1/*
  2 * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/
  3 * Author: Rob Clark <rob.clark@linaro.org>
  4 *
  5 * This program is free software; you can redistribute it and/or modify it
  6 * under the terms of the GNU General Public License version 2 as published by
  7 * the Free Software Foundation.
  8 *
  9 * This program is distributed in the hope that it will be useful, but WITHOUT
 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 12 * more details.
 13 *
 14 * You should have received a copy of the GNU General Public License along with
 15 * this program.  If not, see <http://www.gnu.org/licenses/>.
 16 */
 17
 18#include <linux/dma-buf.h>
 19
 20#include "omap_drv.h"
 21
 22/* -----------------------------------------------------------------------------
 23 * DMABUF Export
 24 */
 25
 26static struct sg_table *omap_gem_map_dma_buf(
 27		struct dma_buf_attachment *attachment,
 28		enum dma_data_direction dir)
 29{
 30	struct drm_gem_object *obj = attachment->dmabuf->priv;
 31	struct sg_table *sg;
 32	dma_addr_t dma_addr;
 33	int ret;
 34
 35	sg = kzalloc(sizeof(*sg), GFP_KERNEL);
 36	if (!sg)
 37		return ERR_PTR(-ENOMEM);
 38
 39	/* camera, etc, need physically contiguous.. but we need a
 40	 * better way to know this..
 41	 */
 42	ret = omap_gem_pin(obj, &dma_addr);
 43	if (ret)
 44		goto out;
 45
 46	ret = sg_alloc_table(sg, 1, GFP_KERNEL);
 47	if (ret)
 48		goto out;
 49
 50	sg_init_table(sg->sgl, 1);
 51	sg_dma_len(sg->sgl) = obj->size;
 52	sg_set_page(sg->sgl, pfn_to_page(PFN_DOWN(dma_addr)), obj->size, 0);
 53	sg_dma_address(sg->sgl) = dma_addr;
 54
 55	/* this must be after omap_gem_pin() to ensure we have pages attached */
 56	omap_gem_dma_sync_buffer(obj, dir);
 57
 58	return sg;
 59out:
 60	kfree(sg);
 61	return ERR_PTR(ret);
 62}
 63
 64static void omap_gem_unmap_dma_buf(struct dma_buf_attachment *attachment,
 65		struct sg_table *sg, enum dma_data_direction dir)
 66{
 67	struct drm_gem_object *obj = attachment->dmabuf->priv;
 68	omap_gem_unpin(obj);
 69	sg_free_table(sg);
 70	kfree(sg);
 71}
 72
 73static int omap_gem_dmabuf_begin_cpu_access(struct dma_buf *buffer,
 74		enum dma_data_direction dir)
 75{
 76	struct drm_gem_object *obj = buffer->priv;
 77	struct page **pages;
 78	if (omap_gem_flags(obj) & OMAP_BO_TILED) {
 79		/* TODO we would need to pin at least part of the buffer to
 80		 * get de-tiled view.  For now just reject it.
