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-mapping.h>
  25
  26 #include <drm/drmP.h>
  27 #include <drm/drm.h>
  28 #include <drm/drm_gem_cma_helper.h>
  29
  30 static unsigned int get_gem_mmap_offset(struct drm_gem_object *obj)
  31 {
  32         return (unsigned int)obj->map_list.hash.key << PAGE_SHIFT;
  33 }
  34
  35 /*
  36  * __drm_gem_cma_create - Create a GEM CMA object without allocating memory
  37  * @drm: The drm device
  38  * @size: The GEM object size
  39  *
  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.
  42  *
  43  * Return a struct drm_gem_cma_object* on success or ERR_PTR values on failure.
  44  */
  45 static struct drm_gem_cma_object *
  46 __drm_gem_cma_create(struct drm_device *drm, unsigned int size)
  47 {
  48         struct drm_gem_cma_object *cma_obj;
  49         struct drm_gem_object *gem_obj;
  50         int ret;
  51
  52         cma_obj = kzalloc(sizeof(*cma_obj), GFP_KERNEL);
  53         if (!cma_obj)
  54                 return ERR_PTR(-ENOMEM);
  55
  56         gem_obj = &cma_obj->base;
  57
  58         ret = drm_gem_object_init(drm, gem_obj, size);
  59         if (ret)
  60                 goto error;
  61
  62         ret = drm_gem_create_mmap_offset(gem_obj);
  63         if (ret) {
  64                 drm_gem_object_release(gem_obj);
  65                 goto error;
  66         }
  67
  68         return cma_obj;
  69
  70 error:
  71         kfree(cma_obj);
  72         return ERR_PTR(ret);
  73 }
  74
  75 /*
  76  * drm_gem_cma_create - allocate an object with the given size
  77  *
  78  * returns a struct drm_gem_cma_object* on success or ERR_PTR values
  79  * on failure.
  80  */
  81 struct drm_gem_cma_object *drm_gem_cma_create(struct drm_device *drm,
  82                 unsigned int size)
  83 {
  84         struct drm_gem_cma_object *cma_obj;
  85
  86         size = round_up(size, PAGE_SIZE);
  87
  88         cma_obj = __drm_gem_cma_create(drm, size);
  89         if (IS_ERR(cma_obj))
  90                 return cma_obj;
  91
  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",
  96                         size);
  97                 drm_gem_cma_free_object(&cma_obj->base);
  98                 return ERR_PTR(-ENOMEM);
  99         }
 100
 101         return cma_obj;
 102 }
 103 EXPORT_SYMBOL_GPL(drm_gem_cma_create);
 104
 105 /*
 106  * drm_gem_cma_create_with_handle - allocate an object with the given
 107  * size and create a gem handle on it
 108  *
 109  * returns a struct drm_gem_cma_object* on success or ERR_PTR values
 110  * on failure.
 111  */
 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)
 116 {
 117         struct drm_gem_cma_object *cma_obj;
 118         struct drm_gem_object *gem_obj;
 119         int ret;
 120
 121         cma_obj = drm_gem_cma_create(drm, size);
 122         if (IS_ERR(cma_obj))
 123                 return cma_obj;
 124
 125         gem_obj = &cma_obj->base;
 126
 127         /*
 128          * allocate a id of idr table where the obj is registered
 129          * and handle has the id what user can see.
 130          */
 131         ret = drm_gem_handle_create(file_priv, gem_obj, handle);
 132         if (ret)
 133                 goto err_handle_create;
 134
 135         /* drop reference from allocate - handle holds it now. */
 136         drm_gem_object_unreference_unlocked(gem_obj);
 137
 138         return cma_obj;
 139
 140 err_handle_create:
 141         drm_gem_cma_free_object(gem_obj);
 142
 143         return ERR_PTR(ret);
 144 }
 145
 146 /*
 147  * drm_gem_cma_free_object - (struct drm_driver)->gem_free_object callback
 148  * function
 149  */
 150 void drm_gem_cma_free_object(struct drm_gem_object *gem_obj)
 151 {
 152         struct drm_gem_cma_object *cma_obj;
 153
 154         if (gem_obj->map_list.map)
 155                 drm_gem_free_mmap_offset(gem_obj);
 156
 157         cma_obj = to_drm_gem_cma_obj(gem_obj);
 158
 159         if (cma_obj->vaddr)
 160                 dma_free_writecombine(gem_obj->dev->dev, cma_obj->base.size,
 161                                       cma_obj->vaddr, cma_obj->paddr);
 162
 163         drm_gem_object_release(gem_obj);
 164
 165         kfree(cma_obj);
 166 }
 167 EXPORT_SYMBOL_GPL(drm_gem_cma_free_object);
 168
 169 /*
 170  * drm_gem_cma_dumb_create - (struct drm_driver)->dumb_create callback
 171  * function
 172  *
 173  * This aligns the pitch and size arguments to the minimum required. wrap
 174  * this into your own function if you need bigger alignment.
