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/export.h>
11 #include <linux/pci.h>
12 #include <linux/slab.h>
17 * pci_enable_rom - enable ROM decoding for a PCI device
18 * @pdev: PCI device to enable
20 * Enable ROM decoding on @dev. This involves simply turning on the last
21 * bit of the PCI ROM BAR. Note that some cards may share address decoders
22 * between the ROM and other resources, so enabling it may disable access
23 * to MMIO registers or other card memory.
25 int pci_enable_rom(struct pci_dev *pdev)
27 struct resource *res = pdev->resource + PCI_ROM_RESOURCE;
28 struct pci_bus_region region;
34 pcibios_resource_to_bus(pdev, ®ion, res);
35 pci_read_config_dword(pdev, pdev->rom_base_reg, &rom_addr);
36 rom_addr &= ~PCI_ROM_ADDRESS_MASK;
37 rom_addr |= region.start | PCI_ROM_ADDRESS_ENABLE;
38 pci_write_config_dword(pdev, pdev->rom_base_reg, rom_addr);
43 * pci_disable_rom - disable ROM decoding for a PCI device
44 * @pdev: PCI device to disable
46 * Disable ROM decoding on a PCI device by turning off the last bit in the
49 void pci_disable_rom(struct pci_dev *pdev)
52 pci_read_config_dword(pdev, pdev->rom_base_reg, &rom_addr);
53 rom_addr &= ~PCI_ROM_ADDRESS_ENABLE;
54 pci_write_config_dword(pdev, pdev->rom_base_reg, rom_addr);
58 * pci_get_rom_size - obtain the actual size of the ROM image
59 * @pdev: target PCI device
60 * @rom: kernel virtual pointer to image of ROM
61 * @size: size of PCI window
62 * return: size of actual ROM image
64 * Determine the actual length of the ROM image.
65 * The PCI window size could be much larger than the
68 size_t pci_get_rom_size(struct pci_dev *pdev, void __iomem *rom, size_t size)
76 /* Standard PCI ROMs start out with these bytes 55 AA */
77 if (readb(image) != 0x55) {
78 dev_err(&pdev->dev, "Invalid ROM contents\n");
81 if (readb(image + 1) != 0xAA)
83 /* get the PCI data structure and check its signature */
84 pds = image + readw(image + 24);
85 if (readb(pds) != 'P')
87 if (readb(pds + 1) != 'C')
89 if (readb(pds + 2) != 'I')
91 if (readb(pds + 3) != 'R')
93 last_image = readb(pds + 21) & 0x80;
94 /* this length is reliable */
95 image += readw(pds + 16) * 512;
96 } while (!last_image);
98 /* never return a size larger than the PCI resource window */
99 /* there are known ROMs that get the size wrong */
100 return min((size_t)(image - rom), size);
104 * pci_map_rom - map a PCI ROM to kernel space
105 * @pdev: pointer to pci device struct
106 * @size: pointer to receive size of pci window over ROM
108 * Return: kernel virtual pointer to image of ROM
110 * Map a PCI ROM into kernel space. If ROM is boot video ROM,
111 * the shadow BIOS copy will be returned instead of the
114 void __iomem *pci_map_rom(struct pci_dev *pdev, size_t *size)
116 struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
121 * IORESOURCE_ROM_SHADOW set on x86, x86_64 and IA64 supports legacy
122 * memory map if the VGA enable bit of the Bridge Control register is
123 * set for embedded VGA.
