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