linux/arch/powerpc/kernel/io-workarounds.c
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   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
  25static struct iowa_bus iowa_busses[IOWA_MAX_BUS];
  26static unsigned int iowa_bus_count;
  27
  28static 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
  56struct iowa_bus *iowa_mem_find_bus(const PCI_IO_ADDR addr)
  57{
  58        struct iowa_bus *bus;
  59        int token;
  60
  61        token = PCI_GET_ADDR_TOKEN(addr);
  62
  63        if (token && token <= iowa_bus_count)
  64                bus = &iowa_busses[token - 1];
  65        else {
  66                unsigned long vaddr, paddr;
  67                pte_t *ptep;
  68
  69                vaddr = (unsigned long)PCI_FIX_ADDR(addr);
  70                if (vaddr < PHB_IO_BASE || vaddr >= PHB_IO_END)
  71                        return NULL;
  72
  73                ptep = find_linux_pte(init_mm.pgd, vaddr);
  74                if (ptep == NULL)
  75                        paddr = 0;
  76                else
  77                        paddr = pte_pfn(*ptep) << PAGE_SHIFT;
  78                bus = iowa_pci_find(vaddr, paddr);
  79
  80                if (bus == NULL)
  81                        return NULL;
  82        }
  83
  84        return bus;
  85}
  86
  87struct iowa_bus *iowa_pio_find_bus(unsigned long port)
  88{
  89        unsigned long vaddr = (unsigned long)pci_io_base + port;
  90        return iowa_pci_find(vaddr, 0);
  91}
  92
  93
  94#define DEF_PCI_AC_RET(name, ret, at, al, space, aa)            \
  95static ret iowa_##name at                                       \
  96{                                                               \
  97        struct iowa_bus *bus;                                   \
  98        bus = iowa_##space##_find_bus(aa);                      \
  99        if (bus && bus->ops && bus->ops->name)                  \
 100                return bus->ops->name al;                       \
 101        return __do_##name al;                                  \
 102}
 103
 104#define DEF_PCI_AC_NORET(name, at, al, space, aa)               \
 105static void iowa_##name at                                      \
 106{                                                               \
 107        struct iowa_bus *bus;                                   \
 108        bus = iowa_##space##_find_bus(aa);                      \
 109        if (bus && bus->ops && bus->ops->name) {                \
 110                bus->ops->name al;                              \
 111                return;                                         \
 112        }                                                       \
 113        __do_##name al;                                         \
 114}
 115
 116#include <asm/io-defs.h>
 117
 118#undef DEF_PCI_AC_RET
 119#undef DEF_PCI_AC_NORET
 120
 121static const struct ppc_pci_io __devinitconst iowa_pci_io = {
 122
 123#define DEF_PCI_AC_RET(name, ret, at, al, space, aa)    .name = iowa_##name,
 124#define DEF_PCI_AC_NORET(name, at, al, space, aa)       .name = iowa_##name,
 125
 126#include <asm/io-defs.h>
 127
 128#undef DEF_PCI_AC_RET
 129#undef DEF_PCI_AC_NORET
 130
 131};
 132
 133static void __iomem *iowa_ioremap(phys_addr_t addr, unsigned long size,
 134                                  unsigned long flags, void *caller)
 135{
 136        struct iowa_bus *bus;
 137        void __iomem *res = __ioremap_caller(addr, size, flags, caller);
 138        int busno;
 139
 140        bus = iowa_pci_find(0, (unsigned long)addr);
 141        if (bus != NULL) {
 142                busno = bus - iowa_busses;
 143                PCI_SET_ADDR_TOKEN(res, busno + 1);
 144        }
 145        return res;
 146}
 147
 148/* Enable IO workaround */
 149static void __devinit io_workaround_init(void)
 150{
 151        static int io_workaround_inited;
 152
 153        if (io_workaround_inited)
 154                return;
 155        ppc_pci_io = iowa_pci_io;
 156        ppc_md.ioremap = iowa_ioremap;
 157        io_workaround_inited = 1;
 158}
 159
 160/* Register new bus to support workaround */
 161void __devinit iowa_register_bus(struct pci_controller *phb,
 162                        struct ppc_pci_io *ops,
 163                        int (*initfunc)(struct iowa_bus *, void *), void *data)
 164{
 165        struct iowa_bus *bus;
 166        struct device_node *np = phb->dn;
 167
 168        io_workaround_init();
 169
 170        if (iowa_bus_count >= IOWA_MAX_BUS) {
 171                pr_err("IOWA:Too many pci bridges, "
 172                       "workarounds disabled for %s\n", np->full_name);
 173                return;
 174        }
 175
 176        bus = &iowa_busses[iowa_bus_count];
 177        bus->phb = phb;
 178        bus->ops = ops;
 179        bus->private = data;
 180
 181        if (initfunc)
 182                if ((*initfunc)(bus, data))
 183                        return;
 184
 185        iowa_bus_count++;
 186
 187        pr_debug("IOWA:[%d]Add bus, %s.\n", iowa_bus_count-1, np->full_name);
 188}
 189
 190