drm: GEM CMA: Add DRM PRIME support (71d7282a) · Commits · e / devices / android_kernel_fairphone_FP5

drivers/gpu/drm/drm_gem_cma_helper.c

+314 −3

Original line number	Diff line number	Diff line
		@@ -21,6 +21,7 @@
		#include <linux/slab.h>
		#include <linux/mutex.h>
		#include <linux/export.h>
		#include <linux/dma-buf.h>
		#include <linux/dma-mapping.h>

		#include <drm/drmP.h>
		@@ -82,6 +83,8 @@ struct drm_gem_cma_object drm_gem_cma_create(struct drm_device drm,
		unsigned int size)
		{
		struct drm_gem_cma_object *cma_obj;
		struct sg_table *sgt = NULL;
		int ret;

		size = round_up(size, PAGE_SIZE);

		@@ -94,11 +97,29 @@ struct drm_gem_cma_object drm_gem_cma_create(struct drm_device drm,
		if (!cma_obj->vaddr) {
		dev_err(drm->dev, "failed to allocate buffer with size %d\n",
		size);
		drm_gem_cma_free_object(&cma_obj->base);
		return ERR_PTR(-ENOMEM);
		ret = -ENOMEM;
		goto error;
		}

		sgt = kzalloc(sizeof(*cma_obj->sgt), GFP_KERNEL);
		if (sgt == NULL) {
		ret = -ENOMEM;
		goto error;
		}

		ret = dma_get_sgtable(drm->dev, sgt, cma_obj->vaddr,
		cma_obj->paddr, size);
		if (ret < 0)
		goto error;

		cma_obj->sgt = sgt;

		return cma_obj;

		error:
		kfree(sgt);
		drm_gem_cma_free_object(&cma_obj->base);
		return ERR_PTR(ret);
		}
		EXPORT_SYMBOL_GPL(drm_gem_cma_create);

		@@ -156,9 +177,16 @@ void drm_gem_cma_free_object(struct drm_gem_object *gem_obj)

		cma_obj = to_drm_gem_cma_obj(gem_obj);

		if (cma_obj->vaddr)
		if (cma_obj->vaddr) {
		dma_free_writecombine(gem_obj->dev->dev, cma_obj->base.size,
		cma_obj->vaddr, cma_obj->paddr);
		if (cma_obj->sgt) {
		sg_free_table(cma_obj->sgt);
		kfree(cma_obj->sgt);
		}
		} else if (gem_obj->import_attach) {
		drm_prime_gem_destroy(gem_obj, cma_obj->sgt);
		}

		drm_gem_object_release(gem_obj);

		@@ -291,3 +319,286 @@ void drm_gem_cma_describe(struct drm_gem_cma_object cma_obj, struct seq_file m
		}
		EXPORT_SYMBOL_GPL(drm_gem_cma_describe);
		#endif

		/* -----------------------------------------------------------------------------
		* DMA-BUF
		*/

		struct drm_gem_cma_dmabuf_attachment {
		struct sg_table sgt;
		enum dma_data_direction dir;
		};

		static int drm_gem_cma_dmabuf_attach(struct dma_buf dmabuf, struct device dev,
		struct dma_buf_attachment *attach)
		{
		struct drm_gem_cma_dmabuf_attachment *cma_attach;

		cma_attach = kzalloc(sizeof(*cma_attach), GFP_KERNEL);
		if (!cma_attach)
		return -ENOMEM;

		cma_attach->dir = DMA_NONE;
		attach->priv = cma_attach;

		return 0;
		}

		static void drm_gem_cma_dmabuf_detach(struct dma_buf *dmabuf,
		struct dma_buf_attachment *attach)
		{
		struct drm_gem_cma_dmabuf_attachment *cma_attach = attach->priv;
		struct sg_table *sgt;

		if (cma_attach == NULL)
		return;

		sgt = &cma_attach->sgt;

		if (cma_attach->dir != DMA_NONE)
		dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents,
		cma_attach->dir);

		sg_free_table(sgt);
		kfree(cma_attach);
		attach->priv = NULL;
		}

		static struct sg_table *
		drm_gem_cma_dmabuf_map(struct dma_buf_attachment *attach,
		enum dma_data_direction dir)
		{
		struct drm_gem_cma_dmabuf_attachment *cma_attach = attach->priv;
		struct drm_gem_cma_object *cma_obj = attach->dmabuf->priv;
		struct drm_device *drm = cma_obj->base.dev;
		struct scatterlist rd, wr;
		struct sg_table *sgt;
		unsigned int i;
		int nents, ret;

