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 static struct platform_device *vgem_platform;
  46
  47 static void vgem_gem_free_object(struct drm_gem_object *obj)
  48 {
  49         struct drm_vgem_gem_object *vgem_obj = to_vgem_bo(obj);
  50
  51         drm_gem_object_release(obj);
  52         kfree(vgem_obj);
  53 }
  54
  55 static int vgem_gem_fault(struct vm_fault *vmf)
  56 {
  57         struct vm_area_struct *vma = vmf->vma;
  58         struct drm_vgem_gem_object *obj = vma->vm_private_data;
  59         /* We don't use vmf->pgoff since that has the fake offset */
  60         unsigned long vaddr = vmf->address;
  61         struct page *page;
  62
  63         page = shmem_read_mapping_page(file_inode(obj->base.filp)->i_mapping,
  64                                        (vaddr - vma->vm_start) >> PAGE_SHIFT);
  65         if (!IS_ERR(page)) {
  66                 vmf->page = page;
  67                 return 0;
  68         } else switch (PTR_ERR(page)) {
  69                 case -ENOSPC:
  70                 case -ENOMEM:
  71                         return VM_FAULT_OOM;
  72                 case -EBUSY:
  73                         return VM_FAULT_RETRY;
  74                 case -EFAULT:
  75                 case -EINVAL:
  76                         return VM_FAULT_SIGBUS;
  77                 default:
  78                         WARN_ON_ONCE(PTR_ERR(page));
  79                         return VM_FAULT_SIGBUS;
  80         }
  81 }
  82
  83 static const struct vm_operations_struct vgem_gem_vm_ops = {
  84         .fault = vgem_gem_fault,
  85         .open = drm_gem_vm_open,
  86         .close = drm_gem_vm_close,
  87 };
  88
  89 static int vgem_open(struct drm_device *dev, struct drm_file *file)
  90 {
  91         struct vgem_file *vfile;
  92         int ret;
  93
  94         vfile = kzalloc(sizeof(*vfile), GFP_KERNEL);
  95         if (!vfile)
  96                 return -ENOMEM;
  97
  98         file->driver_priv = vfile;
  99
 100         ret = vgem_fence_open(vfile);
 101         if (ret) {
 102                 kfree(vfile);
 103                 return ret;
 104         }
 105
 106         return 0;
 107 }
 108
 109 static void vgem_postclose(struct drm_device *dev, struct drm_file *file)
 110 {
 111         struct vgem_file *vfile = file->driver_priv;
 112
 113         vgem_fence_close(vfile);
 114         kfree(vfile);
 115 }
 116
 117 /* ioctls */
 118
 119 static struct drm_gem_object *vgem_gem_create(struct drm_device *dev,
 120                                               struct drm_file *file,
 121                                               unsigned int *handle,
 122                                               unsigned long size)
 123 {
 124         struct drm_vgem_gem_object *obj;
 125         int ret;
 126
 127         obj = kzalloc(sizeof(*obj), GFP_KERNEL);
 128         if (!obj)
 129                 return ERR_PTR(-ENOMEM);
 130
 131         ret = drm_gem_object_init(dev, &obj->base, roundup(size, PAGE_SIZE));
 132         if (ret)
 133                 goto err_free;
 134
 135         ret = drm_gem_handle_create(file, &obj->base, handle);
 136         drm_gem_object_unreference_unlocked(&obj->base);
