1 /*
2 * SPDX-License-Identifier: MIT
3 *
4 * Copyright 2012 Red Hat Inc
5 */
6
7 #include <linux/dma-buf.h>
8 #include <linux/highmem.h>
9 #include <linux/dma-resv.h>
10 #include <linux/module.h>
11
12 #include <asm/smp.h>
13
14 #include "i915_drv.h"
15 #include "i915_gem_object.h"
16 #include "i915_scatterlist.h"
17
18 MODULE_IMPORT_NS(DMA_BUF);
19
I915_SELFTEST_DECLARE(static bool force_different_devices;)20 I915_SELFTEST_DECLARE(static bool force_different_devices;)
21
22 static struct drm_i915_gem_object *dma_buf_to_obj(struct dma_buf *buf)
23 {
24 return to_intel_bo(buf->priv);
25 }
26
i915_gem_map_dma_buf(struct dma_buf_attachment * attachment,enum dma_data_direction dir)27 static struct sg_table *i915_gem_map_dma_buf(struct dma_buf_attachment *attachment,
28 enum dma_data_direction dir)
29 {
30 struct drm_i915_gem_object *obj = dma_buf_to_obj(attachment->dmabuf);
31 struct sg_table *st;
32 struct scatterlist *src, *dst;
33 int ret, i;
34
35 /* Copy sg so that we make an independent mapping */
36 st = kmalloc(sizeof(struct sg_table), GFP_KERNEL);
37 if (st == NULL) {
38 ret = -ENOMEM;
39 goto err;
40 }
41
42 ret = sg_alloc_table(st, obj->mm.pages->nents, GFP_KERNEL);
43 if (ret)
44 goto err_free;
45
46 src = obj->mm.pages->sgl;
47 dst = st->sgl;
48 for (i = 0; i < obj->mm.pages->nents; i++) {
49 sg_set_page(dst, sg_page(src), src->length, 0);
50 dst = sg_next(dst);
51 src = sg_next(src);
52 }
53
54 ret = dma_map_sgtable(attachment->dev, st, dir, DMA_ATTR_SKIP_CPU_SYNC);
55 if (ret)
56 goto err_free_sg;
57
58 return st;
59
60 err_free_sg:
61 sg_free_table(st);
62 err_free:
63 kfree(st);
64 err:
65 return ERR_PTR(ret);
66 }
67
i915_gem_unmap_dma_buf(struct dma_buf_attachment * attachment,struct sg_table * sg,enum dma_data_direction dir)68 static void i915_gem_unmap_dma_buf(struct dma_buf_attachment *attachment,
69 struct sg_table *sg,
70 enum dma_data_direction dir)
71 {
72 dma_unmap_sgtable(attachment->dev, sg, dir, DMA_ATTR_SKIP_CPU_SYNC);
73 sg_free_table(sg);
74 kfree(sg);
75 }
76
i915_gem_dmabuf_vmap(struct dma_buf * dma_buf,struct dma_buf_map * map)77 static int i915_gem_dmabuf_vmap(struct dma_buf *dma_buf, struct dma_buf_map *map)
78 {
79 struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
80 void *vaddr;
81
82 vaddr = i915_gem_object_pin_map_unlocked(obj, I915_MAP_WB);
83 if (IS_ERR(vaddr))
84 return PTR_ERR(vaddr);
85
86 dma_buf_map_set_vaddr(map, vaddr);
87
88 return 0;
89 }
90
i915_gem_dmabuf_vunmap(struct dma_buf * dma_buf,struct dma_buf_map * map)91 static void i915_gem_dmabuf_vunmap(struct dma_buf *dma_buf, struct dma_buf_map *map)
92 {
93 struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
94
95 i915_gem_object_flush_map(obj);
96 i915_gem_object_unpin_map(obj);
97 }
98
i915_gem_dmabuf_mmap(struct dma_buf * dma_buf,struct vm_area_struct * vma)99 static int i915_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma)
100 {
101 struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
102 int ret;
103
104 if (obj->base.size < vma->vm_end - vma->vm_start)
105 return -EINVAL;
106
107 if (!obj->base.filp)
108 return -ENODEV;
109
110 ret = call_mmap(obj->base.filp, vma);
111 if (ret)
112 return ret;
113
114 vma_set_file(vma, obj->base.filp);
115
116 return 0;
117 }
118
i915_gem_begin_cpu_access(struct dma_buf * dma_buf,enum dma_data_direction direction)119 static int i915_gem_begin_cpu_access(struct dma_buf *dma_buf, enum dma_data_direction direction)
