linux/drivers/gpu/drm/vgem/vgem_drv.c
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   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
  45static 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
  53static 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
  80static 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
  86static 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
 106static 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
 116static 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
 139err_free:
 140        kfree(obj);
 141err:
 142        return ERR_PTR(ret);
 143}
 144
 145static 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
 168static 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);
 188unref:
 189        drm_gem_object_unreference_unlocked(obj);
 190
 191        return ret;
 192}
 193
 194static 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
 199static 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
 215static 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
 225static 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
 243static 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
 258static 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
 274static void vgem_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
 275{
 276        vunmap(vaddr);
 277}
 278
 279static 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
 302static 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
 330static struct drm_device *vgem_device;
 331
 332static 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
 348out_unref:
 349        drm_dev_unref(vgem_device);
 350out:
 351        return ret;
 352}
 353
 354static void __exit vgem_exit(void)
 355{
 356        drm_dev_unregister(vgem_device);
 357        drm_dev_unref(vgem_device);
 358}
 359
 360module_init(vgem_init);
 361module_exit(vgem_exit);
 362
 363MODULE_AUTHOR("Red Hat, Inc.");
 364MODULE_AUTHOR("Intel Corporation");
 365MODULE_DESCRIPTION(DRIVER_DESC);
 366MODULE_LICENSE("GPL and additional rights");
 367