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-buf.h>
25 #include <linux/dma-mapping.h>
29 #include <drm/drm_gem_cma_helper.h>
31 static unsigned int get_gem_mmap_offset(struct drm_gem_object *obj)
33 return (unsigned int)obj->map_list.hash.key << PAGE_SHIFT;
37 * __drm_gem_cma_create - Create a GEM CMA object without allocating memory
38 * @drm: The drm device
39 * @size: The GEM object size
41 * This function creates and initializes a GEM CMA object of the given size, but
42 * doesn't allocate any memory to back the object.
44 * Return a struct drm_gem_cma_object* on success or ERR_PTR values on failure.
46 static struct drm_gem_cma_object *
47 __drm_gem_cma_create(struct drm_device *drm, unsigned int size)
49 struct drm_gem_cma_object *cma_obj;
50 struct drm_gem_object *gem_obj;
53 cma_obj = kzalloc(sizeof(*cma_obj), GFP_KERNEL);
55 return ERR_PTR(-ENOMEM);
57 gem_obj = &cma_obj->base;
59 ret = drm_gem_object_init(drm, gem_obj, size);
63 ret = drm_gem_create_mmap_offset(gem_obj);
65 drm_gem_object_release(gem_obj);
77 * drm_gem_cma_create - allocate an object with the given size
79 * returns a struct drm_gem_cma_object* on success or ERR_PTR values
82 struct drm_gem_cma_object *drm_gem_cma_create(struct drm_device *drm,
85 struct drm_gem_cma_object *cma_obj;
86 struct sg_table *sgt = NULL;
89 size = round_up(size, PAGE_SIZE);
91 cma_obj = __drm_gem_cma_create(drm, size);
95 cma_obj->vaddr = dma_alloc_writecombine(drm->dev, size,
96 &cma_obj->paddr, GFP_KERNEL | __GFP_NOWARN);
97 if (!cma_obj->vaddr) {
98 dev_err(drm->dev, "failed to allocate buffer with size %d\n",
104 sgt = kzalloc(sizeof(*cma_obj->sgt), GFP_KERNEL);
110 ret = dma_get_sgtable(drm->dev, sgt, cma_obj->vaddr,
111 cma_obj->paddr, size);
121 drm_gem_cma_free_object(&cma_obj->base);
124 EXPORT_SYMBOL_GPL(drm_gem_cma_create);
127 * drm_gem_cma_create_with_handle - allocate an object with the given
128 * size and create a gem handle on it
130 * returns a struct drm_gem_cma_object* on success or ERR_PTR values
133 static struct drm_gem_cma_object *drm_gem_cma_create_with_handle(
134 struct drm_file *file_priv,
135 struct drm_device *drm, unsigned int size,
136 unsigned int *handle)
138 struct drm_gem_cma_object *cma_obj;
139 struct drm_gem_object *gem_obj;
142 cma_obj = drm_gem_cma_create(drm, size);
146 gem_obj = &cma_obj->base;
149 * allocate a id of idr table where the obj is registered
150 * and handle has the id what user can see.
152 ret = drm_gem_handle_create(file_priv, gem_obj, handle);
154 goto err_handle_create;
156 /* drop reference from allocate - handle holds it now. */
157 drm_gem_object_unreference_unlocked(gem_obj);
162 drm_gem_cma_free_object(gem_obj);
168 * drm_gem_cma_free_object - (struct drm_driver)->gem_free_object callback
171 void drm_gem_cma_free_object(struct drm_gem_object *gem_obj)
173 struct drm_gem_cma_object *cma_obj;
175 if (gem_obj->map_list.map)
176 drm_gem_free_mmap_offset(gem_obj);
178 cma_obj = to_drm_gem_cma_obj(gem_obj);
180 if (cma_obj->vaddr) {
181 dma_free_writecombine(gem_obj->dev->dev, cma_obj->base.size,
182 cma_obj->vaddr, cma_obj->paddr);
184 sg_free_table(cma_obj->sgt);
187 } else if (gem_obj->import_attach) {
188 drm_prime_gem_destroy(gem_obj, cma_obj->sgt);
191 drm_gem_object_release(gem_obj);
195 EXPORT_SYMBOL_GPL(drm_gem_cma_free_object);
198 * drm_gem_cma_dumb_create - (struct drm_driver)->dumb_create callback
201 * This aligns the pitch and size arguments to the minimum required. wrap
202 * this into your own function if you need bigger alignment.
