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#include <drm/drmP.h>
27#include "i915_drv.h"
28#include <linux/dma-buf.h>
29
30static struct drm_i915_gem_object *dma_buf_to_obj(struct dma_buf *buf)
31{
32	return to_intel_bo(buf->priv);
33}
34
35static struct sg_table *i915_gem_map_dma_buf(struct dma_buf_attachment *attachment,
36					     enum dma_data_direction dir)
37{
38	struct drm_i915_gem_object *obj = dma_buf_to_obj(attachment->dmabuf);
39	struct sg_table *st;
40	struct scatterlist *src, *dst;
41	int ret, i;
42
43	ret = i915_mutex_lock_interruptible(obj->base.dev);
44	if (ret)
45		goto err;
46
47	ret = i915_gem_object_get_pages(obj);
48	if (ret)
49		goto err_unlock;
50
51	i915_gem_object_pin_pages(obj);
52
53	/* Copy sg so that we make an independent mapping */
54	st = kmalloc(sizeof(struct sg_table), GFP_KERNEL);
55	if (st == NULL) {
56		ret = -ENOMEM;
57		goto err_unpin;
58	}
59
60	ret = sg_alloc_table(st, obj->pages->nents, GFP_KERNEL);
61	if (ret)
62		goto err_free;
63
64	src = obj->pages->sgl;
65	dst = st->sgl;
66	for (i = 0; i < obj->pages->nents; i++) {
67		sg_set_page(dst, sg_page(src), src->length, 0);
68		dst = sg_next(dst);
69		src = sg_next(src);
70	}
71
72	if (!dma_map_sg(attachment->dev, st->sgl, st->nents, dir)) {
73		ret =-ENOMEM;
74		goto err_free_sg;
75	}
76
77	mutex_unlock(&obj->base.dev->struct_mutex);
78	return st;
79
80err_free_sg:
81	sg_free_table(st);
82err_free:
83	kfree(st);
84err_unpin:
85	i915_gem_object_unpin_pages(obj);
86err_unlock:
87	mutex_unlock(&obj->base.dev->struct_mutex);
88err:
89	return ERR_PTR(ret);
90}
91
92static void i915_gem_unmap_dma_buf(struct dma_buf_attachment *attachment,
93				   struct sg_table *sg,
94				   enum dma_data_direction dir)
95{
96	struct drm_i915_gem_object *obj = dma_buf_to_obj(attachment->dmabuf);
97
98	mutex_lock(&obj->base.dev->struct_mutex);
99
100	dma_unmap_sg(attachment->dev, sg->sgl, sg->nents, dir);
101	sg_free_table(sg);
102	kfree(sg);
103
104	i915_gem_object_unpin_pages(obj);
105
106	mutex_unlock(&obj->base.dev->struct_mutex);
107}
108
109static void *i915_gem_dmabuf_vmap(struct dma_buf *dma_buf)
110{
111	struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
112	struct drm_device *dev = obj->base.dev;
113	struct sg_page_iter sg_iter;
114	struct page **pages;
115	int ret, i;
116
117	ret = i915_mutex_lock_interruptible(dev);
118	if (ret)
119		return ERR_PTR(ret);
120
121	if (obj->dma_buf_vmapping) {
122		obj->vmapping_count++;
123		goto out_unlock;
124	}
125
126	ret = i915_gem_object_get_pages(obj);
127	if (ret)
128		goto err;
129
130	i915_gem_object_pin_pages(obj);
131
132	ret = -ENOMEM;
133
134	pages = drm_malloc_ab(obj->base.size >> PAGE_SHIFT, sizeof(*pages));
135	if (pages == NULL)
136		goto err_unpin;
137
138	i = 0;
139	for_each_sg_page(obj->pages->sgl, &sg_iter, obj->pages->nents, 0)
140		pages[i++] = sg_page_iter_page(&sg_iter);
141
142	obj->dma_buf_vmapping = vmap(pages, i, 0, PAGE_KERNEL);
143	drm_free_large(pages);
144
145	if (!obj->dma_buf_vmapping)
146		goto err_unpin;
147
148	obj->vmapping_count = 1;
149out_unlock:
150	mutex_unlock(&dev->struct_mutex);
151	return obj->dma_buf_vmapping;
152
153err_unpin:
154	i915_gem_object_unpin_pages(obj);
155err:
156	mutex_unlock(&dev->struct_mutex);
157	return ERR_PTR(ret);
158}
159
160static void i915_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
161{
162	struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
163	struct drm_device *dev = obj->base.dev;
164
165	mutex_lock(&dev->struct_mutex);
166	if (--obj->vmapping_count == 0) {
167		vunmap(obj->dma_buf_vmapping);
168		obj->dma_buf_vmapping = NULL;
169
170		i915_gem_object_unpin_pages(obj);
171	}
172	mutex_unlock(&dev->struct_mutex);
173}
174
175static void *i915_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf, unsigned long page_num)
176{
177	return NULL;
178}
179
180static void i915_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf, unsigned long page_num, void *addr)
