| /* |
| * drivers/pci/rom.c |
| * |
| * (C) Copyright 2004 Jon Smirl <jonsmirl@yahoo.com> |
| * (C) Copyright 2004 Silicon Graphics, Inc. Jesse Barnes <jbarnes@sgi.com> |
| * |
| * PCI ROM access routines |
| */ |
| #include <linux/kernel.h> |
| #include <linux/export.h> |
| #include <linux/pci.h> |
| #include <linux/slab.h> |
| |
| #include "pci.h" |
| |
| /** |
| * pci_enable_rom - enable ROM decoding for a PCI device |
| * @pdev: PCI device to enable |
| * |
| * Enable ROM decoding on @dev. This involves simply turning on the last |
| * bit of the PCI ROM BAR. Note that some cards may share address decoders |
| * between the ROM and other resources, so enabling it may disable access |
| * to MMIO registers or other card memory. |
| */ |
| int pci_enable_rom(struct pci_dev *pdev) |
| { |
| struct resource *res = pdev->resource + PCI_ROM_RESOURCE; |
| struct pci_bus_region region; |
| u32 rom_addr; |
| |
| if (!res->flags) |
| return -1; |
| |
| /* |
| * Ideally pci_update_resource() would update the ROM BAR address, |
| * and we would only set the enable bit here. But apparently some |
| * devices have buggy ROM BARs that read as zero when disabled. |
| */ |
| pcibios_resource_to_bus(pdev->bus, ®ion, res); |
| pci_read_config_dword(pdev, pdev->rom_base_reg, &rom_addr); |
| rom_addr &= ~PCI_ROM_ADDRESS_MASK; |
| rom_addr |= region.start | PCI_ROM_ADDRESS_ENABLE; |
| pci_write_config_dword(pdev, pdev->rom_base_reg, rom_addr); |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(pci_enable_rom); |
| |
| /** |
| * pci_disable_rom - disable ROM decoding for a PCI device |
| * @pdev: PCI device to disable |
| * |
| * Disable ROM decoding on a PCI device by turning off the last bit in the |
| * ROM BAR. |
| */ |
| void pci_disable_rom(struct pci_dev *pdev) |
| { |
| u32 rom_addr; |
| pci_read_config_dword(pdev, pdev->rom_base_reg, &rom_addr); |
| rom_addr &= ~PCI_ROM_ADDRESS_ENABLE; |
| pci_write_config_dword(pdev, pdev->rom_base_reg, rom_addr); |
| } |
| EXPORT_SYMBOL_GPL(pci_disable_rom); |
| |
| /** |
| * pci_get_rom_size - obtain the actual size of the ROM image |
| * @pdev: target PCI device |
| * @rom: kernel virtual pointer to image of ROM |
| * @size: size of PCI window |
| * return: size of actual ROM image |
| * |
| * Determine the actual length of the ROM image. |
| * The PCI window size could be much larger than the |
| * actual image size. |
| */ |
| size_t pci_get_rom_size(struct pci_dev *pdev, void __iomem *rom, size_t size) |
| { |
| void __iomem *image; |
| int last_image; |
| unsigned length; |
| |
| image = rom; |
| do { |
| void __iomem *pds; |
| /* Standard PCI ROMs start out with these bytes 55 AA */ |
| if (readb(image) != 0x55) { |
| dev_err(&pdev->dev, "Invalid ROM contents\n"); |
| break; |
| } |
| if (readb(image + 1) != 0xAA) |
| break; |
| /* get the PCI data structure and check its signature */ |
| pds = image + readw(image + 24); |
| if (readb(pds) != 'P') |
| break; |
| if (readb(pds + 1) != 'C') |
| break; |
| if (readb(pds + 2) != 'I') |
| break; |
| if (readb(pds + 3) != 'R') |
| break; |
| last_image = readb(pds + 21) & 0x80; |
| length = readw(pds + 16); |
| image += length * 512; |
| } while (length && !last_image); |
| |
| /* never return a size larger than the PCI resource window */ |
| /* there are known ROMs that get the size wrong */ |
| return min((size_t)(image - rom), size); |
| } |
| |
| /** |
| * pci_map_rom - map a PCI ROM to kernel space |
| * @pdev: pointer to pci device struct |
| * @size: pointer to receive size of pci window over ROM |
| * |
| * Return: kernel virtual pointer to image of ROM |
