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 #ifdef CONFIG_PPC_INDIRECT_MMIO
  57 struct iowa_bus *iowa_mem_find_bus(const PCI_IO_ADDR addr)
  58 {
  59         unsigned hugepage_shift;
  60         struct iowa_bus *bus;
  61         int token;
  62
  63         token = PCI_GET_ADDR_TOKEN(addr);
  64
  65         if (token && token <= iowa_bus_count)
  66                 bus = &iowa_busses[token - 1];
  67         else {
  68                 unsigned long vaddr, paddr;
  69                 pte_t *ptep;
  70
  71                 vaddr = (unsigned long)PCI_FIX_ADDR(addr);
  72                 if (vaddr < PHB_IO_BASE || vaddr >= PHB_IO_END)
  73                         return NULL;
  74                 /*
  75                  * We won't find huge pages here (iomem). Also can't hit
  76                  * a page table free due to init_mm
  77                  */
  78                 ptep = __find_linux_pte_or_hugepte(init_mm.pgd, vaddr,
  79                                                  &hugepage_shift);
  80                 if (ptep == NULL)
  81                         paddr = 0;
  82                 else {
  83                         WARN_ON(hugepage_shift);
  84                         paddr = pte_pfn(*ptep) << PAGE_SHIFT;
  85                 }
  86                 bus = iowa_pci_find(vaddr, paddr);
  87
  88                 if (bus == NULL)
  89                         return NULL;
  90         }
  91
  92         return bus;
  93 }
  94 #else /* CONFIG_PPC_INDIRECT_MMIO */
  95 struct iowa_bus *iowa_mem_find_bus(const PCI_IO_ADDR addr)
  96 {
  97         return NULL;
  98 }
  99 #endif /* !CONFIG_PPC_INDIRECT_MMIO */
 100
 101 #ifdef CONFIG_PPC_INDIRECT_PIO
 102 struct iowa_bus *iowa_pio_find_bus(unsigned long port)
 103 {
 104         unsigned long vaddr = (unsigned long)pci_io_base + port;
 105         return iowa_pci_find(vaddr, 0);
 106 }
 107 #else
 108 struct iowa_bus *iowa_pio_find_bus(unsigned long port)
 109 {
 110         return NULL;
 111 }
 112 #endif
 113
 114 #define DEF_PCI_AC_RET(name, ret, at, al, space, aa)            \
 115 static ret iowa_##name at                                       \
 116 {                                                               \
 117         struct iowa_bus *bus;                                   \
 118         bus = iowa_##space##_find_bus(aa);                      \
 119         if (bus && bus->ops && bus->ops->name)                  \
 120                 return bus->ops->name al;                       \
 121         return __do_##name al;                                  \
 122 }
 123
 124 #define DEF_PCI_AC_NORET(name, at, al, space, aa)               \
 125 static void iowa_##name at                                      \
 126 {                                                               \
 127         struct iowa_bus *bus;                                   \
 128         bus = iowa_##space##_find_bus(aa);                      \
 129         if (bus && bus->ops && bus->ops->name) {                \
 130                 bus->ops->name al;                              \
 131                 return;                                         \
 132         }                                                       \
 133         __do_##name al;                                         \
 134 }
 135
 136 #include <asm/io-defs.h>
 137
 138 #undef DEF_PCI_AC_RET
 139 #undef DEF_PCI_AC_NORET
 140
 141 static const struct ppc_pci_io iowa_pci_io = {
 142
 143 #define DEF_PCI_AC_RET(name, ret, at, al, space, aa)    .name = iowa_##name,
 144 #define DEF_PCI_AC_NORET(name, at, al, space, aa)       .name = iowa_##name,
 145
 146 #include <asm/io-defs.h>
 147
 148 #undef DEF_PCI_AC_RET
 149 #undef DEF_PCI_AC_NORET
 150
 151 };
 152
 153 #ifdef CONFIG_PPC_INDIRECT_MMIO
 154 static void __iomem *iowa_ioremap(phys_addr_t addr, unsigned long size,
 155                                   unsigned long flags, void *caller)
 156 {
 157         struct iowa_bus *bus;
 158         void __iomem *res = __ioremap_caller(addr, size, flags, caller);
 159         int busno;
 160
 161         bus = iowa_pci_find(0, (unsigned long)addr);
 162         if (bus != NULL) {
 163                 busno = bus - iowa_busses;
 164                 PCI_SET_ADDR_TOKEN(res, busno + 1);
 165         }
 166         return res;
 167 }
 168 #else /* CONFIG_PPC_INDIRECT_MMIO */
 169 #define iowa_ioremap NULL
 170 #endif /* !CONFIG_PPC_INDIRECT_MMIO */
 171
 172 /* Enable IO workaround */
 173 static void io_workaround_init(void)
 174 {
 175         static int io_workaround_inited;
 176
 177         if (io_workaround_inited)
 178                 return;
 179         ppc_pci_io = iowa_pci_io;
 180         ppc_md.ioremap = iowa_ioremap;
 181         io_workaround_inited = 1;
 182 }
 183
 184 /* Register new bus to support workaround */
 185 void iowa_register_bus(struct pci_controller *phb, struct ppc_pci_io *ops,
 186                        int (*initfunc)(struct iowa_bus *, void *), void *data)
 187 {
 188         struct iowa_bus *bus;
 189         struct device_node *np = phb->dn;
 190
 191         io_workaround_init();
 192
 193         if (iowa_bus_count >= IOWA_MAX_BUS) {
 194                 pr_err("IOWA:Too many pci bridges, "
 195                        "workarounds disabled for %s\n", np->full_name);
 196                 return;
 197         }
 198
 199         bus = &iowa_busses[iowa_bus_count];
 200         bus->phb = phb;
 201         bus->ops = ops;
 202         bus->private = data;
 203
 204         if (initfunc)
 205                 if ((*initfunc)(bus, data))
 206                         return;
 207
 208         iowa_bus_count++;
 209
 210         pr_debug("IOWA:[%d]Add bus, %s.\n", iowa_bus_count-1, np->full_name);
 211 }
 212