         if (disable_apic)
  72                 return -ENXIO;
  73
  74         cfg = irq_cfg(irq);
  75         err = assign_irq_vector(irq, cfg, apic->target_cpus());
  76         if (err)
  77                 return err;
  78
  79         err = apic->cpu_mask_to_apicid_and(cfg->domain,
  80                                            apic->target_cpus(), &dest);
  81         if (err)
  82                 return err;
  83
  84         msg.address_hi = HT_IRQ_HIGH_DEST_ID(dest);
  85
  86         msg.address_lo =
  87                 HT_IRQ_LOW_BASE |
  88                 HT_IRQ_LOW_DEST_ID(dest) |
  89                 HT_IRQ_LOW_VECTOR(cfg->vector) |
  90                 ((apic->irq_dest_mode == 0) ?
  91                         HT_IRQ_LOW_DM_PHYSICAL :
  92                         HT_IRQ_LOW_DM_LOGICAL) |
  93                 HT_IRQ_LOW_RQEOI_EDGE |
  94                 ((apic->irq_delivery_mode != dest_LowestPrio) ?
  95                         HT_IRQ_LOW_MT_FIXED :
  96                         HT_IRQ_LOW_MT_ARBITRATED) |
  97                 HT_IRQ_LOW_IRQ_MASKED;
  98
  99         write_ht_irq_msg(irq, &msg);
 100
 101         irq_set_chip_and_handler_name(irq, &ht_irq_chip,
 102                                       handle_edge_irq, "edge");
 103
 104         dev_dbg(&dev->dev, "irq %d for HT\n", irq);
 105
 106         return 0;
 107 }