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-buf.h> 25#include <linux/dma-mapping.h> 26 27#include <drm/drmP.h> 28#include <drm/drm.h> 29#include <drm/drm_gem_cma_helper.h> 30#include <drm/drm_vma_manager.h> 31 32/* 33 * __drm_gem_cma_create - Create a GEM CMA object without allocating memory 34 * @drm: The drm device 35 * @size: The GEM object size 36 * 37 * This function creates and initializes a GEM CMA object of the given size, but 38 * doesn't allocate any memory to back the object. 39 * 40 * Return a struct drm_gem_cma_object* on success or ERR_PTR values on failure. 41 */ 42static struct drm_gem_cma_object * 43__drm_gem_cma_create(struct drm_device *drm, unsigned int size) 44{ 45 struct drm_gem_cma_object *cma_obj; 46 struct drm_gem_object *gem_obj; 47 int ret; 48 49 cma_obj = kzalloc(sizeof(*cma_obj), GFP_KERNEL); 50 if (!cma_obj) 51 return ERR_PTR(-ENOMEM); 52 53 gem_obj = &cma_obj->base; 54 55 ret = drm_gem_object_init(drm, gem_obj, size); 56 if (ret) 57 goto error; 58 59 ret = drm_gem_create_mmap_offset(gem_obj); 60 if (ret) { 61 drm_gem_object_release(gem_obj); 62 goto error; 63 } 64 65 return cma_obj; 66 67error: 68 kfree(cma_obj); 69 return ERR_PTR(ret); 70} 71 72/* 73 * drm_gem_cma_create - allocate an object with the given size 74 * 75 * returns a struct drm_gem_cma_object* on success or ERR_PTR values 76 * on failure. 77 */ 78struct drm_gem_cma_object *drm_gem_cma_create(struct drm_device *drm, 79 unsigned int size) 80{ 81 struct drm_gem_cma_object *cma_obj; 82 int ret; 83 84 size = round_up(size, PAGE_SIZE); 85 86 cma_obj = __drm_gem_cma_create(drm, size); 87 if (IS_ERR(cma_obj)) 88 return cma_obj; 89 90 cma_obj->vaddr = dma_alloc_writecombine(drm->dev, size, 91 &cma_obj->paddr, GFP_KERNEL | __GFP_NOWARN); 92 if (!cma_obj->vaddr) { 93 dev_err(drm->dev, "failed to allocate buffer with size %d\n", 94 size); 95 ret = -ENOMEM; 96 goto error; 97 } 98 99 return cma_obj; 100 101error: 102 drm_gem_cma_free_object(&cma_obj->base); 103 return ERR_PTR(ret); 104} 105EXPORT_SYMBOL_GPL(drm_gem_cma_create); 106 107/* 108 * drm_gem_cma_create_with_handle - allocate an object with the given 109 * size and create a gem handle on it 110 * 111 * returns a struct drm_gem_cma_object* on success or ERR_PTR values 112 * on failure. 113 */ 114static struct drm_gem_cma_object *drm_gem_cma_create_with_handle( 115 struct drm_file *file_priv, 116 struct drm_device *drm, unsigned int size, 117 unsigned int *handle) 118{ 119 struct drm_gem_cma_object *cma_obj; 120 struct drm_gem_object *gem_obj; 121 int ret; 122 123 cma_obj = drm_gem_cma_create(drm, size); 124 if (IS_ERR(cma_obj)) 125 return cma_obj; 126 127 gem_obj = &cma_obj->base; 128 129 /* 130 * allocate a id of idr table where the obj is registered 131 * and handle has the id what user can see. 132 */ 133 ret = drm_gem_handle_create(file_priv, gem_obj, handle); 134 if (ret) 135 goto err_handle_create; 136 137 /* drop reference from allocate - handle holds it now. */ 138 drm_gem_object_unreference_unlocked(gem_obj); 139 140 return cma_obj; 141 142err_handle_create: 143 drm_gem_cma_free_object(gem_obj); 144 145 return