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