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 static void drm_gem_cma_buf_destroy(struct drm_device *drm,
  36                 struct drm_gem_cma_object *cma_obj)
  37 {
  38         dma_free_writecombine(drm->dev, cma_obj->base.size, cma_obj->vaddr,
  39                         cma_obj->paddr);
  40 }
  41
  42 /*
  43  * drm_gem_cma_create - allocate an object with the given size
  44  *
  45  * returns a struct drm_gem_cma_object* on success or ERR_PTR values
  46  * on failure.
  47  */
  48 struct drm_gem_cma_object *drm_gem_cma_create(struct drm_device *drm,
  49                 unsigned int size)
  50 {
  51         struct drm_gem_cma_object *cma_obj;
  52         struct drm_gem_object *gem_obj;
  53         int ret;
  54
  55         size = round_up(size, PAGE_SIZE);
  56
  57         cma_obj = kzalloc(sizeof(*cma_obj), GFP_KERNEL);
  58         if (!cma_obj)
  59                 return ERR_PTR(-ENOMEM);
  60
  61         cma_obj->vaddr = dma_alloc_writecombine(drm->dev, size,
  62                         &cma_obj->paddr, GFP_KERNEL | __GFP_NOWARN);
  63         if (!cma_obj->vaddr) {
  64                 dev_err(drm->dev, "failed to allocate buffer with size %d\n", size);
  65                 ret = -ENOMEM;
  66                 goto err_dma_alloc;
  67         }
  68
  69         gem_obj = &cma_obj->base;
  70
  71         ret = drm_gem_object_init(drm, gem_obj, size);
  72         if (ret)
  73                 goto err_obj_init;
  74
  75         ret = drm_gem_create_mmap_offset(gem_obj);
  76         if (ret)
  77                 goto err_create_mmap_offset;
  78
  79         return cma_obj;
  80
  81 err_create_mmap_offset:
  82         drm_gem_object_release(gem_obj);
  83
  84 err_obj_init:
  85         drm_gem_cma_buf_destroy(drm, cma_obj);
  86
  87 err_dma_alloc:
  88         kfree(cma_obj);
  89
  90         return ERR_PTR(ret);
  91 }
  92 EXPORT_SYMBOL_GPL(drm_gem_cma_create);
  93
  94 /*
  95  * drm_gem_cma_create_with_handle - allocate an object with the given
  96  * size and create a gem handle on it
  97  *
  98  * returns a struct drm_gem_cma_object* on success or ERR_PTR values
  99  * on failure.
 100  */
 101 static struct drm_gem_cma_object *drm_gem_cma_create_with_handle(
 102                 struct drm_file *file_priv,
 103                 struct drm_device *drm, unsigned int size,
 104                 unsigned int *handle)
 105 {
 106         struct drm_gem_cma_object *cma_obj;
 107         struct drm_gem_object *gem_obj;
 108         int ret;
 109
 110         cma_obj = drm_gem_cma_create(drm, size);
 111         if (IS_ERR(cma_obj))
 112                 return cma_obj;
 113
 114         gem_obj = &cma_obj->base;
 115
 116         /*
 117          * allocate a id of idr table where the obj is registered
 118          * and handle has the id what user can see.
 119          */
 120         ret = drm_gem_handle_create(file_priv, gem_obj, handle);
 121         if (ret)
 122                 goto err_handle_create;
 123
 124         /* drop reference from allocate - handle holds it now. */
 125         drm_gem_object_unreference_unlocked(gem_obj);
 126
 127         return cma_obj;
 128
 129 err_handle_create:
 130         drm_gem_cma_free_object(gem_obj);
 131
 132         return ERR_PTR(ret);
 133 }
 134
 135 /*
 136  * drm_gem_cma_free_object - (struct drm_driver)->gem_free_object callback
 137  * function
 138  */
 139 void drm_gem_cma_free_object(struct drm_gem_object *gem_obj)
 140 {
 141         struct drm_gem_cma_object *cma_obj;
 142
 143         if (gem_obj->map_list.map)
 144                 drm_gem_free_mmap_offset(gem_obj);
 145
 146         drm_gem_object_release(gem_obj);
 147
 148         cma_obj = to_drm_gem_cma_obj(gem_obj);
 149
 150         drm_gem_cma_buf_destroy(gem_obj->dev, cma_obj);
 151
 152         kfree(cma_obj);
 153 }
 154 EXPORT_SYMBOL_GPL(drm_gem_cma_free_object);
 155
 156 /*
 157  * drm_gem_cma_dumb_create - (struct drm_driver)->dumb_create callback
 158  * function
 159  *
 160  * This aligns the pitch and size arguments to the minimum required. wrap
 161  * this into your own function if you need bigger alignment.
