2 * SPDX-License-Identifier: MIT
4 * Copyright 2012 Red Hat Inc
7 #include <linux/dma-buf.h>
8 #include <linux/highmem.h>
9 #include <linux/dma-resv.h>
12 #include "i915_gem_object.h"
13 #include "i915_scatterlist.h"
15 static struct drm_i915_gem_object *dma_buf_to_obj(struct dma_buf *buf)
17 return to_intel_bo(buf->priv);
20 static struct sg_table *i915_gem_map_dma_buf(struct dma_buf_attachment *attachment,
21 enum dma_data_direction dir)
23 struct drm_i915_gem_object *obj = dma_buf_to_obj(attachment->dmabuf);
25 struct scatterlist *src, *dst;
28 ret = i915_gem_object_pin_pages(obj);
32 /* Copy sg so that we make an independent mapping */
33 st = kmalloc(sizeof(struct sg_table), GFP_KERNEL);
39 ret = sg_alloc_table(st, obj->mm.pages->nents, GFP_KERNEL);
43 src = obj->mm.pages->sgl;
45 for (i = 0; i < obj->mm.pages->nents; i++) {
46 sg_set_page(dst, sg_page(src), src->length, 0);
51 if (!dma_map_sg(attachment->dev, st->sgl, st->nents, dir)) {
63 i915_gem_object_unpin_pages(obj);
68 static void i915_gem_unmap_dma_buf(struct dma_buf_attachment *attachment,
70 enum dma_data_direction dir)
72 struct drm_i915_gem_object *obj = dma_buf_to_obj(attachment->dmabuf);
74 dma_unmap_sg(attachment->dev, sg->sgl, sg->nents, dir);
78 i915_gem_object_unpin_pages(obj);
81 static void *i915_gem_dmabuf_vmap(struct dma_buf *dma_buf)
83 struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
85 return i915_gem_object_pin_map(obj, I915_MAP_WB);
88 static void i915_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
90 struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
92 i915_gem_object_flush_map(obj);
93 i915_gem_object_unpin_map(obj);
96 static void *i915_gem_dmabuf_kmap(struct dma_buf *dma_buf, unsigned long page_num)
98 struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
101 if (page_num >= obj->base.size >> PAGE_SHIFT)
104 if (!i915_gem_object_has_struct_page(obj))
107 if (i915_gem_object_pin_pages(obj))
110 /* Synchronisation is left to the caller (via .begin_cpu_access()) */
111 page = i915_gem_object_get_page(obj, page_num);
118 i915_gem_object_unpin_pages(obj);
122 static void i915_gem_dmabuf_kunmap(struct dma_buf *dma_buf, unsigned long page_num, void *addr)
124 struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
126 kunmap(virt_to_page(addr));
127 i915_gem_object_unpin_pages(obj);
130 static int i915_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma)
132 struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
135 if (obj->base.size < vma->vm_end - vma->vm_start)
141 ret = call_mmap(obj->base.filp, vma);
146 vma->vm_file = get_file(obj->base.filp);
151 static int i915_gem_begin_cpu_access(struct dma_buf *dma_buf, enum dma_data_direction direction)
153 struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
154 bool write = (direction == DMA_BIDIRECTIONAL || direction == DMA_TO_DEVICE);
157 err = i915_gem_object_pin_pages(obj);
161 err = i915_gem_object_lock_interruptible(obj);
165 err = i915_gem_object_set_to_cpu_domain(obj, write);
166 i915_gem_object_unlock(obj);
169 i915_gem_object_unpin_pages(obj);
173 static int i915_gem_end_cpu_access(struct dma_buf *dma_buf, enum dma_data_direction direction)
175 struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
178 err = i915_gem_object_pin_pages(obj);
182 err = i915_gem_object_lock_interruptible(obj);
186 err = i915_gem_object_set_to_gtt_domain(obj, false);
187 i915_gem_object_unlock(obj);
190 i915_gem_object_unpin_pages(obj);
194 static const struct dma_buf_ops i915_dmabuf_ops = {
195 .map_dma_buf = i915_gem_map_dma_buf,
196 .unmap_dma_buf = i915_gem_unmap_dma_buf,
197 .release = drm_gem_dmabuf_release,
198 .map = i915_gem_dmabuf_kmap,
199 .unmap = i915_gem_dmabuf_kunmap,
200 .mmap = i915_gem_dmabuf_mmap,
201 .vmap = i915_gem_dmabuf_vmap,
202 .vunmap = i915_gem_dmabuf_vunmap,
203 .begin_cpu_access = i915_gem_begin_cpu_access,
204 .end_cpu_access = i915_gem_end_cpu_access,
207 struct dma_buf *i915_gem_prime_export(struct drm_gem_object *gem_obj, int flags)
209 struct drm_i915_gem_object *obj = to_intel_bo(gem_obj);
210 DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
212 exp_info.ops = &i915_dmabuf_ops;
213 exp_info.size = gem_obj->size;
214 exp_info.flags = flags;
215 exp_info.priv = gem_obj;
216 exp_info.resv = obj->base.resv;
218 if (obj->ops->dmabuf_export) {
219 int ret = obj->ops->dmabuf_export(obj);
224 return drm_gem_dmabuf_export(gem_obj->dev, &exp_info);
227 static int i915_gem_object_get_pages_dmabuf(struct drm_i915_gem_object *obj)
229 struct sg_table *pages;
230 unsigned int sg_page_sizes;
232 pages = dma_buf_map_attachment(obj->base.import_attach,
235 return PTR_ERR(pages);
237 sg_page_sizes = i915_sg_page_sizes(pages->sgl);
239 __i915_gem_object_set_pages(obj, pages, sg_page_sizes);
244 static void i915_gem_object_put_pages_dmabuf(struct drm_i915_gem_object *obj,
245 struct sg_table *pages)
247 dma_buf_unmap_attachment(obj->base.import_attach, pages,
251 static const struct drm_i915_gem_object_ops i915_gem_object_dmabuf_ops = {
252 .get_pages = i915_gem_object_get_pages_dmabuf,
253 .put_pages = i915_gem_object_put_pages_dmabuf,
256 struct drm_gem_object *i915_gem_prime_import(struct drm_device *dev,
257 struct dma_buf *dma_buf)
259 struct dma_buf_attachment *attach;
260 struct drm_i915_gem_object *obj;
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) {
269 * Importing dmabuf exported from out own gem increases
270 * refcount on gem itself instead of f_count of dmabuf.
272 return &i915_gem_object_get(obj)->base;
277 attach = dma_buf_attach(dma_buf, dev->dev);
279 return ERR_CAST(attach);
281 get_dma_buf(dma_buf);
283 obj = i915_gem_object_alloc();
289 drm_gem_private_object_init(dev, &obj->base, dma_buf->size);
290 i915_gem_object_init(obj, &i915_gem_object_dmabuf_ops);
291 obj->base.import_attach = attach;
292 obj->base.resv = dma_buf->resv;
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.)
301 obj->read_domains = I915_GEM_DOMAIN_GTT;
302 obj->write_domain = 0;
307 dma_buf_detach(dma_buf, attach);
308 dma_buf_put(dma_buf);
313 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
314 #include "selftests/mock_dmabuf.c"
315 #include "selftests/i915_gem_dmabuf.c"