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 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 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_get_rom_size - obtain the actual size of the ROM image 58 * @pdev: target PCI device 59 * @rom: kernel virtual pointer to image of ROM 60 * @size: size of PCI window 61 * return: size of actual ROM image 62 * 63 * Determine the actual length of the ROM image. 64 * The PCI window size could be much larger than the 65 * actual image size. 66 */ 67 size_t pci_get_rom_size(struct pci_dev *pdev, void __iomem *rom, size_t size) 68 { 69 void __iomem *image; 70 int last_image; 71 72 image = rom; 73 do { 74 void __iomem *pds; 75 /* Standard PCI ROMs start out with these bytes 55 AA */ 76 if (readb(image) != 0x55) { 77 dev_err(&pdev->dev, "Invalid ROM contents\n"); 78 break; 79 } 80 if (readb(image + 1) != 0xAA) 81 break; 82 /* get the PCI data structure and check its signature */ 83 pds = image + readw(image + 24); 84 if (readb(pds) != 'P') 85 break; 86 if (readb(pds + 1) != 'C') 87 break; 88 if (readb(pds + 2) != 'I') 89 break; 90 if (readb(pds + 3) != 'R') 91 break; 92 last_image = readb(pds + 21) & 0x80; 93 /* this length is reliable */ 94 image += readw(pds + 16) * 512; 95 } while (!last_image); 96 97 /* never return a size larger than the PCI resource window */ 98 /* there are known ROMs that get the size wrong */ 99 return min((size_t)(image - rom), size); 100 } 101 102 /** 103 * pci_map_rom - map a PCI ROM to kernel space 104 * @pdev: pointer to pci device struct 105 * @size: pointer to receive size of pci window over ROM 106 * 107 * Return: kernel virtual pointer to image of ROM 108 * 109 * Map a PCI ROM into kernel space. If ROM is boot video ROM, 110 * the shadow BIOS copy will be returned instead of the 111 * actual ROM. 112 */ 113 void __iomem *pci_map_rom(struct pci_dev *pdev, size_t *size) 114 { 115 struct resource *res = &pdev->resource[PCI_ROM_RESOURCE]; 116 loff_t start; 117 void __iomem *rom; 118 119 /* 120 * IORESOURCE_ROM_SHADOW set on x86, x86_64 and IA64 supports legacy 121 * memory map if the VGA enable bit of the Bridge Control register is 122 * set for embedded VGA. 123 */ 124 if (res->flags & IORESOURCE_ROM_SHADOW) { 125 /* primary video rom always starts here */ 126 start = (loff_t)0xC0000; 127 *size = 0x20000; /* cover C000:0 through E000:0 */ 128 } else { 129 if (res->flags & 130 (IORESOURCE_ROM_COPY | IORESOURCE_ROM_BIOS_COPY)) { 131 *size = pci_resource_len(pdev, PCI_ROM_RESOURCE); 132 return (void __iomem *)(unsigned long) 133 pci_resource_start(pdev, PCI_ROM_RESOURCE); 134 } else { 135 /* assign the ROM an address if it doesn't have one */ 136 if (res->parent == NULL && 137 pci_assign_resource(pdev,PCI_ROM_RESOURCE)) 138 return NULL; 139 start = pci_resource_start(pdev, PCI_ROM_RESOURCE); 140 *size = pci_resource_len(pdev, PCI_ROM_RESOURCE); 141 if (*size == 0) 142 return NULL; 143 144 /* Enable ROM space decodes */ 145 if (pci_enable_rom(pdev)) 146 return NULL; 147 } 148 } 149 150 rom = ioremap(start, *size); 151 if (!rom) { 152 /* restore enable if ioremap fails */ 153 if (!