diff options
Diffstat (limited to 'drivers/pci/rom.c')
| -rw-r--r-- | drivers/pci/rom.c | 230 |
1 files changed, 230 insertions, 0 deletions
diff --git a/drivers/pci/rom.c b/drivers/pci/rom.c new file mode 100644 index 000000000..eb0ad530d --- /dev/null +++ b/drivers/pci/rom.c @@ -0,0 +1,230 @@ +/* + * 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; + + 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); |