[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.
 */
static 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.
 */
static 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 - internal routine for freeing the ROM copy created
 * by pci_map_rom_copy called from remove.c
 * @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);
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	*/
8085ce08	24	static 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	*/
	48	static 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
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 LT	102	* @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	*/
	109	void __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;
1da177e4	114
b5e4efe7	115	/*
6b5c76b8 EO	116	* 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.
b5e4efe7	119	*/
1da177e4 LT	120	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 {
a2302c68 JK	125	if (res->flags &
a2302c68 JK	126	(IORESOURCE_ROM_COPY \| IORESOURCE_ROM_BIOS_COPY)) {
1da177e4	127	*size = pci_resource_len(pdev, PCI_ROM_RESOURCE);
e31dd6e4 GKH	128	return (void __iomem *)(unsigned long)
e31dd6e4 GKH	129	pci_resource_start(pdev, PCI_ROM_RESOURCE);
1da177e4 LT	130	} else {
1da177e4 LT	131	/* assign the ROM an address if it doesn't have one */
8085ce08 BH	132	if (res->parent == NULL &&
	133	pci_assign_resource(pdev,PCI_ROM_RESOURCE))
	134	return NULL;
1da177e4 LT	135	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 */
8085ce08 BH	141	if (pci_enable_rom(pdev))
8085ce08 BH	142	return NULL;
1da177e4 LT	143	}
	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	*/
d7ad2254	161	size = pci_get_rom_size(rom, size);
1da177e4 LT	162	return rom;
	163	}
	164
b09549ef	165	#if 0
1da177e4 LT	166	/**
1da177e4 LT	167	* pci_map_rom_copy - map a PCI ROM to kernel space, create a copy
67be2dd1	168	* @pdev: pointer to pci device struct
1da177e4 LT	169	* @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	*/
	176	void __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
a2302c68 JK	185	if (res->flags & (IORESOURCE_ROM_COPY \| IORESOURCE_ROM_SHADOW \|
a2302c68 JK	186	IORESOURCE_ROM_BIOS_COPY))
1da177e4 LT	187	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;
e31dd6e4	194	memcpy_fromio((void)(unsigned long)res->start, rom, size);
1da177e4 LT	195	pci_unmap_rom(pdev, rom);
	196	res->flags \|= IORESOURCE_ROM_COPY;
	197
e31dd6e4	198	return (void __iomem *)(unsigned long)res->start;
1da177e4	199	}
b09549ef	200	#endif /* 0 */
1da177e4 LT	201
	202	/**
	203	* pci_unmap_rom - unmap the ROM from kernel space
67be2dd1	204	* @pdev: pointer to pci device struct
1da177e4 LT	205	* @rom: virtual address of the previous mapping
	206	*
	207	* Remove a mapping of a previously mapped ROM
	208	*/
	209	void pci_unmap_rom(struct pci_dev pdev, void __iomem rom)
	210	{
	211	struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
	212
a2302c68	213	if (res->flags & (IORESOURCE_ROM_COPY \| IORESOURCE_ROM_BIOS_COPY))
1da177e4 LT	214	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
b09549ef	223	#if 0
1da177e4 LT	224	/**
1da177e4 LT	225	* pci_remove_rom - disable the ROM and remove its sysfs attribute
67be2dd1	226	* @pdev: pointer to pci device struct
1da177e4 LT	227	*
	228	* Remove the rom file in sysfs and disable ROM decoding.
	229	*/
	230	void 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 \|
a2302c68	238	IORESOURCE_ROM_BIOS_COPY \|
1da177e4 LT	239	IORESOURCE_ROM_COPY)))
	240	pci_disable_rom(pdev);
	241	}
b09549ef	242	#endif /* 0 */
1da177e4 LT	243
	244	/**
	245	* pci_cleanup_rom - internal routine for freeing the ROM copy created
	246	* by pci_map_rom_copy called from remove.c
67be2dd1	247	* @pdev: pointer to pci device struct
1da177e4 LT	248	*
	249	* Free the copied ROM if we allocated one.
	250	*/
	251	void pci_cleanup_rom(struct pci_dev *pdev)
	252	{
	253	struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
	254	if (res->flags & IORESOURCE_ROM_COPY) {
e31dd6e4	255	kfree((void*)(unsigned long)res->start);
1da177e4 LT	256	res->flags &= ~IORESOURCE_ROM_COPY;
	257	res->start = 0;
	258	res->end = 0;
	259	}
	260	}
	261
	262	EXPORT_SYMBOL(pci_map_rom);
1da177e4	263	EXPORT_SYMBOL(pci_unmap_rom);