270 lines
		
	
	
		
			7.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			270 lines
		
	
	
		
			7.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * drivers/pci/rom.c
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 *
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 * (C) Copyright 2004 Jon Smirl <jonsmirl@yahoo.com>
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 * (C) Copyright 2004 Silicon Graphics, Inc. Jesse Barnes <jbarnes@sgi.com>
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 *
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 * PCI ROM access routines
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 */
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#include <linux/kernel.h>
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#include <linux/pci.h>
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#include <linux/slab.h>
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#include "pci.h"
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/**
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 * pci_enable_rom - enable ROM decoding for a PCI device
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 * @pdev: PCI device to enable
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 *
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 * Enable ROM decoding on @dev.  This involves simply turning on the last
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 * bit of the PCI ROM BAR.  Note that some cards may share address decoders
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 * between the ROM and other resources, so enabling it may disable access
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 * to MMIO registers or other card memory.
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 */
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int pci_enable_rom(struct pci_dev *pdev)
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{
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	struct resource *res = pdev->resource + PCI_ROM_RESOURCE;
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	struct pci_bus_region region;
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	u32 rom_addr;
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	if (!res->flags)
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		return -1;
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	pcibios_resource_to_bus(pdev, ®ion, res);
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	pci_read_config_dword(pdev, pdev->rom_base_reg, &rom_addr);
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	rom_addr &= ~PCI_ROM_ADDRESS_MASK;
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	rom_addr |= region.start | PCI_ROM_ADDRESS_ENABLE;
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	pci_write_config_dword(pdev, pdev->rom_base_reg, rom_addr);
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	return 0;
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}
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/**
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 * pci_disable_rom - disable ROM decoding for a PCI device
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 * @pdev: PCI device to disable
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 *
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 * Disable ROM decoding on a PCI device by turning off the last bit in the
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 * ROM BAR.
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 */
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void pci_disable_rom(struct pci_dev *pdev)
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{
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	u32 rom_addr;
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	pci_read_config_dword(pdev, pdev->rom_base_reg, &rom_addr);
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	rom_addr &= ~PCI_ROM_ADDRESS_ENABLE;
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	pci_write_config_dword(pdev, pdev->rom_base_reg, rom_addr);
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}
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/**
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 * pci_get_rom_size - obtain the actual size of the ROM image
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 * @pdev: target PCI device
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 * @rom: kernel virtual pointer to image of ROM
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 * @size: size of PCI window
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 *  return: size of actual ROM image
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 *
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 * Determine the actual length of the ROM image.
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 * The PCI window size could be much larger than the
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 * actual image size.
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 */
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size_t pci_get_rom_size(struct pci_dev *pdev, void __iomem *rom, size_t size)
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{
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	void __iomem *image;
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	int last_image;
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	image = rom;
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	do {
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		void __iomem *pds;
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		/* Standard PCI ROMs start out with these bytes 55 AA */
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		if (readb(image) != 0x55) {
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			dev_err(&pdev->dev, "Invalid ROM contents\n");
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			break;
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		}
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		if (readb(image + 1) != 0xAA)
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			break;
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		/* get the PCI data structure and check its signature */
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		pds = image + readw(image + 24);
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		if (readb(pds) != 'P')
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			break;
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		if (readb(pds + 1) != 'C')
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			break;
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		if (readb(pds + 2) != 'I')
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			break;
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		if (readb(pds + 3) != 'R')
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			break;
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		last_image = readb(pds + 21) & 0x80;
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		/* this length is reliable */
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		image += readw(pds + 16) * 512;
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	} while (!last_image);
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	/* never return a size larger than the PCI resource window */
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	/* there are known ROMs that get the size wrong */
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	return min((size_t)(image - rom), size);
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}
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/**
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 * pci_map_rom - map a PCI ROM to kernel space
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 * @pdev: pointer to pci device struct
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 * @size: pointer to receive size of pci window over ROM
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 *
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 * Return: kernel virtual pointer to image of ROM
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 *
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 * Map a PCI ROM into kernel space. If ROM is boot video ROM,
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 * the shadow BIOS copy will be returned instead of the
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 * actual ROM.
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 */
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void __iomem *pci_map_rom(struct pci_dev *pdev, size_t *size)
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{
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	struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
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	loff_t start;
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	void __iomem *rom;
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	/*
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	 * IORESOURCE_ROM_SHADOW set on x86, x86_64 and IA64 supports legacy
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	 * memory map if the VGA enable bit of the Bridge Control register is
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	 * set for embedded VGA.
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	 */
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	if (res->flags & IORESOURCE_ROM_SHADOW) {
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		/* primary video rom always starts here */
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		start = (loff_t)0xC0000;
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		*size = 0x20000; /* cover C000:0 through E000:0 */
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	} else {
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		if (res->flags &
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			(IORESOURCE_ROM_COPY | IORESOURCE_ROM_BIOS_COPY)) {
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			*size = pci_resource_len(pdev, PCI_ROM_RESOURCE);
