| 1 | |
| 2 | |
| 3 | * Generic PCI resource mmap helper
|
| 4 | *
|
| 5 | * Copyright © 2017 Amazon.com, Inc. or its affiliates.
|
| 6 | *
|
| 7 | * Author: David Woodhouse <[email protected]>
|
| 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(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 |
|
| 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(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
|