1/*
  2 * Copyright 2012 Red Hat Inc
  3 *
  4 * Permission is hereby granted, free of charge, to any person obtaining a
  5 * copy of this software and associated documentation files (the "Software"),
  6 * to deal in the Software without restriction, including without limitation
  7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  8 * and/or sell copies of the Software, and to permit persons to whom the
  9 * Software is furnished to do so, subject to the following conditions:
 10 *
 11 * The above copyright notice and this permission notice (including the next
 12 * paragraph) shall be included in all copies or substantial portions of the
 13 * Software.
 14 *
 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 21 * DEALINGS IN THE SOFTWARE.
 22 *
 23 * Authors:
 24 *	Dave Airlie <airlied@redhat.com>
 25 */
 26
 27#include <linux/dma-buf.h>
 28#include <linux/reservation.h>
 29
 30#include <drm/drmP.h>
 31
 32#include "i915_drv.h"
 33
 34static struct drm_i915_gem_object *dma_buf_to_obj(struct dma_buf *buf)
 35{
 36	return to_intel_bo(buf->priv);
 37}
 38
 39static struct sg_table *i915_gem_map_dma_buf(struct dma_buf_attachment *attachment,
 40					     enum dma_data_direction dir)
 41{
 42	struct drm_i915_gem_object *obj = dma_buf_to_obj(attachment->dmabuf);
 43	struct sg_table *st;
 44	struct scatterlist *src, *dst;
 45	int ret, i;
 46
 47	ret = i915_gem_object_pin_pages(obj);
 48	if (ret)
 49		goto err;
 50
 51	/* Copy sg so that we make an independent mapping */
 52	st = kmalloc(sizeof(struct sg_table), GFP_KERNEL);
 53	if (st == NULL) {
 54		ret = -ENOMEM;
 55		goto err_unpin_pages;
 56	}
 57
 58	ret = sg_alloc_table(st, obj->mm.pages->nents, GFP_KERNEL);
 59	if (ret)
 60		goto err_free;
 61
 62	src = obj->mm.pages->sgl;
 63	dst = st->sgl;
 64	for (i = 0; i < obj->mm.pages->nents; i++) {
 65		sg_set_page(dst, sg_page(src), src->length, 0);
 66		dst = sg_next(dst);
 67		src = sg_next(src);
 68	}
 69
 70	if (!dma_map_sg(attachment->dev, st->sgl, st->nents, dir)) {
 71		ret = -ENOMEM;
 72		goto err_free_sg;
 73	}
 74
 75	return st;
 76
 77err_free_sg:
 78	sg_free_table(st);
 79err_free:
 80	kfree(st);
 81err_unpin_pages:
 82	i915_gem_object_unpin_pages(obj);
 83err:
 84	return ERR_PTR(ret);
 85}
 86
 87static void i915_gem_unmap_dma_buf(struct dma_buf_attachment *attachment,
 88				   struct sg_table *sg,
 89				   enum dma_data_direction dir)
 90{
 91	struct drm_i915_gem_object *obj = dma_buf_to_obj(attachment->dmabuf);
 92
 93	dma_unmap_sg(attachment->dev, sg->sgl, sg->nents, dir);
 94	sg_free_table(sg);
 95	kfree(sg);
 96
 97	i915_gem_object_unpin_pages(obj);
 98}
 99
100static void *i915_gem_dmabuf_vmap(struct dma_buf *dma_buf)
101{
102	struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
103
104	return i915_gem_object_pin_map(obj, I915_MAP_WB);
105}
106
107static void i915_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
108{
109	struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
110
111	i915_gem_object_unpin_map(obj);
112}
113
114static void *i915_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf, unsigned long page_num)
115{
116	return NULL;
117}
118
119static void i915_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf, unsigned long page_num, void *addr)
120{
121
122}
123static void *i915_gem_dmabuf_kmap(struct dma_buf *dma_buf, unsigned long page_num)
124{
125	return NULL;
126}
127
128static void i915_gem_dmabuf_kunmap(struct dma_buf *dma_buf, unsigned long page_num, void *addr)
129{
130
131}
132
133static int i915_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma)
134{
135	struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
136	int ret;
137
138	if (obj->base.size < vma->vm_end - vma->vm_start)
139		return -EINVAL;
140
141	if (!obj->base.filp)
142		return -ENODEV;
143
144	ret = obj->base.filp->f_op->mmap(obj->base.filp, vma);
145	if (ret)
146		return ret;
147
148	fput(vma->vm_file);
149	vma->vm_file = get_file(obj->base.filp);
150
151	return 0;
152}
153
154static int i915_gem_begin_cpu_access(struct dma_buf *dma_buf, enum dma_data_direction direction)
155{
156	struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
157	struct drm_device *dev = obj->base.dev;
158	bool write = (direction == DMA_BIDIRECTIONAL || direction == DMA_TO_DEVICE);
159	int err;
160
161	err = i915_gem_object_pin_pages(obj);
