drivers/gpu/drm/vgem/vgem_drv.c

   1 /*
   2  * Copyright 2011 Red Hat, Inc.
   3  * Copyright © 2014 The Chromium OS Authors
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a
   6  * copy of this software and associated documentation files (the "Software")
   7  * to deal in the software without restriction, including without limitation
   8  * on the rights to use, copy, modify, merge, publish, distribute, sub
   9  * license, and/or sell copies of the Software, and to permit persons to whom
  10  * them Software is furnished to do so, subject to the following conditions:
  11  *
  12  * The above copyright notice and this permission notice (including the next
  13  * paragraph) shall be included in all copies or substantial portions of the
  14  * Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTIBILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.  IN NO EVENT SHALL
  19  * THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES, OR OTHER LIABILITY, WHETHER
  20  * IN AN ACTION OF CONTRACT, TORT, OR OTHERWISE, ARISING FROM, OUT OF OR IN
  21  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  22  *
  23  * Authors:
  24  *      Adam Jackson <ajax@redhat.com>
  25  *      Ben Widawsky <ben@bwidawsk.net>
  26  */
  27
  28 /**
  29  * This is vgem, a (non-hardware-backed) GEM service.  This is used by Mesa's
  30  * software renderer and the X server for efficient buffer sharing.
  31  */
  32
  33 #include <linux/module.h>
  34 #include <linux/ramfs.h>
  35 #include <linux/shmem_fs.h>
  36 #include <linux/dma-buf.h>
  37 #include "vgem_drv.h"
  38
  39 #define DRIVER_NAME     "vgem"
  40 #define DRIVER_DESC     "Virtual GEM provider"
  41 #define DRIVER_DATE     "20120112"
  42 #define DRIVER_MAJOR    1
  43 #define DRIVER_MINOR    0
  44
  45 void vgem_gem_put_pages(struct drm_vgem_gem_object *obj)
  46 {
  47         drm_gem_put_pages(&obj->base, obj->pages, false, false);
  48         obj->pages = NULL;
  49 }
  50
  51 static void vgem_gem_free_object(struct drm_gem_object *obj)
  52 {
  53         struct drm_vgem_gem_object *vgem_obj = to_vgem_bo(obj);
  54
  55         drm_gem_free_mmap_offset(obj);
  56
  57         if (vgem_obj->use_dma_buf && obj->dma_buf) {
  58                 dma_buf_put(obj->dma_buf);
  59                 obj->dma_buf = NULL;
  60         }
  61
  62         drm_gem_object_release(obj);
  63
  64         if (vgem_obj->pages)
  65                 vgem_gem_put_pages(vgem_obj);
  66
  67         vgem_obj->pages = NULL;
  68
  69         kfree(vgem_obj);
  70 }
  71
  72 int vgem_gem_get_pages(struct drm_vgem_gem_object *obj)
  73 {
  74         struct page **pages;
  75
  76         if (obj->pages || obj->use_dma_buf)
  77                 return 0;
  78
  79         pages = drm_gem_get_pages(&obj->base);
  80         if (IS_ERR(pages)) {
  81                 return PTR_ERR(pages);
  82         }
  83
  84         obj->pages = pages;
  85
  86         return 0;
  87 }
  88
  89 static int vgem_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
  90 {
  91         struct drm_vgem_gem_object *obj = vma->vm_private_data;
  92         struct drm_device *dev = obj->base.dev;
  93         loff_t num_pages;
  94         pgoff_t page_offset;
  95         int ret;
  96
  97         /* We don't use vmf->pgoff since that has the fake offset */
  98         page_offset = ((unsigned long)vmf->virtual_address - vma->vm_start) >>
  99                 PAGE_SHIFT;
 100
 101         num_pages = DIV_ROUND_UP(obj->base.size, PAGE_SIZE);
 102
 103         if (page_offset > num_pages)
 104                 return VM_FAULT_SIGBUS;
 105
 106         mutex_lock(&dev->struct_mutex);
 107
 108         ret = vm_insert_page(vma, (unsigned long)vmf->virtual_address,
 109                              obj->pages[page_offset]);
 110
 111         mutex_unlock(&dev->struct_mutex);
 112         switch (ret) {
