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/mm.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 #include <asm/pte-walk.h>
  23
  24
  25 #define IOWA_MAX_BUS    8
  26
  27 static struct iowa_bus iowa_busses[IOWA_MAX_BUS];
  28 static unsigned int iowa_bus_count;
  29
  30 static struct iowa_bus *iowa_pci_find(unsigned long vaddr, unsigned long paddr)
  31 {
  32         int i, j;
  33         struct resource *res;
  34         unsigned long vstart, vend;
  35
  36         for (i = 0; i < iowa_bus_count; i++) {
  37                 struct iowa_bus *bus = &iowa_busses[i];
  38                 struct pci_controller *phb = bus->phb;
  39
  40                 if (vaddr) {
  41                         vstart = (unsigned long)phb->io_base_virt;
  42                         vend = vstart + phb->pci_io_size - 1;
  43                         if ((vaddr >= vstart) && (vaddr <= vend))
  44                                 return bus;
  45                 }
  46
  47                 if (paddr)
  48                         for (j = 0; j < 3; j++) {
  49                                 res = &phb->mem_resources[j];
  50                                 if (paddr >= res->start && paddr <= res->end)
  51                                         return bus;
  52                         }
  53         }
  54
  55         return NULL;
  56 }
  57
  58 #ifdef CONFIG_PPC_INDIRECT_MMIO
  59 struct iowa_bus *iowa_mem_find_bus(const PCI_IO_ADDR addr)
  60 {
  61         unsigned hugepage_shift;
  62         struct iowa_bus *bus;
  63         int token;
  64
  65         token = PCI_GET_ADDR_TOKEN(addr);
  66
  67         if (token && token <= iowa_bus_count)
  68                 bus = &iowa_busses[token - 1];
  69         else {
  70                 unsigned long vaddr, paddr;
  71                 pte_t *ptep;
  72
  73                 vaddr = (unsigned long)PCI_FIX_ADDR(addr);
  74                 if (vaddr < PHB_IO_BASE || vaddr >= PHB_IO_END)
  75                         return NULL;
  76                 /*
  77                  * We won't find huge pages here (iomem). Also can't hit
  78                  * a page table free due to init_mm
  79                  */
  80                 ptep = find_init_mm_pte(vaddr, &hugepage_shift);
  81                 if (ptep == NULL)
  82                         paddr = 0;
  83                 else {
  84                         WARN_ON(hugepage_shift);
  85                         paddr = pte_pfn(*ptep) << PAGE_SHIFT;
  86                 }
  87                 bus = iowa_pci_find(vaddr, paddr);
  88
  89                 if (bus == NULL)
  90                         return NULL;
  91         }
  92
  93         return bus;
  94 }
  95 #else /* CONFIG_PPC_INDIRECT_MMIO */
  96 struct iowa_bus *iowa_mem_find_bus(const PCI_IO_ADDR addr)
  97 {
  98         return NULL;
  99 }
 100 #endif /* !CONFIG_PPC_INDIRECT_MMIO */
 101
 102 #ifdef CONFIG_PPC_INDIRECT_PIO
 103 struct iowa_bus *iowa_pio_find_bus(unsigned long port)
 104 {
 105         unsigned long vaddr = (unsigned long)pci_io_base + port;
 106         return iowa_pci_find(vaddr, 0);
 107 }
 108 #else
 109 struct iowa_bus *iowa_pio_find_bus(unsigned long port)
 110 {
 111         return NULL;
 112 }
 113 #endif
 114
 115 #define DEF_PCI_AC_RET(name, ret, at, al, space, aa)            \
 116 static ret iowa_##name at                                       \
 117 {                                                               \
 118         struct iowa_bus *bus;                                   \
 119         bus = iowa_##space##_find_bus(aa);                      \
 120         if (bus && bus->ops && bus->ops->name)                  \
 121                 return bus->ops->name al;                       \
 122         return __do_##name al;                                  \
 123 }
 124
 125 #define DEF_PCI_AC_NORET(name, at, al, space, aa)               \
 126 static void iowa_##name at                                      \
 127 {                                                               \
 128         struct iowa_bus *bus;                                   \
 129         bus = iowa_##space##_find_bus(aa);                      \
 130         if (bus && bus->ops && bus->ops->name) {                \
 131                 bus->ops->name al;                              \
 132                 return;                                         \
 133         }                                                       \
 134         __do_##name al;                                         \
 135 }
 136
 137 #include <asm/io-defs.h>
 138
 139 #undef DEF_PCI_AC_RET
 140 #undef DEF_PCI_AC_NORET
 141
 142 static const struct ppc_pci_io iowa_pci_io = {
 143
 144 #define DEF_PCI_AC_RET(name, ret, at, al, space, aa)    .name = iowa_##name,
 145 #define DEF_PCI_AC_NORET(name, at, al, space, aa)       .name = iowa_##name,
 146
 147 #include <asm/io-defs.h>
 148
 149 #undef DEF_PCI_AC_RET
 150 #undef DEF_PCI_AC_NORET
 151
 152 };
 153
 154 #ifdef CONFIG_PPC_INDIRECT_MMIO
 155 static void __iomem *iowa_ioremap(phys_addr_t addr, unsigned long size,
 156                                   pgprot_t prot, void *caller)
 157 {
 158         struct iowa_bus *bus;
 159         void __iomem *res = __ioremap_caller(addr, size, prot, caller);
 160         int busno;
 161
 162         bus = iowa_pci_find(0, (unsigned long)addr);
 163         if (bus != NULL) {
 164                 busno = bus - iowa_busses;
 165                 PCI_SET_ADDR_TOKEN(res, busno + 1);
 166         }
 167         return res;
 168 }
 169 #else /* CONFIG_PPC_INDIRECT_MMIO */
 170 #define iowa_ioremap NULL
 171 #endif /* !CONFIG_PPC_INDIRECT_MMIO */
 172
 173 /* Enable IO workaround */
 174 static void io_workaround_init(void)
 175 {
 176         static int io_workaround_inited;
 177
 178         if (io_workaround_inited)
 179                 return;
 180         ppc_pci_io = iowa_pci_io;
 181         ppc_md.ioremap = iowa_ioremap;
 182         io_workaround_inited = 1;
 183 }
 184
 185 /* Register new bus to support workaround */
 186 void iowa_register_bus(struct pci_controller *phb, struct ppc_pci_io *ops,
 187                        int (*initfunc)(struct iowa_bus *, void *), void *data)
 188 {
 189         struct iowa_bus *bus;
 190         struct device_node *np = phb->dn;
 191
 192         io_workaround_init();
 193
 194         if (iowa_bus_count >= IOWA_MAX_BUS) {
 195                 pr_err("IOWA:Too many pci bridges, "
 196                        "workarounds disabled for %pOF\n", np);
 197                 return;
 198         }
 199
 200         bus = &iowa_busses[iowa_bus_count];
 201         bus->phb = phb;
 202         bus->ops = ops;
 203         bus->private = data;
 204
 205         if (initfunc)
 206                 if ((*initfunc)(bus, data))
 207                         return;
 208
 209         iowa_bus_count++;
 210
 211         pr_debug("IOWA:[%d]Add bus, %pOF.\n", iowa_bus_count-1, np);
 212 }
 213