162	if (err)
163		return err;
164
165	err = i915_mutex_lock_interruptible(dev);
166	if (err)
167		goto out;
168
169	err = i915_gem_object_set_to_cpu_domain(obj, write);
170	mutex_unlock(&dev->struct_mutex);
171
172out:
173	i915_gem_object_unpin_pages(obj);
174	return err;
175}
176
177static int i915_gem_end_cpu_access(struct dma_buf *dma_buf, enum dma_data_direction direction)
178{
179	struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
180	struct drm_device *dev = obj->base.dev;
181	int err;
182
183	err = i915_gem_object_pin_pages(obj);
184	if (err)
185		return err;
186
187	err = i915_mutex_lock_interruptible(dev);
188	if (err)
189		goto out;
190
191	err = i915_gem_object_set_to_gtt_domain(obj, false);
192	mutex_unlock(&dev->struct_mutex);
193
194out:
195	i915_gem_object_unpin_pages(obj);
196	return err;
197}
198
199static const struct dma_buf_ops i915_dmabuf_ops =  {
200	.map_dma_buf = i915_gem_map_dma_buf,
201	.unmap_dma_buf = i915_gem_unmap_dma_buf,
202	.release = drm_gem_dmabuf_release,
203	.kmap = i915_gem_dmabuf_kmap,
204	.kmap_atomic = i915_gem_dmabuf_kmap_atomic,
205	.kunmap = i915_gem_dmabuf_kunmap,
206	.kunmap_atomic = i915_gem_dmabuf_kunmap_atomic,
207	.mmap = i915_gem_dmabuf_mmap,
208	.vmap = i915_gem_dmabuf_vmap,
209	.vunmap = i915_gem_dmabuf_vunmap,
210	.begin_cpu_access = i915_gem_begin_cpu_access,
211	.end_cpu_access = i915_gem_end_cpu_access,
212};
213
214struct dma_buf *i915_gem_prime_export(struct drm_device *dev,
215				      struct drm_gem_object *gem_obj, int flags)
216{
217	struct drm_i915_gem_object *obj = to_intel_bo(gem_obj);
218	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
219
220	exp_info.ops = &i915_dmabuf_ops;
221	exp_info.size = gem_obj->size;
222	exp_info.flags = flags;
223	exp_info.priv = gem_obj;
224	exp_info.resv = obj->resv;
225
226	if (obj->ops->dmabuf_export) {
227		int ret = obj->ops->dmabuf_export(obj);
228		if (ret)
229			return ERR_PTR(ret);
230	}
231
232	return drm_gem_dmabuf_export(dev, &exp_info);
233}
234
235static struct sg_table *
236i915_gem_object_get_pages_dmabuf(struct drm_i915_gem_object *obj)
237{
238	return dma_buf_map_attachment(obj->base.import_attach,
239				      DMA_BIDIRECTIONAL);
240}
241
242static void i915_gem_object_put_pages_dmabuf(struct drm_i915_gem_object *obj,
243					     struct sg_table *pages)
244{
245	dma_buf_unmap_attachment(obj->base.import_attach, pages,
246				 DMA_BIDIRECTIONAL);
247}
248
249static const struct drm_i915_gem_object_ops i915_gem_object_dmabuf_ops = {
250	.get_pages = i915_gem_object_get_pages_dmabuf,
251	.put_pages = i915_gem_object_put_pages_dmabuf,
252};
253
254struct drm_gem_object *i915_gem_prime_import(struct drm_device *dev,
255					     struct dma_buf *dma_buf)
256{
257	struct dma_buf_attachment *attach;
258	struct drm_i915_gem_object *obj;
259	int ret;
260
261	/* is this one of own objects? */
262	if (dma_buf->ops == &i915_dmabuf_ops) {
263		obj = dma_buf_to_obj(dma_buf);
264		/* is it from our device? */
265		if (obj->base.dev == dev) {
266			/*
267			 * Importing dmabuf exported from out own gem increases
268			 * refcount on gem itself instead of f_count of dmabuf.
269			 */
270			return &i915_gem_object_get(obj)->base;
271		}
272	}
273
274	/* need to attach */
275	attach = dma_buf_attach(dma_buf, dev->dev);
276	if (IS_ERR(attach))
277		return ERR_CAST(attach);
278
279	get_dma_buf(dma_buf);
280
281	obj = i915_gem_object_alloc(dev);
282	if (obj == NULL) {
283		ret = -ENOMEM;
284		goto fail_detach;
285	}
286
287	drm_gem_private_object_init(dev, &obj->base, dma_buf->size);
288	i915_gem_object_init(obj, &i915_gem_object_dmabuf_ops);
289	obj->base.import_attach = attach;
290	obj->resv = dma_buf->resv;
291
292	/* We use GTT as shorthand for a coherent domain, one that is
293	 * neither in the GPU cache nor in the CPU cache, where all
294	 * writes are immediately visible in memory. (That's not strictly
295	 * true, but it's close! There are internal buffers such as the
296	 * write-combined buffer or a delay through the chipset for GTT
297	 * writes that do require us to treat GTT as a separate cache domain.)
298	 */
299	obj->base.read_domains = I915_GEM_DOMAIN_GTT;
300	obj->base.write_domain = 0;
301
302	return &obj->base;
303
304fail_detach:
305	dma_buf_detach(dma_buf, attach);
306	dma_buf_put(dma_buf);
307
308	return ERR_PTR(ret);
309}