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2
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4
5
6#include <linux/mm.h>
7#include <linux/pagemap.h>
8#include <linux/shmem_fs.h>
9
10#include "gem/i915_gem_object.h"
11#include "shmem_utils.h"
12
13struct file *shmem_create_from_data(const char *name, void *data, size_t len)
14{
15 struct file *file;
16 int err;
17
18 file = shmem_file_setup(name, PAGE_ALIGN(len), VM_NORESERVE);
19 if (IS_ERR(file))
20 return file;
21
22 err = shmem_write(file, 0, data, len);
23 if (err) {
24 fput(file);
25 return ERR_PTR(err);
26 }
27
28 return file;
29}
30
31struct file *shmem_create_from_object(struct drm_i915_gem_object *obj)
32{
33 struct file *file;
34 void *ptr;
35
36 if (i915_gem_object_is_shmem(obj)) {
37 file = obj->base.filp;
38 atomic_long_inc(&file->f_count);
39 return file;
40 }
41
42 ptr = i915_gem_object_pin_map(obj, I915_MAP_WB);
43 if (IS_ERR(ptr))
44 return ERR_CAST(ptr);
45
46 file = shmem_create_from_data("", ptr, obj->base.size);
47 i915_gem_object_unpin_map(obj);
48
49 return file;
50}
51
52void *shmem_pin_map(struct file *file)
53{
54 struct page **pages;
55 size_t n_pages, i;
56 void *vaddr;
57
58 n_pages = file->f_mapping->host->i_size >> PAGE_SHIFT;
59 pages = kvmalloc_array(n_pages, sizeof(*pages), GFP_KERNEL);
60 if (!pages)
61 return NULL;
62
63 for (i = 0; i < n_pages; i++) {
64 pages[i] = shmem_read_mapping_page_gfp(file->f_mapping, i,
65 GFP_KERNEL);
66 if (IS_ERR(pages[i]))
67 goto err_page;
68 }
69
70 vaddr = vmap(pages, n_pages, VM_MAP_PUT_PAGES, PAGE_KERNEL);
71 if (!vaddr)
72 goto err_page;
73 mapping_set_unevictable(file->f_mapping);
74 return vaddr;
75err_page:
76 while (i--)
77 put_page(pages[i]);
78 kvfree(pages);
79 return NULL;
80}
81
82void shmem_unpin_map(struct file *file, void *ptr)
83{
84 mapping_clear_unevictable(file->f_mapping);
85 vfree(ptr);
86}
87
88static int __shmem_rw(struct file *file, loff_t off,
89 void *ptr, size_t len,
90 bool write)
91{
92 unsigned long pfn;
93
94 for (pfn = off >> PAGE_SHIFT; len; pfn++) {
95 unsigned int this =
96 min_t(size_t, PAGE_SIZE - offset_in_page(off), len);
97 struct page *page;
98 void *vaddr;
99
100 page = shmem_read_mapping_page_gfp(file->f_mapping, pfn,
101 GFP_KERNEL);
102 if (IS_ERR(page))
103 return PTR_ERR(page);
104
105 vaddr = kmap(page);
106 if (write) {
107 memcpy(vaddr + offset_in_page(off), ptr, this);
108 set_page_dirty(page);
109 } else {
110 memcpy(ptr, vaddr + offset_in_page(off), this);
111 }
112 mark_page_accessed(page);
113 kunmap(page);
114 put_page(page);
115
116 len -= this;
117 ptr += this;
118 off = 0;
119 }
120
121 return 0;
122}
123
124int shmem_read(struct file *file, loff_t off, void *dst, size_t len)
125{
126 return __shmem_rw(file, off, dst, len, false);
127}
128
129int shmem_write(struct file *file, loff_t off, void *src, size_t len)
130{
131 return __shmem_rw(file, off, src, len, true);
132}
133
134#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
135#include "st_shmem_utils.c"
136#endif
137
