1 files changed, 308 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
new file mode 100644
index 0000000..dc53a52
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
@@ -0,0 +1,308 @@
+/*
+ * Copyright 2012 Red Hat Inc
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Authors:
+ *	Dave Airlie <airlied@redhat.com>
+ */
+#include <drm/drmP.h>
+#include "i915_drv.h"
+#include <linux/dma-buf.h>
+
+static struct sg_table *i915_gem_map_dma_buf(struct dma_buf_attachment *attachment,
+					     enum dma_data_direction dir)
+{
+	struct drm_i915_gem_object *obj = attachment->dmabuf->priv;
+	struct sg_table *st;
+	struct scatterlist *src, *dst;
+	int ret, i;
+
+	ret = i915_mutex_lock_interruptible(obj->base.dev);
+	if (ret)
+		return ERR_PTR(ret);
+
+	ret = i915_gem_object_get_pages(obj);
+	if (ret) {
+		st = ERR_PTR(ret);
+		goto out;
+	}
+
+	/* Copy sg so that we make an independent mapping */
+	st = kmalloc(sizeof(struct sg_table), GFP_KERNEL);
+	if (st == NULL) {
+		st = ERR_PTR(-ENOMEM);
+		goto out;
+	}
+
+	ret = sg_alloc_table(st, obj->pages->nents, GFP_KERNEL);
+	if (ret) {
+		kfree(st);
+		st = ERR_PTR(ret);
+		goto out;
+	}
+
+	src = obj->pages->sgl;
+	dst = st->sgl;
+	for (i = 0; i < obj->pages->nents; i++) {
+		sg_set_page(dst, sg_page(src), src->length, 0);
+		dst = sg_next(dst);
+		src = sg_next(src);
+	}
+
+	if (!dma_map_sg(attachment->dev, st->sgl, st->nents, dir)) {
+		sg_free_table(st);
+		kfree(st);
+		st = ERR_PTR(-ENOMEM);
+		goto out;
+	}
+
+	i915_gem_object_pin_pages(obj);
+
+out:
+	mutex_unlock(&obj->base.dev->struct_mutex);
+	return st;
+}
+
+static void i915_gem_unmap_dma_buf(struct dma_buf_attachment *attachment,
+				   struct sg_table *sg,
+				   enum dma_data_direction dir)
+{
+	dma_unmap_sg(attachment->dev, sg->sgl, sg->nents, dir);
+	sg_free_table(sg);
+	kfree(sg);
+}
+
+static void i915_gem_dmabuf_release(struct dma_buf *dma_buf)
+{
+	struct drm_i915_gem_object *obj = dma_buf->priv;
+
+	if (obj->base.export_dma_buf == dma_buf) {
+		/* drop the reference on the export fd holds */
+		obj->base.export_dma_buf = NULL;
+		drm_gem_object_unreference_unlocked(&obj->base);
+	}
+}
+
+static void *i915_gem_dmabuf_vmap(struct dma_buf *dma_buf)
+{
+	struct drm_i915_gem_object *obj = dma_buf->priv;
+	struct drm_device *dev = obj->base.dev;
+	struct sg_page_iter sg_iter;
+	struct page **pages;
+	int ret, i;
+
+	ret = i915_mutex_lock_interruptible(dev);
+	if (ret)
+		return ERR_PTR(ret);
+
+	if (obj->dma_buf_vmapping) {
+		obj->vmapping_count++;
+		goto out_unlock;
+	}
+
+	ret = i915_gem_object_get_pages(obj);
+	if (ret)
+		goto error;
+
+	ret = -ENOMEM;
+
+	pages = drm_malloc_ab(obj->base.size >> PAGE_SHIFT, sizeof(*pages));
+	if (pages == NULL)
+		goto error;
+
+	i = 0;
+	for_each_sg_page(obj->pages->sgl, &sg_iter, obj->pages->nents, 0)
+		pages[i++] = sg_page_iter_page(&sg_iter);
+
+	obj->dma_buf_vmapping = vmap(pages, i, 0, PAGE_KERNEL);
+	drm_free_large(pages);
+
+	if (!obj->dma_buf_vmapping)
+		goto error;
+
+	obj->vmapping_count = 1;
+	i915_gem_object_pin_pages(obj);
+out_unlock:
+	mutex_unlock(&dev->struct_mutex);
+	return obj->dma_buf_vmapping;
+
+error:
+	mutex_unlock(&dev->struct_mutex);
+	return ERR_PTR(ret);
+}
+
+static void i915_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
+{
+	struct drm_i915_gem_object *obj = dma_buf->priv;
+	struct drm_device *dev = obj->base.dev;
+	int ret;
+
+	ret = i915_mutex_lock_interruptible(dev);
+	if (ret)
+		return;
+
+	if (--obj->vmapping_count == 0) {
+		vunmap(obj->dma_buf_vmapping);
+		obj->dma_buf_vmapping = NULL;
+
+		i915_gem_object_unpin_pages(obj);
+	}
+	mutex_unlock(&dev->struct_mutex);
+}
+