125 if (res->flags & IORESOURCE_ROM_SHADOW) {
126 /* primary video rom always starts here */
127 start = (loff_t)0xC0000;
128 *size = 0x20000; /* cover C000:0 through E000:0 */
131 (IORESOURCE_ROM_COPY | IORESOURCE_ROM_BIOS_COPY)) {
132 *size = pci_resource_len(pdev, PCI_ROM_RESOURCE);
133 return (void __iomem *)(unsigned long)
134 pci_resource_start(pdev, PCI_ROM_RESOURCE);
136 /* assign the ROM an address if it doesn't have one */
137 if (res->parent == NULL &&
138 pci_assign_resource(pdev,PCI_ROM_RESOURCE))
140 start = pci_resource_start(pdev, PCI_ROM_RESOURCE);
141 *size = pci_resource_len(pdev, PCI_ROM_RESOURCE);
145 /* Enable ROM space decodes */
146 if (pci_enable_rom(pdev))
151 rom = ioremap(start, *size);
153 /* restore enable if ioremap fails */
154 if (!(res->flags & (IORESOURCE_ROM_ENABLE |
155 IORESOURCE_ROM_SHADOW |
156 IORESOURCE_ROM_COPY)))
157 pci_disable_rom(pdev);
162 * Try to find the true size of the ROM since sometimes the PCI window
163 * size is much larger than the actual size of the ROM.
164 * True size is important if the ROM is going to be copied.
166 *size = pci_get_rom_size(pdev, rom, *size);
172 * pci_map_rom_copy - map a PCI ROM to kernel space, create a copy
173 * @pdev: pointer to pci device struct
174 * @size: pointer to receive size of pci window over ROM
176 * Return: kernel virtual pointer to image of ROM
178 * Map a PCI ROM into kernel space. If ROM is boot video ROM,
179 * the shadow BIOS copy will be returned instead of the
182 void __iomem *pci_map_rom_copy(struct pci_dev *pdev, size_t *size)
184 struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
187 rom = pci_map_rom(pdev, size);
191 if (res->flags & (IORESOURCE_ROM_COPY | IORESOURCE_ROM_SHADOW |
192 IORESOURCE_ROM_BIOS_COPY))
195 res->start = (unsigned long)kmalloc(*size, GFP_KERNEL);
199 res->end = res->start + *size;
200 memcpy_fromio((void*)(unsigned long)res->start, rom, *size);
201 pci_unmap_rom(pdev, rom);
202 res->flags |= IORESOURCE_ROM_COPY;
204 return (void __iomem *)(unsigned long)res->start;
209 * pci_unmap_rom - unmap the ROM from kernel space
210 * @pdev: pointer to pci device struct
211 * @rom: virtual address of the previous mapping
213 * Remove a mapping of a previously mapped ROM
215 void pci_unmap_rom(struct pci_dev *pdev, void __iomem *rom)
217 struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
219 if (res->flags & (IORESOURCE_ROM_COPY | IORESOURCE_ROM_BIOS_COPY))
224 /* Disable again before continuing, leave enabled if pci=rom */
225 if (!(res->flags & (IORESOURCE_ROM_ENABLE | IORESOURCE_ROM_SHADOW)))
226 pci_disable_rom(pdev);
231 * pci_remove_rom - disable the ROM and remove its sysfs attribute
232 * @pdev: pointer to pci device struct
234 * Remove the rom file in sysfs and disable ROM decoding.
236 void pci_remove_rom(struct pci_dev *pdev)
238 struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
240 if (pci_resource_len(pdev, PCI_ROM_RESOURCE))
241 sysfs_remove_bin_file(&pdev->dev.kobj, pdev->rom_attr);
242 if (!(res->flags & (IORESOURCE_ROM_ENABLE |
243 IORESOURCE_ROM_SHADOW |
244 IORESOURCE_ROM_BIOS_COPY |
245 IORESOURCE_ROM_COPY)))
246 pci_disable_rom(pdev);
251 * pci_cleanup_rom - free the ROM copy created by pci_map_rom_copy
252 * @pdev: pointer to pci device struct
254 * Free the copied ROM if we allocated one.
256 void pci_cleanup_rom(struct pci_dev *pdev)
258 struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
259 if (res->flags & IORESOURCE_ROM_COPY) {
260 kfree((void*)(unsigned long)res->start);
261 res->flags &= ~IORESOURCE_ROM_COPY;
267 EXPORT_SYMBOL(pci_map_rom);
268 EXPORT_SYMBOL(pci_unmap_rom);
269 EXPORT_SYMBOL_GPL(pci_enable_rom);
270 EXPORT_SYMBOL_GPL(pci_disable_rom);