Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame^] | 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/config.h> |
| 10 | #include <linux/kernel.h> |
| 11 | #include <linux/pci.h> |
| 12 | |
| 13 | #include "pci.h" |
| 14 | |
| 15 | /** |
| 16 | * pci_enable_rom - enable ROM decoding for a PCI device |
| 17 | * @dev: 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 void pci_enable_rom(struct pci_dev *pdev) |
| 25 | { |
| 26 | u32 rom_addr; |
| 27 | |
| 28 | pci_read_config_dword(pdev, pdev->rom_base_reg, &rom_addr); |
| 29 | rom_addr |= PCI_ROM_ADDRESS_ENABLE; |
| 30 | pci_write_config_dword(pdev, pdev->rom_base_reg, rom_addr); |
| 31 | } |
| 32 | |
| 33 | /** |
| 34 | * pci_disable_rom - disable ROM decoding for a PCI device |
| 35 | * @dev: PCI device to disable |
| 36 | * |
| 37 | * Disable ROM decoding on a PCI device by turning off the last bit in the |
| 38 | * ROM BAR. |
| 39 | */ |
| 40 | static void pci_disable_rom(struct pci_dev *pdev) |
| 41 | { |
| 42 | u32 rom_addr; |
| 43 | pci_read_config_dword(pdev, pdev->rom_base_reg, &rom_addr); |
| 44 | rom_addr &= ~PCI_ROM_ADDRESS_ENABLE; |
| 45 | pci_write_config_dword(pdev, pdev->rom_base_reg, rom_addr); |
| 46 | } |
| 47 | |
| 48 | /** |
| 49 | * pci_map_rom - map a PCI ROM to kernel space |
| 50 | * @dev: pointer to pci device struct |
| 51 | * @size: pointer to receive size of pci window over ROM |
| 52 | * @return: kernel virtual pointer to image of ROM |
| 53 | * |
| 54 | * Map a PCI ROM into kernel space. If ROM is boot video ROM, |
| 55 | * the shadow BIOS copy will be returned instead of the |
| 56 | * actual ROM. |
| 57 | */ |
| 58 | void __iomem *pci_map_rom(struct pci_dev *pdev, size_t *size) |
| 59 | { |
| 60 | struct resource *res = &pdev->resource[PCI_ROM_RESOURCE]; |
| 61 | loff_t start; |
| 62 | void __iomem *rom; |
| 63 | void __iomem *image; |
| 64 | int last_image; |
| 65 | |
| 66 | /* IORESOURCE_ROM_SHADOW only set on x86 */ |
| 67 | if (res->flags & IORESOURCE_ROM_SHADOW) { |
| 68 | /* primary video rom always starts here */ |
| 69 | start = (loff_t)0xC0000; |
| 70 | *size = 0x20000; /* cover C000:0 through E000:0 */ |
| 71 | } else { |
| 72 | if (res->flags & IORESOURCE_ROM_COPY) { |
| 73 | *size = pci_resource_len(pdev, PCI_ROM_RESOURCE); |
| 74 | return (void __iomem *)pci_resource_start(pdev, PCI_ROM_RESOURCE); |
| 75 | } else { |
| 76 | /* assign the ROM an address if it doesn't have one */ |
| 77 | if (res->parent == NULL) |
| 78 | pci_assign_resource(pdev, PCI_ROM_RESOURCE); |
| 79 | |
| 80 | start = pci_resource_start(pdev, PCI_ROM_RESOURCE); |
| 81 | *size = pci_resource_len(pdev, PCI_ROM_RESOURCE); |
| 82 | if (*size == 0) |
| 83 | return NULL; |
| 84 | |
| 85 | /* Enable ROM space decodes */ |
| 86 | pci_enable_rom(pdev); |
| 87 | } |
| 88 | } |
| 89 | |
| 90 | rom = ioremap(start, *size); |
| 91 | if (!rom) { |
| 92 | /* restore enable if ioremap fails */ |
| 93 | if (!(res->flags & (IORESOURCE_ROM_ENABLE | |
| 94 | IORESOURCE_ROM_SHADOW | |
| 95 | IORESOURCE_ROM_COPY))) |
| 96 | pci_disable_rom(pdev); |
| 97 | return NULL; |
| 98 | } |
| 99 | |
| 100 | /* |
| 101 | * Try to find the true size of the ROM since sometimes the PCI window |
| 102 | * size is much larger than the actual size of the ROM. |
| 103 | * True size is important if the ROM is going to be copied. |
| 104 | */ |
| 105 | image = rom; |
| 106 | do { |
| 107 | void __iomem *pds; |
| 108 | /* Standard PCI ROMs start out with these bytes 55 AA */ |
| 109 | if (readb(image) != 0x55) |
| 110 | break; |
| 111 | if (readb(image + 1) != 0xAA) |
| 112 | break; |
| 113 | /* get the PCI data structure and check its signature */ |
| 114 | pds = image + readw(image + 24); |
| 115 | if (readb(pds) != 'P') |
| 116 | break; |
| 117 | if (readb(pds + 1) != 'C') |
