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