 137         if (ret)
 138                 goto err;
 139
 140         return &obj->base;
 141
 142 err_free:
 143         kfree(obj);
 144 err:
 145         return ERR_PTR(ret);
 146 }
 147
 148 static int vgem_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
 149                                 struct drm_mode_create_dumb *args)
 150 {
 151         struct drm_gem_object *gem_object;
 152         u64 pitch, size;
 153
 154         pitch = args->width * DIV_ROUND_UP(args->bpp, 8);
 155         size = args->height * pitch;
 156         if (size == 0)
 157                 return -EINVAL;
 158
 159         gem_object = vgem_gem_create(dev, file, &args->handle, size);
 160         if (IS_ERR(gem_object))
 161                 return PTR_ERR(gem_object);
 162
 163         args->size = gem_object->size;
 164         args->pitch = pitch;
 165
 166         DRM_DEBUG_DRIVER("Created object of size %lld\n", size);
 167
 168         return 0;
 169 }
 170
 171 static int vgem_gem_dumb_map(struct drm_file *file, struct drm_device *dev,
 172                              uint32_t handle, uint64_t *offset)
 173 {
 174         struct drm_gem_object *obj;
 175         int ret;
 176
 177         obj = drm_gem_object_lookup(file, handle);
 178         if (!obj)
 179                 return -ENOENT;
 180
 181         if (!obj->filp) {
 182                 ret = -EINVAL;
 183                 goto unref;
 184         }
 185
 186         ret = drm_gem_create_mmap_offset(obj);
 187         if (ret)
 188                 goto unref;
 189
 190         *offset = drm_vma_node_offset_addr(&obj->vma_node);
 191 unref:
 192         drm_gem_object_unreference_unlocked(obj);
 193
 194         return ret;
 195 }
 196
 197 static struct drm_ioctl_desc vgem_ioctls[] = {
 198         DRM_IOCTL_DEF_DRV(VGEM_FENCE_ATTACH, vgem_fence_attach_ioctl, DRM_AUTH|DRM_RENDER_ALLOW),
 199         DRM_IOCTL_DEF_DRV(VGEM_FENCE_SIGNAL, vgem_fence_signal_ioctl, DRM_AUTH|DRM_RENDER_ALLOW),
 200 };
 201
 202 static int vgem_mmap(struct file *filp, struct vm_area_struct *vma)
 203 {
 204         unsigned long flags = vma->vm_flags;
 205         int ret;
 206
 207         ret = drm_gem_mmap(filp, vma);
 208         if (ret)
 209                 return ret;
 210
 211         /* Keep the WC mmaping set by drm_gem_mmap() but our pages
 212          * are ordinary and not special.
 213          */
 214         vma->vm_flags = flags | VM_DONTEXPAND | VM_DONTDUMP;
 215         return 0;
 216 }
 217
 218 static const struct file_operations vgem_driver_fops = {
 219         .owner          = THIS_MODULE,
 220         .open           = drm_open,
 221         .mmap           = vgem_mmap,
 222         .poll           = drm_poll,
 223         .read           = drm_read,
 224         .unlocked_ioctl = drm_ioctl,
 225         .release        = drm_release,
 226 };
 227
 228 static int vgem_prime_pin(struct drm_gem_object *obj)
 229 {
 230         long n_pages = obj->size >> PAGE_SHIFT;
 231         struct page **pages;
 232
 233         /* Flush the object from the CPU cache so that importers can rely
 234          * on coherent indirect access via the exported dma-address.
