1 /* 2 * drivers/pci/rom.c 3 * 4 * (C) Copyright 2004 Jon Smirl <jonsmirl@yahoo.com> 5 * (C) Copyright 2004 Silicon Graphics, Inc. Jesse Barnes <jbarnes@sgi.com> 6 * 7 * PCI ROM access routines 8 */ 9 #include <linux/kernel.h> 10 #include <linux/pci.h> 11 #include <linux/slab.h> 12 13 #include "pci.h" 14 15 /** 16 * pci_enable_rom - enable ROM decoding for a PCI device 17 * @pdev: PCI device to enable 18 * 19 * Enable ROM decoding on @dev. This involves simply turning on the last 20 * bit of the PCI ROM BAR. Note that some cards may share address decoders 21 * between the ROM and other resources, so enabling it may disable access 22 * to MMIO registers or other card memory. 23 */ 24 static int pci_enable_rom(struct pci_dev *pdev) 25 { 26 struct resource *res = pdev->resource + PCI_ROM_RESOURCE; 27 struct pci_bus_region region; 28 u32 rom_addr; 29 30 if (!res->flags) 31 return -1; 32 33 pcibios_resource_to_bus(pdev, ®ion, res); 34 pci_read_config_dword(pdev, pdev->rom_base_reg, &rom_addr); 35 rom_addr &= ~PCI_ROM_ADDRESS_MASK; 36 rom_addr |= region.start | PCI_ROM_ADDRESS_ENABLE; 37 pci_write_config_dword(pdev, pdev->rom_base_reg, rom_addr); 38 return 0; 39 } 40 41 /** 42 * pci_disable_rom - disable ROM decoding for a PCI device 43 * @pdev: PCI device to disable 44 * 45 * Disable ROM decoding on a PCI device by turning off the last bit in the 46 * ROM BAR. 47 */ 48 static void pci_disable_rom(struct pci_dev *pdev) 49 { 50 u32 rom_addr; 51 pci_read_config_dword(pdev, pdev->rom_base_reg, &rom_addr); 52 rom_addr &= ~PCI_ROM_ADDRESS_ENABLE; 53 pci_write_config_dword(pdev, pdev->rom_base_reg, rom_addr); 54 } 55 56 /** 57 * pci_map_rom - map a PCI ROM to kernel space 58 * @pdev: pointer to pci device struct 59 * @size: pointer to receive size of pci window over ROM 60 * @return: kernel virtual pointer to image of ROM 61 * 62 * Map a PCI ROM into kernel space. If ROM is boot video ROM, 63 * the shadow BIOS copy will be returned instead of the 64 * actual ROM. 65 */ 66 void __iomem *pci_map_rom(struct pci_dev *pdev, size_t *size) 67 { 68 struct resource *res = &pdev->resource[PCI_ROM_RESOURCE]; 69 loff_t start; 70 void __iomem *rom; 71 void __iomem *image; 72 int last_image; 73 74 /* 75 * IORESOURCE_ROM_SHADOW set on x86, x86_64 and IA64 supports legacy 76 * memory map if the VGA enable bit of the Bridge Control register is 77 * set for embedded VGA. 78 */ 79 if (res->flags & IORESOURCE_ROM_SHADOW) { 80 /* primary video rom always starts here */ 81 start = (loff_t)0xC0000; 82 *size = 0x20000; /* cover C000:0 through E000:0 */ 83 } else { 84 if (res->flags & 85 (IORESOURCE_ROM_COPY | IORESOURCE_ROM_BIOS_COPY)) { 86 *size = pci_resource_len(pdev, PCI_ROM_RESOURCE); 87 return (void __iomem *)(unsigned long) 88 pci_resource_start(pdev, PCI_ROM_RESOURCE); 89 } else { 90 /* assign the ROM an address if it doesn't have one */ 91 if (res->parent == NULL && 92 pci_assign_resource(pdev,PCI_ROM_RESOURCE)) 93 return NULL; 94 start = pci_resource_start(pdev, PCI_ROM_RESOURCE); 95 *size = pci_resource_len(pdev, PCI_ROM_RESOURCE); 96 if (*size == 0) 97 return NULL; 98 99 /* Enable ROM space decodes */ 100 if (pci_enable_rom(pdev)) 101 return NULL; 102 } 103 } 104 105 rom = ioremap(start, *size); 106 if (!rom) { 107 /* restore enable if ioremap fails */ 108 if (!(res->flags & (IORESOURCE_ROM_ENABLE | 109 IORESOURCE_ROM_SHADOW | 110 IORESOURCE_ROM_COPY))) 111 pci_disable_rom(pdev); 112 return NULL; 113 } 114 115 /* 116 * Try to find the true size of the ROM since sometimes the PCI window 117 * size is much larger than the actual size of the ROM. 118 * True size is important if the ROM is going to be copied. 