Line data    Source code

       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             : #ifdef ARCH_GENERIC_PCI_MMAP_RESOURCE
      15             : 
      16             : static const struct vm_operations_struct pci_phys_vm_ops = {
      17             : #ifdef CONFIG_HAVE_IOREMAP_PROT
      18             :         .access = generic_access_phys,
      19             : #endif
      20             : };
      21             : 
      22           0 : int pci_mmap_resource_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             :         unsigned long size;
      27             :         int ret;
      28             : 
      29           0 :         size = ((pci_resource_len(pdev, bar) - 1) >> PAGE_SHIFT) + 1;
      30           0 :         if (vma->vm_pgoff + vma_pages(vma) > size)
      31             :                 return -EINVAL;
      32             : 
      33             :         if (write_combine)
      34             :                 vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
      35             :         else
      36             :                 vma->vm_page_prot = pgprot_device(vma->vm_page_prot);
      37             : 
      38           0 :         if (mmap_state == pci_mmap_io) {
      39             :                 ret = pci_iobar_pfn(pdev, bar, vma);
      40             :                 if (ret)
      41             :                         return ret;
      42             :         } else
      43           0 :                 vma->vm_pgoff += (pci_resource_start(pdev, bar) >> PAGE_SHIFT);
      44             : 
      45           0 :         vma->vm_ops = &pci_phys_vm_ops;
      46             : 
      47           0 :         return io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
      48             :                                   vma->vm_end - vma->vm_start,
      49             :                                   vma->vm_page_prot);
      50             : }
      51             : 
      52             : #endif