[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_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;
	void __iomem *image;
	int last_image;

	/*
	 * IORESOURCE_ROM_SHADOW set 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) {
			*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.
	 */
	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 */
	*size = min((size_t)(image - rom), *size);

	return rom;
}

/**
 * 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))
		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;
}

/**
 * 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)
		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);
}

/**
 * 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_COPY)))
		pci_disable_rom(pdev);
}

/**
 * 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_map_rom_copy);
EXPORT_SYMBOL(pci_unmap_rom);
EXPORT_SYMBOL(pci_remove_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
	56	/**
	57	* pci_map_rom - map a PCI ROM to kernel space
67be2dd1	58	* @pdev: pointer to pci device struct
1da177e4 LT	59	* @size: pointer to receive size of pci window over ROM
	60	* @return: kernel virtual pointer to image of ROM
	61	*
	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
	64	* actual ROM.
	65	*/
	66	void __iomem pci_map_rom(struct pci_dev pdev, size_t *size)
	67	{
	68	struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
	69	loff_t start;
	70	void __iomem *rom;
	71	void __iomem *image;
	72	int last_image;
	73
b5e4efe7	74	/*
	75	* IORESOURCE_ROM_SHADOW set if the VGA enable bit of the Bridge Control
	76	* register is set for embedded VGA.
	77	*/
1da177e4 LT	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 */
	82	} else {
	83	if (res->flags & IORESOURCE_ROM_COPY) {
	84	*size = pci_resource_len(pdev, PCI_ROM_RESOURCE);
e31dd6e4 GKH	85	return (void __iomem *)(unsigned long)
e31dd6e4 GKH	86	pci_resource_start(pdev, PCI_ROM_RESOURCE);
1da177e4 LT	87	} else {
1da177e4 LT	88	/* assign the ROM an address if it doesn't have one */
8085ce08 BH	89	if (res->parent == NULL &&
	90	pci_assign_resource(pdev,PCI_ROM_RESOURCE))
	91	return NULL;
1da177e4 LT	92	start = pci_resource_start(pdev, PCI_ROM_RESOURCE);
	93	*size = pci_resource_len(pdev, PCI_ROM_RESOURCE);
	94	if (*size == 0)
	95	return NULL;
	96
	97	/* Enable ROM space decodes */
8085ce08 BH	98	if (pci_enable_rom(pdev))
8085ce08 BH	99	return NULL;
1da177e4 LT	100	}
	101	}
	102
	103	rom = ioremap(start, *size);
	104	if (!rom) {
	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);
	110	return NULL;
	111	}
	112
	113	/*
	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.
	117	*/
	118	image = rom;
	119	do {
	120	void __iomem *pds;
	121	/* Standard PCI ROMs start out with these bytes 55 AA */
	122	if (readb(image) != 0x55)
	123	break;
	124	if (readb(image + 1) != 0xAA)
	125	break;
	126	/* get the PCI data structure and check its signature */
	127	pds = image + readw(image + 24);
	128	if (readb(pds) != 'P')
	129	break;
	130	if (readb(pds + 1) != 'C')
	131	break;
	132	if (readb(pds + 2) != 'I')
	133	break;
	134	if (readb(pds + 3) != 'R')
	135	break;
	136	last_image = readb(pds + 21) & 0x80;
	137	/* this length is reliable */
	138	image += readw(pds + 16) * 512;
	139	} while (!last_image);
	140
761a3ac0 JS	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);
1da177e4 LT	144
	145	return rom;
	146	}
	147
	148	/**
	149	* pci_map_rom_copy - map a PCI ROM to kernel space, create a copy
67be2dd1	150	* @pdev: pointer to pci device struct
1da177e4 LT	151	* @size: pointer to receive size of pci window over ROM
	152	* @return: kernel virtual pointer to image of ROM
	153	*
	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
	156	* actual ROM.
	157	*/
	158	void __iomem pci_map_rom_copy(struct pci_dev pdev, size_t *size)
	159	{
	160	struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
	161	void __iomem *rom;
	162
	163	rom = pci_map_rom(pdev, size);
	164	if (!rom)
	165	return NULL;
	166
	167	if (res->flags & (IORESOURCE_ROM_COPY \| IORESOURCE_ROM_SHADOW))
	168	return rom;
	169
	170	res->start = (unsigned long)kmalloc(*size, GFP_KERNEL);
	171	if (!res->start)
	172	return rom;
	173
	174	res->end = res->start + *size;
e31dd6e4	175	memcpy_fromio((void)(unsigned long)res->start, rom, size);
1da177e4 LT	176	pci_unmap_rom(pdev, rom);
	177	res->flags \|= IORESOURCE_ROM_COPY;
	178
e31dd6e4	179	return (void __iomem *)(unsigned long)res->start;
1da177e4 LT	180	}
	181
	182	/**
	183	* pci_unmap_rom - unmap the ROM from kernel space
67be2dd1	184	* @pdev: pointer to pci device struct
1da177e4 LT	185	* @rom: virtual address of the previous mapping
	186	*
	187	* Remove a mapping of a previously mapped ROM
	188	*/
	189	void pci_unmap_rom(struct pci_dev pdev, void __iomem rom)
	190	{
	191	struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
	192
	193	if (res->flags & IORESOURCE_ROM_COPY)
	194	return;
	195
	196	iounmap(rom);
	197
	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);
	201	}
	202
	203	/**
	204	* pci_remove_rom - disable the ROM and remove its sysfs attribute
67be2dd1	205	* @pdev: pointer to pci device struct
1da177e4 LT	206	*
	207	* Remove the rom file in sysfs and disable ROM decoding.
	208	*/
	209	void pci_remove_rom(struct pci_dev *pdev)
	210	{
	211	struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
	212
	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);
	219	}
	220
	221	/**
	222	* pci_cleanup_rom - internal routine for freeing the ROM copy created
	223	* by pci_map_rom_copy called from remove.c
67be2dd1	224	* @pdev: pointer to pci device struct
1da177e4 LT	225	*
	226	* Free the copied ROM if we allocated one.
	227	*/
	228	void pci_cleanup_rom(struct pci_dev *pdev)
	229	{
	230	struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
	231	if (res->flags & IORESOURCE_ROM_COPY) {
e31dd6e4	232	kfree((void*)(unsigned long)res->start);
1da177e4 LT	233	res->flags &= ~IORESOURCE_ROM_COPY;
	234	res->start = 0;
	235	res->end = 0;
	236	}
	237	}
	238
	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);