		DRM_DEBUG_PRIME("\n");

		if (WARN_ON(dir == DMA_NONE))
		return ERR_PTR(-EINVAL);

		/* Return the cached mapping when possible. */
		if (cma_attach->dir == dir)
		return &cma_attach->sgt;

		/* Two mappings with different directions for the same attachment are
		* not allowed.
		*/
		if (WARN_ON(cma_attach->dir != DMA_NONE))
		return ERR_PTR(-EBUSY);

		sgt = &cma_attach->sgt;

		ret = sg_alloc_table(sgt, cma_obj->sgt->orig_nents, GFP_KERNEL);
		if (ret) {
		DRM_ERROR("failed to alloc sgt.\n");
		return ERR_PTR(-ENOMEM);
		}

		mutex_lock(&drm->struct_mutex);

		rd = cma_obj->sgt->sgl;
		wr = sgt->sgl;
		for (i = 0; i < sgt->orig_nents; ++i) {
		sg_set_page(wr, sg_page(rd), rd->length, rd->offset);
		rd = sg_next(rd);
		wr = sg_next(wr);
		}

		nents = dma_map_sg(attach->dev, sgt->sgl, sgt->orig_nents, dir);
		if (!nents) {
		DRM_ERROR("failed to map sgl with iommu.\n");
		sg_free_table(sgt);
		sgt = ERR_PTR(-EIO);
		goto done;
		}

		cma_attach->dir = dir;
		attach->priv = cma_attach;

		DRM_DEBUG_PRIME("buffer size = %zu\n", cma_obj->base.size);

		done:
		mutex_unlock(&drm->struct_mutex);
		return sgt;
		}

		static void drm_gem_cma_dmabuf_unmap(struct dma_buf_attachment *attach,
		struct sg_table *sgt,
		enum dma_data_direction dir)
		{
		/* Nothing to do. */
		}

		static void drm_gem_cma_dmabuf_release(struct dma_buf *dmabuf)
		{
		struct drm_gem_cma_object *cma_obj = dmabuf->priv;

		DRM_DEBUG_PRIME("%s\n", __FILE__);

		/*
		* drm_gem_cma_dmabuf_release() call means that file object's
		* f_count is 0 and it calls drm_gem_object_handle_unreference()
		* to drop the references that these values had been increased
		* at drm_prime_handle_to_fd()
		*/
		if (cma_obj->base.export_dma_buf == dmabuf) {
		cma_obj->base.export_dma_buf = NULL;

		/*
		* drop this gem object refcount to release allocated buffer
		* and resources.
		*/
		drm_gem_object_unreference_unlocked(&cma_obj->base);
		}
		}

		static void drm_gem_cma_dmabuf_kmap_atomic(struct dma_buf dmabuf,
		unsigned long page_num)
		{
		/* TODO */

		return NULL;
		}

		static void drm_gem_cma_dmabuf_kunmap_atomic(struct dma_buf *dmabuf,
		unsigned long page_num, void *addr)
		{
		/* TODO */
		}

		static void drm_gem_cma_dmabuf_kmap(struct dma_buf dmabuf,
		unsigned long page_num)
		{
		/* TODO */

		return NULL;
		}

		static void drm_gem_cma_dmabuf_kunmap(struct dma_buf *dmabuf,
		unsigned long page_num, void *addr)
		{
		/* TODO */
		}

		static int drm_gem_cma_dmabuf_mmap(struct dma_buf *dmabuf,
		struct vm_area_struct *vma)
		{
		struct drm_gem_cma_object *cma_obj = dmabuf->priv;
		struct drm_gem_object *gem_obj = &cma_obj->base;
		int ret;

		ret = drm_gem_mmap_obj(gem_obj, gem_obj->size, vma);
		if (ret < 0)
		return ret;

		return drm_gem_cma_mmap_obj(cma_obj, vma);
		}

		static void drm_gem_cma_dmabuf_vmap(struct dma_buf dmabuf)
		{
		struct drm_gem_cma_object *cma_obj = dmabuf->priv;