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			return (void __iomem *)(unsigned long)
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				pci_resource_start(pdev, PCI_ROM_RESOURCE);
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		} else {
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			/* assign the ROM an address if it doesn't have one */
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			if (res->parent == NULL &&
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			    pci_assign_resource(pdev,PCI_ROM_RESOURCE))
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				return NULL;
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			start = pci_resource_start(pdev, PCI_ROM_RESOURCE);
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			*size = pci_resource_len(pdev, PCI_ROM_RESOURCE);
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			if (*size == 0)
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				return NULL;
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			/* Enable ROM space decodes */
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			if (pci_enable_rom(pdev))
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				return NULL;
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		}
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	}
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	rom = ioremap(start, *size);
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	if (!rom) {
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		/* restore enable if ioremap fails */
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		if (!(res->flags & (IORESOURCE_ROM_ENABLE |
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				    IORESOURCE_ROM_SHADOW |
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				    IORESOURCE_ROM_COPY)))
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			pci_disable_rom(pdev);
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		return NULL;
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	}
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	/*
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	 * Try to find the true size of the ROM since sometimes the PCI window
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	 * size is much larger than the actual size of the ROM.
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	 * True size is important if the ROM is going to be copied.
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	 */
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	*size = pci_get_rom_size(pdev, rom, *size);
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	return rom;
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}
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#if 0
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/**
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 * pci_map_rom_copy - map a PCI ROM to kernel space, create a copy
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 * @pdev: pointer to pci device struct
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 * @size: pointer to receive size of pci window over ROM
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 *
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 * Return: kernel virtual pointer to image of ROM
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 *
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 * Map a PCI ROM into kernel space. If ROM is boot video ROM,
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 * the shadow BIOS copy will be returned instead of the
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 * actual ROM.
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 */
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void __iomem *pci_map_rom_copy(struct pci_dev *pdev, size_t *size)
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{
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	struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
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	void __iomem *rom;
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	rom = pci_map_rom(pdev, size);
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	if (!rom)
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		return NULL;
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	if (res->flags & (IORESOURCE_ROM_COPY | IORESOURCE_ROM_SHADOW |
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			  IORESOURCE_ROM_BIOS_COPY))
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		return rom;
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	res->start = (unsigned long)kmalloc(*size, GFP_KERNEL);
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	if (!res->start)
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		return rom;
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	res->end = res->start + *size;
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	memcpy_fromio((void*)(unsigned long)res->start, rom, *size);
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	pci_unmap_rom(pdev, rom);
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	res->flags |= IORESOURCE_ROM_COPY;
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	return (void __iomem *)(unsigned long)res->start;
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}
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#endif  /*  0  */
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/**
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 * pci_unmap_rom - unmap the ROM from kernel space
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 * @pdev: pointer to pci device struct
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 * @rom: virtual address of the previous mapping
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 *
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 * Remove a mapping of a previously mapped ROM
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 */
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void pci_unmap_rom(struct pci_dev *pdev, void __iomem *rom)
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{
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	struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
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	if (res->flags & (IORESOURCE_ROM_COPY | IORESOURCE_ROM_BIOS_COPY))
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		return;
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	iounmap(rom);
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	/* Disable again before continuing, leave enabled if pci=rom */
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	if (!(res->flags & (IORESOURCE_ROM_ENABLE | IORESOURCE_ROM_SHADOW)))
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		pci_disable_rom(pdev);
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}
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#if 0
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/**
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 * pci_remove_rom - disable the ROM and remove its sysfs attribute
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 * @pdev: pointer to pci device struct
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 *
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 * Remove the rom file in sysfs and disable ROM decoding.
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 */
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void pci_remove_rom(struct pci_dev *pdev)
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{
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	struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
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	if (pci_resource_len(pdev, PCI_ROM_RESOURCE))
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		sysfs_remove_bin_file(&pdev->dev.kobj, pdev->rom_attr);
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	if (!(res->flags & (IORESOURCE_ROM_ENABLE |
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			    IORESOURCE_ROM_SHADOW |
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			    IORESOURCE_ROM_BIOS_COPY |
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			    IORESOURCE_ROM_COPY)))
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		pci_disable_rom(pdev);
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}
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#endif  /*  0  */
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/**
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 * pci_cleanup_rom - free the ROM copy created by pci_map_rom_copy
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 * @pdev: pointer to pci device struct
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 *
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 * Free the copied ROM if we allocated one.
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 */
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void pci_cleanup_rom(struct pci_dev *pdev)
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{
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	struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];
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	if (res->flags & IORESOURCE_ROM_COPY) {
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		kfree((void*)(unsigned long)res->start);
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		res->flags &= ~IORESOURCE_ROM_COPY;
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		res->start = 0;
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		res->end = 0;
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	}
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}
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EXPORT_SYMBOL(pci_map_rom);
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EXPORT_SYMBOL(pci_unmap_rom);
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EXPORT_SYMBOL_GPL(pci_enable_rom);
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EXPORT_SYMBOL_GPL(pci_disable_rom);
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