4 * (C) Copyright 2004 Jon Smirl <jonsmirl@yahoo.com>
5 * (C) Copyright 2004 Silicon Graphics, Inc. Jesse Barnes <jbarnes@sgi.com>
7 * PCI ROM access routines
9 #include <linux/kernel.h>
10 #include <linux/pci.h>
11 #include <linux/slab.h>
16 * pci_enable_rom - enable ROM decoding for a PCI device
17 * @pdev: PCI device to enable
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.
24 int pci_enable_rom(struct pci_dev *pdev)
26 struct resource *res = pdev->resource + PCI_ROM_RESOURCE;
27 struct pci_bus_region region;
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);
42 * pci_disable_rom - disable ROM decoding for a PCI device
43 * @pdev: PCI device to disable
45 * Disable ROM decoding on a PCI device by turning off the last bit in the
48 void pci_disable_rom(struct pci_dev *pdev)
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);
57 * pci_get_rom_size - obtain the actual size of the ROM image
58 * @pdev: target PCI device
59 * @rom: kernel virtual pointer to image of ROM
60 * @size: size of PCI window
61 * return: size of actual ROM image
63 * Determine the actual length of the ROM image.
64 * The PCI window size could be much larger than the
67 size_t pci_get_rom_size(struct pci_dev *pdev, void __iomem *rom, size_t size)
75 /* Standard PCI ROMs start out with these bytes 55 AA */
76 if (readb(image) != 0x55) {
77 dev_err(&pdev->dev, "Invalid ROM contents\n");
80 if (readb(image + 1) != 0xAA)
82 /* get the PCI data structure and check its signature */
83 pds = image + readw(image + 24);
84 if (readb(pds) != 'P')
86 if (readb(pds + 1) != 'C')
88 if (readb(pds + 2) != 'I')
90 if (readb(pds + 3) != 'R')
92 last_image = readb(pds + 21) & 0x80;
93 /* this length is reliable */
94 image += readw(pds + 16) * 512;
95 } while (!last_image);
97 /* never return a size larger than the PCI resource window */
98 /* there are known ROMs that get the size wrong */
99 return min((size_t)(image - rom), size);
103 * pci_map_rom - map a PCI ROM to kernel space
104 * @pdev: pointer to pci device struct
105 * @size: pointer to receive size of pci window over ROM
107 * Return: kernel virtual pointer to image of ROM
109 * Map a PCI ROM into kernel space. If ROM is boot video ROM,
110 * the shadow BIOS copy will be returned instead of the
113 void __iomem *pci_map_rom(struct pci_dev *pdev, size_t *size)
115 struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
120 * IORESOURCE_ROM_SHADOW set on x86, x86_64 and IA64 supports legacy
121 * memory map if the VGA enable bit of the Bridge Control register is
122 * set for embedded VGA.
124 if (res->flags & IORESOURCE_ROM_SHADOW) {
125 /* primary video rom always starts here */
126 start = (loff_t)0xC0000;
127 *size = 0x20000; /* cover C000:0 through E000:0 */
130 (IORESOURCE_ROM_COPY | IORESOURCE_ROM_BIOS_COPY)) {
131 *size = pci_resource_len(pdev, PCI_ROM_RESOURCE);
132 return (void __iomem *)(unsigned long)
133 pci_resource_start(pdev, PCI_ROM_RESOURCE);
135 /* assign the ROM an address if it doesn't have one */
136 if (res->parent == NULL &&
137 pci_assign_resource(pdev,PCI_ROM_RESOURCE))
139 start = pci_resource_start(pdev, PCI_ROM_RESOURCE);
140 *size = pci_resource_len(pdev, PCI_ROM_RESOURCE);
144 /* Enable ROM space decodes */
145 if (pci_enable_rom(pdev))
150 rom = ioremap(start, *size);
152 /* restore enable if ioremap fails */
153 if (!(res->flags & (IORESOURCE_ROM_ENABLE |
154 IORESOURCE_ROM_SHADOW |
155 IORESOURCE_ROM_COPY)))
156 pci_disable_rom(pdev);
161 * Try to find the true size of the ROM since sometimes the PCI window
162 * size is much larger than the actual size of the ROM.
163 * True size is important if the ROM is going to be copied.
165 *size = pci_get_rom_size(pdev, rom, *size);
171 * pci_map_rom_copy - map a PCI ROM to kernel space, create a copy
172 * @pdev: pointer to pci device struct
173 * @size: pointer to receive size of pci window over ROM
175 * Return: kernel virtual pointer to image of ROM
177 * Map a PCI ROM into kernel space. If ROM is boot video ROM,
178 * the shadow BIOS copy will be returned instead of the
181 void __iomem *pci_map_rom_copy(struct pci_dev *pdev, size_t *size)
183 struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
186 rom = pci_map_rom(pdev, size);
190 if (res->flags & (IORESOURCE_ROM_COPY | IORESOURCE_ROM_SHADOW |
191 IORESOURCE_ROM_BIOS_COPY))
194 res->start = (unsigned long)kmalloc(*size, GFP_KERNEL);
198 res->end = res->start + *size;
199 memcpy_fromio((void*)(unsigned long)res->start, rom, *size);
200 pci_unmap_rom(pdev, rom);
201 res->flags |= IORESOURCE_ROM_COPY;
203 return (void __iomem *)(unsigned long)res->start;
208 * pci_unmap_rom - unmap the ROM from kernel space
209 * @pdev: pointer to pci device struct
210 * @rom: virtual address of the previous mapping
212 * Remove a mapping of a previously mapped ROM
214 void pci_unmap_rom(struct pci_dev *pdev, void __iomem *rom)
216 struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
218 if (res->flags & (IORESOURCE_ROM_COPY | IORESOURCE_ROM_BIOS_COPY))
223 /* Disable again before continuing, leave enabled if pci=rom */
224 if (!(res->flags & (IORESOURCE_ROM_ENABLE | IORESOURCE_ROM_SHADOW)))
225 pci_disable_rom(pdev);
230 * pci_remove_rom - disable the ROM and remove its sysfs attribute
231 * @pdev: pointer to pci device struct
233 * Remove the rom file in sysfs and disable ROM decoding.
235 void pci_remove_rom(struct pci_dev *pdev)
237 struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
239 if (pci_resource_len(pdev, PCI_ROM_RESOURCE))
240 sysfs_remove_bin_file(&pdev->dev.kobj, pdev->rom_attr);
241 if (!(res->flags & (IORESOURCE_ROM_ENABLE |
242 IORESOURCE_ROM_SHADOW |
243 IORESOURCE_ROM_BIOS_COPY |
244 IORESOURCE_ROM_COPY)))
245 pci_disable_rom(pdev);
250 * pci_cleanup_rom - free the ROM copy created by pci_map_rom_copy
251 * @pdev: pointer to pci device struct
253 * Free the copied ROM if we allocated one.
255 void pci_cleanup_rom(struct pci_dev *pdev)
257 struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
258 if (res->flags & IORESOURCE_ROM_COPY) {
259 kfree((void*)(unsigned long)res->start);
260 res->flags &= ~IORESOURCE_ROM_COPY;
266 EXPORT_SYMBOL(pci_map_rom);
267 EXPORT_SYMBOL(pci_unmap_rom);
268 EXPORT_SYMBOL_GPL(pci_enable_rom);
269 EXPORT_SYMBOL_GPL(pci_disable_rom);