drivers/gpu/drm/drm_gem_cma_helper.c

   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  */
  42 static 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
  67 error:
  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  */
  78 struct 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
 101 error:
 102         drm_gem_cma_free_object(&cma_obj->base);
 103         return ERR_PTR(ret);
 104 }
 105 EXPORT_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  */
 114 static 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
 142 err_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  */
 152 void 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 }
 171 EXPORT_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  */
 180 int 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 }
 196 EXPORT_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  */
 202 int 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 }
 224 EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_map_offset);
 225
 226 const struct vm_operations_struct drm_gem_cma_vm_ops = {
 227         .open = drm_gem_vm_open,
 228         .close = drm_gem_vm_close,
 229 };
 230 EXPORT_SYMBOL_GPL(drm_gem_cma_vm_ops);
 231
 232 static 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  */
 257 int 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 }
 272 EXPORT_SYMBOL_GPL(drm_gem_cma_mmap);
 273
 274 #ifdef CONFIG_DEBUG_FS
 275 void 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 }
 291 EXPORT_SYMBOL_GPL(drm_gem_cma_describe);
 292 #endif
 293
 294 /* low-level interface prime helpers */
 295 struct 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
 312 out:
 313         kfree(sgt);
 314         return NULL;
 315 }
 316 EXPORT_SYMBOL_GPL(drm_gem_cma_prime_get_sg_table);
 317
 318 struct drm_gem_object *
 319 drm_gem_cma_prime_import_sg_table(struct drm_device *dev, size_t size,
 320                                   struct sg_table *sgt)
 321 {
 322         struct drm_gem_cma_object *cma_obj;
 323
 324         if (sgt->nents != 1)
 325                 return ERR_PTR(-EINVAL);
 326
 327         /* Create a CMA GEM buffer. */
 328         cma_obj = __drm_gem_cma_create(dev, size);
 329         if (IS_ERR(cma_obj))
 330                 return ERR_PTR(PTR_ERR(cma_obj));
 331
 332         cma_obj->paddr = sg_dma_address(sgt->sgl);
 333         cma_obj->sgt = sgt;
 334
 335         DRM_DEBUG_PRIME("dma_addr = %pad, size = %zu\n", &cma_obj->paddr, size);
 336
 337         return &cma_obj->base;
 338 }
 339 EXPORT_SYMBOL_GPL(drm_gem_cma_prime_import_sg_table);
 340
 341 int drm_gem_cma_prime_mmap(struct drm_gem_object *obj,
 342                            struct vm_area_struct *vma)
 343 {
 344         struct drm_gem_cma_object *cma_obj;
 345         struct drm_device *dev = obj->dev;
 346         int ret;
 347
 348         mutex_lock(&dev->struct_mutex);
 349         ret = drm_gem_mmap_obj(obj, obj->size, vma);
 350         mutex_unlock(&dev->struct_mutex);
 351         if (ret < 0)
 352                 return ret;
 353
 354         cma_obj = to_drm_gem_cma_obj(obj);
 355         return drm_gem_cma_mmap_obj(cma_obj, vma);
 356 }
 357 EXPORT_SYMBOL_GPL(drm_gem_cma_prime_mmap);
 358
 359 void *drm_gem_cma_prime_vmap(struct drm_gem_object *obj)
 360 {
 361         struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(obj);
 362
 363         return cma_obj->vaddr;
 364 }
 365 EXPORT_SYMBOL_GPL(drm_gem_cma_prime_vmap);
 366
 367 void drm_gem_cma_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
 368 {
 369         /* Nothing to do */
 370 }
 371 EXPORT_SYMBOL_GPL(drm_gem_cma_prime_vunmap);