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#include "pci.h"
15
16#ifdef ARCH_GENERIC_PCI_MMAP_RESOURCE
17
18static const struct vm_operations_struct pci_phys_vm_ops = {
19#ifdef CONFIG_HAVE_IOREMAP_PROT
20 .access = generic_access_phys,
21#endif
22};
23
24int pci_mmap_resource_range(struct pci_dev *pdev, int bar,
25 struct vm_area_struct *vma,
26 enum pci_mmap_state mmap_state, int write_combine)
27{
28 unsigned long size;
29 int ret;
30
31 size = ((pci_resource_len(pdev, bar) - 1) >> PAGE_SHIFT) + 1;
32 if (vma->vm_pgoff + vma_pages(vma) > size)
33 return -EINVAL;
34
35 if (write_combine)
36 vma->vm_page_prot = pgprot_writecombine(prot: vma->vm_page_prot);
37 else
38 vma->vm_page_prot = pgprot_device(vma->vm_page_prot);
39
40 if (mmap_state == pci_mmap_io) {
41 ret = pci_iobar_pfn(pdev, bar, vma);
42 if (ret)
43 return ret;
44 } else
45 vma->vm_pgoff += (pci_resource_start(pdev, bar) >> PAGE_SHIFT);
46
47 vma->vm_ops = &pci_phys_vm_ops;
48
49 return io_remap_pfn_range(vma, addr: vma->vm_start, pfn: vma->vm_pgoff,
50 size: vma->vm_end - vma->vm_start,
51 prot: vma->vm_page_prot);
52}
53
54#endif
55
56#if (defined(CONFIG_SYSFS) || defined(CONFIG_PROC_FS)) && \
57 (defined(HAVE_PCI_MMAP) || defined(ARCH_GENERIC_PCI_MMAP_RESOURCE))
58
59int pci_mmap_fits(struct pci_dev *pdev, int resno, struct vm_area_struct *vma,
60 enum pci_mmap_api mmap_api)
61{
62 resource_size_t pci_start = 0, pci_end;
63 unsigned long nr, start, size;
64
65 if (pci_resource_len(pdev, resno) == 0)
66 return 0;
67 nr = vma_pages(vma);
68 start = vma->vm_pgoff;
69 size = ((pci_resource_len(pdev, resno) - 1) >> PAGE_SHIFT) + 1;
70 if (mmap_api == PCI_MMAP_PROCFS) {
71 pci_resource_to_user(dev: pdev, bar: resno, rsrc: &pdev->resource[resno],
72 start: &pci_start, end: &pci_end);
73 pci_start >>= PAGE_SHIFT;
74 }
75 if (start >= pci_start && start < pci_start + size &&
76 start + nr <= pci_start + size)
77 return 1;
78 return 0;
79}
80
81#endif
82