 113         case 0:
 114                 return VM_FAULT_NOPAGE;
 115         case -ENOMEM:
 116                 return VM_FAULT_OOM;
 117         case -EBUSY:
 118                 return VM_FAULT_RETRY;
 119         case -EFAULT:
 120         case -EINVAL:
 121                 return VM_FAULT_SIGBUS;
 122         default:
 123                 WARN_ON(1);
 124                 return VM_FAULT_SIGBUS;
 125         }
 126 }
 127
 128 static struct vm_operations_struct vgem_gem_vm_ops = {
 129         .fault = vgem_gem_fault,
 130         .open = drm_gem_vm_open,
 131         .close = drm_gem_vm_close,
 132 };
 133
 134 /* ioctls */
 135
 136 static struct drm_gem_object *vgem_gem_create(struct drm_device *dev,
 137                                               struct drm_file *file,
 138                                               unsigned int *handle,
 139                                               unsigned long size)
 140 {
 141         struct drm_vgem_gem_object *obj;
 142         struct drm_gem_object *gem_object;
 143         int err;
 144
 145         size = roundup(size, PAGE_SIZE);
 146
 147         obj = kzalloc(sizeof(*obj), GFP_KERNEL);
 148         if (!obj)
 149                 return ERR_PTR(-ENOMEM);
 150
 151         gem_object = &obj->base;
 152
 153         err = drm_gem_object_init(dev, gem_object, size);
 154         if (err)
 155                 goto out;
 156
 157         err = drm_gem_handle_create(file, gem_object, handle);
 158         if (err)
 159                 goto handle_out;
 160
 161         drm_gem_object_unreference_unlocked(gem_object);
 162
 163         return gem_object;
 164
 165 handle_out:
 166         drm_gem_object_release(gem_object);
 167 out:
 168         kfree(obj);
 169         return ERR_PTR(err);
 170 }
 171
 172 static int vgem_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
 173                                 struct drm_mode_create_dumb *args)
 174 {
 175         struct drm_gem_object *gem_object;
 176         uint64_t size;
 177         uint64_t pitch = args->width * DIV_ROUND_UP(args->bpp, 8);
 178
 179         size = args->height * pitch;
 180         if (size == 0)
 181                 return -EINVAL;
 182
 183         gem_object = vgem_gem_create(dev, file, &args->handle, size);
 184
 185         if (IS_ERR(gem_object)) {
 186                 DRM_DEBUG_DRIVER("object creation failed\n");
 187                 return PTR_ERR(gem_object);
 188         }
 189
 190         args->size = gem_object->size;
 191         args->pitch = pitch;
 192
 193         DRM_DEBUG_DRIVER("Created object of size %lld\n", size);
 194
 195         return 0;
 196 }
 197
 198 int vgem_gem_dumb_map(struct drm_file *file, struct drm_device *dev,
 199                       uint32_t handle, uint64_t *offset)
 200 {
 201         int ret = 0;
 202         struct drm_gem_object *obj;
 203
 204         mutex_lock(&dev->struct_mutex);
 205         obj = drm_gem_object_lookup(dev, file, handle);
 206         if (!obj) {
 207                 ret = -ENOENT;
 208                 goto unlock;
 209         }
 210
 211         if (!drm_vma_node_has_offset(&obj->vma_node)) {
 212                 ret = drm_gem_create_mmap_offset(obj);
 213                 if (ret)
 214                         goto unref;
 215         }
 216
 217         BUG_ON(!obj->filp);
 218
 219         obj->filp->private_data = obj;
 220
 221         ret = vgem_gem_get_pages(to_vgem_bo(obj));
 222         if (ret)
 223                 goto fail_get_pages;
 224
 225         *offset = drm_vma_node_offset_addr(&obj->vma_node);
 226
 227         goto unref;
 228
 229 fail_get_pages:
 230         drm_gem_free_mmap_offset(obj);
 231 unref:
 232         drm_gem_object_unreference(obj);
 233 unlock:
 234         mutex_unlock(&dev->struct_mutex);
 235         return ret;
 236 }
 237
