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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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 */
Linus Torvalds1da177e2005-04-16 15:20:36 -07009#include <linux/kernel.h>
10#include <linux/pci.h>
Tim Schmielau4e57b682005-10-30 15:03:48 -080011#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070012
13#include "pci.h"
14
15/**
16 * pci_enable_rom - enable ROM decoding for a PCI device
Martin Waitz67be2dd2005-05-01 08:59:26 -070017 * @pdev: PCI device to enable
Linus Torvalds1da177e2005-04-16 15:20:36 -070018 *
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 */
Benjamin Herrenschmidt8085ce082005-08-31 14:16:53 +100024static int pci_enable_rom(struct pci_dev *pdev)
Linus Torvalds1da177e2005-04-16 15:20:36 -070025{
Benjamin Herrenschmidt8085ce082005-08-31 14:16:53 +100026 struct resource *res = pdev->resource + PCI_ROM_RESOURCE;
27 struct pci_bus_region region;
Linus Torvalds1da177e2005-04-16 15:20:36 -070028 u32 rom_addr;
29
Benjamin Herrenschmidt8085ce082005-08-31 14:16:53 +100030 if (!res->flags)
31 return -1;
32
33 pcibios_resource_to_bus(pdev, &region, res);
Linus Torvalds1da177e2005-04-16 15:20:36 -070034 pci_read_config_dword(pdev, pdev->rom_base_reg, &rom_addr);
Benjamin Herrenschmidt8085ce082005-08-31 14:16:53 +100035 rom_addr &= ~PCI_ROM_ADDRESS_MASK;
36 rom_addr |= region.start | PCI_ROM_ADDRESS_ENABLE;
Linus Torvalds1da177e2005-04-16 15:20:36 -070037 pci_write_config_dword(pdev, pdev->rom_base_reg, rom_addr);
Benjamin Herrenschmidt8085ce082005-08-31 14:16:53 +100038 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070039}
40
41/**
42 * pci_disable_rom - disable ROM decoding for a PCI device
Martin Waitz67be2dd2005-05-01 08:59:26 -070043 * @pdev: PCI device to disable
Linus Torvalds1da177e2005-04-16 15:20:36 -070044 *
45 * Disable ROM decoding on a PCI device by turning off the last bit in the
46 * ROM BAR.
47 */
48static void pci_disable_rom(struct pci_dev *pdev)
49{
50 u32 rom_addr;
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);
54}
55
56/**
John Kellerd7ad2252007-07-09 11:42:24 -070057 * pci_get_rom_size - obtain the actual size of the ROM image
58 * @rom: kernel virtual pointer to image of ROM
59 * @size: size of PCI window
60 * return: size of actual ROM image
61 *
62 * Determine the actual length of the ROM image.
63 * The PCI window size could be much larger than the
64 * actual image size.
65 */
66size_t pci_get_rom_size(void __iomem *rom, size_t size)
67{
68 void __iomem *image;
69 int last_image;
70
71 image = rom;
72 do {
73 void __iomem *pds;
74 /* Standard PCI ROMs start out with these bytes 55 AA */
75 if (readb(image) != 0x55)
76 break;
77 if (readb(image + 1) != 0xAA)
78 break;
79 /* get the PCI data structure and check its signature */
80 pds = image + readw(image + 24);
81 if (readb(pds) != 'P')
82 break;
83 if (readb(pds + 1) != 'C')
84 break;
85 if (readb(pds + 2) != 'I')
86 break;
87 if (readb(pds + 3) != 'R')
88 break;
89 last_image = readb(pds + 21) & 0x80;
90 /* this length is reliable */
91 image += readw(pds + 16) * 512;
92 } while (!last_image);
93
94 /* never return a size larger than the PCI resource window */
95 /* there are known ROMs that get the size wrong */
96 return min((size_t)(image - rom), size);
97}
98
99/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100 * pci_map_rom - map a PCI ROM to kernel space
Martin Waitz67be2dd2005-05-01 08:59:26 -0700101 * @pdev: pointer to pci device struct
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102 * @size: pointer to receive size of pci window over ROM
103 * @return: kernel virtual pointer to image of ROM
104 *
105 * Map a PCI ROM into kernel space. If ROM is boot video ROM,
106 * the shadow BIOS copy will be returned instead of the
107 * actual ROM.
