2 * drm gem CMA (contiguous memory allocator) helper functions
4 * Copyright (C) 2012 Sascha Hauer, Pengutronix
6 * Based on Samsung Exynos code
8 * Copyright (c) 2011 Samsung Electronics Co., Ltd.
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.
21 #include <linux/slab.h>
22 #include <linux/mutex.h>
23 #include <linux/export.h>
24 #include <linux/dma-mapping.h>
28 #include <drm/drm_gem_cma_helper.h>
30 static unsigned int get_gem_mmap_offset(struct drm_gem_object
*obj
)
32 return (unsigned int)obj
->map_list
.hash
.key
<< PAGE_SHIFT
;
35 static void drm_gem_cma_buf_destroy(struct drm_device
*drm
,
36 struct drm_gem_cma_object
*cma_obj
)
38 dma_free_writecombine(drm
->dev
, cma_obj
->base
.size
, cma_obj
->vaddr
,
43 * drm_gem_cma_create - allocate an object with the given size
45 * returns a struct drm_gem_cma_object* on success or ERR_PTR values
48 struct drm_gem_cma_object
*drm_gem_cma_create(struct drm_device
*drm
,
51 struct drm_gem_cma_object
*cma_obj
;
52 struct drm_gem_object
*gem_obj
;
55 size
= round_up(size
, PAGE_SIZE
);
57 cma_obj
= kzalloc(sizeof(*cma_obj
), GFP_KERNEL
);
59 return ERR_PTR(-ENOMEM
);
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
);
69 gem_obj
= &cma_obj
->base
;
71 ret
= drm_gem_object_init(drm
, gem_obj
, size
);
75 ret
= drm_gem_create_mmap_offset(gem_obj
);
77 goto err_create_mmap_offset
;
81 err_create_mmap_offset
:
82 drm_gem_object_release(gem_obj
);
85 drm_gem_cma_buf_destroy(drm
, cma_obj
);
92 EXPORT_SYMBOL_GPL(drm_gem_cma_create
);
95 * drm_gem_cma_create_with_handle - allocate an object with the given
96 * size and create a gem handle on it
98 * returns a struct drm_gem_cma_object* on success or ERR_PTR values
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
)
106 struct drm_gem_cma_object
*cma_obj
;
107 struct drm_gem_object
*gem_obj
;
110 cma_obj
= drm_gem_cma_create(drm
, size
);
114 gem_obj
= &cma_obj
->base
;
117 * allocate a id of idr table where the obj is registered
118 * and handle has the id what user can see.
120 ret
= drm_gem_handle_create(file_priv
, gem_obj
, handle
);
122 goto err_handle_create
;
124 /* drop reference from allocate - handle holds it now. */
125 drm_gem_object_unreference_unlocked(gem_obj
);
130 drm_gem_cma_free_object(gem_obj
);
136 * drm_gem_cma_free_object - (struct drm_driver)->gem_free_object callback
139 void drm_gem_cma_free_object(struct drm_gem_object
*gem_obj
)
141 struct drm_gem_cma_object
*cma_obj
;
143 if (gem_obj
->map_list
.map
)
144 drm_gem_free_mmap_offset(gem_obj
);
146 drm_gem_object_release(gem_obj
);
148 cma_obj
= to_drm_gem_cma_obj(gem_obj
);
150 drm_gem_cma_buf_destroy(gem_obj
->dev
, cma_obj
);
154 EXPORT_SYMBOL_GPL(drm_gem_cma_free_object
);
157 * drm_gem_cma_dumb_create - (struct drm_driver)->dumb_create callback
160 * This aligns the pitch and size arguments to the minimum required. wrap
161 * this into your own function if you need bigger alignment.
163 int drm_gem_cma_dumb_create(struct drm_file
*file_priv
,
164 struct drm_device
*dev
, struct drm_mode_create_dumb
*args
)
166 struct drm_gem_cma_object
*cma_obj
;
167 int min_pitch
= DIV_ROUND_UP(args
->width
* args
->bpp
, 8);
169 if (args
->pitch
< min_pitch
)
170 args
->pitch
= min_pitch
;
172 if (args
->size
< args
->pitch
* args
->height
)
173 args
->size
= args
->pitch
* args
->height
;
175 cma_obj
= drm_gem_cma_create_with_handle(file_priv
, dev
,
176 args
->size
, &args
->handle
);
178 return PTR_ERR(cma_obj
);
182 EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_create
);
185 * drm_gem_cma_dumb_map_offset - (struct drm_driver)->dumb_map_offset callback
188 int drm_gem_cma_dumb_map_offset(struct drm_file
*file_priv
,
189 struct drm_device
*drm
, uint32_t handle
, uint64_t *offset
)
191 struct drm_gem_object
*gem_obj
;
193 mutex_lock(&drm
->struct_mutex
);
195 gem_obj
= drm_gem_object_lookup(drm
, file_priv
, handle
);
197 dev_err(drm
->dev
, "failed to lookup gem object\n");
198 mutex_unlock(&drm
->struct_mutex
);
202 *offset
= get_gem_mmap_offset(gem_obj
);
204 drm_gem_object_unreference(gem_obj
);
206 mutex_unlock(&drm
->struct_mutex
);
210 EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_map_offset
);
212 const struct vm_operations_struct drm_gem_cma_vm_ops
= {
213 .open
= drm_gem_vm_open
,
214 .close
= drm_gem_vm_close
,
216 EXPORT_SYMBOL_GPL(drm_gem_cma_vm_ops
);
219 * drm_gem_cma_mmap - (struct file_operation)->mmap callback function
221 int drm_gem_cma_mmap(struct file
*filp
, struct vm_area_struct
*vma
)
223 struct drm_gem_object
*gem_obj
;
224 struct drm_gem_cma_object
*cma_obj
;
227 ret
= drm_gem_mmap(filp
, vma
);
231 gem_obj
= vma
->vm_private_data
;
232 cma_obj
= to_drm_gem_cma_obj(gem_obj
);
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
);
237 drm_gem_vm_close(vma
);
241 EXPORT_SYMBOL_GPL(drm_gem_cma_mmap
);
244 * drm_gem_cma_dumb_destroy - (struct drm_driver)->dumb_destroy callback function
246 int drm_gem_cma_dumb_destroy(struct drm_file
*file_priv
,
247 struct drm_device
*drm
, unsigned int handle
)
249 return drm_gem_handle_delete(file_priv
, handle
);
251 EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_destroy
);
253 #ifdef CONFIG_DEBUG_FS
254 void drm_gem_cma_describe(struct drm_gem_cma_object
*cma_obj
, struct seq_file
*m
)
256 struct drm_gem_object
*obj
= &cma_obj
->base
;
257 struct drm_device
*dev
= obj
->dev
;
260 WARN_ON(!mutex_is_locked(&dev
->struct_mutex
));
262 if (obj
->map_list
.map
)
263 off
= (uint64_t)obj
->map_list
.hash
.key
;
265 seq_printf(m
, "%2d (%2d) %08llx %08Zx %p %d",
266 obj
->name
, obj
->refcount
.refcount
.counter
,
267 off
, cma_obj
->paddr
, cma_obj
->vaddr
, obj
->size
);
271 EXPORT_SYMBOL_GPL(drm_gem_cma_describe
);