119 */ 120 image = rom; 121 do { 122 void __iomem *pds; 123 /* Standard PCI ROMs start out with these bytes 55 AA */ 124 if (readb(image) != 0x55) 125 break; 126 if (readb(image + 1) != 0xAA) 127 break; 128 /* get the PCI data structure and check its signature */ 129 pds = image + readw(image + 24); 130 if (readb(pds) != 'P') 131 break; 132 if (readb(pds + 1) != 'C') 133 break; 134 if (readb(pds + 2) != 'I') 135 break; 136 if (readb(pds + 3) != 'R') 137 break; 138 last_image = readb(pds + 21) & 0x80; 139 /* this length is reliable */ 140 image += readw(pds + 16) * 512; 141 } while (!last_image); 142 143 /* never return a size larger than the PCI resource window */ 144 /* there are known ROMs that get the size wrong */ 145 *size = min((size_t)(image - rom), *size); 146 147 return rom; 148 } 149 150 /** 151 * pci_map_rom_copy - map a PCI ROM to kernel space, create a copy 152 * @pdev: pointer to pci device struct 153 * @size: pointer to receive size of pci window over ROM 154 * @return: kernel virtual pointer to image of ROM 155 * 156 * Map a PCI ROM into kernel space. If ROM is boot video ROM, 157 * the shadow BIOS copy will be returned instead of the 158 * actual ROM. 159 */ 160 void __iomem *pci_map_rom_copy(struct pci_dev *pdev, size_t *size) 161 { 162 struct resource *res = &pdev->resource[PCI_ROM_RESOURCE]; 163 void __iomem *rom; 164 165 rom = pci_map_rom(pdev, size); 166 if (!rom) 167 return NULL; 168 169 if (res->flags & (IORESOURCE_ROM_COPY | IORESOURCE_ROM_SHADOW | 170 IORESOURCE_ROM_BIOS_COPY)) 171 return rom; 172 173 res->start = (unsigned long)kmalloc(*size, GFP_KERNEL); 174 if (!res->start) 175 return rom; 176 177 res->end = res->start + *size; 178 memcpy_fromio((void*)(unsigned long)res->start, rom, *size); 179 pci_unmap_rom(pdev, rom); 180 res->flags |= IORESOURCE_ROM_COPY; 181 182 return (void __iomem *)(unsigned long)res->start; 183 } 184 185 /** 186 * pci_unmap_rom - unmap the ROM from kernel space 187 * @pdev: pointer to pci device struct 188 * @rom: virtual address of the previous mapping 189 * 190 * Remove a mapping of a previously mapped ROM 191 */ 192 void pci_unmap_rom(struct pci_dev *pdev, void __iomem *rom) 193 { 194 struct resource *res = &pdev->resource[PCI_ROM_RESOURCE]; 195 196 if (res->flags & (IORESOURCE_ROM_COPY | IORESOURCE_ROM_BIOS_COPY)) 197 return; 198 199 iounmap(rom); 200 201 /* Disable again before continuing, leave enabled if pci=rom */ 202 if (!(res->flags & (IORESOURCE_ROM_ENABLE | IORESOURCE_ROM_SHADOW))) 203 pci_disable_rom(pdev); 204 } 205 206 /** 207 * pci_remove_rom - disable the ROM and remove its sysfs attribute 208 * @pdev: pointer to pci device struct 209 * 210 * Remove the rom file in sysfs and disable ROM decoding. 211 */ 212 void pci_remove_rom(struct pci_dev *pdev) 213 { 214 struct resource *res = &pdev->resource[PCI_ROM_RESOURCE]; 215 216 if (pci_resource_len(pdev, PCI_ROM_RESOURCE)) 217 sysfs_remove_bin_file(&pdev->dev.kobj, pdev->rom_attr); 218 if (!(res->flags & (IORESOURCE_ROM_ENABLE | 219 IORESOURCE_ROM_SHADOW | 220 IORESOURCE_ROM_BIOS_COPY | 221 IORESOURCE_ROM_COPY))) 222 pci_disable_rom(pdev); 223 } 224 225 /** 226 * pci_cleanup_rom - internal routine for freeing the ROM copy created 227 * by pci_map_rom_copy called from remove.c 228 * @pdev: pointer to pci device struct 229 * 230 * Free the copied ROM if we allocated one. 231 */ 232 void pci_cleanup_rom(struct pci_dev *pdev) 233 { 234 struct resource *res = &pdev->resource[PCI_ROM_RESOURCE]; 235 if (res->flags & IORESOURCE_ROM_COPY) { 236 kfree((void*)(unsigned long)res->start); 237 res->flags &= ~IORESOURCE_ROM_COPY; 238 res->start = 0; 239 res->end = 0; 240 } 241 } 242 243 EXPORT_SYMBOL(pci_map_rom); 244 EXPORT_SYMBOL(pci_map_rom_copy); 245 EXPORT_SYMBOL(pci_unmap_rom); 246 EXPORT_SYMBOL(pci_remove_rom); 247