1 /* $NetBSD: i915_gem_dmabuf.c,v 1.6 2021/12/19 11:33:30 riastradh Exp $ */
2
3 /*
4 * SPDX-License-Identifier: MIT
5 *
6 * Copyright 2012 Red Hat Inc
7 */
8
9 #include <sys/cdefs.h>
10 __KERNEL_RCSID(0, "$NetBSD: i915_gem_dmabuf.c,v 1.6 2021/12/19 11:33:30 riastradh Exp $");
11
12 #include <linux/dma-buf.h>
13 #include <linux/highmem.h>
14 #include <linux/dma-resv.h>
15
16 #include "i915_drv.h"
17 #include "i915_gem_object.h"
18 #include "i915_scatterlist.h"
19
dma_buf_to_obj(struct dma_buf * buf)20 static struct drm_i915_gem_object *dma_buf_to_obj(struct dma_buf *buf)
21 {
22 struct drm_gem_object *obj = buf->priv;
23
24 return to_intel_bo(obj);
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 ret = i915_gem_object_pin_pages(obj);
36 if (ret)
37 goto err;
38
39 /* Copy sg so that we make an independent mapping */
40 st = kmalloc(sizeof(struct sg_table), GFP_KERNEL);
41 if (st == NULL) {
42 ret = -ENOMEM;
43 goto err_unpin_pages;
44 }
45
46 ret = sg_alloc_table(st, obj->mm.pages->nents, GFP_KERNEL);
47 if (ret)
48 goto err_free;
49
50 #ifdef __NetBSD__
51 __USE(i);
52 __USE(src);
53 __USE(dst);
54 memcpy(st->sgl->sg_pgs, obj->mm.pages->sgl->sg_pgs,
55 obj->mm.pages->nents * sizeof(st->sgl->sg_pgs[0]));
56 #else
57
58 src = obj->mm.pages->sgl;
59 dst = st->sgl;
60 for (i = 0; i < obj->mm.pages->nents; i++) {
61 sg_set_page(dst, sg_page(src), src->length, 0);
62 dst = sg_next(dst);
63 src = sg_next(src);
64 }
65 #endif
66
67 if (!dma_map_sg(attachment->dev, st->sgl, st->nents, dir)) {
68 ret = -ENOMEM;
69 goto err_free_sg;
70 }
71
72 return st;
73
74 err_free_sg:
75 sg_free_table(st);
76 err_free:
77 kfree(st);
78 err_unpin_pages:
79 i915_gem_object_unpin_pages(obj);
80 err:
81 return ERR_PTR(ret);
82 }
83
i915_gem_unmap_dma_buf(struct dma_buf_attachment * attachment,struct sg_table * sg,enum dma_data_direction dir)84 static void i915_gem_unmap_dma_buf(struct dma_buf_attachment *attachment,
85 struct sg_table *sg,
86 enum dma_data_direction dir)
87 {
88 struct drm_i915_gem_object *obj = dma_buf_to_obj(attachment->dmabuf);
89
90 dma_unmap_sg(attachment->dev, sg->sgl, sg->nents, dir);
91 sg_free_table(sg);
92 kfree(sg);
93
94 i915_gem_object_unpin_pages(obj);
95 }
96
i915_gem_dmabuf_vmap(struct dma_buf * dma_buf)97 static void *i915_gem_dmabuf_vmap(struct dma_buf *dma_buf)
98 {
99 struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
100
101 return i915_gem_object_pin_map(obj, I915_MAP_WB);
102 }
103
i915_gem_dmabuf_vunmap(struct dma_buf * dma_buf,void * vaddr)104 static void i915_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
105 {
106 struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
107
108 i915_gem_object_flush_map(obj);
109 i915_gem_object_unpin_map(obj);
110 }
111
112 #ifdef __NetBSD__
i915_gem_dmabuf_mmap(struct dma_buf * dma_buf,off_t * offp,size_t size,int prot,int * flagsp,int * advicep,struct uvm_object ** uobjp,int * maxprotp)113 static int i915_gem_dmabuf_mmap(struct dma_buf *dma_buf, off_t *offp,
114 size_t size, int prot, int *flagsp, int *advicep,