ERR_PTR(ret); 146} 147 148/* 149 * drm_gem_cma_free_object - (struct drm_driver)->gem_free_object callback 150 * function 151 */ 152void drm_gem_cma_free_object(struct drm_gem_object *gem_obj) 153{ 154 struct drm_gem_cma_object *cma_obj; 155 156 drm_gem_free_mmap_offset(gem_obj); 157 158 cma_obj = to_drm_gem_cma_obj(gem_obj); 159 160 if (cma_obj->vaddr) { 161 dma_free_writecombine(gem_obj->dev->dev, cma_obj->base.size, 162 cma_obj->vaddr, cma_obj->paddr); 163 } else if (gem_obj->import_attach) { 164 drm_prime_gem_destroy(gem_obj, cma_obj->sgt); 165 } 166 167 drm_gem_object_release(gem_obj); 168 169 kfree(cma_obj); 170} 171EXPORT_SYMBOL_GPL(drm_gem_cma_free_object); 172 173/* 174 * drm_gem_cma_dumb_create - (struct drm_driver)->dumb_create callback 175 * function 176 * 177 * This aligns the pitch and size arguments to the minimum required. wrap 178 * this into your own function if you need bigger alignment. 179 */ 180int drm_gem_cma_dumb_create(struct drm_file *file_priv, 181 struct drm_device *dev, struct drm_mode_create_dumb *args) 182{ 183 struct drm_gem_cma_object *cma_obj; 184 int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8); 185 186 if (args->pitch < min_pitch) 187 args->pitch = min_pitch; 188 189 if (args->size < args->pitch * args->height) 190 args->size = args->pitch * args->height; 191 192 cma_obj = drm_gem_cma_create_with_handle(file_priv, dev, 193 args->size, &args->handle); 194 return PTR_ERR_OR_ZERO(cma_obj); 195} 196EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_create); 197 198/* 199 * drm_gem_cma_dumb_map_offset - (struct drm_driver)->dumb_map_offset callback 200 * function 201 */ 202int drm_gem_cma_dumb_map_offset(struct drm_file *file_priv, 203 struct drm_device *drm, uint32_t handle, uint64_t *offset) 204{ 205 struct drm_gem_object *gem_obj; 206 207 mutex_lock(&drm->struct_mutex); 208 209 gem_obj = drm_gem_object_lookup(drm, file_priv, handle); 210 if (!gem_obj) { 211 dev_err(drm->dev, "failed to lookup gem object\n"); 212 mutex_unlock(&drm->struct_mutex); 213 return -EINVAL; 214 } 215 216 *offset = drm_vma_node_offset_addr(&gem_obj->vma_node); 217 218 drm_gem_object_unreference(gem_obj); 219 220 mutex_unlock(&drm->struct_mutex); 221 222 return 0; 223} 224EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_map_offset); 225 226const struct vm_operations_struct drm_gem_cma_vm_ops = { 227 .open = drm_gem_vm_open, 228 .close = drm_gem_vm_close, 229}; 230EXPORT_SYMBOL_GPL(drm_gem_cma_vm_ops); 231 232static int drm_gem_cma_mmap_obj(struct drm_gem_cma_object *cma_obj, 233 struct vm_area_struct *vma) 234{ 235 int ret; 236 237 /* 238 * Clear the VM_PFNMAP flag that was set by drm_gem_mmap(), and set the 239 * vm_pgoff (used as a fake buffer offset by DRM) to 0 as we want to map 240 * the whole buffer. 