arch/powerpc/sysdev/mpic_u3msi.c

   1 /*
   2  * Copyright 2006, Segher Boessenkool, IBM Corporation.
   3  * Copyright 2006-2007, Michael Ellerman, IBM Corporation.
   4  *
   5  * This program is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU General Public License
   7  * as published by the Free Software Foundation; version 2 of the
   8  * License.
   9  *
  10  */
  11
  12 #include <linux/irq.h>
  13 #include <linux/bootmem.h>
  14 #include <linux/msi.h>
  15 #include <asm/mpic.h>
  16 #include <asm/prom.h>
  17 #include <asm/hw_irq.h>
  18 #include <asm/ppc-pci.h>
  19 #include <asm/msi_bitmap.h>
  20
  21 #include "mpic.h"
  22
  23 /* A bit ugly, can we get this from the pci_dev somehow? */
  24 static struct mpic *msi_mpic;
  25
  26 static void mpic_u3msi_mask_irq(unsigned int irq)
  27 {
  28         mask_msi_irq(irq);
  29         mpic_mask_irq(irq);
  30 }
  31
  32 static void mpic_u3msi_unmask_irq(unsigned int irq)
  33 {
  34         mpic_unmask_irq(irq);
  35         unmask_msi_irq(irq);
  36 }
  37
  38 static struct irq_chip mpic_u3msi_chip = {
  39         .shutdown       = mpic_u3msi_mask_irq,
  40         .mask           = mpic_u3msi_mask_irq,
  41         .unmask         = mpic_u3msi_unmask_irq,
  42         .eoi            = mpic_end_irq,
  43         .set_type       = mpic_set_irq_type,
  44         .set_affinity   = mpic_set_affinity,
  45         .typename       = "MPIC-U3MSI",
  46 };
  47
  48 static u64 read_ht_magic_addr(struct pci_dev *pdev, unsigned int pos)
  49 {
  50         u8 flags;
  51         u32 tmp;
  52         u64 addr;
  53
  54         pci_read_config_byte(pdev, pos + HT_MSI_FLAGS, &flags);
  55
  56         if (flags & HT_MSI_FLAGS_FIXED)
  57                 return HT_MSI_FIXED_ADDR;
  58
  59         pci_read_config_dword(pdev, pos + HT_MSI_ADDR_LO, &tmp);
  60         addr = tmp & HT_MSI_ADDR_LO_MASK;
  61         pci_read_config_dword(pdev, pos + HT_MSI_ADDR_HI, &tmp);
  62         addr = addr | ((u64)tmp << 32);
  63
  64         return addr;
  65 }
  66
  67 static u64 find_ht_magic_addr(struct pci_dev *pdev)
  68 {
  69         struct pci_bus *bus;
  70         unsigned int pos;
  71
  72         for (bus = pdev->bus; bus; bus = bus->parent) {
  73                 pos = pci_find_ht_capability(bus->self, HT_CAPTYPE_MSI_MAPPING);
  74                 if (pos)
  75                         return read_ht_magic_addr(bus->self, pos);
  76         }
  77
  78         return 0;
  79 }
  80
  81 static int u3msi_msi_check_device(struct pci_dev *pdev, int nvec, int type)
  82 {
  83         if (type == PCI_CAP_ID_MSIX)
  84                 pr_debug("u3msi: MSI-X untested, trying anyway.\n");
  85
  86         /* If we can't find a magic address then MSI ain't gonna work */
  87         if (find_ht_magic_addr(pdev) == 0) {
  88                 pr_debug("u3msi: no magic address found for %s\n",
  89                          pci_name(pdev));
  90                 return -ENXIO;
  91         }
  92
  93         return 0;
  94 }
  95
  96 static void u3msi_teardown_msi_irqs(struct pci_dev *pdev)
  97 {
  98         struct msi_desc *entry;
  99
 100         list_for_each_entry(entry, &pdev->msi_list, list) {
 101                 if (entry->irq == NO_IRQ)
 102                         continue;
 103
 104                 set_irq_msi(entry->irq, NULL);
 105                 msi_bitmap_free_hwirqs(&msi_mpic->msi_bitmap,
 106                                        virq_to_hw(entry->irq), 1);
 107                 irq_dispose_mapping(entry->irq);
 108         }
 109
 110         return;
 111 }
 112
 113 static int u3msi_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
 114 {
 115         unsigned int virq;
 116         struct msi_desc *entry;
 117         struct msi_msg msg;
 118         u64 addr;
 119         int hwirq;
 120
 121         addr = find_ht_magic_addr(pdev);
 122         msg.address_lo = addr & 0xFFFFFFFF;
 123         msg.address_hi = addr >> 32;
 124
 125         list_for_each_entry(entry, &pdev->msi_list, list) {
 126                 hwirq = msi_bitmap_alloc_hwirqs(&msi_mpic->msi_bitmap, 1);
 127                 if (hwirq < 0) {
 128                         pr_debug("u3msi: failed allocating hwirq\n");
 129                         return hwirq;
 130                 }
 131
 132                 virq = irq_create_mapping(msi_mpic->irqhost, hwirq);
 133                 if (virq == NO_IRQ) {
 134                         pr_debug("u3msi: failed mapping hwirq 0x%x\n", hwirq);
 135                         msi_bitmap_free_hwirqs(&msi_mpic->msi_bitmap, hwirq, 1);
 136                         return -ENOSPC;
 137                 }
 138
 139                 set_irq_msi(virq, entry);
 140                 set_irq_chip(virq, &mpic_u3msi_chip);
 141                 set_irq_type(virq, IRQ_TYPE_EDGE_RISING);
 142
 143                 pr_debug("u3msi: allocated virq 0x%x (hw 0x%x) addr 0x%lx\n",
 144                           virq, hwirq, (unsigned long)addr);
 145
 146                 msg.data = hwirq;
 147                 write_msi_msg(virq, &msg);
 148
 149                 hwirq++;
 150         }
 151
 152         return 0;
 153 }
 154
 155 int mpic_u3msi_init(struct mpic *mpic)
 156 {
 157         int rc;
 158
 159         rc = mpic_msi_init_allocator(mpic);
 160         if (rc) {
 161                 pr_debug("u3msi: Error allocating bitmap!\n");
 162                 return rc;
 163         }
 164
 165         pr_debug("u3msi: Registering MPIC U3 MSI callbacks.\n");
 166
 167         BUG_ON(msi_mpic);
 168         msi_mpic = mpic;
 169
 170         WARN_ON(ppc_md.setup_msi_irqs);
 171         ppc_md.setup_msi_irqs = u3msi_setup_msi_irqs;
 172         ppc_md.teardown_msi_irqs = u3msi_teardown_msi_irqs;
 173         ppc_md.msi_check_device = u3msi_msi_check_device;
 174
 175         return 0;
 176 }