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