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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/dma-buf.h>
34#include <linux/module.h>
35#include <linux/platform_device.h>
36#include <linux/shmem_fs.h>
37#include <linux/vmalloc.h>
38
39#include <drm/drm_drv.h>
40#include <drm/drm_file.h>
41#include <drm/drm_ioctl.h>
42#include <drm/drm_managed.h>
43#include <drm/drm_prime.h>
44
45#include "vgem_drv.h"
46
47#define DRIVER_NAME "vgem"
48#define DRIVER_DESC "Virtual GEM provider"
49#define DRIVER_DATE "20120112"
50#define DRIVER_MAJOR 1
51#define DRIVER_MINOR 0
52
53static const struct drm_gem_object_funcs vgem_gem_object_funcs;
54
55static struct vgem_device {
56 struct drm_device drm;
57 struct platform_device *platform;
58} *vgem_device;
59
60static void vgem_gem_free_object(struct drm_gem_object *obj)
61{
62 struct drm_vgem_gem_object *vgem_obj = to_vgem_bo(obj);
63
64 kvfree(vgem_obj->pages);
65 mutex_destroy(&vgem_obj->pages_lock);
66
67 if (obj->import_attach)
68 drm_prime_gem_destroy(obj, vgem_obj->table);
69
70 drm_gem_object_release(obj);
71 kfree(vgem_obj);
72}
73
74static vm_fault_t vgem_gem_fault(struct vm_fault *vmf)
75{
76 struct vm_area_struct *vma = vmf->vma;
77 struct drm_vgem_gem_object *obj = vma->vm_private_data;
78 /* We don't use vmf->pgoff since that has the fake offset */
79 unsigned long vaddr = vmf->address;
80 vm_fault_t ret = VM_FAULT_SIGBUS;
81 loff_t num_pages;
82 pgoff_t page_offset;
83 page_offset = (vaddr - vma->vm_start) >> PAGE_SHIFT;
84
85 num_pages = DIV_ROUND_UP(obj->base.size, PAGE_SIZE);
86
87 if (page_offset >= num_pages)
88 return VM_FAULT_SIGBUS;
89
90 mutex_lock(&obj->pages_lock);
91 if (obj->pages) {
92 get_page(obj->pages[page_offset]);
93 vmf->page = obj->pages[page_offset];
94 ret = 0;
95 }
96 mutex_unlock(&obj->pages_lock);
97 if (ret) {
98 struct page *page;
99
100 page = shmem_read_mapping_page(
101 file_inode(obj->base.filp)->i_mapping,
102 page_offset);
103 if (!IS_ERR(page)) {
104 vmf->page = page;
105 ret = 0;
106 } else switch (PTR_ERR(page)) {
107 case -ENOSPC:
108 case -ENOMEM:
109 ret = VM_FAULT_OOM;
110 break;
111 case -EBUSY:
112 ret = VM_FAULT_RETRY;
113 break;
114 case -EFAULT:
115 case -EINVAL:
116 ret = VM_FAULT_SIGBUS;
117 break;
118 default:
119 WARN_ON(PTR_ERR(page));
120 ret = VM_FAULT_SIGBUS;
121 break;
122 }
123
124 }
125 return ret;
126}
127
128static const 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
134static int vgem_open(struct drm_device *dev, struct drm_file *file)
135{
136 struct vgem_file *vfile;
137 int ret;
138
139 vfile = kzalloc(sizeof(*vfile), GFP_KERNEL);
140 if (!vfile)
141 return -ENOMEM;
142
143 file->driver_priv = vfile;
144
145 ret = vgem_fence_open(vfile);
146 if (ret) {
147 kfree(vfile);
148 return ret;
149 }
150
151 return 0;
152}
153
154static void vgem_postclose(struct drm_device *dev, struct drm_file *file)
155{
156 struct vgem_file *vfile = file->driver_priv;
157
158 vgem_fence_close(vfile);
159 kfree(vfile);
160}
161
162static struct drm_vgem_gem_object *__vgem_gem_create(struct drm_device *dev,
163 unsigned long size)
164{
165 struct drm_vgem_gem_object *obj;
166 int ret;
167
168 obj = kzalloc(sizeof(*obj), GFP_KERNEL);
169 if (!obj)
170 return ERR_PTR(-ENOMEM);
171
172 obj->base.funcs = &vgem_gem_object_funcs;
173
174 ret = drm_gem_object_init(dev, &obj->base, roundup(size, PAGE_SIZE));
175 if (ret) {
