[deliverable/linux.git] / drivers / pci / rom.c

/*
 * drivers/pci/rom.c
 *
 * (C) Copyright 2004 Jon Smirl <jonsmirl@yahoo.com>
 * (C) Copyright 2004 Silicon Graphics, Inc. Jesse Barnes <jbarnes@sgi.com>
 *
 * PCI ROM access routines
 */
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/pci.h>
#include <linux/slab.h>

#include "pci.h"

/**
 * pci_enable_rom - enable ROM decoding for a PCI device
 * @pdev: PCI device to enable
 *
 * Enable ROM decoding on @dev.  This involves simply turning on the last
 * bit of the PCI ROM BAR.  Note that some cards may share address decoders
 * between the ROM and other resources, so enabling it may disable access
 * to MMIO registers or other card memory.
 */
int pci_enable_rom(struct pci_dev *pdev)
{
	struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
	struct pci_bus_region region;
	u32 rom_addr;

	if (!res->flags)
		return -1;

	/* Nothing to enable if we're using a shadow copy in RAM */
	if (res->flags & IORESOURCE_ROM_SHADOW)
		return 0;

	pcibios_resource_to_bus(pdev->bus, &region, res);
	pci_read_config_dword(pdev, pdev->rom_base_reg, &rom_addr);
	rom_addr &= ~PCI_ROM_ADDRESS_MASK;
	rom_addr |= region.start | PCI_ROM_ADDRESS_ENABLE;
	pci_write_config_dword(pdev, pdev->rom_base_reg, rom_addr);
	return 0;
}
EXPORT_SYMBOL_GPL(pci_enable_rom);

/**
 * pci_disable_rom - disable ROM decoding for a PCI device
 * @pdev: PCI device to disable
 *
 * Disable ROM decoding on a PCI device by turning off the last bit in the
 * ROM BAR.
 */
void pci_disable_rom(struct pci_dev *pdev)
{
	struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
	u32 rom_addr;

	if (res->flags & IORESOURCE_ROM_SHADOW)
		return;

	pci_read_config_dword(pdev, pdev->rom_base_reg, &rom_addr);
	rom_addr &= ~PCI_ROM_ADDRESS_ENABLE;
	pci_write_config_dword(pdev, pdev->rom_base_reg, rom_addr);
}
EXPORT_SYMBOL_GPL(pci_disable_rom);

/**
 * pci_get_rom_size - obtain the actual size of the ROM image
 * @pdev: target PCI device
 * @rom: kernel virtual pointer to image of ROM
 * @size: size of PCI window
 *  return: size of actual ROM image
 *
 * Determine the actual length of the ROM image.
 * The PCI window size could be much larger than the
 * actual image size.
 */
size_t pci_get_rom_size(struct pci_dev *pdev, void __iomem *rom, size_t size)
{
	void __iomem *image;
	int last_image;
	unsigned length;

	image = rom;
	do {
		void __iomem *pds;
		/* Standard PCI ROMs start out with these bytes 55 AA */
		if (readw(image) != 0xAA55) {
			dev_err(&pdev->dev, "Invalid PCI ROM header signature: expecting 0xaa55, got %#06x\n",
				readw(image));
			break;
		}
		/* get the PCI data structure and check its "PCIR" signature */
		pds = image + readw(image + 24);
		if (readl(pds) != 0x52494350) {
			dev_err(&pdev->dev, "Invalid PCI ROM data signature: expecting 0x52494350, got %#010x\n",
				readl(pds));
			break;
		}
		last_image = readb(pds + 21) & 0x80;
		length = readw(pds + 16);
		image += length * 512;
		/* Avoid iterating through memory outside the resource window */
		if (image > rom + size)
			break;
	} while (length && !last_image);

	/* never return a size larger than the PCI resource window */
	/* there are known ROMs that get the size wrong */
	return min((size_t)(image - rom), size);
}

/**
 * pci_map_rom - map a PCI ROM to kernel space
 * @pdev: pointer to pci device struct
 * @size: pointer to receive size of pci window over ROM
 *
 * Return: kernel virtual pointer to image of ROM
 *
 * Map a PCI ROM into kernel space. If ROM is boot video ROM,
 * the shadow BIOS copy will be returned instead of the
 * actual ROM.
 */
void __iomem *pci_map_rom(struct pci_dev *pdev, size_t *size)
{
	struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
	loff_t start;
	void __iomem *rom;

	if (res->flags & (IORESOURCE_ROM_COPY | IORESOURCE_ROM_BIOS_COPY)) {
		*size = pci_resource_len(pdev, PCI_ROM_RESOURCE);
		return (void __iomem *)(unsigned long)
			pci_resource_start(pdev, PCI_ROM_RESOURCE);
	}