| * |
| * Map a PCI ROM into kernel space. If ROM is boot video ROM, |
| * the shadow BIOS copy will be returned instead of the |
| * actual ROM. |
| */ |
| void __iomem *pci_map_rom(struct pci_dev *pdev, size_t *size) |
| { |
| struct resource *res = &pdev->resource[PCI_ROM_RESOURCE]; |
| loff_t start; |
| void __iomem *rom; |
| |
| /* |
| * IORESOURCE_ROM_SHADOW set on x86, x86_64 and IA64 supports legacy |
| * memory map if the VGA enable bit of the Bridge Control register is |
| * set for embedded VGA. |
| */ |
| if (res->flags & IORESOURCE_ROM_SHADOW) { |
| /* primary video rom always starts here */ |
| start = (loff_t)0xC0000; |
| *size = 0x20000; /* cover C000:0 through E000:0 */ |
| } else { |
| if (res->flags & |
| (IORESOURCE_ROM_COPY | IORESOURCE_ROM_BIOS_COPY)) { |
| *size = pci_resource_len(pdev, PCI_ROM_RESOURCE); |
| return (void __iomem *)(unsigned long) |
| pci_resource_start(pdev, PCI_ROM_RESOURCE); |
| } else { |
| /* assign the ROM an address if it doesn't have one */ |
| if (res->parent == NULL && |
| pci_assign_resource(pdev, PCI_ROM_RESOURCE)) |
| return NULL; |
| start = pci_resource_start(pdev, PCI_ROM_RESOURCE); |
| *size = pci_resource_len(pdev, PCI_ROM_RESOURCE); |
| if (*size == 0) |
| return NULL; |
| |
| /* Enable ROM space decodes */ |
| if (pci_enable_rom(pdev)) |
| return NULL; |
| } |
| } |
| |
| rom = ioremap(start, *size); |
| if (!rom) { |
| /* restore enable if ioremap fails */ |
| if (!(res->flags & (IORESOURCE_ROM_ENABLE | |
| IORESOURCE_ROM_SHADOW | |
| IORESOURCE_ROM_COPY))) |
| pci_disable_rom(pdev); |
| return NULL; |
| } |
| |
| /* |
| * Try to find the true size of the ROM since sometimes the PCI window |
| * size is much larger than the actual size of the ROM. |
| * True size is important if the ROM is going to be copied. |
| */ |
| *size = pci_get_rom_size(pdev, rom, *size); |
| return rom; |
| } |
| EXPORT_SYMBOL(pci_map_rom); |
| |
| /** |
| * pci_unmap_rom - unmap the ROM from kernel space |
| * @pdev: pointer to pci device struct |
| * @rom: virtual address of the previous mapping |
| * |
| * Remove a mapping of a previously mapped ROM |
| */ |
| void pci_unmap_rom(struct pci_dev *pdev, void __iomem *rom) |
| { |
| struct resource *res = &pdev->resource[PCI_ROM_RESOURCE]; |
| |
| if (res->flags & (IORESOURCE_ROM_COPY | IORESOURCE_ROM_BIOS_COPY)) |
| return; |
| |
| iounmap(rom); |
| |
| /* Disable again before continuing, leave enabled if pci=rom */ |
| if (!(res->flags & (IORESOURCE_ROM_ENABLE | IORESOURCE_ROM_SHADOW))) |
| pci_disable_rom(pdev); |
| } |
| EXPORT_SYMBOL(pci_unmap_rom); |
| |
| /** |
| * pci_cleanup_rom - free the ROM copy created by pci_map_rom_copy |
| * @pdev: pointer to pci device struct |
| * |
| * Free the copied ROM if we allocated one. |
| */ |
| void pci_cleanup_rom(struct pci_dev *pdev) |
| { |
| struct resource *res = &pdev->resource[PCI_ROM_RESOURCE]; |
| |
| if (res->flags & IORESOURCE_ROM_COPY) { |
| kfree((void *)(unsigned long)res->start); |
| res->flags |= IORESOURCE_UNSET; |
| res->flags &= ~IORESOURCE_ROM_COPY; |
| res->start = 0; |
| res->end = 0; |
| } |
| } |
| |
| /** |
| * pci_platform_rom - provides a pointer to any ROM image provided by the |
| * platform |
| * @pdev: pointer to pci device struct |
| * @size: pointer to receive size of pci window over ROM |
| */ |
| void __iomem *pci_platform_rom(struct pci_dev *pdev, size_t *size) |
| { |
| if (pdev->rom && pdev->romlen) { |
| *size = pdev->romlen; |
| return phys_to_virt((phys_addr_t)pdev->rom); |
| } |
| |
| return NULL; |
| } |
| EXPORT_SYMBOL(pci_platform_rom); |