115 struct uvm_object **uobjp, int *maxprotp)
116 #else
117 static int i915_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma)
118 #endif
119 {
120 struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
121 int ret;
122
123 #ifdef __NetBSD__
124 __USE(ret);
125 if (obj->base.size < size)
126 return -EINVAL;
127 if (!obj->base.filp)
128 return -ENODEV;
129 /* XXX review mmap refcount */
130 drm_gem_object_get(&obj->base);
131 *advicep = UVM_ADV_RANDOM;
132 *uobjp = &obj->base.gemo_uvmobj;
133 *maxprotp = prot;
134 #else
135 if (obj->base.size < vma->vm_end - vma->vm_start)
136 return -EINVAL;
137
138 if (!obj->base.filp)
139 return -ENODEV;
140
141 ret = call_mmap(obj->base.filp, vma);
142 if (ret)
143 return ret;
144
145 fput(vma->vm_file);
146 vma->vm_file = get_file(obj->base.filp);
147 #endif
148
149 return 0;
150 }
151
i915_gem_begin_cpu_access(struct dma_buf * dma_buf,enum dma_data_direction direction)152 static int i915_gem_begin_cpu_access(struct dma_buf *dma_buf, enum dma_data_direction direction)
153 {
154 struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
155 bool write = (direction == DMA_BIDIRECTIONAL || direction == DMA_TO_DEVICE);
156 int err;
157
158 err = i915_gem_object_pin_pages(obj);
159 if (err)
160 return err;
161
162 err = i915_gem_object_lock_interruptible(obj);
163 if (err)
164 goto out;
165
166 err = i915_gem_object_set_to_cpu_domain(obj, write);
167 i915_gem_object_unlock(obj);
168
169 out:
170 i915_gem_object_unpin_pages(obj);
171 return err;
172 }
173
i915_gem_end_cpu_access(struct dma_buf * dma_buf,enum dma_data_direction direction)174 static int i915_gem_end_cpu_access(struct dma_buf *dma_buf, enum dma_data_direction direction)
175 {
176 struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
177 int err;
178
179 err = i915_gem_object_pin_pages(obj);
180 if (err)
181 return err;
182
183 err = i915_gem_object_lock_interruptible(obj);
184 if (err)
185 goto out;
186
187 err = i915_gem_object_set_to_gtt_domain(obj, false);
188 i915_gem_object_unlock(obj);
189
190 out:
191 i915_gem_object_unpin_pages(obj);
192 return err;
193 }
194
195 static const struct dma_buf_ops i915_dmabuf_ops = {
196 .map_dma_buf = i915_gem_map_dma_buf,
197 .unmap_dma_buf = i915_gem_unmap_dma_buf,
198 .release = drm_gem_dmabuf_release,
199 .mmap = i915_gem_dmabuf_mmap,
200 .vmap = i915_gem_dmabuf_vmap,
201 .vunmap = i915_gem_dmabuf_vunmap,
202 .begin_cpu_access = i915_gem_begin_cpu_access,
203 .end_cpu_access = i915_gem_end_cpu_access,
204 };
205
i915_gem_prime_export(struct drm_gem_object * gem_obj,int flags)206 struct dma_buf *i915_gem_prime_export(struct drm_gem_object *gem_obj, int flags)
207 {
208 struct drm_i915_gem_object *obj = to_intel_bo(gem_obj);
209 DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
210
211 exp_info.ops = &i915_dmabuf_ops;
212 exp_info.size = gem_obj->size;
213 exp_info.flags = flags;
214 exp_info.priv = gem_obj;
215 exp_info.resv = obj->base.resv;
216
217 if (obj->ops->dmabuf_export) {
218 int ret = obj->ops->dmabuf_export(obj);
219 if (ret)
220 return ERR_PTR(ret);
