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 #include <linux/sched.h>        /* for init_mm */
  16
  17 #include <asm/io.h>
  18 #include <asm/machdep.h>
  19 #include <asm/pgtable.h>
  20 #include <asm/ppc-pci.h>
  21 #include <asm/io-workarounds.h>
  22
  23 #define IOWA_MAX_BUS    8
  24
  25 static struct iowa_bus iowa_busses[IOWA_MAX_BUS];
  26 static unsigned int iowa_bus_count;
  27
  28 static struct iowa_bus *iowa_pci_find(unsigned long vaddr, unsigned long paddr)
  29 {
  30         int i, j;
  31         struct resource *res;
  32         unsigned long vstart, vend;
  33
  34         for (i = 0; i < iowa_bus_count; i++) {
  35                 struct iowa_bus *bus = &iowa_busses[i];
  36                 struct pci_controller *phb = bus->phb;
  37
  38                 if (vaddr) {
  39                         vstart = (unsigned long)phb->io_base_virt;
  40                         vend = vstart + phb->pci_io_size - 1;
  41                         if ((vaddr >= vstart) && (vaddr <= vend))
  42                                 return bus;
  43                 }
  44
  45                 if (paddr)
  46                         for (j = 0; j < 3; j++) {
  47                                 res = &phb->mem_resources[j];
  48                                 if (paddr >= res->start && paddr <= res->end)
  49                                         return bus;
  50                         }
  51         }
  52
  53         return NULL;
  54 }
  55
  56 struct iowa_bus *iowa_mem_find_bus(const PCI_IO_ADDR addr)
  57 {
  58         unsigned hugepage_shift;
  59         struct iowa_bus *bus;
  60         int token;
  61
  62         token = PCI_GET_ADDR_TOKEN(addr);
  63
  64         if (token && token <= iowa_bus_count)
  65                 bus = &iowa_busses[token - 1];
  66         else {
  67                 unsigned long vaddr, paddr;
  68                 pte_t *ptep;
  69
  70                 vaddr = (unsigned long)PCI_FIX_ADDR(addr);
  71                 if (vaddr < PHB_IO_BASE || vaddr >= PHB_IO_END)
  72                         return NULL;
  73
  74                 ptep = find_linux_pte_or_hugepte(init_mm.pgd, vaddr,
  75                                                  &hugepage_shift);
  76                 if (ptep == NULL)
  77                         paddr = 0;
  78                 else {
  79                         /*
  80                          * we don't have hugepages backing iomem
  81                          */
  82                         WARN_ON(hugepage_shift);
  83                         paddr = pte_pfn(*ptep) << PAGE_SHIFT;
  84                 }
  85                 bus = iowa_pci_find(vaddr, paddr);
  86
  87                 if (bus == NULL)
  88                         return NULL;
  89         }
  90
  91         return bus;
  92 }
  93
  94 struct iowa_bus *iowa_pio_find_bus(unsigned long port)
  95 {
  96         unsigned long vaddr = (unsigned long)pci_io_base + port;
  97         return iowa_pci_find(vaddr, 0);
  98 }
  99
 100
 101 #define DEF_PCI_AC_RET(name, ret, at, al, space, aa)            \
 102 static ret iowa_##name at                                       \
 103 {                                                               \
 104         struct iowa_bus *bus;                                   \
 105         bus = iowa_##space##_find_bus(aa);                      \
 106         if (bus && bus->ops && bus->ops->name)                  \
 107                 return bus->ops->name al;                       \
 108         return __do_##name al;                                  \
 109 }
 110
 111 #define DEF_PCI_AC_NORET(name, at, al, space, aa)               \
 112 static void iowa_##name at                                      \
 113 {                                                               \
 114         struct iowa_bus *bus;                                   \
 115         bus = iowa_##space##_find_bus(aa);                      \
 116         if (bus && bus->ops && bus->ops->name) {                \
 117                 bus->ops->name al;                              \
 118                 return;                                         \
 119         }                                                       \
 120         __do_##name al;                                         \
 121 }
 122
 123 #include <asm/io-defs.h>
 124
 125 #undef DEF_PCI_AC_RET
 126 #undef DEF_PCI_AC_NORET
 127
 128 static const struct ppc_pci_io iowa_pci_io = {
 129
 130 #define DEF_PCI_AC_RET(name, ret, at, al, space, aa)    .name = iowa_##name,
 131 #define DEF_PCI_AC_NORET(name, at, al, space, aa)       .name = iowa_##name,
 132
 133 #include <asm/io-defs.h>
 134
 135 #undef DEF_PCI_AC_RET
 136 #undef DEF_PCI_AC_NORET
 137
 138 };
 139
 140 static void __iomem *iowa_ioremap(phys_addr_t addr, unsigned long size,
 141                                   unsigned long flags, void *caller)
 142 {
 143         struct iowa_bus *bus;
 144         void __iomem *res = __ioremap_caller(addr, size, flags, caller);
 145         int busno;
 146
 147         bus = iowa_pci_find(0, (unsigned long)addr);
 148         if (bus != NULL) {
 149                 busno = bus - iowa_busses;
 150                 PCI_SET_ADDR_TOKEN(res, busno + 1);
 151         }
 152         return res;
 153 }
 154
 155 /* Enable IO workaround */
 156 static void io_workaround_init(void)
 157 {
 158         static int io_workaround_inited;
 159
 160         if (io_workaround_inited)
 161                 return;
 162         ppc_pci_io = iowa_pci_io;
 163         ppc_md.ioremap = iowa_ioremap;
 164         io_workaround_inited = 1;
 165 }
 166
 167 /* Register new bus to support workaround */
 168 void iowa_register_bus(struct pci_controller *phb, struct ppc_pci_io *ops,
 169                        int (*initfunc)(struct iowa_bus *, void *), void *data)
 170 {
 171         struct iowa_bus *bus;
 172         struct device_node *np = phb->dn;
 173
 174         io_workaround_init();
 175
 176         if (iowa_bus_count >= IOWA_MAX_BUS) {
 177                 pr_err("IOWA:Too many pci bridges, "
 178                        "workarounds disabled for %s\n", np->full_name);
 179                 return;
 180         }
 181
 182         bus = &iowa_busses[iowa_bus_count];
 183         bus->phb = phb;
 184         bus->ops = ops;
 185         bus->private = data;
 186
 187         if (initfunc)
 188                 if ((*initfunc)(bus, data))
 189                         return;
 190
 191         iowa_bus_count++;
 192
 193         pr_debug("IOWA:[%d]Add bus, %s.\n", iowa_bus_count-1, np->full_name);
 194 }
 195