[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/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;

	pcibios_resource_to_bus(pdev, &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;
}

/**
 * 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)
{
	u32 rom_addr;
	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);
}

/**
 * pci_get_rom_size - obtain the actual size of the ROM image
 * @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(void __iomem *rom, size_t size)
{
	void __iomem *image;
	int last_image;

	image = rom;
	do {
		void __iomem *pds;
		/* Standard PCI ROMs start out with these bytes 55 AA */
		if (readb(image) != 0x55)
			break;
		if (readb(image + 1) != 0xAA)
			break;
		/* get the PCI data structure and check its signature */
		pds = image + readw(image + 24);
		if (readb(pds) != 'P')
			break;
		if (readb(pds + 1) != 'C')
			break;
		if (readb(pds + 2) != 'I')
			break;
		if (readb(pds + 3) != 'R')
			break;
		last_image = readb(pds + 21) & 0x80;
		/* this length is reliable */
		image += readw(pds + 16) * 512;
	} while (!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;

	/*
	 * IORESOURCE_ROM_SHADOW set on x86, x86_64 and IA64 supports legacy
	 * memory map if the VGA enable bit of the Bridge Control register is
	 * set for embedded VGA.
	 */
	if (res->flags & IORESOURCE_ROM_SHADOW) {
		/* primary video rom always starts here */
		start = (loff_t)0xC0000;
		*size = 0x20000; /* cover C000:0 through E000:0 */
	} else {
		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);
		} else {
			/* 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_SHADOW |
				    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(rom, *size);
	return rom;
}

#if 0
/**
 * pci_map_rom_copy - map a PCI ROM to kernel space, create a copy
 * @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_copy(struct pci_dev *pdev, size_t *size)
{
	struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
	void __iomem *rom;

	rom = pci_map_rom(pdev, size);
	if (!rom)
		return NULL;

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

	res->start = (unsigned long)kmalloc(*size, GFP_KERNEL);
	if (!res->start)
		return rom;

	res->end = res->start + *size;
	memcpy_fromio((void*)(unsigned long)res->start, rom, *size);
	pci_unmap_rom(pdev, rom);
	res->flags |= IORESOURCE_ROM_COPY;

	return (void __iomem *)(unsigned long)res->start;
}
#endif  /*  0  */

/**
 * 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, leave enabled if pci=rom */
	if (!(res->flags & (IORESOURCE_ROM_ENABLE | IORESOURCE_ROM_SHADOW)))
		pci_disable_rom(pdev);
}

#if 0
/**
 * pci_remove_rom - disable the ROM and remove its sysfs attribute
 * @pdev: pointer to pci device struct
 *
 * Remove the rom file in sysfs and disable ROM decoding.
 */
void pci_remove_rom(struct pci_dev *pdev)
{
	struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];

	if (pci_resource_len(pdev, PCI_ROM_RESOURCE))
		sysfs_remove_bin_file(&pdev->dev.kobj, pdev->rom_attr);
	if (!(res->flags & (IORESOURCE_ROM_ENABLE |
			    IORESOURCE_ROM_SHADOW |
			    IORESOURCE_ROM_BIOS_COPY |
			    IORESOURCE_ROM_COPY)))
		pci_disable_rom(pdev);
}
#endif  /*  0  */

/**
 * 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_ROM_COPY;
		res->start = 0;
		res->end = 0;
	}
}