221 }
222
223 return drm_gem_dmabuf_export(gem_obj->dev, &exp_info);
224 }
225
i915_gem_object_get_pages_dmabuf(struct drm_i915_gem_object * obj)226 static int i915_gem_object_get_pages_dmabuf(struct drm_i915_gem_object *obj)
227 {
228 struct sg_table *pages;
229 unsigned int sg_page_sizes;
230
231 pages = dma_buf_map_attachment(obj->base.import_attach,
232 DMA_BIDIRECTIONAL);
233 if (IS_ERR(pages))
234 return PTR_ERR(pages);
235
236 sg_page_sizes = i915_sg_page_sizes(pages->sgl);
237
238 __i915_gem_object_set_pages(obj, pages, sg_page_sizes);
239
240 return 0;
241 }
242
i915_gem_object_put_pages_dmabuf(struct drm_i915_gem_object * obj,struct sg_table * pages)243 static void i915_gem_object_put_pages_dmabuf(struct drm_i915_gem_object *obj,
244 struct sg_table *pages)
245 {
246 dma_buf_unmap_attachment(obj->base.import_attach, pages,
247 DMA_BIDIRECTIONAL);
248 }
249
250 static const struct drm_i915_gem_object_ops i915_gem_object_dmabuf_ops = {
251 .get_pages = i915_gem_object_get_pages_dmabuf,
252 .put_pages = i915_gem_object_put_pages_dmabuf,
253 };
254
i915_gem_prime_import(struct drm_device * dev,struct dma_buf * dma_buf)255 struct drm_gem_object *i915_gem_prime_import(struct drm_device *dev,
256 struct dma_buf *dma_buf)
257 {
258 static struct lock_class_key lock_class;
259 struct dma_buf_attachment *attach;
260 struct drm_i915_gem_object *obj;
261 int ret;
262
263 /* is this one of own objects? */
264 if (dma_buf->ops == &i915_dmabuf_ops) {
265 obj = dma_buf_to_obj(dma_buf);
266 /* is it from our device? */
267 if (obj->base.dev == dev) {
268 /*
269 * Importing dmabuf exported from out own gem increases
270 * refcount on gem itself instead of f_count of dmabuf.
271 */
272 return &i915_gem_object_get(obj)->base;
273 }
274 }
275
276 /* need to attach */
277 attach = dma_buf_attach(dma_buf, dev->dmat);
278 if (IS_ERR(attach))
279 return ERR_CAST(attach);
280
281 get_dma_buf(dma_buf);
282
283 obj = i915_gem_object_alloc();
284 if (obj == NULL) {
285 ret = -ENOMEM;
286 goto fail_detach;
287 }
288
289 drm_gem_private_object_init(dev, &obj->base, dma_buf->size);
290 i915_gem_object_init(obj, &i915_gem_object_dmabuf_ops, &lock_class);
291 obj->base.import_attach = attach;
292 obj->base.resv = dma_buf->resv;
293
294 /* We use GTT as shorthand for a coherent domain, one that is
295 * neither in the GPU cache nor in the CPU cache, where all
296 * writes are immediately visible in memory. (That's not strictly
297 * true, but it's close! There are internal buffers such as the
298 * write-combined buffer or a delay through the chipset for GTT
299 * writes that do require us to treat GTT as a separate cache domain.)
300 */
301 obj->read_domains = I915_GEM_DOMAIN_GTT;
302 obj->write_domain = 0;
303
304 return &obj->base;
305
306 fail_detach:
307 dma_buf_detach(dma_buf, attach);
308 dma_buf_put(dma_buf);
309
310 return ERR_PTR(ret);
311 }
312
313 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
314 #include "selftests/mock_dmabuf.c"
315 #include "selftests/i915_gem_dmabuf.c"
316 #endif
317