120 {
121 struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
122 bool write = (direction == DMA_BIDIRECTIONAL || direction == DMA_TO_DEVICE);
123 struct i915_gem_ww_ctx ww;
124 int err;
125
126 i915_gem_ww_ctx_init(&ww, true);
127 retry:
128 err = i915_gem_object_lock(obj, &ww);
129 if (!err)
130 err = i915_gem_object_pin_pages(obj);
131 if (!err) {
132 err = i915_gem_object_set_to_cpu_domain(obj, write);
133 i915_gem_object_unpin_pages(obj);
134 }
135 if (err == -EDEADLK) {
136 err = i915_gem_ww_ctx_backoff(&ww);
137 if (!err)
138 goto retry;
139 }
140 i915_gem_ww_ctx_fini(&ww);
141 return err;
142 }
143
i915_gem_end_cpu_access(struct dma_buf * dma_buf,enum dma_data_direction direction)144 static int i915_gem_end_cpu_access(struct dma_buf *dma_buf, enum dma_data_direction direction)
145 {
146 struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
147 struct i915_gem_ww_ctx ww;
148 int err;
149
150 i915_gem_ww_ctx_init(&ww, true);
151 retry:
152 err = i915_gem_object_lock(obj, &ww);
153 if (!err)
154 err = i915_gem_object_pin_pages(obj);
155 if (!err) {
156 err = i915_gem_object_set_to_gtt_domain(obj, false);
157 i915_gem_object_unpin_pages(obj);
158 }
159 if (err == -EDEADLK) {
160 err = i915_gem_ww_ctx_backoff(&ww);
161 if (!err)
162 goto retry;
163 }
164 i915_gem_ww_ctx_fini(&ww);
165 return err;
166 }
167
i915_gem_dmabuf_attach(struct dma_buf * dmabuf,struct dma_buf_attachment * attach)168 static int i915_gem_dmabuf_attach(struct dma_buf *dmabuf,
169 struct dma_buf_attachment *attach)
170 {
171 struct drm_i915_gem_object *obj = dma_buf_to_obj(dmabuf);
172 struct i915_gem_ww_ctx ww;
173 int err;
174
175 if (!i915_gem_object_can_migrate(obj, INTEL_REGION_SMEM))
176 return -EOPNOTSUPP;
177
178 for_i915_gem_ww(&ww, err, true) {
179 err = i915_gem_object_lock(obj, &ww);
180 if (err)
181 continue;
182
183 err = i915_gem_object_migrate(obj, &ww, INTEL_REGION_SMEM);
184 if (err)
185 continue;
186
187 err = i915_gem_object_wait_migration(obj, 0);
188 if (err)
189 continue;
190
191 err = i915_gem_object_pin_pages(obj);
192 }
193
194 return err;
195 }
196
i915_gem_dmabuf_detach(struct dma_buf * dmabuf,struct dma_buf_attachment * attach)197 static void i915_gem_dmabuf_detach(struct dma_buf *dmabuf,
198 struct dma_buf_attachment *attach)
199 {
200 struct drm_i915_gem_object *obj = dma_buf_to_obj(dmabuf);
201
202 i915_gem_object_unpin_pages(obj);
203 }
204
205 static const struct dma_buf_ops i915_dmabuf_ops = {
206 .attach = i915_gem_dmabuf_attach,
207 .detach = i915_gem_dmabuf_detach,
208 .map_dma_buf = i915_gem_map_dma_buf,
209 .unmap_dma_buf = i915_gem_unmap_dma_buf,
210 .release = drm_gem_dmabuf_release,
211 .mmap = i915_gem_dmabuf_mmap,
212 .vmap = i915_gem_dmabuf_vmap,
213 .vunmap = i915_gem_dmabuf_vunmap,
214 .begin_cpu_access = i915_gem_begin_cpu_access,
215 .end_cpu_access = i915_gem_end_cpu_access,
216 };
217
i915_gem_prime_export(struct drm_gem_object * gem_obj,int flags)218 struct dma_buf *i915_gem_prime_export(struct drm_gem_object *gem_obj, int flags)
219 {
220 struct drm_i915_gem_object *obj = to_intel_bo(gem_obj);
221 DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
222
223 exp_info.ops = &i915_dmabuf_ops;
224 exp_info.size = gem_obj->size;
225 exp_info.flags = flags;
226 exp_info.priv = gem_obj;
227 exp_info.resv = obj->base.resv;
