blob: 3e64ff64b38c1bc6bdc047926a8e77a2a33f3306 [file] [log] [blame]
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 */
9#include <linux/config.h>
10#include <linux/kernel.h>
11#include <linux/pci.h>
12
13#include "pci.h"
14
15/**
16 * pci_enable_rom - enable ROM decoding for a PCI device
17 * @dev: PCI device to enable
18 *
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 */
24static void pci_enable_rom(struct pci_dev *pdev)
25{
26 u32 rom_addr;
27
28 pci_read_config_dword(pdev, pdev->rom_base_reg, &rom_addr);
29 rom_addr |= PCI_ROM_ADDRESS_ENABLE;
30 pci_write_config_dword(pdev, pdev->rom_base_reg, rom_addr);
31}
32
33/**
34 * pci_disable_rom - disable ROM decoding for a PCI device
35 * @dev: PCI device to disable
36 *
37 * Disable ROM decoding on a PCI device by turning off the last bit in the
38 * ROM BAR.
39 */
40static void pci_disable_rom(struct pci_dev *pdev)
41{
42 u32 rom_addr;
43 pci_read_config_dword(pdev, pdev->rom_base_reg, &rom_addr);
44 rom_addr &= ~PCI_ROM_ADDRESS_ENABLE;
45 pci_write_config_dword(pdev, pdev->rom_base_reg, rom_addr);
46}
47
48/**
49 * pci_map_rom - map a PCI ROM to kernel space
50 * @dev: pointer to pci device struct
51 * @size: pointer to receive size of pci window over ROM
52 * @return: kernel virtual pointer to image of ROM
53 *
54 * Map a PCI ROM into kernel space. If ROM is boot video ROM,
55 * the shadow BIOS copy will be returned instead of the
56 * actual ROM.
57 */
58void __iomem *pci_map_rom(struct pci_dev *pdev, size_t *size)
59{
60 struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
61 loff_t start;
62 void __iomem *rom;
63 void __iomem *image;
64 int last_image;
65
66 /* IORESOURCE_ROM_SHADOW only set on x86 */
67 if (res->flags & IORESOURCE_ROM_SHADOW) {
68 /* primary video rom always starts here */
69 start = (loff_t)0xC0000;
70 *size = 0x20000; /* cover C000:0 through E000:0 */
71 } else {
72 if (res->flags & IORESOURCE_ROM_COPY) {
73 *size = pci_resource_len(pdev, PCI_ROM_RESOURCE);
74 return (void __iomem *)pci_resource_start(pdev, PCI_ROM_RESOURCE);
75 } else {
76 /* assign the ROM an address if it doesn't have one */
77 if (res->parent == NULL)
78 pci_assign_resource(pdev, PCI_ROM_RESOURCE);
79
80 start = pci_resource_start(pdev, PCI_ROM_RESOURCE);
81 *size = pci_resource_len(pdev, PCI_ROM_RESOURCE);
82 if (*size == 0)
83 return NULL;
84
85 /* Enable ROM space decodes */
86 pci_enable_rom(pdev);
87 }
88 }
89
90 rom = ioremap(start, *size);
91 if (!rom) {
92 /* restore enable if ioremap fails */
93 if (!(res->flags & (IORESOURCE_ROM_ENABLE |
94 IORESOURCE_ROM_SHADOW |
95 IORESOURCE_ROM_COPY)))
96 pci_disable_rom(pdev);
97 return NULL;
98 }
99
100 /*
101 * Try to find the true size of the ROM since sometimes the PCI window
102 * size is much larger than the actual size of the ROM.
103 * True size is important if the ROM is going to be copied.
