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(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, vma->vm_start, vma->vm_pgoff,
50				  vma->vm_end - vma->vm_start,
51				  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(pdev, resno, &pdev->resource[resno],
72				     &pci_start, &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