arch/powerpc/kernel/io-workarounds.c

   1 /*
   2  * Support PCI IO workaround
   3  *
   4  *  Copyright (C) 2006 Benjamin Herrenschmidt <benh@kernel.crashing.org>
   5  *                     IBM, Corp.
   6  *  (C) Copyright 2007-2008 TOSHIBA CORPORATION
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12 #undef DEBUG
  13
  14 #include <linux/kernel.h>
  15
  16 #include <asm/io.h>
  17 #include <asm/machdep.h>
  18 #include <asm/pgtable.h>
  19 #include <asm/ppc-pci.h>
  20 #include <asm/io-workarounds.h>
  21
  22 #define IOWA_MAX_BUS    8
  23
  24 static struct iowa_bus iowa_busses[IOWA_MAX_BUS];
  25 static unsigned int iowa_bus_count;
  26
  27 static struct iowa_bus *iowa_pci_find(unsigned long vaddr, unsigned long paddr)
  28 {
  29         int i, j;
  30         struct resource *res;
  31         unsigned long vstart, vend;
  32
  33         for (i = 0; i < iowa_bus_count; i++) {
  34                 struct iowa_bus *bus = &iowa_busses[i];
  35                 struct pci_controller *phb = bus->phb;
  36
  37                 if (vaddr) {
  38                         vstart = (unsigned long)phb->io_base_virt;
  39                         vend = vstart + phb->pci_io_size - 1;
  40                         if ((vaddr >= vstart) && (vaddr <= vend))
  41                                 return bus;
  42                 }
  43
  44                 if (paddr)
  45                         for (j = 0; j < 3; j++) {
  46                                 res = &phb->mem_resources[j];
  47                                 if (paddr >= res->start && paddr <= res->end)
  48                                         return bus;
  49                         }
  50         }
  51
  52         return NULL;
  53 }
  54
  55 struct iowa_bus *iowa_mem_find_bus(const PCI_IO_ADDR addr)
  56 {
  57         struct iowa_bus *bus;
  58         int token;
  59
  60         token = PCI_GET_ADDR_TOKEN(addr);
  61
  62         if (token && token <= iowa_bus_count)
  63                 bus = &iowa_busses[token - 1];
  64         else {
  65                 unsigned long vaddr, paddr;
  66                 pte_t *ptep;
  67
  68                 vaddr = (unsigned long)PCI_FIX_ADDR(addr);
  69                 if (vaddr < PHB_IO_BASE || vaddr >= PHB_IO_END)
  70                         return NULL;
  71
  72                 ptep = find_linux_pte(init_mm.pgd, vaddr);
  73                 if (ptep == NULL)
  74                         paddr = 0;
  75                 else
  76                         paddr = pte_pfn(*ptep) << PAGE_SHIFT;
  77                 bus = iowa_pci_find(vaddr, paddr);
  78
  79                 if (bus == NULL)
  80                         return NULL;
  81         }
  82
  83         return bus;
  84 }
  85
  86 struct iowa_bus *iowa_pio_find_bus(unsigned long port)
  87 {
  88         unsigned long vaddr = (unsigned long)pci_io_base + port;
  89         return iowa_pci_find(vaddr, 0);
  90 }
  91
  92
  93 #define DEF_PCI_AC_RET(name, ret, at, al, space, aa)            \
  94 static ret iowa_##name at                                       \
  95 {                                                               \
  96         struct iowa_bus *bus;                                   \
  97         bus = iowa_##space##_find_bus(aa);                      \
  98         if (bus && bus->ops && bus->ops->name)                  \
  99                 return bus->ops->name al;                       \
 100         return __do_##name al;                                  \
 101 }
 102
 103 #define DEF_PCI_AC_NORET(name, at, al, space, aa)               \
 104 static void iowa_##name at                                      \
 105 {                                                               \
 106         struct iowa_bus *bus;                                   \
 107         bus = iowa_##space##_find_bus(aa);                      \
 108         if (bus && bus->ops && bus->ops->name) {                \
 109                 bus->ops->name al;                              \
 110                 return;                                         \
 111         }                                                       \
 112         __do_##name al;                                         \
 113 }
 114
 115 #include <asm/io-defs.h>
 116
 117 #undef DEF_PCI_AC_RET
 118 #undef DEF_PCI_AC_NORET
 119
 120 static const struct ppc_pci_io __devinitconst iowa_pci_io = {
 121
 122 #define DEF_PCI_AC_RET(name, ret, at, al, space, aa)    .name = iowa_##name,
 123 #define DEF_PCI_AC_NORET(name, at, al, space, aa)       .name = iowa_##name,
 124
 125 #include <asm/io-defs.h>
 126
 127 #undef DEF_PCI_AC_RET
 128 #undef DEF_PCI_AC_NORET
 129
 130 };
 131
 132 static void __iomem *iowa_ioremap(phys_addr_t addr, unsigned long size,
 133                                   unsigned long flags, void *caller)
 134 {
 135         struct iowa_bus *bus;
 136         void __iomem *res = __ioremap_caller(addr, size, flags, caller);
 137         int busno;
 138
 139         bus = iowa_pci_find(0, (unsigned long)addr);
 140         if (bus != NULL) {
 141                 busno = bus - iowa_busses;
 142                 PCI_SET_ADDR_TOKEN(res, busno + 1);
 143         }
 144         return res;
 145 }
 146
 147 /* Enable IO workaround */
 148 static void __devinit io_workaround_init(void)
 149 {
 150         static int io_workaround_inited;
 151
 152         if (io_workaround_inited)
 153                 return;
 154         ppc_pci_io = iowa_pci_io;
 155         ppc_md.ioremap = iowa_ioremap;
 156         io_workaround_inited = 1;
 157 }
 158
 159 /* Register new bus to support workaround */
 160 void __devinit iowa_register_bus(struct pci_controller *phb,
 161                         struct ppc_pci_io *ops,
 162                         int (*initfunc)(struct iowa_bus *, void *), void *data)
 163 {
 164         struct iowa_bus *bus;
 165         struct device_node *np = phb->dn;
 166
 167         io_workaround_init();
 168
 169         if (iowa_bus_count >= IOWA_MAX_BUS) {
 170                 pr_err("IOWA:Too many pci bridges, "
 171                        "workarounds disabled for %s\n", np->full_name);
 172                 return;
 173         }
 174
 175         bus = &iowa_busses[iowa_bus_count];
 176         bus->phb = phb;
 177         bus->ops = ops;
 178         bus->private = data;
 179
 180         if (initfunc)
 181                 if ((*initfunc)(bus, data))
 182                         return;
 183
 184         iowa_bus_count++;
 185
 186         pr_debug("IOWA:[%d]Add bus, %s.\n", iowa_bus_count-1, np->full_name);
 187 }
 188