1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Generic PCI resource mmap helper
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Copyright © 2017 Amazon.com, Inc. or its affiliates.
6*4882a593Smuzhiyun *
7*4882a593Smuzhiyun * Author: David Woodhouse <dwmw2@infradead.org>
8*4882a593Smuzhiyun */
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun #include <linux/kernel.h>
11*4882a593Smuzhiyun #include <linux/mm.h>
12*4882a593Smuzhiyun #include <linux/pci.h>
13*4882a593Smuzhiyun
14*4882a593Smuzhiyun #ifdef ARCH_GENERIC_PCI_MMAP_RESOURCE
15*4882a593Smuzhiyun
16*4882a593Smuzhiyun /*
17*4882a593Smuzhiyun * Modern setup: generic pci_mmap_resource_range(), and implement the legacy
18*4882a593Smuzhiyun * pci_mmap_page_range() (if needed) as a wrapper round it.
19*4882a593Smuzhiyun */
20*4882a593Smuzhiyun
21*4882a593Smuzhiyun #ifdef HAVE_PCI_MMAP
pci_mmap_page_range(struct pci_dev * pdev,int bar,struct vm_area_struct * vma,enum pci_mmap_state mmap_state,int write_combine)22*4882a593Smuzhiyun int pci_mmap_page_range(struct pci_dev *pdev, int bar,
23*4882a593Smuzhiyun struct vm_area_struct *vma,
24*4882a593Smuzhiyun enum pci_mmap_state mmap_state, int write_combine)
25*4882a593Smuzhiyun {
26*4882a593Smuzhiyun resource_size_t start, end;
27*4882a593Smuzhiyun
28*4882a593Smuzhiyun pci_resource_to_user(pdev, bar, &pdev->resource[bar], &start, &end);
29*4882a593Smuzhiyun
30*4882a593Smuzhiyun /* Adjust vm_pgoff to be the offset within the resource */
31*4882a593Smuzhiyun vma->vm_pgoff -= start >> PAGE_SHIFT;
32*4882a593Smuzhiyun return pci_mmap_resource_range(pdev, bar, vma, mmap_state,
33*4882a593Smuzhiyun write_combine);
34*4882a593Smuzhiyun }
35*4882a593Smuzhiyun #endif
36*4882a593Smuzhiyun
37*4882a593Smuzhiyun static const struct vm_operations_struct pci_phys_vm_ops = {
38*4882a593Smuzhiyun #ifdef CONFIG_HAVE_IOREMAP_PROT
39*4882a593Smuzhiyun .access = generic_access_phys,
40*4882a593Smuzhiyun #endif
41*4882a593Smuzhiyun };
42*4882a593Smuzhiyun
pci_mmap_resource_range(struct pci_dev * pdev,int bar,struct vm_area_struct * vma,enum pci_mmap_state mmap_state,int write_combine)43*4882a593Smuzhiyun int pci_mmap_resource_range(struct pci_dev *pdev, int bar,
44*4882a593Smuzhiyun struct vm_area_struct *vma,
45*4882a593Smuzhiyun enum pci_mmap_state mmap_state, int write_combine)
46*4882a593Smuzhiyun {
47*4882a593Smuzhiyun unsigned long size;
48*4882a593Smuzhiyun int ret;
49*4882a593Smuzhiyun
50*4882a593Smuzhiyun size = ((pci_resource_len(pdev, bar) - 1) >> PAGE_SHIFT) + 1;
51*4882a593Smuzhiyun if (vma->vm_pgoff + vma_pages(vma) > size)
52*4882a593Smuzhiyun return -EINVAL;
53*4882a593Smuzhiyun
54*4882a593Smuzhiyun if (write_combine)
55*4882a593Smuzhiyun vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
56*4882a593Smuzhiyun else
57*4882a593Smuzhiyun vma->vm_page_prot = pgprot_device(vma->vm_page_prot);
58*4882a593Smuzhiyun
59*4882a593Smuzhiyun if (mmap_state == pci_mmap_io) {
60*4882a593Smuzhiyun ret = pci_iobar_pfn(pdev, bar, vma);
61*4882a593Smuzhiyun if (ret)
62*4882a593Smuzhiyun return ret;
63*4882a593Smuzhiyun } else
64*4882a593Smuzhiyun vma->vm_pgoff += (pci_resource_start(pdev, bar) >> PAGE_SHIFT);
65*4882a593Smuzhiyun
66*4882a593Smuzhiyun vma->vm_ops = &pci_phys_vm_ops;
67*4882a593Smuzhiyun
68*4882a593Smuzhiyun return io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
69*4882a593Smuzhiyun vma->vm_end - vma->vm_start,
70*4882a593Smuzhiyun vma->vm_page_prot);
71*4882a593Smuzhiyun }
72*4882a593Smuzhiyun
73*4882a593Smuzhiyun #elif defined(HAVE_PCI_MMAP) /* && !ARCH_GENERIC_PCI_MMAP_RESOURCE */
74*4882a593Smuzhiyun
75*4882a593Smuzhiyun /*
76*4882a593Smuzhiyun * Legacy setup: Implement pci_mmap_resource_range() as a wrapper around
77*4882a593Smuzhiyun * the architecture's pci_mmap_page_range(), converting to "user visible"
78*4882a593Smuzhiyun * addresses as necessary.
79*4882a593Smuzhiyun */
80*4882a593Smuzhiyun
pci_mmap_resource_range(struct pci_dev * pdev,int bar,struct vm_area_struct * vma,enum pci_mmap_state mmap_state,int write_combine)81*4882a593Smuzhiyun int pci_mmap_resource_range(struct pci_dev *pdev, int bar,
82*4882a593Smuzhiyun struct vm_area_struct *vma,
83*4882a593Smuzhiyun enum pci_mmap_state mmap_state, int write_combine)
84*4882a593Smuzhiyun {
85*4882a593Smuzhiyun resource_size_t start, end;
86*4882a593Smuzhiyun
87*4882a593Smuzhiyun /*
88*4882a593Smuzhiyun * pci_mmap_page_range() expects the same kind of entry as coming
89*4882a593Smuzhiyun * from /proc/bus/pci/ which is a "user visible" value. If this is
90*4882a593Smuzhiyun * different from the resource itself, arch will do necessary fixup.
91*4882a593Smuzhiyun */
92*4882a593Smuzhiyun pci_resource_to_user(pdev, bar, &pdev->resource[bar], &start, &end);
93*4882a593Smuzhiyun vma->vm_pgoff += start >> PAGE_SHIFT;
94*4882a593Smuzhiyun return pci_mmap_page_range(pdev, bar, vma, mmap_state, write_combine);
95*4882a593Smuzhiyun }
96*4882a593Smuzhiyun #endif
97