(res->flags & (IORESOURCE_ROM_ENABLE | 154 IORESOURCE_ROM_SHADOW | 155 IORESOURCE_ROM_COPY))) 156 pci_disable_rom(pdev); 157 return NULL; 158 } 159 160 /* 161 * Try to find the true size of the ROM since sometimes the PCI window 162 * size is much larger than the actual size of the ROM. 163 * True size is important if the ROM is going to be copied. 164 */ 165 *size = pci_get_rom_size(pdev, rom, *size); 166 return rom; 167 } 168 169 #if 0 170 /** 171 * pci_map_rom_copy - map a PCI ROM to kernel space, create a copy 172 * @pdev: pointer to pci device struct 173 * @size: pointer to receive size of pci window over ROM 174 * 175 * Return: kernel virtual pointer to image of ROM 176 * 177 * Map a PCI ROM into kernel space. If ROM is boot video ROM, 178 * the shadow BIOS copy will be returned instead of the 179 * actual ROM. 180 */ 181 void __iomem *pci_map_rom_copy(struct pci_dev *pdev, size_t *size) 182 { 183 struct resource *res = &pdev->resource[PCI_ROM_RESOURCE]; 184 void __iomem *rom; 185 186 rom = pci_map_rom(pdev, size); 187 if (!rom) 188 return NULL; 189 190 if (res->flags & (IORESOURCE_ROM_COPY | IORESOURCE_ROM_SHADOW | 191 IORESOURCE_ROM_BIOS_COPY)) 192 return rom; 193 194 res->start = (unsigned long)kmalloc(*size, GFP_KERNEL); 195 if (!res->start) 196 return rom; 197 198 res->end = res->start + *size; 199 memcpy_fromio((void*)(unsigned long)res->start, rom, *size); 200 pci_unmap_rom(pdev, rom); 201 res->flags |= IORESOURCE_ROM_COPY; 202 203 return (void __iomem *)(unsigned long)res->start; 204 } 205 #endif /* 0 */ 206 207 /** 208 * pci_unmap_rom - unmap the ROM from kernel space 209 * @pdev: pointer to pci device struct 210 * @rom: virtual address of the previous mapping 211 * 212 * Remove a mapping of a previously mapped ROM 213 */ 214 void pci_unmap_rom(struct pci_dev *pdev, void __iomem *rom) 215 { 216 struct resource *res = &pdev->resource[PCI_ROM_RESOURCE]; 217 218 if (res->flags & (IORESOURCE_ROM_COPY | IORESOURCE_ROM_BIOS_COPY)) 219 return; 220 221 iounmap(rom); 222 223 /* Disable again before continuing, leave enabled if pci=rom */ 224 if (!(res->flags & (IORESOURCE_ROM_ENABLE | IORESOURCE_ROM_SHADOW))) 225 pci_disable_rom(pdev); 226 } 227 228 #if 0 229 /** 230 * pci_remove_rom - disable the ROM and remove its sysfs attribute 231 * @pdev: pointer to pci device struct 232 * 233 * Remove the rom file in sysfs and disable ROM decoding. 234 */ 235 void pci_remove_rom(struct pci_dev *pdev) 236 { 237 struct resource *res = &pdev->resource[PCI_ROM_RESOURCE]; 238 239 if (pci_resource_len(pdev, PCI_ROM_RESOURCE)) 240 sysfs_remove_bin_file(&pdev->dev.kobj, pdev->rom_attr); 241 if (!(res->flags & (IORESOURCE_ROM_ENABLE | 242 IORESOURCE_ROM_SHADOW | 243 IORESOURCE_ROM_BIOS_COPY | 244 IORESOURCE_ROM_COPY))) 245 pci_disable_rom(pdev); 246 } 247 #endif /* 0 */ 248 249 /** 250 * pci_cleanup_rom - free the ROM copy created by pci_map_rom_copy 251 * @pdev: pointer to pci device struct 252 * 253 * Free the copied ROM if we allocated one. 254 */ 255 void pci_cleanup_rom(struct pci_dev *pdev) 256 { 257 struct resource *res = &pdev->resource[PCI_ROM_RESOURCE]; 258 if (res->flags & IORESOURCE_ROM_COPY) { 259 kfree((void*)(unsigned long)res->start); 260 res->flags &= ~IORESOURCE_ROM_COPY; 261 res->start = 0; 262 res->end = 0; 263 } 264 } 265 266 EXPORT_SYMBOL(pci_map_rom); 267 EXPORT_SYMBOL(pci_unmap_rom); 268 EXPORT_SYMBOL_GPL(pci_enable_rom); 269 EXPORT_SYMBOL_GPL(pci_disable_rom); 270