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;
36 * __drm_gem_cma_create - Create a GEM CMA object without allocating memory
37 * @drm: The drm device
38 * @size: The GEM object size
40 * This function creates and initializes a GEM CMA object of the given size, but
41 * doesn't allocate any memory to back the object.
43 * Return a struct drm_gem_cma_object* on success or ERR_PTR values on failure.
45 static struct drm_gem_cma_object *
46 __drm_gem_cma_create(struct drm_device *drm, unsigned int size)
48 struct drm_gem_cma_object *cma_obj;
49 struct drm_gem_object *gem_obj;
52 cma_obj = kzalloc(sizeof(*cma_obj), GFP_KERNEL);
54 return ERR_PTR(-ENOMEM);
56 gem_obj = &cma_obj->base;
58 ret = drm_gem_object_init(drm, gem_obj, size);
62 ret = drm_gem_create_mmap_offset(gem_obj);
64 drm_gem_object_release(gem_obj);
76 * drm_gem_cma_create - allocate an object with the given size
78 * returns a struct drm_gem_cma_object* on success or ERR_PTR values
81 struct drm_gem_cma_object *drm_gem_cma_create(struct drm_device *drm,
84 struct drm_gem_cma_object *cma_obj;
86 size = round_up(size, PAGE_SIZE);
88 cma_obj = __drm_gem_cma_create(drm, size);
92 cma_obj->vaddr = dma_alloc_writecombine(drm->dev, size,
93 &cma_obj->paddr, GFP_KERNEL | __GFP_NOWARN);
94 if (!cma_obj->vaddr) {
95 dev_err(drm->dev, "failed to allocate buffer with size %d\n",
97 drm_gem_cma_free_object(&cma_obj->base);
98 return ERR_PTR(-ENOMEM);
103 EXPORT_SYMBOL_GPL(drm_gem_cma_create);
106 * drm_gem_cma_create_with_handle - allocate an object with the given
107 * size and create a gem handle on it
109 * returns a struct drm_gem_cma_object* on success or ERR_PTR values
112 static struct drm_gem_cma_object *drm_gem_cma_create_with_handle(
113 struct drm_file *file_priv,
114 struct drm_device *drm, unsigned int size,
115 unsigned int *handle)
117 struct drm_gem_cma_object *cma_obj;
118 struct drm_gem_object *gem_obj;
121 cma_obj = drm_gem_cma_create(drm, size);
125 gem_obj = &cma_obj->base;
128 * allocate a id of idr table where the obj is registered
129 * and handle has the id what user can see.
131 ret = drm_gem_handle_create(file_priv, gem_obj, handle);
133 goto err_handle_create;
135 /* drop reference from allocate - handle holds it now. */
136 drm_gem_object_unreference_unlocked(gem_obj);
141 drm_gem_cma_free_object(gem_obj);
147 * drm_gem_cma_free_object - (struct drm_driver)->gem_free_object callback
150 void drm_gem_cma_free_object(struct drm_gem_object *gem_obj)
152 struct drm_gem_cma_object *cma_obj;
154 if (gem_obj->map_list.map)
155 drm_gem_free_mmap_offset(gem_obj);
157 cma_obj = to_drm_gem_cma_obj(gem_obj);
160 dma_free_writecombine(gem_obj->dev->dev, cma_obj->base.size,
161 cma_obj->vaddr, cma_obj->paddr);
163 drm_gem_object_release(gem_obj);
167 EXPORT_SYMBOL_GPL(drm_gem_cma_free_object);
170 * drm_gem_cma_dumb_create - (struct drm_driver)->dumb_create callback
173 * This aligns the pitch and size arguments to the minimum required. wrap
174 * this into your own function if you need bigger alignment.
176 int drm_gem_cma_dumb_create(struct drm_file *file_priv,
177 struct drm_device *dev, struct drm_mode_create_dumb *args)
179 struct drm_gem_cma_object *cma_obj;
180 int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
182 if (args->pitch < min_pitch)
183 args->pitch = min_pitch;
185 if (args->size < args->pitch * args->height)
186 args->size = args->pitch * args->height;
188 cma_obj = drm_gem_cma_create_with_handle(file_priv, dev,
189 args->size, &args->handle);
191 return PTR_ERR(cma_obj);
195 EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_create);
198 * drm_gem_cma_dumb_map_offset - (struct drm_driver)->dumb_map_offset callback
201 int drm_gem_cma_dumb_map_offset(struct drm_file *file_priv,
202 struct drm_device *drm, uint32_t handle, uint64_t *offset)
204 struct drm_gem_object *gem_obj;
206 mutex_lock(&drm->struct_mutex);
208 gem_obj = drm_gem_object_lookup(drm, file_priv, handle);
210 dev_err(drm->dev, "failed to lookup gem object\n");
211 mutex_unlock(&drm->struct_mutex);
215 *offset = get_gem_mmap_offset(gem_obj);
217 drm_gem_object_unreference(gem_obj);
219 mutex_unlock(&drm->struct_mutex);
223 EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_map_offset);
225 const struct vm_operations_struct drm_gem_cma_vm_ops = {
226 .open = drm_gem_vm_open,
227 .close = drm_gem_vm_close,
229 EXPORT_SYMBOL_GPL(drm_gem_cma_vm_ops);
232 * drm_gem_cma_mmap - (struct file_operation)->mmap callback function
234 int drm_gem_cma_mmap(struct file *filp, struct vm_area_struct *vma)
236 struct drm_gem_object *gem_obj;
237 struct drm_gem_cma_object *cma_obj;
240 ret = drm_gem_mmap(filp, vma);
244 gem_obj = vma->vm_private_data;
245 cma_obj = to_drm_gem_cma_obj(gem_obj);
247 ret = remap_pfn_range(vma, vma->vm_start, cma_obj->paddr >> PAGE_SHIFT,
248 vma->vm_end - vma->vm_start, vma->vm_page_prot);
250 drm_gem_vm_close(vma);
254 EXPORT_SYMBOL_GPL(drm_gem_cma_mmap);
257 * drm_gem_cma_dumb_destroy - (struct drm_driver)->dumb_destroy callback function
259 int drm_gem_cma_dumb_destroy(struct drm_file *file_priv,
260 struct drm_device *drm, unsigned int handle)
262 return drm_gem_handle_delete(file_priv, handle);
264 EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_destroy);
266 #ifdef CONFIG_DEBUG_FS
267 void drm_gem_cma_describe(struct drm_gem_cma_object *cma_obj, struct seq_file *m)
269 struct drm_gem_object *obj = &cma_obj->base;
270 struct drm_device *dev = obj->dev;
273 WARN_ON(!mutex_is_locked(&dev->struct_mutex));
275 if (obj->map_list.map)
276 off = (uint64_t)obj->map_list.hash.key;
278 seq_printf(m, "%2d (%2d) %08llx %08Zx %p %d",
279 obj->name, obj->refcount.refcount.counter,
280 off, cma_obj->paddr, cma_obj->vaddr, obj->size);
284 EXPORT_SYMBOL_GPL(drm_gem_cma_describe);