1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2011 Texas Instruments Incorporated - http://www.ti.com/
4 * Author: Rob Clark <rob.clark@linaro.org>
5 */
6
7 #include <linux/dma-buf.h>
8 #include <linux/highmem.h>
9
10 #include <drm/drm_prime.h>
11
12 #include "omap_drv.h"
13
14 /* -----------------------------------------------------------------------------
15 * DMABUF Export
16 */
17
omap_gem_map_dma_buf(struct dma_buf_attachment * attachment,enum dma_data_direction dir)18 static struct sg_table *omap_gem_map_dma_buf(
19 struct dma_buf_attachment *attachment,
20 enum dma_data_direction dir)
21 {
22 struct drm_gem_object *obj = attachment->dmabuf->priv;
23 struct sg_table *sg;
24 dma_addr_t dma_addr;
25 int ret;
26
27 sg = kzalloc(sizeof(*sg), GFP_KERNEL);
28 if (!sg)
29 return ERR_PTR(-ENOMEM);
30
31 /* camera, etc, need physically contiguous.. but we need a
32 * better way to know this..
33 */
34 ret = omap_gem_pin(obj, &dma_addr);
35 if (ret)
36 goto out;
37
38 ret = sg_alloc_table(sg, 1, GFP_KERNEL);
39 if (ret)
40 goto out;
41
42 sg_init_table(sg->sgl, 1);
43 sg_dma_len(sg->sgl) = obj->size;
44 sg_set_page(sg->sgl, pfn_to_page(PFN_DOWN(dma_addr)), obj->size, 0);
45 sg_dma_address(sg->sgl) = dma_addr;
46
47 /* this must be after omap_gem_pin() to ensure we have pages attached */
48 omap_gem_dma_sync_buffer(obj, dir);
49
50 return sg;
51 out:
52 kfree(sg);
53 return ERR_PTR(ret);
54 }
55
omap_gem_unmap_dma_buf(struct dma_buf_attachment * attachment,struct sg_table * sg,enum dma_data_direction dir)56 static void omap_gem_unmap_dma_buf(struct dma_buf_attachment *attachment,
57 struct sg_table *sg, enum dma_data_direction dir)
58 {
59 struct drm_gem_object *obj = attachment->dmabuf->priv;
60 omap_gem_unpin(obj);
61 sg_free_table(sg);
62 kfree(sg);
63 }
64
omap_gem_dmabuf_begin_cpu_access(struct dma_buf * buffer,enum dma_data_direction dir)65 static int omap_gem_dmabuf_begin_cpu_access(struct dma_buf *buffer,
66 enum dma_data_direction dir)
67 {
68 struct drm_gem_object *obj = buffer->priv;
69 struct page **pages;
70 if (omap_gem_flags(obj) & OMAP_BO_TILED) {
71 /* TODO we would need to pin at least part of the buffer to
72 * get de-tiled view. For now just reject it.
