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b9d47450 SH |
1 | /* |
2 | * drm gem CMA (contiguous memory allocator) helper functions | |
3 | * | |
4 | * Copyright (C) 2012 Sascha Hauer, Pengutronix | |
5 | * | |
6 | * Based on Samsung Exynos code | |
7 | * | |
8 | * Copyright (c) 2011 Samsung Electronics Co., Ltd. | |
9 | * | |
10 | * This program is free software; you can redistribute it and/or | |
11 | * modify it under the terms of the GNU General Public License | |
12 | * as published by the Free Software Foundation; either version 2 | |
13 | * of the License, or (at your option) any later version. | |
14 | * This program is distributed in the hope that it will be useful, | |
15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | * GNU General Public License for more details. | |
18 | */ | |
19 | ||
20 | #include <linux/mm.h> | |
21 | #include <linux/slab.h> | |
22 | #include <linux/mutex.h> | |
23 | #include <linux/export.h> | |
24 | #include <linux/dma-mapping.h> | |
25 | ||
26 | #include <drm/drmP.h> | |
27 | #include <drm/drm.h> | |
28 | #include <drm/drm_gem_cma_helper.h> | |
29 | ||
30 | static unsigned int get_gem_mmap_offset(struct drm_gem_object *obj) | |
31 | { | |
32 | return (unsigned int)obj->map_list.hash.key << PAGE_SHIFT; | |
33 | } | |
34 | ||
35 | static void drm_gem_cma_buf_destroy(struct drm_device *drm, | |
36 | struct drm_gem_cma_object *cma_obj) | |
37 | { | |
38 | dma_free_writecombine(drm->dev, cma_obj->base.size, cma_obj->vaddr, | |
39 | cma_obj->paddr); | |
40 | } | |
41 | ||
42 | /* | |
43 | * drm_gem_cma_create - allocate an object with the given size | |
44 | * | |
45 | * returns a struct drm_gem_cma_object* on success or ERR_PTR values | |
46 | * on failure. | |
47 | */ | |
48 | struct drm_gem_cma_object *drm_gem_cma_create(struct drm_device *drm, | |
49 | unsigned int size) | |
50 | { | |
51 | struct drm_gem_cma_object *cma_obj; | |
52 | struct drm_gem_object *gem_obj; | |
53 | int ret; | |
54 | ||
55 | size = round_up(size, PAGE_SIZE); | |
56 | ||
57 | cma_obj = kzalloc(sizeof(*cma_obj), GFP_KERNEL); | |
58 | if (!cma_obj) | |
59 | return ERR_PTR(-ENOMEM); | |
60 | ||
61 | cma_obj->vaddr = dma_alloc_writecombine(drm->dev, size, | |
62 | &cma_obj->paddr, GFP_KERNEL | __GFP_NOWARN); | |
63 | if (!cma_obj->vaddr) { | |
64 | dev_err(drm->dev, "failed to allocate buffer with size %d\n", size); | |
65 | ret = -ENOMEM; | |
66 | goto err_dma_alloc; | |
67 | } | |
68 | ||
69 | gem_obj = &cma_obj->base; | |
70 | ||
71 | ret = drm_gem_object_init(drm, gem_obj, size); | |
72 | if (ret) | |
73 | goto err_obj_init; | |
74 | ||
75 | ret = drm_gem_create_mmap_offset(gem_obj); | |
76 | if (ret) | |
77 | goto err_create_mmap_offset; | |
78 | ||
79 | return cma_obj; | |
80 | ||
81 | err_create_mmap_offset: | |
82 | drm_gem_object_release(gem_obj); | |
83 | ||
84 | err_obj_init: | |
85 | drm_gem_cma_buf_destroy(drm, cma_obj); | |
86 | ||
87 | err_dma_alloc: | |
88 | kfree(cma_obj); | |
89 | ||
90 | return ERR_PTR(ret); | |
91 | } | |
92 | EXPORT_SYMBOL_GPL(drm_gem_cma_create); | |
93 | ||
94 | /* | |
95 | * drm_gem_cma_create_with_handle - allocate an object with the given | |
96 | * size and create a gem handle on it | |
97 | * | |
98 | * returns a struct drm_gem_cma_object* on success or ERR_PTR values | |
99 | * on failure. | |
100 | */ | |
101 | static struct drm_gem_cma_object *drm_gem_cma_create_with_handle( | |
102 | struct drm_file *file_priv, | |
103 | struct drm_device *drm, unsigned int size, | |
104 | unsigned int *handle) | |
105 | { | |
106 | struct drm_gem_cma_object *cma_obj; | |
107 | struct drm_gem_object *gem_obj; | |
108 | int ret; | |
109 | ||
110 | cma_obj = drm_gem_cma_create(drm, size); | |
111 | if (IS_ERR(cma_obj)) | |
112 | return cma_obj; | |
113 | ||
114 | gem_obj = &cma_obj->base; | |
115 | ||
116 | /* | |
117 | * allocate a id of idr table where the obj is registered | |
118 | * and handle has the id what user can see. | |
119 | */ | |
120 | ret = drm_gem_handle_create(file_priv, gem_obj, handle); | |
121 | if (ret) | |
122 | goto err_handle_create; | |
123 | ||
124 | /* drop reference from allocate - handle holds it now. */ | |
125 | drm_gem_object_unreference_unlocked(gem_obj); | |