 175  */
 176 int drm_gem_cma_dumb_create(struct drm_file *file_priv,
 177                 struct drm_device *dev, struct drm_mode_create_dumb *args)
 178 {
 179         struct drm_gem_cma_object *cma_obj;
 180         int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
 181
 182         if (args->pitch < min_pitch)
 183                 args->pitch = min_pitch;
 184
 185         if (args->size < args->pitch * args->height)
 186                 args->size = args->pitch * args->height;
 187
 188         cma_obj = drm_gem_cma_create_with_handle(file_priv, dev,
 189                         args->size, &args->handle);
 190         if (IS_ERR(cma_obj))
 191                 return PTR_ERR(cma_obj);
 192
 193         return 0;
 194 }
 195 EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_create);
 196
 197 /*
 198  * drm_gem_cma_dumb_map_offset - (struct drm_driver)->dumb_map_offset callback
 199  * function
 200  */
 201 int drm_gem_cma_dumb_map_offset(struct drm_file *file_priv,
 202                 struct drm_device *drm, uint32_t handle, uint64_t *offset)
 203 {
 204         struct drm_gem_object *gem_obj;
 205
 206         mutex_lock(&drm->struct_mutex);
 207
 208         gem_obj = drm_gem_object_lookup(drm, file_priv, handle);
 209         if (!gem_obj) {
 210                 dev_err(drm->dev, "failed to lookup gem object\n");
 211                 mutex_unlock(&drm->struct_mutex);
 212                 return -EINVAL;
 213         }
 214
 215         *offset = get_gem_mmap_offset(gem_obj);
 216
 217         drm_gem_object_unreference(gem_obj);
 218
 219         mutex_unlock(&drm->struct_mutex);
 220
 221         return 0;
 222 }
 223 EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_map_offset);
 224
 225 const struct vm_operations_struct drm_gem_cma_vm_ops = {
 226         .open = drm_gem_vm_open,
 227         .close = drm_gem_vm_close,
 228 };
 229 EXPORT_SYMBOL_GPL(drm_gem_cma_vm_ops);
 230
 231 /*
 232  * drm_gem_cma_mmap - (struct file_operation)->mmap callback function
 233  */
 234 int drm_gem_cma_mmap(struct file *filp, struct vm_area_struct *vma)
 235 {
 236         struct drm_gem_object *gem_obj;
 237         struct drm_gem_cma_object *cma_obj;
 238         int ret;
 239
 240         ret = drm_gem_mmap(filp, vma);
 241         if (ret)
 242                 return ret;
 243
 244         gem_obj = vma->vm_private_data;
 245         cma_obj = to_drm_gem_cma_obj(gem_obj);
 246
 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);
 249         if (ret)
 250                 drm_gem_vm_close(vma);
 251
 252         return ret;
 253 }
 254 EXPORT_SYMBOL_GPL(drm_gem_cma_mmap);
 255
 256 /*
 257  * drm_gem_cma_dumb_destroy - (struct drm_driver)->dumb_destroy callback function
 258  */
 259 int drm_gem_cma_dumb_destroy(struct drm_file *file_priv,
 260                 struct drm_device *drm, unsigned int handle)
 261 {
 262         return drm_gem_handle_delete(file_priv, handle);
 263 }
 264 EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_destroy);
 265
 266 #ifdef CONFIG_DEBUG_FS
 267 void drm_gem_cma_describe(struct drm_gem_cma_object *cma_obj, struct seq_file *m)
 268 {
 269         struct drm_gem_object *obj = &cma_obj->base;
 270         struct drm_device *dev = obj->dev;
 271         uint64_t off = 0;
 272
 273         WARN_ON(!mutex_is_locked(&dev->struct_mutex));
 274
 275         if (obj->map_list.map)
 276                 off = (uint64_t)obj->map_list.hash.key;
 277
 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);
 281
 282         seq_printf(m, "\n");
 283 }
 284 EXPORT_SYMBOL_GPL(drm_gem_cma_describe);
 285 #endif