73 */
74 return -ENOMEM;
75 }
76 /* make sure we have the pages: */
77 return omap_gem_get_pages(obj, &pages, true);
78 }
79
omap_gem_dmabuf_end_cpu_access(struct dma_buf * buffer,enum dma_data_direction dir)80 static int omap_gem_dmabuf_end_cpu_access(struct dma_buf *buffer,
81 enum dma_data_direction dir)
82 {
83 struct drm_gem_object *obj = buffer->priv;
84 omap_gem_put_pages(obj);
85 return 0;
86 }
87
omap_gem_dmabuf_kmap(struct dma_buf * buffer,unsigned long page_num)88 static void *omap_gem_dmabuf_kmap(struct dma_buf *buffer,
89 unsigned long page_num)
90 {
91 struct drm_gem_object *obj = buffer->priv;
92 struct page **pages;
93 omap_gem_get_pages(obj, &pages, false);
94 omap_gem_cpu_sync_page(obj, page_num);
95 return kmap(pages[page_num]);
96 }
97
omap_gem_dmabuf_kunmap(struct dma_buf * buffer,unsigned long page_num,void * addr)98 static void omap_gem_dmabuf_kunmap(struct dma_buf *buffer,
99 unsigned long page_num, void *addr)
100 {
101 struct drm_gem_object *obj = buffer->priv;
102 struct page **pages;
103 omap_gem_get_pages(obj, &pages, false);
104 kunmap(pages[page_num]);
105 }
106
omap_gem_dmabuf_mmap(struct dma_buf * buffer,struct vm_area_struct * vma)107 static int omap_gem_dmabuf_mmap(struct dma_buf *buffer,
108 struct vm_area_struct *vma)
109 {
110 struct drm_gem_object *obj = buffer->priv;
111 int ret = 0;
112
113 ret = drm_gem_mmap_obj(obj, omap_gem_mmap_size(obj), vma);
114 if (ret < 0)
115 return ret;
116
117 return omap_gem_mmap_obj(obj, vma);
118 }
119
120 static const struct dma_buf_ops omap_dmabuf_ops = {
121 .map_dma_buf = omap_gem_map_dma_buf,
122 .unmap_dma_buf = omap_gem_unmap_dma_buf,
123 .release = drm_gem_dmabuf_release,
124 .begin_cpu_access = omap_gem_dmabuf_begin_cpu_access,
125 .end_cpu_access = omap_gem_dmabuf_end_cpu_access,
126 .map = omap_gem_dmabuf_kmap,
127 .unmap = omap_gem_dmabuf_kunmap,
128 .mmap = omap_gem_dmabuf_mmap,
129 };
130
omap_gem_prime_export(struct drm_gem_object * obj,int flags)131 struct dma_buf *omap_gem_prime_export(struct drm_gem_object *obj, int flags)
132 {
133 DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
134
135 exp_info.ops = &omap_dmabuf_ops;
136 exp_info.size = obj->size;
137 exp_info.flags = flags;
138 exp_info.priv = obj;
139
140 return drm_gem_dmabuf_export(obj->dev, &exp_info);
141 }
142
143 /* -----------------------------------------------------------------------------
144 * DMABUF Import
145 */
146
omap_gem_prime_import(struct drm_device * dev,struct dma_buf * dma_buf)147 struct drm_gem_object *omap_gem_prime_import(struct drm_device *dev,
148 struct dma_buf *dma_buf)
149 {
150 struct dma_buf_attachment *attach;
151 struct drm_gem_object *obj;
152 struct sg_table *sgt;
153 int ret;
154
155 if (dma_buf->ops == &omap_dmabuf_ops) {
156 obj = dma_buf->priv;
157 if (obj->dev == dev) {
158 /*
159 * Importing dmabuf exported from out own gem increases
160 * refcount on gem itself instead of f_count of dmabuf.
161 */
162 drm_gem_object_get(obj);
163 return obj;
164 }
165 }
166
167 attach = dma_buf_attach(dma_buf, dev->dev);
168 if (IS_ERR(attach))
169 return ERR_CAST(attach);
170
171 get_dma_buf(dma_buf);
172
173 sgt = dma_buf_map_attachment(attach, DMA_TO_DEVICE);
174 if (IS_ERR(sgt)) {
175 ret = PTR_ERR(sgt);
176 goto fail_detach;
177 }
178
179 obj = omap_gem_new_dmabuf(dev, dma_buf->size, sgt);
180 if (IS_ERR(obj)) {
181 ret = PTR_ERR(obj);
182 goto fail_unmap;
183 }
184
185 obj->import_attach = attach;
186
187 return obj;
188
189 fail_unmap:
190 dma_buf_unmap_attachment(attach, sgt, DMA_TO_DEVICE);
191 fail_detach:
192 dma_buf_detach(dma_buf, attach);
193 dma_buf_put(dma_buf);
194
195 return ERR_PTR(ret);
196 }
197
