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(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 82