EXPORT_SYMBOL(pci_map_rom);
EXPORT_SYMBOL(pci_unmap_rom);
EXPORT_SYMBOL_GPL(pci_enable_rom);
EXPORT_SYMBOL_GPL(pci_disable_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 LT	9	#include <linux/kernel.h>
1da177e4 LT	10	#include <linux/pci.h>
4e57b681	11	#include <linux/slab.h>
1da177e4 LT	12
	13	#include "pci.h"
	14
	15	/**
	16	* pci_enable_rom - enable ROM decoding for a PCI device
67be2dd1	17	* @pdev: PCI device to enable
1da177e4 LT	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	*/
e416de5e	24	int pci_enable_rom(struct pci_dev *pdev)
1da177e4	25	{
8085ce08 BH	26	struct resource *res = pdev->resource + PCI_ROM_RESOURCE;
8085ce08 BH	27	struct pci_bus_region region;
1da177e4 LT	28	u32 rom_addr;
1da177e4 LT	29
8085ce08 BH	30	if (!res->flags)
	31	return -1;
	32
	33	pcibios_resource_to_bus(pdev, &region, res);
1da177e4	34	pci_read_config_dword(pdev, pdev->rom_base_reg, &rom_addr);
8085ce08 BH	35	rom_addr &= ~PCI_ROM_ADDRESS_MASK;
8085ce08 BH	36	rom_addr \|= region.start \| PCI_ROM_ADDRESS_ENABLE;
1da177e4	37	pci_write_config_dword(pdev, pdev->rom_base_reg, rom_addr);
8085ce08	38	return 0;
1da177e4 LT	39	}
	40
	41	/**
	42	* pci_disable_rom - disable ROM decoding for a PCI device
67be2dd1	43	* @pdev: PCI device to disable
1da177e4 LT	44	*
	45	* Disable ROM decoding on a PCI device by turning off the last bit in the
	46	* ROM BAR.
	47	*/
e416de5e	48	void pci_disable_rom(struct pci_dev *pdev)
1da177e4 LT	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
d7ad2254 JK	56	/**
	57	* 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	*/
	66	size_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
1da177e4 LT	99	/**
1da177e4 LT	100	* pci_map_rom - map a PCI ROM to kernel space
67be2dd1	101	* @pdev: pointer to pci device struct
1da177e4	102	* @size: pointer to receive size of pci window over ROM
f5dafca5 RD	103	*
f5dafca5 RD	104	* Return: kernel virtual pointer to image of ROM
1da177e4 LT	105	*
	106	* Map a PCI ROM into kernel space. If ROM is boot video ROM,
	107	* the shadow BIOS copy will be returned instead of the
	108	* actual ROM.
	109	*/
	110	void __iomem pci_map_rom(struct pci_dev pdev, size_t *size)
	111	{
	112	struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
	113	loff_t start;
	114	void __iomem *rom;
1da177e4	115
b5e4efe7	116	/*
6b5c76b8 EO	117	* IORESOURCE_ROM_SHADOW set on x86, x86_64 and IA64 supports legacy
	118	* memory map if the VGA enable bit of the Bridge Control register is
	119	* set for embedded VGA.
b5e4efe7	120	*/
1da177e4 LT	121	if (res->flags & IORESOURCE_ROM_SHADOW) {
	122	/* primary video rom always starts here */
	123	start = (loff_t)0xC0000;
	124	size = 0x20000; / cover C000:0 through E000:0 */
	125	} else {
a2302c68 JK	126	if (res->flags &
a2302c68 JK	127	(IORESOURCE_ROM_COPY \| IORESOURCE_ROM_BIOS_COPY)) {
1da177e4	128	*size = pci_resource_len(pdev, PCI_ROM_RESOURCE);
e31dd6e4 GKH	129	return (void __iomem *)(unsigned long)
e31dd6e4 GKH	130	pci_resource_start(pdev, PCI_ROM_RESOURCE);
1da177e4 LT	131	} else {
1da177e4 LT	132	/* assign the ROM an address if it doesn't have one */
8085ce08 BH	133	if (res->parent == NULL &&
	134	pci_assign_resource(pdev,PCI_ROM_RESOURCE))
	135	return NULL;
1da177e4 LT	136	start = pci_resource_start(pdev, PCI_ROM_RESOURCE);
	137	*size = pci_resource_len(pdev, PCI_ROM_RESOURCE);
	138	if (*size == 0)
	139	return NULL;
	140
	141	/* Enable ROM space decodes */
8085ce08 BH	142	if (pci_enable_rom(pdev))
8085ce08 BH	143	return NULL;
1da177e4 LT	144	}
	145	}
	146
	147	rom = ioremap(start, *size);
	148	if (!rom) {
	149	/* restore enable if ioremap fails */
	150	if (!(res->flags & (IORESOURCE_ROM_ENABLE \|
	151	IORESOURCE_ROM_SHADOW \|
	152	IORESOURCE_ROM_COPY)))
	153	pci_disable_rom(pdev);
	154	return NULL;
	155	}
	156
	157	/*
