linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 * Generic PCI resource mmap helper

 *

 * Copyright © 2017 Amazon.com, Inc. or its affiliates.

 *

 * Author: David Woodhouse <dwmw2@infradead.org>

 */

​

#include <linux/kernel.h>

#include <linux/mm.h>

#include <linux/pci.h>

​

#ifdef ARCH_GENERIC_PCI_MMAP_RESOURCE

​

/*

 * Modern setup: generic pci_mmap_resource_range(), and implement the legacy

 * pci_mmap_page_range() (if needed) as a wrapper round it.

 */

​

#ifdef HAVE_PCI_MMAP

int pci_mmap_page_range(struct pci_dev *pdev, int bar,

            struct vm_area_struct *vma,

            enum pci_mmap_state mmap_state, int write_combine)

{

    resource_size_t start, end;

​

    pci_resource_to_user(pdev, bar, &pdev->resource[bar], &start, &end);

​

    /* Adjust vm_pgoff to be the offset within the resource */

    vma->vm_pgoff -= start >> PAGE_SHIFT;

    return pci_mmap_resource_range(pdev, bar, vma, mmap_state,

                       write_combine);

}

#endif

​

static const struct vm_operations_struct pci_phys_vm_ops = {

#ifdef CONFIG_HAVE_IOREMAP_PROT

    .access = generic_access_phys,

#endif

};

​

int pci_mmap_resource_range(struct pci_dev *pdev, int bar,

                struct vm_area_struct *vma,

                enum pci_mmap_state mmap_state, int write_combine)

{

    unsigned long size;

    int ret;

​

    size = ((pci_resource_len(pdev, bar) - 1) >> PAGE_SHIFT) + 1;

    if (vma->vm_pgoff + vma_pages(vma) > size)

        return -EINVAL;

​

    if (write_combine)

        vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);

    else

        vma->vm_page_prot = pgprot_device(vma->vm_page_prot);

​

    if (mmap_state == pci_mmap_io) {

        ret = pci_iobar_pfn(pdev, bar, vma);

        if (ret)

            return ret;

    } else