	/* assign the ROM an address if it doesn't have one */
	if (res->parent == NULL && pci_assign_resource(pdev, PCI_ROM_RESOURCE))
		return NULL;

	start = pci_resource_start(pdev, PCI_ROM_RESOURCE);
	*size = pci_resource_len(pdev, PCI_ROM_RESOURCE);
	if (*size == 0)
		return NULL;

	/* Enable ROM space decodes */
	if (pci_enable_rom(pdev))
		return NULL;

	rom = ioremap(start, *size);
	if (!rom) {
		/* restore enable if ioremap fails */
		if (!(res->flags & (IORESOURCE_ROM_ENABLE |
				    IORESOURCE_ROM_COPY)))
			pci_disable_rom(pdev);
		return NULL;
	}

	/*
	 * Try to find the true size of the ROM since sometimes the PCI window
	 * size is much larger than the actual size of the ROM.
	 * True size is important if the ROM is going to be copied.
	 */
	*size = pci_get_rom_size(pdev, rom, *size);
	return rom;
}
EXPORT_SYMBOL(pci_map_rom);

/**
 * pci_unmap_rom - unmap the ROM from kernel space
 * @pdev: pointer to pci device struct
 * @rom: virtual address of the previous mapping
 *
 * Remove a mapping of a previously mapped ROM
 */
void pci_unmap_rom(struct pci_dev *pdev, void __iomem *rom)
{
	struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];

	if (res->flags & (IORESOURCE_ROM_COPY | IORESOURCE_ROM_BIOS_COPY))
		return;

	iounmap(rom);

	/* Disable again before continuing */
	if (!(res->flags & IORESOURCE_ROM_ENABLE))
		pci_disable_rom(pdev);
}
EXPORT_SYMBOL(pci_unmap_rom);

/**
 * pci_cleanup_rom - free the ROM copy created by pci_map_rom_copy
 * @pdev: pointer to pci device struct
 *
 * Free the copied ROM if we allocated one.
 */
void pci_cleanup_rom(struct pci_dev *pdev)
{
	struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];

	if (res->flags & IORESOURCE_ROM_COPY) {
		kfree((void *)(unsigned long)res->start);
		res->flags |= IORESOURCE_UNSET;
		res->flags &= ~IORESOURCE_ROM_COPY;
		res->start = 0;
		res->end = 0;
	}
}

/**
 * pci_platform_rom - provides a pointer to any ROM image provided by the
 * platform
 * @pdev: pointer to pci device struct
 * @size: pointer to receive size of pci window over ROM
 */
void __iomem *pci_platform_rom(struct pci_dev *pdev, size_t *size)
{
	if (pdev->rom && pdev->romlen) {
		*size = pdev->romlen;
		return phys_to_virt((phys_addr_t)pdev->rom);
	}