181{
182
183}
184static void *i915_gem_dmabuf_kmap(struct dma_buf *dma_buf, unsigned long page_num)
185{
186	return NULL;
187}
188
189static void i915_gem_dmabuf_kunmap(struct dma_buf *dma_buf, unsigned long page_num, void *addr)
190{
191
192}
193
194static int i915_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma)
195{
196	return -EINVAL;
197}
198
199static int i915_gem_begin_cpu_access(struct dma_buf *dma_buf, size_t start, size_t length, enum dma_data_direction direction)
200{
201	struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
202	struct drm_device *dev = obj->base.dev;
203	int ret;
204	bool write = (direction == DMA_BIDIRECTIONAL || direction == DMA_TO_DEVICE);
205
206	ret = i915_mutex_lock_interruptible(dev);
207	if (ret)
208		return ret;
209
210	ret = i915_gem_object_set_to_cpu_domain(obj, write);
211	mutex_unlock(&dev->struct_mutex);
212	return ret;
213}
214
215static const struct dma_buf_ops i915_dmabuf_ops =  {
216	.map_dma_buf = i915_gem_map_dma_buf,
217	.unmap_dma_buf = i915_gem_unmap_dma_buf,
218	.release = drm_gem_dmabuf_release,
219	.kmap = i915_gem_dmabuf_kmap,
220	.kmap_atomic = i915_gem_dmabuf_kmap_atomic,
221	.kunmap = i915_gem_dmabuf_kunmap,
222	.kunmap_atomic = i915_gem_dmabuf_kunmap_atomic,
223	.mmap = i915_gem_dmabuf_mmap,
224	.vmap = i915_gem_dmabuf_vmap,
225	.vunmap = i915_gem_dmabuf_vunmap,
226	.begin_cpu_access = i915_gem_begin_cpu_access,
227};
228
229struct dma_buf *i915_gem_prime_export(struct drm_device *dev,
230				      struct drm_gem_object *gem_obj, int flags)
231{
232	struct drm_i915_gem_object *obj = to_intel_bo(gem_obj);
233	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
234
235	exp_info.ops = &i915_dmabuf_ops;
236	exp_info.size = gem_obj->size;
237	exp_info.flags = flags;
238	exp_info.priv = gem_obj;
239
240
241	if (obj->ops->dmabuf_export) {
242		int ret = obj->ops->dmabuf_export(obj);
243		if (ret)
244			return ERR_PTR(ret);
245	}
246
247	return dma_buf_export(&exp_info);
248}
249
250static int i915_gem_object_get_pages_dmabuf(struct drm_i915_gem_object *obj)
251{
252	struct sg_table *sg;
253
254	sg = dma_buf_map_attachment(obj->base.import_attach, DMA_BIDIRECTIONAL);
255	if (IS_ERR(sg))
256		return PTR_ERR(sg);
257
258	obj->pages = sg;
259	obj->has_dma_mapping = true;
260	return 0;
261}
262
263static void i915_gem_object_put_pages_dmabuf(struct drm_i915_gem_object *obj)
264{
265	dma_buf_unmap_attachment(obj->base.import_attach,
266				 obj->pages, DMA_BIDIRECTIONAL);
267	obj->has_dma_mapping = false;
268}
269
270static const struct drm_i915_gem_object_ops i915_gem_object_dmabuf_ops = {
271	.get_pages = i915_gem_object_get_pages_dmabuf,
272	.put_pages = i915_gem_object_put_pages_dmabuf,
273};
274
275struct drm_gem_object *i915_gem_prime_import(struct drm_device *dev,
276					     struct dma_buf *dma_buf)
277{
278	struct dma_buf_attachment *attach;
279	struct drm_i915_gem_object *obj;
280	int ret;
281
282	/* is this one of own objects? */
283	if (dma_buf->ops == &i915_dmabuf_ops) {
284		obj = dma_buf_to_obj(dma_buf);
285		/* is it from our device? */
286		if (obj->base.dev == dev) {
287			/*
288			 * Importing dmabuf exported from out own gem increases
289			 * refcount on gem itself instead of f_count of dmabuf.
290			 */
291			drm_gem_object_reference(&obj->base);
292			return &obj->base;
293		}
294	}
295
296	/* need to attach */
297	attach = dma_buf_attach(dma_buf, dev->dev);
298	if (IS_ERR(attach))
299		return ERR_CAST(attach);
300
301	get_dma_buf(dma_buf);
302
303	obj = i915_gem_object_alloc(dev);
304	if (obj == NULL) {
305		ret = -ENOMEM;
306		goto fail_detach;
307	}
308
309	drm_gem_private_object_init(dev, &obj->base, dma_buf->size);
310	i915_gem_object_init(obj, &i915_gem_object_dmabuf_ops);
311	obj->base.import_attach = attach;
312
313	return &obj->base;
314
315fail_detach:
316	dma_buf_detach(dma_buf, attach);
317	dma_buf_put(dma_buf);
318
319	return ERR_PTR(ret);
320}
321