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