	158	* Try to find the true size of the ROM since sometimes the PCI window
	159	* size is much larger than the actual size of the ROM.
	160	* True size is important if the ROM is going to be copied.
	161	*/
d7ad2254	162	size = pci_get_rom_size(rom, size);
1da177e4 LT	163	return rom;
	164	}
	165
b09549ef	166	#if 0
1da177e4 LT	167	/**
1da177e4 LT	168	* pci_map_rom_copy - map a PCI ROM to kernel space, create a copy
67be2dd1	169	* @pdev: pointer to pci device struct
1da177e4	170	* @size: pointer to receive size of pci window over ROM
f5dafca5 RD	171	*
f5dafca5 RD	172	* Return: kernel virtual pointer to image of ROM
1da177e4 LT	173	*
	174	* Map a PCI ROM into kernel space. If ROM is boot video ROM,
	175	* the shadow BIOS copy will be returned instead of the
	176	* actual ROM.
	177	*/
	178	void __iomem pci_map_rom_copy(struct pci_dev pdev, size_t *size)
	179	{
	180	struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
	181	void __iomem *rom;
	182
	183	rom = pci_map_rom(pdev, size);
	184	if (!rom)
	185	return NULL;
	186
a2302c68 JK	187	if (res->flags & (IORESOURCE_ROM_COPY \| IORESOURCE_ROM_SHADOW \|
a2302c68 JK	188	IORESOURCE_ROM_BIOS_COPY))
1da177e4 LT	189	return rom;
	190
	191	res->start = (unsigned long)kmalloc(*size, GFP_KERNEL);
	192	if (!res->start)
	193	return rom;
	194
	195	res->end = res->start + *size;
e31dd6e4	196	memcpy_fromio((void)(unsigned long)res->start, rom, size);
1da177e4 LT	197	pci_unmap_rom(pdev, rom);
	198	res->flags \|= IORESOURCE_ROM_COPY;
	199
e31dd6e4	200	return (void __iomem *)(unsigned long)res->start;
1da177e4	201	}
b09549ef	202	#endif /* 0 */
1da177e4 LT	203
	204	/**
	205	* pci_unmap_rom - unmap the ROM from kernel space
67be2dd1	206	* @pdev: pointer to pci device struct
1da177e4 LT	207	* @rom: virtual address of the previous mapping
	208	*
	209	* Remove a mapping of a previously mapped ROM
	210	*/
	211	void pci_unmap_rom(struct pci_dev pdev, void __iomem rom)
	212	{
	213	struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
	214
a2302c68	215	if (res->flags & (IORESOURCE_ROM_COPY \| IORESOURCE_ROM_BIOS_COPY))
1da177e4 LT	216	return;
	217
	218	iounmap(rom);
	219
	220	/* Disable again before continuing, leave enabled if pci=rom */
	221	if (!(res->flags & (IORESOURCE_ROM_ENABLE \| IORESOURCE_ROM_SHADOW)))
	222	pci_disable_rom(pdev);
	223	}
	224
b09549ef	225	#if 0
1da177e4 LT	226	/**
1da177e4 LT	227	* pci_remove_rom - disable the ROM and remove its sysfs attribute
67be2dd1	228	* @pdev: pointer to pci device struct
1da177e4 LT	229	*
	230	* Remove the rom file in sysfs and disable ROM decoding.
	231	*/
	232	void pci_remove_rom(struct pci_dev *pdev)
	233	{
	234	struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
	235
	236	if (pci_resource_len(pdev, PCI_ROM_RESOURCE))
	237	sysfs_remove_bin_file(&pdev->dev.kobj, pdev->rom_attr);
	238	if (!(res->flags & (IORESOURCE_ROM_ENABLE \|
	239	IORESOURCE_ROM_SHADOW \|
a2302c68	240	IORESOURCE_ROM_BIOS_COPY \|
1da177e4 LT	241	IORESOURCE_ROM_COPY)))
	242	pci_disable_rom(pdev);
	243	}
b09549ef	244	#endif /* 0 */
1da177e4 LT	245
1da177e4 LT	246	/**
0643245f	247	* pci_cleanup_rom - free the ROM copy created by pci_map_rom_copy
67be2dd1	248	* @pdev: pointer to pci device struct
1da177e4 LT	249	*
	250	* Free the copied ROM if we allocated one.
	251	*/
	252	void pci_cleanup_rom(struct pci_dev *pdev)
	253	{
	254	struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
	255	if (res->flags & IORESOURCE_ROM_COPY) {
e31dd6e4	256	kfree((void*)(unsigned long)res->start);
1da177e4 LT	257	res->flags &= ~IORESOURCE_ROM_COPY;
	258	res->start = 0;
	259	res->end = 0;
	260	}
	261	}
	262
	263	EXPORT_SYMBOL(pci_map_rom);
1da177e4	264	EXPORT_SYMBOL(pci_unmap_rom);
e416de5e AC	265	EXPORT_SYMBOL_GPL(pci_enable_rom);
e416de5e AC	266	EXPORT_SYMBOL_GPL(pci_disable_rom);