228
229 if (obj->ops->dmabuf_export) {
230 int ret = obj->ops->dmabuf_export(obj);
231 if (ret)
232 return ERR_PTR(ret);
233 }
234
235 return drm_gem_dmabuf_export(gem_obj->dev, &exp_info);
236 }
237
i915_gem_object_get_pages_dmabuf(struct drm_i915_gem_object * obj)238 static int i915_gem_object_get_pages_dmabuf(struct drm_i915_gem_object *obj)
239 {
240 struct drm_i915_private *i915 = to_i915(obj->base.dev);
241 struct sg_table *pages;
242 unsigned int sg_page_sizes;
243
244 assert_object_held(obj);
245
246 pages = dma_buf_map_attachment(obj->base.import_attach,
247 DMA_BIDIRECTIONAL);
248 if (IS_ERR(pages))
249 return PTR_ERR(pages);
250
251 /* XXX: consider doing a vmap flush or something */
252 if (!HAS_LLC(i915) || i915_gem_object_can_bypass_llc(obj))
253 wbinvd_on_all_cpus();
254
255 sg_page_sizes = i915_sg_dma_sizes(pages->sgl);
256 __i915_gem_object_set_pages(obj, pages, sg_page_sizes);
257
258 return 0;
259 }
260
i915_gem_object_put_pages_dmabuf(struct drm_i915_gem_object * obj,struct sg_table * pages)261 static void i915_gem_object_put_pages_dmabuf(struct drm_i915_gem_object *obj,
262 struct sg_table *pages)
263 {
264 dma_buf_unmap_attachment(obj->base.import_attach, pages,
265 DMA_BIDIRECTIONAL);
266 }
267
268 static const struct drm_i915_gem_object_ops i915_gem_object_dmabuf_ops = {
269 .name = "i915_gem_object_dmabuf",
270 .get_pages = i915_gem_object_get_pages_dmabuf,
271 .put_pages = i915_gem_object_put_pages_dmabuf,
272 };
273
i915_gem_prime_import(struct drm_device * dev,struct dma_buf * dma_buf)274 struct drm_gem_object *i915_gem_prime_import(struct drm_device *dev,
275 struct dma_buf *dma_buf)
276 {
277 static struct lock_class_key lock_class;
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 !I915_SELFTEST_ONLY(force_different_devices)) {
288 /*
289 * Importing dmabuf exported from out own gem increases
290 * refcount on gem itself instead of f_count of dmabuf.
291 */
292 return &i915_gem_object_get(obj)->base;
293 }
294 }
295
296 if (i915_gem_object_size_2big(dma_buf->size))
297 return ERR_PTR(-E2BIG);
298
299 /* need to attach */
300 attach = dma_buf_attach(dma_buf, dev->dev);
301 if (IS_ERR(attach))
302 return ERR_CAST(attach);
303
304 get_dma_buf(dma_buf);
305
306 obj = i915_gem_object_alloc();
307 if (obj == NULL) {
308 ret = -ENOMEM;
309 goto fail_detach;
310 }
311
312 drm_gem_private_object_init(dev, &obj->base, dma_buf->size);
313 i915_gem_object_init(obj, &i915_gem_object_dmabuf_ops, &lock_class,
314 I915_BO_ALLOC_USER);
315 obj->base.import_attach = attach;
316 obj->base.resv = dma_buf->resv;
317
318 /* We use GTT as shorthand for a coherent domain, one that is
319 * neither in the GPU cache nor in the CPU cache, where all
320 * writes are immediately visible in memory. (That's not strictly
321 * true, but it's close! There are internal buffers such as the
322 * write-combined buffer or a delay through the chipset for GTT
323 * writes that do require us to treat GTT as a separate cache domain.)
324 */
325 obj->read_domains = I915_GEM_DOMAIN_GTT;
326 obj->write_domain = 0;
327
328 return &obj->base;
329
330 fail_detach:
331 dma_buf_detach(dma_buf, attach);
332 dma_buf_put(dma_buf);
333
334 return ERR_PTR(ret);
335 }
336
337 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
338 #include "selftests/mock_dmabuf.c"
339 #include "selftests/i915_gem_dmabuf.c"
340 #endif
341