 238 int vgem_drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
 239 {
 240         struct drm_file *priv = filp->private_data;
 241         struct drm_device *dev = priv->minor->dev;
 242         struct drm_vma_offset_node *node;
 243         struct drm_gem_object *obj;
 244         struct drm_vgem_gem_object *vgem_obj;
 245         int ret = 0;
 246
 247         mutex_lock(&dev->struct_mutex);
 248
 249         node = drm_vma_offset_exact_lookup(dev->vma_offset_manager,
 250                                            vma->vm_pgoff,
 251                                            vma_pages(vma));
 252         if (!node) {
 253                 ret = -EINVAL;
 254                 goto out_unlock;
 255         } else if (!drm_vma_node_is_allowed(node, filp)) {
 256                 ret = -EACCES;
 257                 goto out_unlock;
 258         }
 259
 260         obj = container_of(node, struct drm_gem_object, vma_node);
 261
 262         vgem_obj = to_vgem_bo(obj);
 263
 264         if (obj->dma_buf && vgem_obj->use_dma_buf) {
 265                 ret = dma_buf_mmap(obj->dma_buf, vma, 0);
 266                 goto out_unlock;
 267         }
 268
 269         if (!obj->dev->driver->gem_vm_ops) {
 270                 ret = -EINVAL;
 271                 goto out_unlock;
 272         }
 273
 274         vma->vm_flags |= VM_IO | VM_MIXEDMAP | VM_DONTEXPAND | VM_DONTDUMP;
 275         vma->vm_ops = obj->dev->driver->gem_vm_ops;
 276         vma->vm_private_data = vgem_obj;
 277         vma->vm_page_prot =
 278                 pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
 279
 280         mutex_unlock(&dev->struct_mutex);
 281         drm_gem_vm_open(vma);
 282         return ret;
 283
 284 out_unlock:
 285         mutex_unlock(&dev->struct_mutex);
 286
 287         return ret;
 288 }
 289
 290
 291 static struct drm_ioctl_desc vgem_ioctls[] = {
 292 };
 293
 294 static const struct file_operations vgem_driver_fops = {
 295         .owner          = THIS_MODULE,
 296         .open           = drm_open,
 297         .mmap           = vgem_drm_gem_mmap,
 298         .poll           = drm_poll,
 299         .read           = drm_read,
 300         .unlocked_ioctl = drm_ioctl,
 301         .release        = drm_release,
 302 };
 303
 304 static struct drm_driver vgem_driver = {
 305         .driver_features                = DRIVER_GEM,
 306         .gem_free_object                = vgem_gem_free_object,
 307         .gem_vm_ops                     = &vgem_gem_vm_ops,
 308         .ioctls                         = vgem_ioctls,
 309         .fops                           = &vgem_driver_fops,
 310         .dumb_create                    = vgem_gem_dumb_create,
 311         .dumb_map_offset                = vgem_gem_dumb_map,
 312         .name   = DRIVER_NAME,
 313         .desc   = DRIVER_DESC,
 314         .date   = DRIVER_DATE,
 315         .major  = DRIVER_MAJOR,
 316         .minor  = DRIVER_MINOR,
 317 };
 318
 319 struct drm_device *vgem_device;
 320
 321 static int __init vgem_init(void)
 322 {
 323         int ret;
 324
 325         vgem_device = drm_dev_alloc(&vgem_driver, NULL);
 326         if (!vgem_device) {
 327                 ret = -ENOMEM;
 328                 goto out;
 329         }
 330
 331         drm_dev_set_unique(vgem_device, "vgem");
 332
 333         ret  = drm_dev_register(vgem_device, 0);
 334
 335         if (ret)
 336                 goto out_unref;
 337
 338         return 0;
 339
 340 out_unref:
 341         drm_dev_unref(vgem_device);
 342 out:
 343         return ret;
 344 }
 345
 346 static void __exit vgem_exit(void)
 347 {
 348         drm_dev_unregister(vgem_device);
 349         drm_dev_unref(vgem_device);
 350 }
 351
 352 module_init(vgem_init);
 353 module_exit(vgem_exit);
 354
 355 MODULE_AUTHOR("Red Hat, Inc.");
 356 MODULE_DESCRIPTION(DRIVER_DESC);
 357 MODULE_LICENSE("GPL and additional rights");