108 */
109void __iomem *pci_map_rom(struct pci_dev *pdev, size_t *size)
110{
111 struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
112 loff_t start;
113 void __iomem *rom;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114
eiichiro.oiwa.nm@hitachi.comb5e4efe2006-09-28 13:55:47 +0900115 /*
Eiichiro Oiwa6b5c76b2006-10-23 15:14:07 +0900116 * IORESOURCE_ROM_SHADOW set on x86, x86_64 and IA64 supports legacy
117 * memory map if the VGA enable bit of the Bridge Control register is
118 * set for embedded VGA.
eiichiro.oiwa.nm@hitachi.comb5e4efe2006-09-28 13:55:47 +0900119 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120 if (res->flags & IORESOURCE_ROM_SHADOW) {
121 /* primary video rom always starts here */
122 start = (loff_t)0xC0000;
123 *size = 0x20000; /* cover C000:0 through E000:0 */
124 } else {
John Kellera2302c62006-10-04 16:49:52 -0500125 if (res->flags &
126 (IORESOURCE_ROM_COPY | IORESOURCE_ROM_BIOS_COPY)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 *size = pci_resource_len(pdev, PCI_ROM_RESOURCE);
Greg Kroah-Hartmane31dd6e2006-06-12 17:06:02 -0700128 return (void __iomem *)(unsigned long)
129 pci_resource_start(pdev, PCI_ROM_RESOURCE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130 } else {
131 /* assign the ROM an address if it doesn't have one */
Benjamin Herrenschmidt8085ce082005-08-31 14:16:53 +1000132 if (res->parent == NULL &&
133 pci_assign_resource(pdev,PCI_ROM_RESOURCE))
134 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 start = pci_resource_start(pdev, PCI_ROM_RESOURCE);
136 *size = pci_resource_len(pdev, PCI_ROM_RESOURCE);
137 if (*size == 0)
138 return NULL;
139
140 /* Enable ROM space decodes */
Benjamin Herrenschmidt8085ce082005-08-31 14:16:53 +1000141 if (pci_enable_rom(pdev))
142 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143 }
144 }
145
146 rom = ioremap(start, *size);
147 if (!rom) {
148 /* restore enable if ioremap fails */
149 if (!(res->flags & (IORESOURCE_ROM_ENABLE |
150 IORESOURCE_ROM_SHADOW |
151 IORESOURCE_ROM_COPY)))
152 pci_disable_rom(pdev);
153 return NULL;
154 }
155
156 /*
157 * Try to find the true size of the ROM since sometimes the PCI window
158 * size is much larger than the actual size of the ROM.
159 * True size is important if the ROM is going to be copied.
160 */
John Kellerd7ad2252007-07-09 11:42:24 -0700161 *size = pci_get_rom_size(rom, *size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162 return rom;
163}
164
Adrian Bunkb09549e2007-10-27 03:06:25 +0200165#if 0
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166/**
167 * pci_map_rom_copy - map a PCI ROM to kernel space, create a copy
Martin Waitz67be2dd2005-05-01 08:59:26 -0700168 * @pdev: pointer to pci device struct
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169 * @size: pointer to receive size of pci window over ROM
170 * @return: kernel virtual pointer to image of ROM
171 *
172 * Map a PCI ROM into kernel space. If ROM is boot video ROM,
173 * the shadow BIOS copy will be returned instead of the
174 * actual ROM.
