1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Generic PCI resource mmap helper
4 *
5 * Copyright © 2017 Amazon.com, Inc. or its affiliates.
6 *
7 * Author: David Woodhouse <dwmw2@infradead.org>
8 */
9
10 #include <linux/kernel.h>
11 #include <linux/mm.h>
12 #include <linux/pci.h>
13
14 #ifdef ARCH_GENERIC_PCI_MMAP_RESOURCE
15
16 static const struct vm_operations_struct pci_phys_vm_ops = {
17 #ifdef CONFIG_HAVE_IOREMAP_PROT
18 .access = generic_access_phys,
19 #endif
20 };
21
pci_mmap_resource_range(struct pci_dev * pdev,int bar,struct vm_area_struct * vma,enum pci_mmap_state mmap_state,int write_combine)22 int pci_mmap_resource_range(struct pci_dev *pdev, int bar,
23 struct vm_area_struct *vma,
24 enum pci_mmap_state mmap_state, int write_combine)
25 {
26 unsigned long size;
27 int ret;
28
29 size = ((pci_resource_len(pdev, bar) - 1) >> PAGE_SHIFT) + 1;
30 if (vma->vm_pgoff + vma_pages(vma) > size)
31 return -EINVAL;
32
33 if (write_combine)
34 vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
35 else
36 vma->vm_page_prot = pgprot_device(vma->vm_page_prot);
37
38 if (mmap_state == pci_mmap_io) {
39 ret = pci_iobar_pfn(pdev, bar, vma);
40 if (ret)
41 return ret;
42 } else
43 vma->vm_pgoff += (pci_resource_start(pdev, bar) >> PAGE_SHIFT);
44
45 vma->vm_ops = &pci_phys_vm_ops;
46
47 return io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
48 vma->vm_end - vma->vm_start,
49 vma->vm_page_prot);
50 }
51
52 #endif
53