176 kfree(obj);
177 return ERR_PTR(ret);
178 }
179
180 mutex_init(&obj->pages_lock);
181
182 return obj;
183}
184
185static void __vgem_gem_destroy(struct drm_vgem_gem_object *obj)
186{
187 drm_gem_object_release(&obj->base);
188 kfree(obj);
189}
190
191static struct drm_gem_object *vgem_gem_create(struct drm_device *dev,
192 struct drm_file *file,
193 unsigned int *handle,
194 unsigned long size)
195{
196 struct drm_vgem_gem_object *obj;
197 int ret;
198
199 obj = __vgem_gem_create(dev, size);
200 if (IS_ERR(obj))
201 return ERR_CAST(obj);
202
203 ret = drm_gem_handle_create(file, &obj->base, handle);
204 if (ret) {
205 drm_gem_object_put(&obj->base);
206 return ERR_PTR(ret);
207 }
208
209 return &obj->base;
210}
211
212static int vgem_gem_dumb_create(struct drm_file *file, struct drm_device *dev,
213 struct drm_mode_create_dumb *args)
214{
215 struct drm_gem_object *gem_object;
216 u64 pitch, size;
217
218 pitch = args->width * DIV_ROUND_UP(args->bpp, 8);
219 size = args->height * pitch;
220 if (size == 0)
221 return -EINVAL;
222
223 gem_object = vgem_gem_create(dev, file, &args->handle, size);
224 if (IS_ERR(gem_object))
225 return PTR_ERR(gem_object);
226
227 args->size = gem_object->size;
228 args->pitch = pitch;
229
230 drm_gem_object_put(gem_object);
231
232 DRM_DEBUG("Created object of size %llu\n", args->size);
233
234 return 0;
235}
236
237static struct drm_ioctl_desc vgem_ioctls[] = {
238 DRM_IOCTL_DEF_DRV(VGEM_FENCE_ATTACH, vgem_fence_attach_ioctl, DRM_RENDER_ALLOW),
239 DRM_IOCTL_DEF_DRV(VGEM_FENCE_SIGNAL, vgem_fence_signal_ioctl, DRM_RENDER_ALLOW),
240};
241
242static int vgem_mmap(struct file *filp, struct vm_area_struct *vma)
243{
244 unsigned long flags = vma->vm_flags;
245 int ret;
246
247 ret = drm_gem_mmap(filp, vma);
248 if (ret)
249 return ret;
250
251 /* Keep the WC mmaping set by drm_gem_mmap() but our pages
252 * are ordinary and not special.
253 */
254 vma->vm_flags = flags | VM_DONTEXPAND | VM_DONTDUMP;
255 return 0;
256}
257
258static const struct file_operations vgem_driver_fops = {
259 .owner = THIS_MODULE,
260 .open = drm_open,
261 .mmap = vgem_mmap,
262 .poll = drm_poll,
263 .read = drm_read,
264 .unlocked_ioctl = drm_ioctl,
265 .compat_ioctl = drm_compat_ioctl,
266 .release = drm_release,
267};
268
269static struct page **vgem_pin_pages(struct drm_vgem_gem_object *bo)
270{
271 mutex_lock(&bo->pages_lock);
272 if (bo->pages_pin_count++ == 0) {
273 struct page **pages;
274
275 pages = drm_gem_get_pages(&bo->base);
276 if (IS_ERR(pages)) {
277 bo->pages_pin_count--;
278 mutex_unlock(&bo->pages_lock);
279 return pages;
280 }
281
282 bo->pages = pages;
283 }
284 mutex_unlock(&bo->pages_lock);
285
286 return bo->pages;
287}
288
289static void vgem_unpin_pages(struct drm_vgem_gem_object *bo)
290{
291 mutex_lock(&bo->pages_lock);
292 if (--bo->pages_pin_count == 0) {
293 drm_gem_put_pages(&bo->base, bo->pages, true, true);
294 bo->pages = NULL;
295 }
296 mutex_unlock(&bo->pages_lock);
297}
298
299static int vgem_prime_pin(struct drm_gem_object *obj)
300{
301 struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
302 long n_pages = obj->size >> PAGE_SHIFT;
303 struct page **pages;
304
305 pages = vgem_pin_pages(bo);
306 if (IS_ERR(pages))
307 return PTR_ERR(pages);
308
309 /* Flush the object from the CPU cache so that importers can rely
310 * on coherent indirect access via the exported dma-address.