104 */
105 image = rom;
106 do {
107 void __iomem *pds;
108 /* Standard PCI ROMs start out with these bytes 55 AA */
109 if (readb(image) != 0x55)
110 break;
111 if (readb(image + 1) != 0xAA)
112 break;
113 /* get the PCI data structure and check its signature */
114 pds = image + readw(image + 24);
115 if (readb(pds) != 'P')
116 break;
117 if (readb(pds + 1) != 'C')
118 break;
119 if (readb(pds + 2) != 'I')
120 break;
121 if (readb(pds + 3) != 'R')
122 break;
123 last_image = readb(pds + 21) & 0x80;
124 /* this length is reliable */
125 image += readw(pds + 16) * 512;
126 } while (!last_image);
127
128 *size = image - rom;
129
130 return rom;
131}
132
133/**
134 * pci_map_rom_copy - map a PCI ROM to kernel space, create a copy
135 * @dev: pointer to pci device struct
136 * @size: pointer to receive size of pci window over ROM
137 * @return: kernel virtual pointer to image of ROM
138 *
139 * Map a PCI ROM into kernel space. If ROM is boot video ROM,
140 * the shadow BIOS copy will be returned instead of the
141 * actual ROM.
142 */
143void __iomem *pci_map_rom_copy(struct pci_dev *pdev, size_t *size)
144{
145 struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
146 void __iomem *rom;
147
148 rom = pci_map_rom(pdev, size);
149 if (!rom)
150 return NULL;
151
152 if (res->flags & (IORESOURCE_ROM_COPY | IORESOURCE_ROM_SHADOW))
153 return rom;
154
155 res->start = (unsigned long)kmalloc(*size, GFP_KERNEL);
156 if (!res->start)
157 return rom;
158
159 res->end = res->start + *size;
160 memcpy_fromio((void*)res->start, rom, *size);
161 pci_unmap_rom(pdev, rom);
162 res->flags |= IORESOURCE_ROM_COPY;
163
164 return (void __iomem *)res->start;
165}
166
167/**
168 * pci_unmap_rom - unmap the ROM from kernel space
169 * @dev: pointer to pci device struct
170 * @rom: virtual address of the previous mapping
171 *
172 * Remove a mapping of a previously mapped ROM
173 */
174void pci_unmap_rom(struct pci_dev *pdev, void __iomem *rom)
175{
176 struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
177
178 if (res->flags & IORESOURCE_ROM_COPY)
179 return;
180
181 iounmap(rom);
182
183 /* Disable again before continuing, leave enabled if pci=rom */
184 if (!(res->flags & (IORESOURCE_ROM_ENABLE | IORESOURCE_ROM_SHADOW)))
185 pci_disable_rom(pdev);
186}
187
188/**
189 * pci_remove_rom - disable the ROM and remove its sysfs attribute
190 * @dev: pointer to pci device struct
191 *
192 * Remove the rom file in sysfs and disable ROM decoding.
193 */
194void pci_remove_rom(struct pci_dev *pdev)
195{
196 struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
197
198 if (pci_resource_len(pdev, PCI_ROM_RESOURCE))
199 sysfs_remove_bin_file(&pdev->dev.kobj, pdev->rom_attr);
200 if (!(res->flags & (IORESOURCE_ROM_ENABLE |
201 IORESOURCE_ROM_SHADOW |
202 IORESOURCE_ROM_COPY)))
203 pci_disable_rom(pdev);
204}
205
206/**
207 * pci_cleanup_rom - internal routine for freeing the ROM copy created
208 * by pci_map_rom_copy called from remove.c
209 * @dev: pointer to pci device struct
210 *
211 * Free the copied ROM if we allocated one.
212 */
213void pci_cleanup_rom(struct pci_dev *pdev)
214{
215 struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
216 if (res->flags & IORESOURCE_ROM_COPY) {
217 kfree((void*)res->start);
218 res->flags &= ~IORESOURCE_ROM_COPY;
219 res->start = 0;
220 res->end = 0;
221 }
222}
223
224EXPORT_SYMBOL(pci_map_rom);
225EXPORT_SYMBOL(pci_map_rom_copy);
226EXPORT_SYMBOL(pci_unmap_rom);
227EXPORT_SYMBOL(pci_remove_rom);