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 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 NULL, &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 } 212 213