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 static 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 static 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_map_rom - map a PCI ROM to kernel space
58 * @pdev: pointer to pci device struct
59 * @size: pointer to receive size of pci window over ROM
60 * @return: kernel virtual pointer to image of ROM
62 * Map a PCI ROM into kernel space. If ROM is boot video ROM,
63 * the shadow BIOS copy will be returned instead of the
66 void __iomem
*pci_map_rom(struct pci_dev
*pdev
, size_t *size
)
68 struct resource
*res
= &pdev
->resource
[PCI_ROM_RESOURCE
];
75 * IORESOURCE_ROM_SHADOW set if the VGA enable bit of the Bridge Control
76 * register is set for embedded VGA.
78 if (res
->flags
& IORESOURCE_ROM_SHADOW
) {
79 /* primary video rom always starts here */
80 start
= (loff_t
)0xC0000;
81 *size
= 0x20000; /* cover C000:0 through E000:0 */
83 if (res
->flags
& IORESOURCE_ROM_COPY
) {
84 *size
= pci_resource_len(pdev
, PCI_ROM_RESOURCE
);
85 return (void __iomem
*)(unsigned long)
86 pci_resource_start(pdev
, PCI_ROM_RESOURCE
);
88 /* assign the ROM an address if it doesn't have one */
89 if (res
->parent
== NULL
&&
90 pci_assign_resource(pdev
,PCI_ROM_RESOURCE
))
92 start
= pci_resource_start(pdev
, PCI_ROM_RESOURCE
);
93 *size
= pci_resource_len(pdev
, PCI_ROM_RESOURCE
);
97 /* Enable ROM space decodes */
98 if (pci_enable_rom(pdev
))
103 rom
= ioremap(start
, *size
);
105 /* restore enable if ioremap fails */
106 if (!(res
->flags
& (IORESOURCE_ROM_ENABLE
|
107 IORESOURCE_ROM_SHADOW
|
108 IORESOURCE_ROM_COPY
)))
109 pci_disable_rom(pdev
);
114 * Try to find the true size of the ROM since sometimes the PCI window
115 * size is much larger than the actual size of the ROM.
116 * True size is important if the ROM is going to be copied.
121 /* Standard PCI ROMs start out with these bytes 55 AA */
122 if (readb(image
) != 0x55)
124 if (readb(image
+ 1) != 0xAA)
126 /* get the PCI data structure and check its signature */
127 pds
= image
+ readw(image
+ 24);
128 if (readb(pds
) != 'P')
130 if (readb(pds
+ 1) != 'C')
132 if (readb(pds
+ 2) != 'I')
134 if (readb(pds
+ 3) != 'R')
136 last_image
= readb(pds
+ 21) & 0x80;
137 /* this length is reliable */
138 image
+= readw(pds
+ 16) * 512;
139 } while (!last_image
);
141 /* never return a size larger than the PCI resource window */
142 /* there are known ROMs that get the size wrong */
143 *size
= min((size_t)(image
- rom
), *size
);
149 * pci_map_rom_copy - map a PCI ROM to kernel space, create a copy
150 * @pdev: pointer to pci device struct
151 * @size: pointer to receive size of pci window over ROM
152 * @return: kernel virtual pointer to image of ROM
154 * Map a PCI ROM into kernel space. If ROM is boot video ROM,
155 * the shadow BIOS copy will be returned instead of the
158 void __iomem
*pci_map_rom_copy(struct pci_dev
*pdev
, size_t *size
)
160 struct resource
*res
= &pdev
->resource
[PCI_ROM_RESOURCE
];
163 rom
= pci_map_rom(pdev
, size
);
167 if (res
->flags
& (IORESOURCE_ROM_COPY
| IORESOURCE_ROM_SHADOW
))
170 res
->start
= (unsigned long)kmalloc(*size
, GFP_KERNEL
);
174 res
->end
= res
->start
+ *size
;
175 memcpy_fromio((void*)(unsigned long)res
->start
, rom
, *size
);
176 pci_unmap_rom(pdev
, rom
);
177 res
->flags
|= IORESOURCE_ROM_COPY
;
179 return (void __iomem
*)(unsigned long)res
->start
;
183 * pci_unmap_rom - unmap the ROM from kernel space
184 * @pdev: pointer to pci device struct
185 * @rom: virtual address of the previous mapping
187 * Remove a mapping of a previously mapped ROM
189 void pci_unmap_rom(struct pci_dev
*pdev
, void __iomem
*rom
)
191 struct resource
*res
= &pdev
->resource
[PCI_ROM_RESOURCE
];
193 if (res
->flags
& IORESOURCE_ROM_COPY
)
198 /* Disable again before continuing, leave enabled if pci=rom */
199 if (!(res
->flags
& (IORESOURCE_ROM_ENABLE
| IORESOURCE_ROM_SHADOW
)))
200 pci_disable_rom(pdev
);
204 * pci_remove_rom - disable the ROM and remove its sysfs attribute
205 * @pdev: pointer to pci device struct
207 * Remove the rom file in sysfs and disable ROM decoding.
209 void pci_remove_rom(struct pci_dev
*pdev
)
211 struct resource
*res
= &pdev
->resource
[PCI_ROM_RESOURCE
];
213 if (pci_resource_len(pdev
, PCI_ROM_RESOURCE
))
214 sysfs_remove_bin_file(&pdev
->dev
.kobj
, pdev
->rom_attr
);
215 if (!(res
->flags
& (IORESOURCE_ROM_ENABLE
|
216 IORESOURCE_ROM_SHADOW
|
217 IORESOURCE_ROM_COPY
)))
218 pci_disable_rom(pdev
);
222 * pci_cleanup_rom - internal routine for freeing the ROM copy created
223 * by pci_map_rom_copy called from remove.c
224 * @pdev: pointer to pci device struct
226 * Free the copied ROM if we allocated one.
228 void pci_cleanup_rom(struct pci_dev
*pdev
)
230 struct resource
*res
= &pdev
->resource
[PCI_ROM_RESOURCE
];
231 if (res
->flags
& IORESOURCE_ROM_COPY
) {
232 kfree((void*)(unsigned long)res
->start
);
233 res
->flags
&= ~IORESOURCE_ROM_COPY
;
239 EXPORT_SYMBOL(pci_map_rom
);
240 EXPORT_SYMBOL(pci_map_rom_copy
);
241 EXPORT_SYMBOL(pci_unmap_rom
);
242 EXPORT_SYMBOL(pci_remove_rom
);
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