1// SPDX-License-Identifier: MIT
2/*
3 * Copyright © 2020 Intel Corporation
4 */
5
6#include <linux/iosys-map.h>
7#include <linux/mm.h>
8#include <linux/pagemap.h>
9#include <linux/shmem_fs.h>
10#include <linux/vmalloc.h>
11
12#include "i915_drv.h"
13#include "gem/i915_gem_object.h"
14#include "gem/i915_gem_lmem.h"
15#include "shmem_utils.h"
16
17struct file *shmem_create_from_data(const char *name, void *data, size_t len)
18{
19 struct file *file;
20 int err;
21
22 file = shmem_file_setup(name, PAGE_ALIGN(len), VM_NORESERVE);
23 if (IS_ERR(ptr: file))
24 return file;
25
26 err = shmem_write(file, off: 0, src: data, len);
27 if (err) {
28 fput(file);
29 return ERR_PTR(error: err);
30 }
31
32 return file;
33}
34
35struct file *shmem_create_from_object(struct drm_i915_gem_object *obj)
36{
37 enum i915_map_type map_type;
38 struct file *file;
39 void *ptr;
40
41 if (i915_gem_object_is_shmem(obj)) {
42 file = obj->base.filp;
43 get_file(f: file);
44 return file;
45 }
46
47 map_type = i915_gem_object_is_lmem(obj) ? I915_MAP_WC : I915_MAP_WB;
48 ptr = i915_gem_object_pin_map_unlocked(obj, type: map_type);
49 if (IS_ERR(ptr))
50 return ERR_CAST(ptr);
51
52 file = shmem_create_from_data(name: "", data: ptr, len: obj->base.size);
53 i915_gem_object_unpin_map(obj);
54
55 return file;
56}
57
58void *shmem_pin_map(struct file *file)
59{
60 struct page **pages;
61 size_t n_pages, i;
62 void *vaddr;
63
64 n_pages = file->f_mapping->host->i_size >> PAGE_SHIFT;
65 pages = kvmalloc_array(n_pages, sizeof(*pages), GFP_KERNEL);
66 if (!pages)
67 return NULL;
68
69 for (i = 0; i < n_pages; i++) {
70 pages[i] = shmem_read_mapping_page_gfp(mapping: file->f_mapping, index: i,
71 GFP_KERNEL);
72 if (IS_ERR(ptr: pages[i]))
73 goto err_page;
74 }
75
76 vaddr = vmap(pages, count: n_pages, VM_MAP_PUT_PAGES, PAGE_KERNEL);
77 if (!vaddr)
78 goto err_page;
79 mapping_set_unevictable(mapping: file->f_mapping);
80 return vaddr;
81err_page:
82 while (i--)
83 put_page(page: pages[i]);
84 kvfree(addr: pages);
85 return NULL;
86}
87
88void shmem_unpin_map(struct file *file, void *ptr)
89{
90 mapping_clear_unevictable(mapping: file->f_mapping);
91 vfree(addr: ptr);
92}
93
94static int __shmem_rw(struct file *file, loff_t off,
95 void *ptr, size_t len,
96 bool write)
97{
98 unsigned long pfn;
99
100 for (pfn = off >> PAGE_SHIFT; len; pfn++) {
101 unsigned int this =
102 min_t(size_t, PAGE_SIZE - offset_in_page(off), len);
103 struct page *page;
104 void *vaddr;
105
106 page = shmem_read_mapping_page_gfp(mapping: file->f_mapping, index: pfn,
107 GFP_KERNEL);
108 if (IS_ERR(ptr: page))
109 return PTR_ERR(ptr: page);
110
111 vaddr = kmap_local_page(page);
112 if (write) {
113 memcpy(vaddr + offset_in_page(off), ptr, this);
114 set_page_dirty(page);
115 } else {
116 memcpy(ptr, vaddr + offset_in_page(off), this);
117 }
118 mark_page_accessed(page);
119 kunmap_local(vaddr);
120 put_page(page);
121
122 len -= this;
123 ptr += this;
124 off = 0;
125 }
126
127 return 0;
128}
129
130int shmem_read_to_iosys_map(struct file *file, loff_t off,
131 struct iosys_map *map, size_t map_off, size_t len)
132{
133 unsigned long pfn;
134
135 for (pfn = off >> PAGE_SHIFT; len; pfn++) {
136 unsigned int this =
137 min_t(size_t, PAGE_SIZE - offset_in_page(off), len);
138 struct page *page;
139 void *vaddr;
140
141 page = shmem_read_mapping_page_gfp(mapping: file->f_mapping, index: pfn,
142 GFP_KERNEL);
143 if (IS_ERR(ptr: page))
144 return PTR_ERR(ptr: page);
145
146 vaddr = kmap_local_page(page);
147 iosys_map_memcpy_to(dst: map, dst_offset: map_off, src: vaddr + offset_in_page(off),
148 len: this);
149 mark_page_accessed(page);
150 kunmap_local(vaddr);
151 put_page(page);
152
153 len -= this;
154 map_off += this;
155 off = 0;
156 }
157
158 return 0;
159}
160
161int shmem_read(struct file *file, loff_t off, void *dst, size_t len)
162{
163 return __shmem_rw(file, off, ptr: dst, len, write: false);
164}
165
166int shmem_write(struct file *file, loff_t off, void *src, size_t len)
167{
168 return __shmem_rw(file, off, ptr: src, len, write: true);
169}
170
171#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
172#include "st_shmem_utils.c"
173#endif
174

source code of linux/drivers/gpu/drm/i915/gt/shmem_utils.c