 81		 */
 82		return -ENOMEM;
 83	}
 84	/* make sure we have the pages: */
 85	return omap_gem_get_pages(obj, &pages, true);
 86}
 87
 88static int omap_gem_dmabuf_end_cpu_access(struct dma_buf *buffer,
 89					  enum dma_data_direction dir)
 90{
 91	struct drm_gem_object *obj = buffer->priv;
 92	omap_gem_put_pages(obj);
 93	return 0;
 94}
 95
 96
 97static void *omap_gem_dmabuf_kmap_atomic(struct dma_buf *buffer,
 98		unsigned long page_num)
 99{
100	struct drm_gem_object *obj = buffer->priv;
101	struct page **pages;
102	omap_gem_get_pages(obj, &pages, false);
103	omap_gem_cpu_sync_page(obj, page_num);
104	return kmap_atomic(pages[page_num]);
105}
106
107static void omap_gem_dmabuf_kunmap_atomic(struct dma_buf *buffer,
108		unsigned long page_num, void *addr)
109{
110	kunmap_atomic(addr);
111}
112
113static void *omap_gem_dmabuf_kmap(struct dma_buf *buffer,
114		unsigned long page_num)
115{
116	struct drm_gem_object *obj = buffer->priv;
117	struct page **pages;
118	omap_gem_get_pages(obj, &pages, false);
119	omap_gem_cpu_sync_page(obj, page_num);
120	return kmap(pages[page_num]);
121}
122
123static void omap_gem_dmabuf_kunmap(struct dma_buf *buffer,
124		unsigned long page_num, void *addr)
125{
126	struct drm_gem_object *obj = buffer->priv;
127	struct page **pages;
128	omap_gem_get_pages(obj, &pages, false);
129	kunmap(pages[page_num]);
130}
131
132static int omap_gem_dmabuf_mmap(struct dma_buf *buffer,
133		struct vm_area_struct *vma)
134{
135	struct drm_gem_object *obj = buffer->priv;
136	int ret = 0;
137
138	ret = drm_gem_mmap_obj(obj, omap_gem_mmap_size(obj), vma);
139	if (ret < 0)
140		return ret;
141
142	return omap_gem_mmap_obj(obj, vma);
143}
144
145static const struct dma_buf_ops omap_dmabuf_ops = {
146	.map_dma_buf = omap_gem_map_dma_buf,
147	.unmap_dma_buf = omap_gem_unmap_dma_buf,
148	.release = drm_gem_dmabuf_release,
149	.begin_cpu_access = omap_gem_dmabuf_begin_cpu_access,
150	.end_cpu_access = omap_gem_dmabuf_end_cpu_access,
151	.map_atomic = omap_gem_dmabuf_kmap_atomic,
152	.unmap_atomic = omap_gem_dmabuf_kunmap_atomic,
153	.map = omap_gem_dmabuf_kmap,
154	.unmap = omap_gem_dmabuf_kunmap,
155	.mmap = omap_gem_dmabuf_mmap,
156};
157
158struct dma_buf *omap_gem_prime_export(struct drm_device *dev,
159		struct drm_gem_object *obj, int flags)
160{
161	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
162
163	exp_info.ops = &omap_dmabuf_ops;
164	exp_info.size = obj->size;
165	exp_info.flags = flags;
166	exp_info.priv = obj;
167
168	return drm_gem_dmabuf_export(dev, &exp_info);
169}
170
171/* -----------------------------------------------------------------------------
172 * DMABUF Import
173 */
174
175struct drm_gem_object *omap_gem_prime_import(struct drm_device *dev,
176					     struct dma_buf *dma_buf)
177{
178	struct dma_buf_attachment *attach;
179	struct drm_gem_object *obj;
180	struct sg_table *sgt;
181	int ret;
182
183	if (dma_buf->ops == &omap_dmabuf_ops) {
184		obj = dma_buf->priv;
185		if (obj->dev == dev) {
186			/*
187			 * Importing dmabuf exported from out own gem increases
188			 * refcount on gem itself instead of f_count of dmabuf.
189			 */
190			drm_gem_object_reference(obj);
191			return obj;
192		}
193	}
194
195	attach = dma_buf_attach(dma_buf, dev->dev);
196	if (IS_ERR(attach))
197		return ERR_CAST(attach);
198
199	get_dma_buf(dma_buf);
200
201	sgt = dma_buf_map_attachment(attach, DMA_TO_DEVICE);
202	if (IS_ERR(sgt)) {
203		ret = PTR_ERR(sgt);
204		goto fail_detach;
205	}
206
207	obj = omap_gem_new_dmabuf(dev, dma_buf->size, sgt);
208	if (IS_ERR(obj)) {
209		ret = PTR_ERR(obj);
210		goto fail_unmap;
211	}
212
213	obj->import_attach = attach;
214
215	return obj;
216
217fail_unmap:
218	dma_buf_unmap_attachment(attach, sgt, DMA_TO_DEVICE);
219fail_detach:
220	dma_buf_detach(dma_buf, attach);
221	dma_buf_put(dma_buf);
222
223	return ERR_PTR(ret);
224}