	return NULL;
}
EXPORT_SYMBOL(pci_platform_rom);
Commit	Line	Data
1da177e4 LT	1	/*
	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	*/
1da177e4	9	#include <linux/kernel.h>
363c75db	10	#include <linux/export.h>
1da177e4	11	#include <linux/pci.h>
4e57b681	12	#include <linux/slab.h>
1da177e4 LT	13
	14	#include "pci.h"
	15
	16	/**
	17	* pci_enable_rom - enable ROM decoding for a PCI device
67be2dd1	18	* @pdev: PCI device to enable
1da177e4 LT	19	*
	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.
	24	*/
e416de5e	25	int pci_enable_rom(struct pci_dev *pdev)
1da177e4	26	{
4708f9a5	27	struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
8085ce08	28	struct pci_bus_region region;
1da177e4 LT	29	u32 rom_addr;
1da177e4 LT	30
8085ce08 BH	31	if (!res->flags)
	32	return -1;
	33
4708f9a5 BH	34	/* Nothing to enable if we're using a shadow copy in RAM */
	35	if (res->flags & IORESOURCE_ROM_SHADOW)
	36	return 0;
	37
fc279850	38	pcibios_resource_to_bus(pdev->bus, &region, res);
1da177e4	39	pci_read_config_dword(pdev, pdev->rom_base_reg, &rom_addr);
8085ce08 BH	40	rom_addr &= ~PCI_ROM_ADDRESS_MASK;
8085ce08 BH	41	rom_addr \|= region.start \| PCI_ROM_ADDRESS_ENABLE;
1da177e4	42	pci_write_config_dword(pdev, pdev->rom_base_reg, rom_addr);
8085ce08	43	return 0;
1da177e4	44	}
b7fe9434	45	EXPORT_SYMBOL_GPL(pci_enable_rom);
1da177e4 LT	46
	47	/**
	48	* pci_disable_rom - disable ROM decoding for a PCI device
67be2dd1	49	* @pdev: PCI device to disable
1da177e4 LT	50	*
	51	* Disable ROM decoding on a PCI device by turning off the last bit in the
	52	* ROM BAR.
	53	*/
e416de5e	54	void pci_disable_rom(struct pci_dev *pdev)
1da177e4	55	{
4708f9a5	56	struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
1da177e4	57	u32 rom_addr;
4708f9a5 BH	58
	59	if (res->flags & IORESOURCE_ROM_SHADOW)
	60	return;
	61
1da177e4 LT	62	pci_read_config_dword(pdev, pdev->rom_base_reg, &rom_addr);
	63	rom_addr &= ~PCI_ROM_ADDRESS_ENABLE;
	64	pci_write_config_dword(pdev, pdev->rom_base_reg, rom_addr);
	65	}
b7fe9434	66	EXPORT_SYMBOL_GPL(pci_disable_rom);
1da177e4	67
d7ad2254 JK	68	/**
d7ad2254 JK	69	* pci_get_rom_size - obtain the actual size of the ROM image
4cc59c72	70	* @pdev: target PCI device
d7ad2254 JK	71	* @rom: kernel virtual pointer to image of ROM
	72	* @size: size of PCI window
	73	* return: size of actual ROM image
	74	*
	75	* Determine the actual length of the ROM image.
	76	* The PCI window size could be much larger than the
	77	* actual image size.
	78	*/
97c44836	79	size_t pci_get_rom_size(struct pci_dev pdev, void __iomem rom, size_t size)
d7ad2254 JK	80	{
	81	void __iomem *image;
	82	int last_image;
16b036af	83	unsigned length;
d7ad2254 JK	84
	85	image = rom;
	86	do {
	87	void __iomem *pds;
	88	/* Standard PCI ROMs start out with these bytes 55 AA */
4066df63 VD	89	if (readw(image) != 0xAA55) {
	90	dev_err(&pdev->dev, "Invalid PCI ROM header signature: expecting 0xaa55, got %#06x\n",
	91	readw(image));
d7ad2254	92	break;
97c44836	93	}
4066df63	94	/* get the PCI data structure and check its "PCIR" signature */
d7ad2254	95	pds = image + readw(image + 24);
4066df63 VD	96	if (readl(pds) != 0x52494350) {
	97	dev_err(&pdev->dev, "Invalid PCI ROM data signature: expecting 0x52494350, got %#010x\n",
	98	readl(pds));
d7ad2254	99	break;
4066df63	100	}
d7ad2254	101	last_image = readb(pds + 21) & 0x80;
16b036af MD	102	length = readw(pds + 16);
16b036af MD	103	image += length * 512;
47b975d2 EC	104	/* Avoid iterating through memory outside the resource window */
	105	if (image > rom + size)
	106	break;
16b036af	107	} while (length && !last_image);
d7ad2254 JK	108
	109	/* never return a size larger than the PCI resource window */
	110	/* there are known ROMs that get the size wrong */
