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