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 | |
18 | static const struct vm_operations_struct pci_phys_vm_ops = { |
19 | #ifdef CONFIG_HAVE_IOREMAP_PROT |
20 | .access = generic_access_phys, |
21 | #endif |
22 | }; |
23 | |
24 | int 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 | |
59 | int 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 | |