175 */
176void __iomem *pci_map_rom_copy(struct pci_dev *pdev, size_t *size)
177{
178 struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
179 void __iomem *rom;
180
181 rom = pci_map_rom(pdev, size);
182 if (!rom)
183 return NULL;
184
John Kellera2302c62006-10-04 16:49:52 -0500185 if (res->flags & (IORESOURCE_ROM_COPY | IORESOURCE_ROM_SHADOW |
186 IORESOURCE_ROM_BIOS_COPY))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 return rom;
188
189 res->start = (unsigned long)kmalloc(*size, GFP_KERNEL);
190 if (!res->start)
191 return rom;
192
193 res->end = res->start + *size;
Greg Kroah-Hartmane31dd6e2006-06-12 17:06:02 -0700194 memcpy_fromio((void*)(unsigned long)res->start, rom, *size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195 pci_unmap_rom(pdev, rom);
196 res->flags |= IORESOURCE_ROM_COPY;
197
Greg Kroah-Hartmane31dd6e2006-06-12 17:06:02 -0700198 return (void __iomem *)(unsigned long)res->start;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199}
Adrian Bunkb09549e2007-10-27 03:06:25 +0200200#endif /* 0 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201
202/**
203 * pci_unmap_rom - unmap the ROM from kernel space
Martin Waitz67be2dd2005-05-01 08:59:26 -0700204 * @pdev: pointer to pci device struct
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205 * @rom: virtual address of the previous mapping
206 *
207 * Remove a mapping of a previously mapped ROM
208 */
209void pci_unmap_rom(struct pci_dev *pdev, void __iomem *rom)
210{
211 struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
212
John Kellera2302c62006-10-04 16:49:52 -0500213 if (res->flags & (IORESOURCE_ROM_COPY | IORESOURCE_ROM_BIOS_COPY))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214 return;
215
216 iounmap(rom);
217
218 /* Disable again before continuing, leave enabled if pci=rom */
219 if (!(res->flags & (IORESOURCE_ROM_ENABLE | IORESOURCE_ROM_SHADOW)))
220 pci_disable_rom(pdev);
221}
222
Adrian Bunkb09549e2007-10-27 03:06:25 +0200223#if 0
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224/**
225 * pci_remove_rom - disable the ROM and remove its sysfs attribute
Martin Waitz67be2dd2005-05-01 08:59:26 -0700226 * @pdev: pointer to pci device struct
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 *
228 * Remove the rom file in sysfs and disable ROM decoding.
229 */
230void pci_remove_rom(struct pci_dev *pdev)
231{
232 struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
233
234 if (pci_resource_len(pdev, PCI_ROM_RESOURCE))
235 sysfs_remove_bin_file(&pdev->dev.kobj, pdev->rom_attr);
236 if (!(res->flags & (IORESOURCE_ROM_ENABLE |
237 IORESOURCE_ROM_SHADOW |
John Kellera2302c62006-10-04 16:49:52 -0500238 IORESOURCE_ROM_BIOS_COPY |
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239 IORESOURCE_ROM_COPY)))
240 pci_disable_rom(pdev);
241}
Adrian Bunkb09549e2007-10-27 03:06:25 +0200242#endif /* 0 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243
244/**
Randy Dunlap06432452008-02-29 22:03:15 -0800245 * pci_cleanup_rom - free the ROM copy created by pci_map_rom_copy
Martin Waitz67be2dd2005-05-01 08:59:26 -0700246 * @pdev: pointer to pci device struct
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247 *
248 * Free the copied ROM if we allocated one.
249 */
250void pci_cleanup_rom(struct pci_dev *pdev)
251{
252 struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
253 if (res->flags & IORESOURCE_ROM_COPY) {
Greg Kroah-Hartmane31dd6e2006-06-12 17:06:02 -0700254 kfree((void*)(unsigned long)res->start);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255 res->flags &= ~IORESOURCE_ROM_COPY;
256 res->start = 0;
257 res->end = 0;
258 }
259}
260
261EXPORT_SYMBOL(pci_map_rom);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262EXPORT_SYMBOL(pci_unmap_rom);