204 int drm_gem_cma_dumb_create(struct drm_file *file_priv,
205 struct drm_device *dev, struct drm_mode_create_dumb *args)
207 struct drm_gem_cma_object *cma_obj;
208 int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
210 if (args->pitch < min_pitch)
211 args->pitch = min_pitch;
213 if (args->size < args->pitch * args->height)
214 args->size = args->pitch * args->height;
216 cma_obj = drm_gem_cma_create_with_handle(file_priv, dev,
217 args->size, &args->handle);
218 return PTR_RET(cma_obj);
220 EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_create);
223 * drm_gem_cma_dumb_map_offset - (struct drm_driver)->dumb_map_offset callback
226 int drm_gem_cma_dumb_map_offset(struct drm_file *file_priv,
227 struct drm_device *drm, uint32_t handle, uint64_t *offset)
229 struct drm_gem_object *gem_obj;
231 mutex_lock(&drm->struct_mutex);
233 gem_obj = drm_gem_object_lookup(drm, file_priv, handle);
235 dev_err(drm->dev, "failed to lookup gem object\n");
236 mutex_unlock(&drm->struct_mutex);
240 *offset = get_gem_mmap_offset(gem_obj);
242 drm_gem_object_unreference(gem_obj);
244 mutex_unlock(&drm->struct_mutex);
248 EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_map_offset);
250 const struct vm_operations_struct drm_gem_cma_vm_ops = {
251 .open = drm_gem_vm_open,
252 .close = drm_gem_vm_close,
254 EXPORT_SYMBOL_GPL(drm_gem_cma_vm_ops);
256 static int drm_gem_cma_mmap_obj(struct drm_gem_cma_object *cma_obj,
257 struct vm_area_struct *vma)
261 ret = remap_pfn_range(vma, vma->vm_start, cma_obj->paddr >> PAGE_SHIFT,
262 vma->vm_end - vma->vm_start, vma->vm_page_prot);
264 drm_gem_vm_close(vma);
270 * drm_gem_cma_mmap - (struct file_operation)->mmap callback function
272 int drm_gem_cma_mmap(struct file *filp, struct vm_area_struct *vma)
274 struct drm_gem_cma_object *cma_obj;
275 struct drm_gem_object *gem_obj;
278 ret = drm_gem_mmap(filp, vma);
282 gem_obj = vma->vm_private_data;
283 cma_obj = to_drm_gem_cma_obj(gem_obj);
285 return drm_gem_cma_mmap_obj(cma_obj, vma);
287 EXPORT_SYMBOL_GPL(drm_gem_cma_mmap);
290 * drm_gem_cma_dumb_destroy - (struct drm_driver)->dumb_destroy callback function
292 int drm_gem_cma_dumb_destroy(struct drm_file *file_priv,
293 struct drm_device *drm, unsigned int handle)
295 return drm_gem_handle_delete(file_priv, handle);
297 EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_destroy);
299 #ifdef CONFIG_DEBUG_FS
300 void drm_gem_cma_describe(struct drm_gem_cma_object *cma_obj, struct seq_file *m)
302 struct drm_gem_object *obj = &cma_obj->base;
303 struct drm_device *dev = obj->dev;
306 WARN_ON(!mutex_is_locked(&dev->struct_mutex));
308 if (obj->map_list.map)
309 off = (uint64_t)obj->map_list.hash.key;
311 seq_printf(m, "%2d (%2d) %08llx %08Zx %p %d",
312 obj->name, obj->refcount.refcount.counter,
313 off, cma_obj->paddr, cma_obj->vaddr, obj->size);
317 EXPORT_SYMBOL_GPL(drm_gem_cma_describe);
320 /* low-level interface prime helpers */
321 struct sg_table *drm_gem_cma_prime_get_sg_table(struct drm_gem_object *obj)
323 struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(obj);
324 struct sg_table *sgt;
327 sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
331 ret = dma_get_sgtable(obj->dev->dev, sgt, cma_obj->vaddr,
332 cma_obj->paddr, obj->size);
342 EXPORT_SYMBOL_GPL(drm_gem_cma_prime_get_sg_table);
344 struct drm_gem_object *
345 drm_gem_cma_prime_import_sg_table(struct drm_device *dev, size_t size,
346 struct sg_table *sgt)
348 struct drm_gem_cma_object *cma_obj;
351 return ERR_PTR(-EINVAL);
353 /* Create a CMA GEM buffer. */
354 cma_obj = __drm_gem_cma_create(dev, size);
356 return ERR_PTR(PTR_ERR(cma_obj));
358 cma_obj->paddr = sg_dma_address(sgt->sgl);
361 DRM_DEBUG_PRIME("dma_addr = 0x%x, size = %zu\n", cma_obj->paddr, size);
363 return &cma_obj->base;
365 EXPORT_SYMBOL_GPL(drm_gem_cma_prime_import_sg_table);
367 int drm_gem_cma_prime_mmap(struct drm_gem_object *obj,
368 struct vm_area_struct *vma)
370 struct drm_gem_cma_object *cma_obj;
371 struct drm_device *dev = obj->dev;
374 mutex_lock(&dev->struct_mutex);
375 ret = drm_gem_mmap_obj(obj, obj->size, vma);
376 mutex_unlock(&dev->struct_mutex);
380 cma_obj = to_drm_gem_cma_obj(obj);
381 return drm_gem_cma_mmap_obj(cma_obj, vma);
383 EXPORT_SYMBOL_GPL(drm_gem_cma_prime_mmap);
385 void *drm_gem_cma_prime_vmap(struct drm_gem_object *obj)
387 struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(obj);
389 return cma_obj->vaddr;
391 EXPORT_SYMBOL_GPL(drm_gem_cma_prime_vmap);
393 void drm_gem_cma_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
397 EXPORT_SYMBOL_GPL(drm_gem_cma_prime_vunmap);