release/src-rt-6.x/linux/linux-2.6/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
  20 #include "mpic.h"
  21
  22 /* A bit ugly, can we get this from the pci_dev somehow? */
  23 static struct mpic *msi_mpic;
  24
  25 static void mpic_u3msi_mask_irq(unsigned int irq)
  26 {
  27         mask_msi_irq(irq);
  28         mpic_mask_irq(irq);
  29 }
  30
  31 static void mpic_u3msi_unmask_irq(unsigned int irq)
  32 {
  33         mpic_unmask_irq(irq);
  34         unmask_msi_irq(irq);
  35 }
  36
  37 static struct irq_chip mpic_u3msi_chip = {
  38         .shutdown       = mpic_u3msi_mask_irq,
  39         .mask           = mpic_u3msi_mask_irq,
  40         .unmask         = mpic_u3msi_unmask_irq,
  41         .eoi            = mpic_end_irq,
  42         .set_type       = mpic_set_irq_type,
  43         .typename       = "MPIC-U3MSI",
  44 };
  45
  46 static u64 read_ht_magic_addr(struct pci_dev *pdev, unsigned int pos)
  47 {
  48         u8 flags;
  49         u32 tmp;
  50         u64 addr;
  51
  52         pci_read_config_byte(pdev, pos + HT_MSI_FLAGS, &flags);
  53
  54         if (flags & HT_MSI_FLAGS_FIXED)
  55                 return HT_MSI_FIXED_ADDR;
  56
  57         pci_read_config_dword(pdev, pos + HT_MSI_ADDR_LO, &tmp);
  58         addr = tmp & HT_MSI_ADDR_LO_MASK;
  59         pci_read_config_dword(pdev, pos + HT_MSI_ADDR_HI, &tmp);
  60         addr = addr | ((u64)tmp << 32);
  61
  62         return addr;
  63 }
  64
  65 static u64 find_ht_magic_addr(struct pci_dev *pdev)
  66 {
  67         struct pci_bus *bus;
  68         unsigned int pos;
  69
  70         for (bus = pdev->bus; bus; bus = bus->parent) {
  71                 pos = pci_find_ht_capability(bus->self, HT_CAPTYPE_MSI_MAPPING);
  72                 if (pos)
  73                         return read_ht_magic_addr(bus->self, pos);
  74         }
  75
  76         return 0;
  77 }
  78
  79 static int u3msi_msi_check_device(struct pci_dev *pdev, int nvec, int type)
  80 {
  81         if (type == PCI_CAP_ID_MSIX)
  82                 pr_debug("u3msi: MSI-X untested, trying anyway.\n");
  83
  84         /* If we can't find a magic address then MSI ain't gonna work */
  85         if (find_ht_magic_addr(pdev) == 0) {
  86                 pr_debug("u3msi: no magic address found for %s\n",
  87                          pci_name(pdev));
  88                 return -ENXIO;
  89         }
  90
  91         return 0;
  92 }
  93
  94 static void u3msi_teardown_msi_irqs(struct pci_dev *pdev)
  95 {
  96         struct msi_desc *entry;
  97
  98         list_for_each_entry(entry, &pdev->msi_list, list) {
  99                 if (entry->irq == NO_IRQ)
 100                         continue;
 101
 102                 set_irq_msi(entry->irq, NULL);
 103                 mpic_msi_free_hwirqs(msi_mpic, virq_to_hw(entry->irq), 1);
 104                 irq_dispose_mapping(entry->irq);
 105         }
 106
 107         return;
 108 }
 109
 110 static void u3msi_compose_msi_msg(struct pci_dev *pdev, int virq,
 111                                   struct msi_msg *msg)
 112 {
 113         u64 addr;
 114
 115         addr = find_ht_magic_addr(pdev);
 116         msg->address_lo = addr & 0xFFFFFFFF;
 117         msg->address_hi = addr >> 32;
 118         msg->data = virq_to_hw(virq);
 119
 120         pr_debug("u3msi: allocated virq 0x%x (hw 0x%lx) at address 0x%lx\n",
 121                  virq, virq_to_hw(virq), addr);
 122 }
 123
 124 static int u3msi_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
 125 {
 126         irq_hw_number_t hwirq;
 127         int rc;
 128         unsigned int virq;
 129         struct msi_desc *entry;
 130         struct msi_msg msg;
 131
 132         list_for_each_entry(entry, &pdev->msi_list, list) {
 133                 hwirq = mpic_msi_alloc_hwirqs(msi_mpic, 1);
 134                 if (hwirq < 0) {
 135                         rc = hwirq;
 136                         pr_debug("u3msi: failed allocating hwirq\n");
 137                         goto out_free;
 138                 }
 139
 140                 virq = irq_create_mapping(msi_mpic->irqhost, hwirq);
 141                 if (virq == NO_IRQ) {
 142                         pr_debug("u3msi: failed mapping hwirq 0x%lx\n", hwirq);
 143                         mpic_msi_free_hwirqs(msi_mpic, hwirq, 1);
 144                         rc = -ENOSPC;
 145                         goto out_free;
 146                 }
 147
 148                 set_irq_msi(virq, entry);
 149                 set_irq_chip(virq, &mpic_u3msi_chip);
 150                 set_irq_type(virq, IRQ_TYPE_EDGE_RISING);
 151
 152                 u3msi_compose_msi_msg(pdev, virq, &msg);
 153                 write_msi_msg(virq, &msg);
 154
 155                 hwirq++;
 156         }
 157
 158         return 0;
 159
 160  out_free:
 161         u3msi_teardown_msi_irqs(pdev);
 162         return rc;
 163 }
 164
 165 int mpic_u3msi_init(struct mpic *mpic)
 166 {
 167         int rc;
 168
 169         rc = mpic_msi_init_allocator(mpic);
 170         if (rc) {
 171                 pr_debug("u3msi: Error allocating bitmap!\n");
 172                 return rc;
 173         }
 174
 175         pr_debug("u3msi: Registering MPIC U3 MSI callbacks.\n");
 176
 177         BUG_ON(msi_mpic);
 178         msi_mpic = mpic;
 179
 180         WARN_ON(ppc_md.setup_msi_irqs);
 181         ppc_md.setup_msi_irqs = u3msi_setup_msi_irqs;
 182         ppc_md.teardown_msi_irqs = u3msi_teardown_msi_irqs;
 183         ppc_md.msi_check_device = u3msi_msi_check_device;
 184
 185         return 0;
 186 }