311 */
312 drm_clflush_pages(pages, n_pages);
313
314 return 0;
315}
316
317static void vgem_prime_unpin(struct drm_gem_object *obj)
318{
319 struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
320
321 vgem_unpin_pages(bo);
322}
323
324static struct sg_table *vgem_prime_get_sg_table(struct drm_gem_object *obj)
325{
326 struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
327
328 return drm_prime_pages_to_sg(obj->dev, bo->pages, bo->base.size >> PAGE_SHIFT);
329}
330
331static struct drm_gem_object* vgem_prime_import(struct drm_device *dev,
332 struct dma_buf *dma_buf)
333{
334 struct vgem_device *vgem = container_of(dev, typeof(*vgem), drm);
335
336 return drm_gem_prime_import_dev(dev, dma_buf, &vgem->platform->dev);
337}
338
339static struct drm_gem_object *vgem_prime_import_sg_table(struct drm_device *dev,
340 struct dma_buf_attachment *attach, struct sg_table *sg)
341{
342 struct drm_vgem_gem_object *obj;
343 int npages;
344
345 obj = __vgem_gem_create(dev, attach->dmabuf->size);
346 if (IS_ERR(obj))
347 return ERR_CAST(obj);
348
349 npages = PAGE_ALIGN(attach->dmabuf->size) / PAGE_SIZE;
350
351 obj->table = sg;
352 obj->pages = kvmalloc_array(npages, sizeof(struct page *), GFP_KERNEL);
353 if (!obj->pages) {
354 __vgem_gem_destroy(obj);
355 return ERR_PTR(-ENOMEM);
356 }
357
358 obj->pages_pin_count++; /* perma-pinned */
359 drm_prime_sg_to_page_array(obj->table, obj->pages, npages);
360 return &obj->base;
361}
362
363static int vgem_prime_vmap(struct drm_gem_object *obj, struct dma_buf_map *map)
364{
365 struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
366 long n_pages = obj->size >> PAGE_SHIFT;
367 struct page **pages;
368 void *vaddr;
369
370 pages = vgem_pin_pages(bo);
371 if (IS_ERR(pages))
372 return PTR_ERR(pages);
373
374 vaddr = vmap(pages, n_pages, 0, pgprot_writecombine(PAGE_KERNEL));
375 if (!vaddr)
376 return -ENOMEM;
377 dma_buf_map_set_vaddr(map, vaddr);
378
379 return 0;
380}
381
382static void vgem_prime_vunmap(struct drm_gem_object *obj, struct dma_buf_map *map)
383{
384 struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
385
386 vunmap(map->vaddr);
387 vgem_unpin_pages(bo);
388}
389
390static int vgem_prime_mmap(struct drm_gem_object *obj,
391 struct vm_area_struct *vma)
392{
393 int ret;
394
395 if (obj->size < vma->vm_end - vma->vm_start)
396 return -EINVAL;
397
398 if (!obj->filp)
399 return -ENODEV;
400
401 ret = call_mmap(obj->filp, vma);
402 if (ret)
403 return ret;
404
405 vma_set_file(vma, obj->filp);
406 vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
407 vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
408
409 return 0;
410}
411
412static const struct drm_gem_object_funcs vgem_gem_object_funcs = {
413 .free = vgem_gem_free_object,
414 .pin = vgem_prime_pin,
415 .unpin = vgem_prime_unpin,
416 .get_sg_table = vgem_prime_get_sg_table,
417 .vmap = vgem_prime_vmap,
418 .vunmap = vgem_prime_vunmap,
419 .vm_ops = &vgem_gem_vm_ops,
420};
421
422static const struct drm_driver vgem_driver = {
423 .driver_features = DRIVER_GEM | DRIVER_RENDER,
424 .open = vgem_open,
425 .postclose = vgem_postclose,
426 .ioctls = vgem_ioctls,
427 .num_ioctls = ARRAY_SIZE(vgem_ioctls),
428 .fops = &vgem_driver_fops,
429
430 .dumb_create = vgem_gem_dumb_create,
431
432 .prime_handle_to_fd = drm_gem_prime_handle_to_fd,
433 .prime_fd_to_handle = drm_gem_prime_fd_to_handle,
434 .gem_prime_import = vgem_prime_import,
435 .gem_prime_import_sg_table = vgem_prime_import_sg_table,
436 .gem_prime_mmap = vgem_prime_mmap,
437
438 .name = DRIVER_NAME,
439 .desc = DRIVER_DESC,
440 .date = DRIVER_DATE,
441 .major = DRIVER_MAJOR,
442 .minor = DRIVER_MINOR,
443};
444
445static int __init vgem_init(void)
446{
447 int ret;
448 struct platform_device *pdev;
449
450 pdev = platform_device_register_simple("vgem", -1, NULL, 0);
451 if (IS_ERR(pdev))
452 return PTR_ERR(pdev);
453
454 if (!devres_open_group(&pdev->dev, NULL, GFP_KERNEL)) {
455 ret = -ENOMEM;
456 goto out_unregister;
457 }
458
459 dma_coerce_mask_and_coherent(&pdev->dev,
460 DMA_BIT_MASK(64));
461
462 vgem_device = devm_drm_dev_alloc(&pdev->dev, &vgem_driver,
463 struct vgem_device, drm);
464 if (IS_ERR(vgem_device)) {
465 ret = PTR_ERR(vgem_device);
466 goto out_devres;
467 }
468 vgem_device->platform = pdev;
469
470 /* Final step: expose the device/driver to userspace */
471 ret = drm_dev_register(&vgem_device->drm, 0);
472 if (ret)
473 goto out_devres;
474
475 return 0;
476
477out_devres:
478 devres_release_group(&pdev->dev, NULL);
479out_unregister:
480 platform_device_unregister(pdev);
481 return ret;
482}
483
484static void __exit vgem_exit(void)
485{
486 struct platform_device *pdev = vgem_device->platform;
487
488 drm_dev_unregister(&vgem_device->drm);
489 devres_release_group(&pdev->dev, NULL);
490 platform_device_unregister(pdev);
491}
492
493module_init(vgem_init);
494module_exit(vgem_exit);
495
496MODULE_AUTHOR("Red Hat, Inc.");
497MODULE_AUTHOR("Intel Corporation");
498MODULE_DESCRIPTION(DRIVER_DESC);
499MODULE_LICENSE("GPL and additional rights");