drivers/pci/rom.c - maze/linux - Git at Google

 /*
  * 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;

 	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;
 }

 /**
  * 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
  * @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;

 	image = rom;
 	do {
 		void __iomem *pds;
 		/* Standard PCI ROMs start out with these bytes 55 AA */
 		if (readb(image) != 0x55) {
 			dev_err(&pdev->dev, "Invalid ROM contents\n");
 			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(pdev, rom, *size);
 	return 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, leave enabled if pci=rom */
 	if (!(res->flags & (IORESOURCE_ROM_ENABLE | IORESOURCE_ROM_SHADOW)))
 		pci_disable_rom(pdev);
 }

 /**
  * 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_map_rom);
 EXPORT_SYMBOL(pci_unmap_rom);
 EXPORT_SYMBOL_GPL(pci_enable_rom);
 EXPORT_SYMBOL_GPL(pci_disable_rom);
 EXPORT_SYMBOL(pci_platform_rom);
	/*
	* 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;

	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;
	}

	/**
	* 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
	* @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;

	image = rom;
	do {
	void __iomem *pds;
	/* Standard PCI ROMs start out with these bytes 55 AA */
	if (readb(image) != 0x55) {
	dev_err(&pdev->dev, "Invalid ROM contents\n");
	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(pdev, rom, size);
	return 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, leave enabled if pci=rom */
	if (!(res->flags & (IORESOURCE_ROM_ENABLE \| IORESOURCE_ROM_SHADOW)))
	pci_disable_rom(pdev);
	}

	/**
	* 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_map_rom);
	EXPORT_SYMBOL(pci_unmap_rom);
	EXPORT_SYMBOL_GPL(pci_enable_rom);
	EXPORT_SYMBOL_GPL(pci_disable_rom);
	EXPORT_SYMBOL(pci_platform_rom);