projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 8cfab3cf | 1 | // SPDX-License-Identifier: GPL-2.0 |
| f7195824 | 2 | /* |
| df62ab5e | 3 | * Generic PCI resource mmap helper |
| f7195824 DW |
4 | * |
| 5 | * Copyright © 2017 Amazon.com, Inc. or its affiliates. | |
| 6 | * | |
| 7 | * Author: David Woodhouse <[email protected]> | |
| f7195824 DW |
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 | /* | |
| 17 | * Modern setup: generic pci_mmap_resource_range(), and implement the legacy | |
| 18 | * pci_mmap_page_range() (if needed) as a wrapper round it. | |
| 19 | */ | |
| 20 | ||
| 21 | #ifdef HAVE_PCI_MMAP | |
| 22 | int pci_mmap_page_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 | resource_size_t start, end; | |
| 27 | ||
| 28 | pci_resource_to_user(pdev, bar, &pdev->resource[bar], &start, &end); | |
| 29 | ||
| 30 | /* Adjust vm_pgoff to be the offset within the resource */ | |
| 31 | vma->vm_pgoff -= start >> PAGE_SHIFT; | |
| 32 | return pci_mmap_resource_range(pdev, bar, vma, mmap_state, | |
| 33 | write_combine); | |
| 34 | } | |
| 35 | #endif | |
| 36 | ||
| 37 | static const struct vm_operations_struct pci_phys_vm_ops = { | |
| 38 | #ifdef CONFIG_HAVE_IOREMAP_PROT | |
| 39 | .access = generic_access_phys, | |
| 40 | #endif | |
| 41 | }; | |
| 42 | ||
| 43 | int pci_mmap_resource_range(struct pci_dev *pdev, int bar, | |
| 44 | struct vm_area_struct *vma, | |
| 45 | enum pci_mmap_state mmap_state, int write_combine) | |
| 46 | { | |
| 47 | unsigned long size; | |
| 2bea36fd | 48 | int ret; |
| f7195824 DW |
49 | |
| 50 | size = ((pci_resource_len(pdev, bar) - 1) >> PAGE_SHIFT) + 1; | |
| 51 | if (vma->vm_pgoff + vma_pages(vma) > size) | |
| 52 | return -EINVAL; | |
| 53 | ||
| 54 | if (write_combine) | |
| 55 | vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot); | |
| 56 | else | |
| 57 | vma->vm_page_prot = pgprot_device(vma->vm_page_prot); | |
| 58 | ||
| 2bea36fd DW |
59 | if (mmap_state == pci_mmap_io) { |
| 60 | ret = pci_iobar_pfn(pdev, bar, vma); | |
| 61 | if (ret) | |
| 62 | return ret; | |
| 63 | } else | |
| 64 | vma->vm_pgoff += (pci_resource_start(pdev, bar) >> PAGE_SHIFT); | |
| 65 | ||
| f7195824 DW |
66 | vma->vm_ops = &pci_phys_vm_ops; |
| 67 | ||
| 68 | return io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff, | |
| 69 | vma->vm_end - vma->vm_start, | |
| 70 | vma->vm_page_prot); | |
| 71 | } | |
| 72 | ||
| 73 | #elif defined(HAVE_PCI_MMAP) /* && !ARCH_GENERIC_PCI_MMAP_RESOURCE */ | |
| 74 | ||
| 75 | /* | |
| 76 | * Legacy setup: Impement pci_mmap_resource_range() as a wrapper around | |
| 77 | * the architecture's pci_mmap_page_range(), converting to "user visible" | |
| 78 | * addresses as necessary. | |
| 79 | */ | |
| 80 | ||
| 81 | int pci_mmap_resource_range(struct pci_dev *pdev, int bar, | |
| 82 | struct vm_area_struct *vma, | |
| 83 | enum pci_mmap_state mmap_state, int write_combine) | |
| 84 | { | |
| 85 | resource_size_t start, end; | |
| 86 | ||
| 87 | /* | |
| 88 | * pci_mmap_page_range() expects the same kind of entry as coming | |
| 89 | * from /proc/bus/pci/ which is a "user visible" value. If this is | |
| 90 | * different from the resource itself, arch will do necessary fixup. | |
| 91 | */ | |
| 92 | pci_resource_to_user(pdev, bar, &pdev->resource[bar], &start, &end); | |
| 93 | vma->vm_pgoff += start >> PAGE_SHIFT; | |
| 94 | return pci_mmap_page_range(pdev, bar, vma, mmap_state, write_combine); | |
| 95 | } | |
| 96 | #endif |