linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 * PCI ROM access routines

 *

 * (C) Copyright 2004 Jon Smirl <jonsmirl@yahoo.com>

 * (C) Copyright 2004 Silicon Graphics, Inc. Jesse Barnes <jbarnes@sgi.com>

 */

#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;

​

    /* Nothing to enable if we're using a shadow copy in RAM */

    if (res->flags & IORESOURCE_ROM_SHADOW)

        return 0;

​

    /*

     * Ideally pci_update_resource() would update the ROM BAR address,

     * and we would only set the enable bit here.  But apparently some

     * devices have buggy ROM BARs that read as zero when disabled.

     */

    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;

}

EXPORT_SYMBOL_GPL(pci_enable_rom);

​

/**

 * 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)

{

    struct resource *res = &pdev->resource[PCI_ROM_RESOURCE];

    u32 rom_addr;

​

    if (res->flags & IORESOURCE_ROM_SHADOW)