	111	return min((size_t)(image - rom), size);
	112	}
	113
1da177e4 LT	114	/**
1da177e4 LT	115	* pci_map_rom - map a PCI ROM to kernel space
67be2dd1	116	* @pdev: pointer to pci device struct
1da177e4	117	* @size: pointer to receive size of pci window over ROM
f5dafca5 RD	118	*
f5dafca5 RD	119	* Return: kernel virtual pointer to image of ROM
1da177e4 LT	120	*
	121	* Map a PCI ROM into kernel space. If ROM is boot video ROM,
	122	* the shadow BIOS copy will be returned instead of the
	123	* actual ROM.
	124	*/
	125	void __iomem pci_map_rom(struct pci_dev pdev, size_t *size)
	126	{
	127	struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
fffe01f7	128	loff_t start;
1da177e4	129	void __iomem *rom;
1da177e4	130
f50dd8c3 BH	131	if (res->flags & (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);
	135	}
	136
	137	/* assign the ROM an address if it doesn't have one */
	138	if (res->parent == NULL && pci_assign_resource(pdev, PCI_ROM_RESOURCE))
	139	return NULL;
	140
	141	start = pci_resource_start(pdev, PCI_ROM_RESOURCE);
	142	*size = pci_resource_len(pdev, PCI_ROM_RESOURCE);
	143	if (*size == 0)
	144	return NULL;
	145
	146	/* Enable ROM space decodes */
	147	if (pci_enable_rom(pdev))
	148	return NULL;
547b5246	149
1da177e4 LT	150	rom = ioremap(start, *size);
	151	if (!rom) {
	152	/* restore enable if ioremap fails */
	153	if (!(res->flags & (IORESOURCE_ROM_ENABLE \|
1da177e4 LT	154	IORESOURCE_ROM_COPY)))
	155	pci_disable_rom(pdev);
	156	return NULL;
	157	}
	158
	159	/*
	160	* Try to find the true size of the ROM since sometimes the PCI window
	161	* size is much larger than the actual size of the ROM.
	162	* True size is important if the ROM is going to be copied.
	163	*/
97c44836	164	size = pci_get_rom_size(pdev, rom, size);
1da177e4 LT	165	return rom;
1da177e4 LT	166	}
b7fe9434	167	EXPORT_SYMBOL(pci_map_rom);
1da177e4	168
1da177e4 LT	169	/**
1da177e4 LT	170	* pci_unmap_rom - unmap the ROM from kernel space
67be2dd1	171	* @pdev: pointer to pci device struct
1da177e4 LT	172	* @rom: virtual address of the previous mapping
	173	*
	174	* Remove a mapping of a previously mapped ROM
	175	*/
	176	void pci_unmap_rom(struct pci_dev pdev, void __iomem rom)
	177	{
	178	struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
	179
a2302c68	180	if (res->flags & (IORESOURCE_ROM_COPY \| IORESOURCE_ROM_BIOS_COPY))
1da177e4 LT	181	return;
1da177e4 LT	182
fffe01f7	183	iounmap(rom);
1da177e4	184
4708f9a5 BH	185	/* Disable again before continuing */
4708f9a5 BH	186	if (!(res->flags & IORESOURCE_ROM_ENABLE))
1da177e4 LT	187	pci_disable_rom(pdev);
1da177e4 LT	188	}
b7fe9434	189	EXPORT_SYMBOL(pci_unmap_rom);
1da177e4	190
1da177e4	191	/**
0643245f	192	* pci_cleanup_rom - free the ROM copy created by pci_map_rom_copy
67be2dd1	193	* @pdev: pointer to pci device struct
1da177e4 LT	194	*
	195	* Free the copied ROM if we allocated one.
	196	*/
	197	void pci_cleanup_rom(struct pci_dev *pdev)
	198	{
	199	struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
bd064f0a	200
1da177e4	201	if (res->flags & IORESOURCE_ROM_COPY) {
3c78bc61	202	kfree((void *)(unsigned long)res->start);
bd064f0a	203	res->flags \|= IORESOURCE_UNSET;
1da177e4 LT	204	res->flags &= ~IORESOURCE_ROM_COPY;
	205	res->start = 0;
	206	res->end = 0;
	207	}
	208	}
	209
fffe01f7 MG	210	/**
	211	* pci_platform_rom - provides a pointer to any ROM image provided by the
	212	* platform
	213	* @pdev: pointer to pci device struct
	214	* @size: pointer to receive size of pci window over ROM
	215	*/
	216	void __iomem pci_platform_rom(struct pci_dev pdev, size_t *size)
	217	{
	218	if (pdev->rom && pdev->romlen) {
	219	*size = pdev->romlen;
	220	return phys_to_virt((phys_addr_t)pdev->rom);
	221	}
	222
	223	return NULL;
	224	}
fffe01f7	225	EXPORT_SYMBOL(pci_platform_rom);