241 */ 242 vma->vm_flags &= ~VM_PFNMAP; 243 vma->vm_pgoff = 0; 244 245 ret = dma_mmap_writecombine(cma_obj->base.dev->dev, vma, 246 cma_obj->vaddr, cma_obj->paddr, 247 vma->vm_end - vma->vm_start); 248 if (ret) 249 drm_gem_vm_close(vma); 250 251 return ret; 252} 253 254/* 255 * drm_gem_cma_mmap - (struct file_operation)->mmap callback function 256 */ 257int drm_gem_cma_mmap(struct file *filp, struct vm_area_struct *vma) 258{ 259 struct drm_gem_cma_object *cma_obj; 260 struct drm_gem_object *gem_obj; 261 int ret; 262 263 ret = drm_gem_mmap(filp, vma); 264 if (ret) 265 return ret; 266 267 gem_obj = vma->vm_private_data; 268 cma_obj = to_drm_gem_cma_obj(gem_obj); 269 270 return drm_gem_cma_mmap_obj(cma_obj, vma); 271} 272EXPORT_SYMBOL_GPL(drm_gem_cma_mmap); 273 274#ifdef CONFIG_DEBUG_FS 275void drm_gem_cma_describe(struct drm_gem_cma_object *cma_obj, struct seq_file *m) 276{ 277 struct drm_gem_object *obj = &cma_obj->base; 278 struct drm_device *dev = obj->dev; 279 uint64_t off; 280 281 WARN_ON(!mutex_is_locked(&dev->struct_mutex)); 282 283 off = drm_vma_node_start(&obj->vma_node); 284 285 seq_printf(m, "%2d (%2d) %08llx %pad %p %d", 286 obj->name, obj->refcount.refcount.counter, 287 off, &cma_obj->paddr, cma_obj->vaddr, obj->size); 288 289 seq_printf(m, "\n"); 290} 291EXPORT_SYMBOL_GPL(drm_gem_cma_describe); 292#endif 293 294/* low-level interface prime helpers */ 295struct sg_table *drm_gem_cma_prime_get_sg_table(struct drm_gem_object *obj) 296{ 297 struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(obj); 298 struct sg_table *sgt; 299 int ret; 300 301 sgt = kzalloc(sizeof(*sgt), GFP_KERNEL); 302 if (!sgt) 303 return NULL; 304 305 ret = dma_get_sgtable(obj->dev->dev, sgt, cma_obj->vaddr, 306 cma_obj->paddr, obj->size); 307 if (ret < 0) 308 goto out; 309 310 return sgt; 311 312out: 313 kfree(sgt); 314 return NULL; 315} 316EXPORT_SYMBOL_GPL(drm_gem_cma_prime_get_sg_table); 317 318struct drm_gem_object * 319drm_gem_cma_prime_import_sg_table(struct drm_device *dev, 320 struct dma_buf_attachment *attach, 321 struct sg_table *sgt) 322{ 323 struct drm_gem_cma_object *cma_obj; 324 325 if (sgt->nents != 1) 326 return ERR_PTR(-EINVAL); 327 328 /* Create a CMA GEM buffer. */ 329 cma_obj = __drm_gem_cma_create(dev, attach->dmabuf->size); 330 if (IS_ERR(cma_obj)) 331 return ERR_CAST(cma_obj); 332 333 cma_obj->paddr = sg_dma_address(sgt->sgl); 334 cma_obj->sgt = sgt; 335 336 DRM_DEBUG_PRIME("dma_addr = %pad, size = %zu\n", &cma_obj->paddr, attach->dmabuf->size); 337 338 return &cma_obj->base; 339} 340EXPORT_SYMBOL_GPL(drm_gem_cma_prime_import_sg_table); 341 342int drm_gem_cma_prime_mmap(struct drm_gem_object *obj, 343 struct vm_area_struct *vma) 344{ 345 struct drm_gem_cma_object *cma_obj; 346 struct drm_device *dev = obj->dev; 347 int ret; 348 349 mutex_lock(&dev->struct_mutex); 350 ret = drm_gem_mmap_obj(obj, obj->size, vma); 351 mutex_unlock(&dev->struct_mutex); 352 if (ret < 0) 353 return ret; 354 355 cma_obj = to_drm_gem_cma_obj(obj); 356 return drm_gem_cma_mmap_obj(cma_obj, vma); 357} 358EXPORT_SYMBOL_GPL(drm_gem_cma_prime_mmap); 359 360void *drm_gem_cma_prime_vmap(struct drm_gem_object *obj) 361{ 362 struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(obj); 363 364 return cma_obj->vaddr; 365} 366EXPORT_SYMBOL_GPL(drm_gem_cma_prime_vmap); 367 368void drm_gem_cma_prime_vunmap(struct drm_gem_object *obj, void *vaddr) 369{ 370 /* Nothing to do */ 371} 372EXPORT_SYMBOL_GPL(drm_gem_cma_prime_vunmap); 373