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 } 213 214