mmap.c 1.2 KB

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  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 <[email protected]>
  8. */
  9. #include <linux/kernel.h>
  10. #include <linux/mm.h>
  11. #include <linux/pci.h>
  12. #ifdef ARCH_GENERIC_PCI_MMAP_RESOURCE
  13. static const struct vm_operations_struct pci_phys_vm_ops = {
  14. #ifdef CONFIG_HAVE_IOREMAP_PROT
  15. .access = generic_access_phys,
  16. #endif
  17. };
  18. int pci_mmap_resource_range(struct pci_dev *pdev, int bar,
  19. struct vm_area_struct *vma,
  20. enum pci_mmap_state mmap_state, int write_combine)
  21. {
  22. unsigned long size;
  23. int ret;
  24. size = ((pci_resource_len(pdev, bar) - 1) >> PAGE_SHIFT) + 1;
  25. if (vma->vm_pgoff + vma_pages(vma) > size)
  26. return -EINVAL;
  27. if (write_combine)
  28. vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
  29. else
  30. vma->vm_page_prot = pgprot_device(vma->vm_page_prot);
  31. if (mmap_state == pci_mmap_io) {
  32. ret = pci_iobar_pfn(pdev, bar, vma);
  33. if (ret)
  34. return ret;
  35. } else
  36. vma->vm_pgoff += (pci_resource_start(pdev, bar) >> PAGE_SHIFT);
  37. vma->vm_ops = &pci_phys_vm_ops;
  38. return io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
  39. vma->vm_end - vma->vm_start,
  40. vma->vm_page_prot);
  41. }
  42. #endif