		return cma_obj->vaddr;
		}

		static struct dma_buf_ops drm_gem_cma_dmabuf_ops = {
		.attach = drm_gem_cma_dmabuf_attach,
		.detach = drm_gem_cma_dmabuf_detach,
		.map_dma_buf = drm_gem_cma_dmabuf_map,
		.unmap_dma_buf = drm_gem_cma_dmabuf_unmap,
		.kmap = drm_gem_cma_dmabuf_kmap,
		.kmap_atomic = drm_gem_cma_dmabuf_kmap_atomic,
		.kunmap = drm_gem_cma_dmabuf_kunmap,
		.kunmap_atomic = drm_gem_cma_dmabuf_kunmap_atomic,
		.mmap = drm_gem_cma_dmabuf_mmap,
		.vmap = drm_gem_cma_dmabuf_vmap,
		.release = drm_gem_cma_dmabuf_release,
		};

		struct dma_buf drm_gem_cma_dmabuf_export(struct drm_device drm,
		struct drm_gem_object *obj, int flags)
		{
		struct drm_gem_cma_object *cma_obj = to_drm_gem_cma_obj(obj);

		return dma_buf_export(cma_obj, &drm_gem_cma_dmabuf_ops,
		cma_obj->base.size, flags);
		}
		EXPORT_SYMBOL_GPL(drm_gem_cma_dmabuf_export);

		struct drm_gem_object drm_gem_cma_dmabuf_import(struct drm_device drm,
		struct dma_buf *dma_buf)
		{
		struct drm_gem_cma_object *cma_obj;
		struct dma_buf_attachment *attach;
		struct sg_table *sgt;
		int ret;

		DRM_DEBUG_PRIME("%s\n", __FILE__);

		/* is this one of own objects? */
		if (dma_buf->ops == &drm_gem_cma_dmabuf_ops) {
		struct drm_gem_object *obj;

		cma_obj = dma_buf->priv;
		obj = &cma_obj->base;

		/* is it from our device? */
		if (obj->dev == drm) {
		/*
		* Importing dmabuf exported from out own gem increases
		* refcount on gem itself instead of f_count of dmabuf.
		*/
		drm_gem_object_reference(obj);
		dma_buf_put(dma_buf);
		return obj;
		}
		}

		/* Create a CMA GEM buffer. */
		cma_obj = __drm_gem_cma_create(drm, dma_buf->size);
		if (IS_ERR(cma_obj))
		return ERR_PTR(PTR_ERR(cma_obj));

		/* Attach to the buffer and map it. Make sure the mapping is contiguous
		* on the device memory bus, as that's all we support.
		*/
		attach = dma_buf_attach(dma_buf, drm->dev);
		if (IS_ERR(attach)) {
		ret = -EINVAL;
		goto error_gem_free;
		}

		sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
		if (IS_ERR_OR_NULL(sgt)) {
		ret = sgt ? PTR_ERR(sgt) : -ENOMEM;
		goto error_buf_detach;
		}

		if (sgt->nents != 1) {
		ret = -EINVAL;
		goto error_buf_unmap;
		}

		cma_obj->base.import_attach = attach;
		cma_obj->paddr = sg_dma_address(sgt->sgl);
		cma_obj->sgt = sgt;

		DRM_DEBUG_PRIME("dma_addr = 0x%x, size = %zu\n", cma_obj->paddr,
		dma_buf->size);

		return &cma_obj->base;

		error_buf_unmap:
		dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL);
		error_buf_detach:
		dma_buf_detach(dma_buf, attach);
		error_gem_free:
		drm_gem_cma_free_object(&cma_obj->base);
		return ERR_PTR(ret);
		}
		EXPORT_SYMBOL_GPL(drm_gem_cma_dmabuf_import);

include/drm/drm_gem_cma_helper.h

+9 −0

Original line number	Diff line number	Diff line
		@@ -4,6 +4,9 @@
		struct drm_gem_cma_object {
		struct drm_gem_object base;
		dma_addr_t paddr;
		struct sg_table *sgt;

		/* For objects with DMA memory allocated by GEM CMA */
		void *vaddr;
		};

		@@ -45,4 +48,10 @@ extern const struct vm_operations_struct drm_gem_cma_vm_ops;
		void drm_gem_cma_describe(struct drm_gem_cma_object obj, struct seq_file m);
		#endif

		struct dma_buf drm_gem_cma_dmabuf_export(struct drm_device drm_dev,
		struct drm_gem_object *obj,
		int flags);
		struct drm_gem_object drm_gem_cma_dmabuf_import(struct drm_device drm_dev,
		struct dma_buf *dma_buf);

		#endif /* __DRM_GEM_CMA_HELPER_H__ */