| 118 | break; |
| 119 | if (readb(pds + 2) != 'I') |
| 120 | break; |
| 121 | if (readb(pds + 3) != 'R') |
| 122 | break; |
| 123 | last_image = readb(pds + 21) & 0x80; |
| 124 | /* this length is reliable */ |
| 125 | image += readw(pds + 16) * 512; |
| 126 | } while (!last_image); |
| 127 | |
| 128 | *size = image - rom; |
| 129 | |
| 130 | return rom; |
| 131 | } |
| 132 | |
| 133 | /** |
| 134 | * pci_map_rom_copy - map a PCI ROM to kernel space, create a copy |
| 135 | * @dev: pointer to pci device struct |
| 136 | * @size: pointer to receive size of pci window over ROM |
| 137 | * @return: kernel virtual pointer to image of ROM |
| 138 | * |
| 139 | * Map a PCI ROM into kernel space. If ROM is boot video ROM, |
| 140 | * the shadow BIOS copy will be returned instead of the |
| 141 | * actual ROM. |
| 142 | */ |
| 143 | void __iomem *pci_map_rom_copy(struct pci_dev *pdev, size_t *size) |
| 144 | { |
| 145 | struct resource *res = &pdev->resource[PCI_ROM_RESOURCE]; |
| 146 | void __iomem *rom; |
| 147 | |
| 148 | rom = pci_map_rom(pdev, size); |
| 149 | if (!rom) |
| 150 | return NULL; |
| 151 | |
| 152 | if (res->flags & (IORESOURCE_ROM_COPY | IORESOURCE_ROM_SHADOW)) |
| 153 | return rom; |
| 154 | |
| 155 | res->start = (unsigned long)kmalloc(*size, GFP_KERNEL); |
| 156 | if (!res->start) |
| 157 | return rom; |
| 158 | |
| 159 | res->end = res->start + *size; |
| 160 | memcpy_fromio((void*)res->start, rom, *size); |
| 161 | pci_unmap_rom(pdev, rom); |
| 162 | res->flags |= IORESOURCE_ROM_COPY; |
| 163 | |
| 164 | return (void __iomem *)res->start; |
| 165 | } |
| 166 | |
| 167 | /** |
| 168 | * pci_unmap_rom - unmap the ROM from kernel space |
| 169 | * @dev: pointer to pci device struct |
| 170 | * @rom: virtual address of the previous mapping |
| 171 | * |
| 172 | * Remove a mapping of a previously mapped ROM |
| 173 | */ |
| 174 | void pci_unmap_rom(struct pci_dev *pdev, void __iomem *rom) |
| 175 | { |
| 176 | struct resource *res = &pdev->resource[PCI_ROM_RESOURCE]; |
| 177 | |
| 178 | if (res->flags & IORESOURCE_ROM_COPY) |
| 179 | return; |
| 180 | |
| 181 | iounmap(rom); |
| 182 | |
| 183 | /* Disable again before continuing, leave enabled if pci=rom */ |
| 184 | if (!(res->flags & (IORESOURCE_ROM_ENABLE | IORESOURCE_ROM_SHADOW))) |
| 185 | pci_disable_rom(pdev); |
| 186 | } |
| 187 | |
| 188 | /** |
| 189 | * pci_remove_rom - disable the ROM and remove its sysfs attribute |
| 190 | * @dev: pointer to pci device struct |
| 191 | * |
| 192 | * Remove the rom file in sysfs and disable ROM decoding. |
| 193 | */ |
| 194 | void pci_remove_rom(struct pci_dev *pdev) |
| 195 | { |
| 196 | struct resource *res = &pdev->resource[PCI_ROM_RESOURCE]; |
| 197 | |
| 198 | if (pci_resource_len(pdev, PCI_ROM_RESOURCE)) |
| 199 | sysfs_remove_bin_file(&pdev->dev.kobj, pdev->rom_attr); |
| 200 | if (!(res->flags & (IORESOURCE_ROM_ENABLE | |
| 201 | IORESOURCE_ROM_SHADOW | |
| 202 | IORESOURCE_ROM_COPY))) |
| 203 | pci_disable_rom(pdev); |
| 204 | } |
| 205 | |
| 206 | /** |
| 207 | * pci_cleanup_rom - internal routine for freeing the ROM copy created |
| 208 | * by pci_map_rom_copy called from remove.c |
| 209 | * @dev: pointer to pci device struct |
| 210 | * |
| 211 | * Free the copied ROM if we allocated one. |
| 212 | */ |
| 213 | void pci_cleanup_rom(struct pci_dev *pdev) |
| 214 | { |
| 215 | struct resource *res = &pdev->resource[PCI_ROM_RESOURCE]; |
| 216 | if (res->flags & IORESOURCE_ROM_COPY) { |
| 217 | kfree((void*)res->start); |
| 218 | res->flags &= ~IORESOURCE_ROM_COPY; |
| 219 | res->start = 0; |
| 220 | res->end = 0; |
| 221 | } |
| 222 | } |
| 223 | |
| 224 | EXPORT_SYMBOL(pci_map_rom); |
| 225 | EXPORT_SYMBOL(pci_map_rom_copy); |
| 226 | EXPORT_SYMBOL(pci_unmap_rom); |
| 227 | EXPORT_SYMBOL(pci_remove_rom); |