 162  */
 163 int drm_gem_cma_dumb_create(struct drm_file *file_priv,
 164                 struct drm_device *dev, struct drm_mode_create_dumb *args)
 165 {
 166         struct drm_gem_cma_object *cma_obj;
 167         int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
 168
 169         if (args->pitch < min_pitch)
 170                 args->pitch = min_pitch;
 171
 172         if (args->size < args->pitch * args->height)
 173                 args->size = args->pitch * args->height;
 174
 175         cma_obj = drm_gem_cma_create_with_handle(file_priv, dev,
 176                         args->size, &args->handle);
 177         if (IS_ERR(cma_obj))
 178                 return PTR_ERR(cma_obj);
 179
 180         return 0;
 181 }
 182 EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_create);
 183
 184 /*
 185  * drm_gem_cma_dumb_map_offset - (struct drm_driver)->dumb_map_offset callback
 186  * function
 187  */
 188 int drm_gem_cma_dumb_map_offset(struct drm_file *file_priv,
 189                 struct drm_device *drm, uint32_t handle, uint64_t *offset)
 190 {
 191         struct drm_gem_object *gem_obj;
 192
 193         mutex_lock(&drm->struct_mutex);
 194
 195         gem_obj = drm_gem_object_lookup(drm, file_priv, handle);
 196         if (!gem_obj) {
 197                 dev_err(drm->dev, "failed to lookup gem object\n");
 198                 mutex_unlock(&drm->struct_mutex);
 199                 return -EINVAL;
 200         }
 201
 202         *offset = get_gem_mmap_offset(gem_obj);
 203
 204         drm_gem_object_unreference(gem_obj);
 205
 206         mutex_unlock(&drm->struct_mutex);
 207
 208         return 0;
 209 }
 210 EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_map_offset);
 211
 212 const struct vm_operations_struct drm_gem_cma_vm_ops = {
 213         .open = drm_gem_vm_open,
 214         .close = drm_gem_vm_close,
 215 };
 216 EXPORT_SYMBOL_GPL(drm_gem_cma_vm_ops);
 217
 218 /*
 219  * drm_gem_cma_mmap - (struct file_operation)->mmap callback function
 220  */
 221 int drm_gem_cma_mmap(struct file *filp, struct vm_area_struct *vma)
 222 {
 223         struct drm_gem_object *gem_obj;
 224         struct drm_gem_cma_object *cma_obj;
 225         int ret;
 226
 227         ret = drm_gem_mmap(filp, vma);
 228         if (ret)
 229                 return ret;
 230
 231         gem_obj = vma->vm_private_data;
 232         cma_obj = to_drm_gem_cma_obj(gem_obj);
 233
 234         ret = remap_pfn_range(vma, vma->vm_start, cma_obj->paddr >> PAGE_SHIFT,
 235                         vma->vm_end - vma->vm_start, vma->vm_page_prot);
 236         if (ret)
 237                 drm_gem_vm_close(vma);
 238
 239         return ret;
 240 }
 241 EXPORT_SYMBOL_GPL(drm_gem_cma_mmap);
 242
 243 /*
 244  * drm_gem_cma_dumb_destroy - (struct drm_driver)->dumb_destroy callback function
 245  */
 246 int drm_gem_cma_dumb_destroy(struct drm_file *file_priv,
 247                 struct drm_device *drm, unsigned int handle)
 248 {
 249         return drm_gem_handle_delete(file_priv, handle);
 250 }
 251 EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_destroy);
 252
 253 #ifdef CONFIG_DEBUG_FS
 254 void drm_gem_cma_describe(struct drm_gem_cma_object *cma_obj, struct seq_file *m)
 255 {
 256         struct drm_gem_object *obj = &cma_obj->base;
 257         struct drm_device *dev = obj->dev;
 258         uint64_t off = 0;
 259
 260         WARN_ON(!mutex_is_locked(&dev->struct_mutex));
 261
 262         if (obj->map_list.map)
 263                 off = (uint64_t)obj->map_list.hash.key;
 264
 265         seq_printf(m, "%2d (%2d) %08llx %08Zx %p %d",
 266                         obj->name, obj->refcount.refcount.counter,
 267                         off, cma_obj->paddr, cma_obj->vaddr, obj->size);
 268
 269         seq_printf(m, "\n");
 270 }
 271 EXPORT_SYMBOL_GPL(drm_gem_cma_describe);
 272 #endif