126 | ||
127 | return cma_obj; | |
128 | ||
129 | err_handle_create: | |
130 | drm_gem_cma_free_object(gem_obj); | |
131 | ||
132 | return ERR_PTR(ret); | |
133 | } | |
134 | ||
135 | /* | |
136 | * drm_gem_cma_free_object - (struct drm_driver)->gem_free_object callback | |
137 | * function | |
138 | */ | |
139 | void drm_gem_cma_free_object(struct drm_gem_object *gem_obj) | |
140 | { | |
141 | struct drm_gem_cma_object *cma_obj; | |
142 | ||
143 | if (gem_obj->map_list.map) | |
144 | drm_gem_free_mmap_offset(gem_obj); | |
145 | ||
146 | drm_gem_object_release(gem_obj); | |
147 | ||
148 | cma_obj = to_drm_gem_cma_obj(gem_obj); | |
149 | ||
150 | drm_gem_cma_buf_destroy(gem_obj->dev, cma_obj); | |
151 | ||
152 | kfree(cma_obj); | |
153 | } | |
154 | EXPORT_SYMBOL_GPL(drm_gem_cma_free_object); | |
155 | ||
156 | /* | |
157 | * drm_gem_cma_dumb_create - (struct drm_driver)->dumb_create callback | |
158 | * function | |
159 | * | |
160 | * This aligns the pitch and size arguments to the minimum required. wrap | |
161 | * this into your own function if you need bigger alignment. | |
162 | */ | |
163 | int drm_gem_cma_dumb_create(struct drm_file *file_priv, | |
164 | struct drm_device *dev, struct drm_mode_create_dumb *args) | |
165 | { | |
166 | struct drm_gem_cma_object *cma_obj; | |
167 | int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8); | |
168 | ||
169 | if (args->pitch < min_pitch) | |
170 | args->pitch = min_pitch; | |
171 | ||
172 | if (args->size < args->pitch * args->height) | |
173 | args->size = args->pitch * args->height; | |
174 | ||
175 | cma_obj = drm_gem_cma_create_with_handle(file_priv, dev, | |
176 | args->size, &args->handle); | |
177 | if (IS_ERR(cma_obj)) | |
178 | return PTR_ERR(cma_obj); | |
179 | ||
180 | return 0; | |
181 | } | |
182 | EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_create); | |
183 | ||
184 | /* | |
185 | * drm_gem_cma_dumb_map_offset - (struct drm_driver)->dumb_map_offset callback | |
186 | * function | |
187 | */ | |
188 | int drm_gem_cma_dumb_map_offset(struct drm_file *file_priv, | |
189 | struct drm_device *drm, uint32_t handle, uint64_t *offset) | |
190 | { | |
191 | struct drm_gem_object *gem_obj; | |
192 | ||
193 | mutex_lock(&drm->struct_mutex); | |
194 | ||
195 | gem_obj = drm_gem_object_lookup(drm, file_priv, handle); | |
196 | if (!gem_obj) { | |
197 | dev_err(drm->dev, "failed to lookup gem object\n"); | |
198 | mutex_unlock(&drm->struct_mutex); | |
199 | return -EINVAL; | |
200 | } | |
201 | ||
202 | *offset = get_gem_mmap_offset(gem_obj); | |
203 | ||
204 | drm_gem_object_unreference(gem_obj); | |
205 | ||
206 | mutex_unlock(&drm->struct_mutex); | |
207 | ||
208 | return 0; | |
209 | } | |
210 | EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_map_offset); | |
211 | ||
212 | const struct vm_operations_struct drm_gem_cma_vm_ops = { | |
213 | .open = drm_gem_vm_open, | |
214 | .close = drm_gem_vm_close, | |
215 | }; | |
216 | EXPORT_SYMBOL_GPL(drm_gem_cma_vm_ops); | |
217 | ||
218 | /* | |
219 | * drm_gem_cma_mmap - (struct file_operation)->mmap callback function | |
220 | */ | |
221 | int drm_gem_cma_mmap(struct file *filp, struct vm_area_struct *vma) | |
222 | { | |
223 | struct drm_gem_object *gem_obj; | |
224 | struct drm_gem_cma_object *cma_obj; | |
225 | int ret; | |
226 | ||
227 | ret = drm_gem_mmap(filp, vma); | |
228 | if (ret) | |
229 | return ret; | |
230 | ||
231 | gem_obj = vma->vm_private_data; | |
232 | cma_obj = to_drm_gem_cma_obj(gem_obj); | |
233 | ||
234 | ret = remap_pfn_range(vma, vma->vm_start, cma_obj->paddr >> PAGE_SHIFT, | |
235 | vma->vm_end - vma->vm_start, vma->vm_page_prot); | |
236 | if (ret) | |
237 | drm_gem_vm_close(vma); | |
238 | ||
239 | return ret; | |
240 | } | |
241 | EXPORT_SYMBOL_GPL(drm_gem_cma_mmap); | |
242 | ||
243 | /* | |
244 | * drm_gem_cma_dumb_destroy - (struct drm_driver)->dumb_destroy callback function | |
245 | */ | |
246 | int drm_gem_cma_dumb_destroy(struct drm_file *file_priv, | |
247 | struct drm_device *drm, unsigned int handle) | |
248 | { | |
249 | return drm_gem_handle_delete(file_priv, handle); | |
250 | } | |
251 | EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_destroy); |