 235          */
 236         pages = drm_gem_get_pages(obj);
 237         if (IS_ERR(pages))
 238                 return PTR_ERR(pages);
 239
 240         drm_clflush_pages(pages, n_pages);
 241         drm_gem_put_pages(obj, pages, true, false);
 242
 243         return 0;
 244 }
 245
 246 static struct sg_table *vgem_prime_get_sg_table(struct drm_gem_object *obj)
 247 {
 248         struct sg_table *st;
 249         struct page **pages;
 250
 251         pages = drm_gem_get_pages(obj);
 252         if (IS_ERR(pages))
 253                 return ERR_CAST(pages);
 254
 255         st = drm_prime_pages_to_sg(pages, obj->size >> PAGE_SHIFT);
 256         drm_gem_put_pages(obj, pages, false, false);
 257
 258         return st;
 259 }
 260
 261 static void *vgem_prime_vmap(struct drm_gem_object *obj)
 262 {
 263         long n_pages = obj->size >> PAGE_SHIFT;
 264         struct page **pages;
 265         void *addr;
 266
 267         pages = drm_gem_get_pages(obj);
 268         if (IS_ERR(pages))
 269                 return NULL;
 270
 271         addr = vmap(pages, n_pages, 0, pgprot_writecombine(PAGE_KERNEL));
 272         drm_gem_put_pages(obj, pages, false, false);
 273
 274         return addr;
 275 }
 276
 277 static void vgem_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
 278 {
 279         vunmap(vaddr);
 280 }
 281
 282 static int vgem_prime_mmap(struct drm_gem_object *obj,
 283                            struct vm_area_struct *vma)
 284 {
 285         int ret;
 286
 287         if (obj->size < vma->vm_end - vma->vm_start)
 288                 return -EINVAL;
 289
 290         if (!obj->filp)
 291                 return -ENODEV;
 292
 293         ret = call_mmap(obj->filp, vma);
 294         if (ret)
 295                 return ret;
 296
 297         fput(vma->vm_file);
 298         vma->vm_file = get_file(obj->filp);
 299         vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
 300         vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
 301
 302         return 0;
 303 }
 304
 305 static struct drm_driver vgem_driver = {
 306         .driver_features                = DRIVER_GEM | DRIVER_PRIME,
 307         .open                           = vgem_open,
 308         .postclose                      = vgem_postclose,
 309         .gem_free_object_unlocked       = vgem_gem_free_object,
 310         .gem_vm_ops                     = &vgem_gem_vm_ops,
 311         .ioctls                         = vgem_ioctls,
 312         .num_ioctls                     = ARRAY_SIZE(vgem_ioctls),
 313         .fops                           = &vgem_driver_fops,
 314
 315         .dumb_create                    = vgem_gem_dumb_create,
 316         .dumb_map_offset                = vgem_gem_dumb_map,
 317
 318         .prime_handle_to_fd = drm_gem_prime_handle_to_fd,
 319         .gem_prime_pin = vgem_prime_pin,
 320         .gem_prime_export = drm_gem_prime_export,
 321         .gem_prime_get_sg_table = vgem_prime_get_sg_table,
 322         .gem_prime_vmap = vgem_prime_vmap,
 323         .gem_prime_vunmap = vgem_prime_vunmap,
 324         .gem_prime_mmap = vgem_prime_mmap,
 325
 326         .name   = DRIVER_NAME,
 327         .desc   = DRIVER_DESC,
 328         .date   = DRIVER_DATE,
 329         .major  = DRIVER_MAJOR,
 330         .minor  = DRIVER_MINOR,
 331 };
 332
 333 static struct drm_device *vgem_device;
 334
 335 static int __init vgem_init(void)
 336 {
 337         int ret;
 338
 339         vgem_device = drm_dev_alloc(&vgem_driver, NULL);
 340         if (IS_ERR(vgem_device))
 341                 return PTR_ERR(vgem_device);
 342
 343         vgem_platform = platform_device_register_simple("vgem",
 344                                         -1, NULL, 0);
 345
 346         if (!vgem_platform) {
 347                 ret = -ENODEV;
 348                 goto out;
 349         }
 350
 351         dma_coerce_mask_and_coherent(&vgem_platform->dev,
 352                                         DMA_BIT_MASK(64));
 353
 354         ret  = drm_dev_register(vgem_device, 0);
 355         if (ret)
 356                 goto out_unref;
 357
 358         return 0;
 359
 360 out_unref:
 361         platform_device_unregister(vgem_platform);
 362 out:
 363         drm_dev_unref(vgem_device);
 364         return ret;
 365 }
 366
 367 static void __exit vgem_exit(void)
 368 {
 369         platform_device_unregister(vgem_platform);
 370         drm_dev_unregister(vgem_device);
 371         drm_dev_unref(vgem_device);
 372 }
 373
 374 module_init(vgem_init);
 375 module_exit(vgem_exit);
 376
 377 MODULE_AUTHOR("Red Hat, Inc.");
 378 MODULE_AUTHOR("Intel Corporation");
 379 MODULE_DESCRIPTION(DRIVER_DESC);
 380 MODULE_LICENSE("GPL and additional rights");