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1/*
2 * Copyright © 2014 Intel Corporation
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 * IN THE SOFTWARE.
22 *
23 */
24
25#include <linux/mm.h>
26#include <linux/io-mapping.h>
27
28
29#include "i915_drv.h"
30#include "i915_mm.h"
31
32struct remap_pfn {
33 struct mm_struct *mm;
34 unsigned long pfn;
35 pgprot_t prot;
36
37 struct sgt_iter sgt;
38 resource_size_t iobase;
39};
40
41#define use_dma(io) ((io) != -1)
42
43static inline unsigned long sgt_pfn(const struct remap_pfn *r)
44{
45 if (use_dma(r->iobase))
46 return (r->sgt.dma + r->sgt.curr + r->iobase) >> PAGE_SHIFT;
47 else
48 return r->sgt.pfn + (r->sgt.curr >> PAGE_SHIFT);
49}
50
51static int remap_sg(pte_t *pte, unsigned long addr, void *data)
52{
53 struct remap_pfn *r = data;
54
55 if (GEM_WARN_ON(!r->sgt.sgp))
56 return -EINVAL;
57
58 /* Special PTE are not associated with any struct page */
59 set_pte_at(r->mm, addr, pte,
60 pte_mkspecial(pfn_pte(sgt_pfn(r), r->prot)));
61 r->pfn++; /* track insertions in case we need to unwind later */
62
63 r->sgt.curr += PAGE_SIZE;
64 if (r->sgt.curr >= r->sgt.max)
65 r->sgt = __sgt_iter(__sg_next(r->sgt.sgp), use_dma(r->iobase));
66
67 return 0;
68}
69
70#define EXPECTED_FLAGS (VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP)
71
72#if IS_ENABLED(CONFIG_X86)
73static int remap_pfn(pte_t *pte, unsigned long addr, void *data)
74{
75 struct remap_pfn *r = data;
76
77 /* Special PTE are not associated with any struct page */
78 set_pte_at(r->mm, addr, pte, pte_mkspecial(pfn_pte(r->pfn, r->prot)));
79 r->pfn++;
80
81 return 0;
82}
83
84/**
85 * remap_io_mapping - remap an IO mapping to userspace
86 * @vma: user vma to map to
87 * @addr: target user address to start at
88 * @pfn: physical address of kernel memory
89 * @size: size of map area
90 * @iomap: the source io_mapping
91 *
92 * Note: this is only safe if the mm semaphore is held when called.
93 */
94int remap_io_mapping(struct vm_area_struct *vma,
95 unsigned long addr, unsigned long pfn, unsigned long size,
96 struct io_mapping *iomap)
97{
98 struct remap_pfn r;
99 int err;
100
101 GEM_BUG_ON((vma->vm_flags & EXPECTED_FLAGS) != EXPECTED_FLAGS);
102
103 /* We rely on prevalidation of the io-mapping to skip track_pfn(). */
104 r.mm = vma->vm_mm;
105 r.pfn = pfn;
106 r.prot = __pgprot((pgprot_val(iomap->prot) & _PAGE_CACHE_MASK) |
107 (pgprot_val(vma->vm_page_prot) & ~_PAGE_CACHE_MASK));
108
109 err = apply_to_page_range(r.mm, addr, size, remap_pfn, &r);
110 if (unlikely(err)) {
111 zap_vma_ptes(vma, addr, (r.pfn - pfn) << PAGE_SHIFT);
112 return err;
113 }
114
115 return 0;
116}
117#endif
118
119/**
120 * remap_io_sg - remap an IO mapping to userspace
121 * @vma: user vma to map to
122 * @addr: target user address to start at
123 * @size: size of map area
124 * @sgl: Start sg entry
125 * @iobase: Use stored dma address offset by this address or pfn if -1
126 *
127 * Note: this is only safe if the mm semaphore is held when called.
128 */
129int remap_io_sg(struct vm_area_struct *vma,
130 unsigned long addr, unsigned long size,
131 struct scatterlist *sgl, resource_size_t iobase)
132{
133 struct remap_pfn r = {
134 .mm = vma->vm_mm,
135 .prot = vma->vm_page_prot,
136 .sgt = __sgt_iter(sgl, use_dma(iobase)),
137 .iobase = iobase,
138 };
139 int err;
140
141 /* We rely on prevalidation of the io-mapping to skip track_pfn(). */
142 GEM_BUG_ON((vma->vm_flags & EXPECTED_FLAGS) != EXPECTED_FLAGS);
143
144 if (!use_dma(iobase))
145 flush_cache_range(vma, addr, size);
146
147 err = apply_to_page_range(r.mm, addr, size, remap_sg, &r);
148 if (unlikely(err)) {
149 zap_vma_ptes(vma, addr, r.pfn << PAGE_SHIFT);
150 return err;
151 }
152
153 return 0;
154}
1/*
2 * Copyright © 2014 Intel Corporation
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
10 *
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
13 * Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21 * IN THE SOFTWARE.
22 *
23 */
24
25#include <linux/mm.h>
26#include <linux/io-mapping.h>
27
28#include <asm/pgtable.h>
29
30#include "i915_drv.h"
31
32struct remap_pfn {
33 struct mm_struct *mm;
34 unsigned long pfn;
35 pgprot_t prot;
36};
37
38static int remap_pfn(pte_t *pte, pgtable_t token,
39 unsigned long addr, void *data)
40{
41 struct remap_pfn *r = data;
42
43 /* Special PTE are not associated with any struct page */
44 set_pte_at(r->mm, addr, pte, pte_mkspecial(pfn_pte(r->pfn, r->prot)));
45 r->pfn++;
46
47 return 0;
48}
49
50/**
51 * remap_io_mapping - remap an IO mapping to userspace
52 * @vma: user vma to map to
53 * @addr: target user address to start at
54 * @pfn: physical address of kernel memory
55 * @size: size of map area
56 * @iomap: the source io_mapping
57 *
58 * Note: this is only safe if the mm semaphore is held when called.
59 */
60int remap_io_mapping(struct vm_area_struct *vma,
61 unsigned long addr, unsigned long pfn, unsigned long size,
62 struct io_mapping *iomap)
63{
64 struct remap_pfn r;
65 int err;
66
67 GEM_BUG_ON((vma->vm_flags &
68 (VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP)) !=
69 (VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP));
70
71 /* We rely on prevalidation of the io-mapping to skip track_pfn(). */
72 r.mm = vma->vm_mm;
73 r.pfn = pfn;
74 r.prot = __pgprot((pgprot_val(iomap->prot) & _PAGE_CACHE_MASK) |
75 (pgprot_val(vma->vm_page_prot) & ~_PAGE_CACHE_MASK));
76
77 err = apply_to_page_range(r.mm, addr, size, remap_pfn, &r);
78 if (unlikely(err)) {
79 zap_vma_ptes(vma, addr, (r.pfn - pfn) << PAGE_SHIFT);
80 return err;
81 }
82
83 return 0;
84}