+static void *i915_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf, unsigned long page_num)
+{
+	return NULL;
+}
+
+static void i915_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf, unsigned long page_num, void *addr)
+{
+
+}
+static void *i915_gem_dmabuf_kmap(struct dma_buf *dma_buf, unsigned long page_num)
+{
+	return NULL;
+}
+
+static void i915_gem_dmabuf_kunmap(struct dma_buf *dma_buf, unsigned long page_num, void *addr)
+{
+
+}
+
+static int i915_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma)
+{
+	return -EINVAL;
+}
+
+static int i915_gem_begin_cpu_access(struct dma_buf *dma_buf, size_t start, size_t length, enum dma_data_direction direction)
+{
+	struct drm_i915_gem_object *obj = dma_buf->priv;
+	struct drm_device *dev = obj->base.dev;
+	int ret;
+	bool write = (direction == DMA_BIDIRECTIONAL || direction == DMA_TO_DEVICE);
+
+	ret = i915_mutex_lock_interruptible(dev);
+	if (ret)
+		return ret;
+
+	ret = i915_gem_object_set_to_cpu_domain(obj, write);
+	mutex_unlock(&dev->struct_mutex);
+	return ret;
+}
+
+static const struct dma_buf_ops i915_dmabuf_ops =  {
+	.map_dma_buf = i915_gem_map_dma_buf,
+	.unmap_dma_buf = i915_gem_unmap_dma_buf,
+	.release = i915_gem_dmabuf_release,
+	.kmap = i915_gem_dmabuf_kmap,
+	.kmap_atomic = i915_gem_dmabuf_kmap_atomic,
+	.kunmap = i915_gem_dmabuf_kunmap,
+	.kunmap_atomic = i915_gem_dmabuf_kunmap_atomic,
+	.mmap = i915_gem_dmabuf_mmap,
+	.vmap = i915_gem_dmabuf_vmap,
+	.vunmap = i915_gem_dmabuf_vunmap,
+	.begin_cpu_access = i915_gem_begin_cpu_access,
+};
+
+struct dma_buf *i915_gem_prime_export(struct drm_device *dev,
+				      struct drm_gem_object *gem_obj, int flags)
+{
+	struct drm_i915_gem_object *obj = to_intel_bo(gem_obj);
+
+	return dma_buf_export(obj, &i915_dmabuf_ops, obj->base.size, flags);
+}
+
+static int i915_gem_object_get_pages_dmabuf(struct drm_i915_gem_object *obj)
+{
+	struct sg_table *sg;
+
+	sg = dma_buf_map_attachment(obj->base.import_attach, DMA_BIDIRECTIONAL);
+	if (IS_ERR(sg))
+		return PTR_ERR(sg);
+
+	obj->pages = sg;
+	obj->has_dma_mapping = true;
+	return 0;
+}
+
+static void i915_gem_object_put_pages_dmabuf(struct drm_i915_gem_object *obj)
+{
+	dma_buf_unmap_attachment(obj->base.import_attach,
+				 obj->pages, DMA_BIDIRECTIONAL);
+	obj->has_dma_mapping = false;
+}
+
+static const struct drm_i915_gem_object_ops i915_gem_object_dmabuf_ops = {
+	.get_pages = i915_gem_object_get_pages_dmabuf,
+	.put_pages = i915_gem_object_put_pages_dmabuf,
+};
+
+struct drm_gem_object *i915_gem_prime_import(struct drm_device *dev,
+					     struct dma_buf *dma_buf)
+{
+	struct dma_buf_attachment *attach;
+	struct drm_i915_gem_object *obj;
+	int ret;
+
+	/* is this one of own objects? */
+	if (dma_buf->ops == &i915_dmabuf_ops) {
+		obj = dma_buf->priv;
+		/* is it from our device? */
+		if (obj->base.dev == dev) {
+			/*
+			 * Importing dmabuf exported from out own gem increases
+			 * refcount on gem itself instead of f_count of dmabuf.
+			 */
+			drm_gem_object_reference(&obj->base);
+			return &obj->base;
+		}
+	}
+
+	/* need to attach */
+	attach = dma_buf_attach(dma_buf, dev->dev);
+	if (IS_ERR(attach))
+		return ERR_CAST(attach);
+
+	get_dma_buf(dma_buf);
+
+	obj = i915_gem_object_alloc(dev);
+	if (obj == NULL) {
+		ret = -ENOMEM;
+		goto fail_detach;
+	}
+
+	ret = drm_gem_private_object_init(dev, &obj->base, dma_buf->size);
+	if (ret) {
+		i915_gem_object_free(obj);
+		goto fail_detach;
+	}
+
+	i915_gem_object_init(obj, &i915_gem_object_dmabuf_ops);
+	obj->base.import_attach = attach;
+
+	return &obj->base;
+
+fail_detach:
+	dma_buf_detach(dma_buf, attach);
+	dma_buf_put(dma_buf);
+
+	return ERR_PTR(ret);
+}