From 024f67a40bc9ca992a7b932f08aac87f320f20d1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20K=C3=B6nig?= <christian.koenig@amd.com>
Date: Thu, 22 Mar 2018 17:09:42 +0100
Subject: dma-buf: add peer2peer flag
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Git-commit: 09606b5446c25b2c3b16c5bd2977eca730e3a570
Patch-mainline: v5.8-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322

Add a peer2peer flag noting that the importer can deal with device
resources which are not backed by pages.

Signed-off-by: Christian König <christian.koenig@amd.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
Link: https://patchwork.freedesktop.org/patch/359286/
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/dma-buf/dma-buf.c |  2 ++
 include/linux/dma-buf.h   | 10 ++++++++++
 2 files changed, 12 insertions(+)

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index 07df88f2e305..01ce125f8e8d 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -691,6 +691,8 @@ dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev,
 
 	attach->dev = dev;
 	attach->dmabuf = dmabuf;
+	if (importer_ops)
+		attach->peer2peer = importer_ops->allow_peer2peer;
 	attach->importer_ops = importer_ops;
 	attach->importer_priv = importer_priv;
 
diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h
index 57bcef6f988a..ab0c156abee6 100644
--- a/include/linux/dma-buf.h
+++ b/include/linux/dma-buf.h
@@ -333,6 +333,14 @@ struct dma_buf {
  * Attachment operations implemented by the importer.
  */
 struct dma_buf_attach_ops {
+	/**
+	 * @allow_peer2peer:
+	 *
+	 * If this is set to true the importer must be able to handle peer
+	 * resources without struct pages.
+	 */
+	bool allow_peer2peer;
+
 	/**
 	 * @move_notify: [optional] notification that the DMA-buf is moving
 	 *
@@ -361,6 +369,7 @@ struct dma_buf_attach_ops {
  * @node: list of dma_buf_attachment, protected by dma_resv lock of the dmabuf.
  * @sgt: cached mapping.
  * @dir: direction of cached mapping.
+ * @peer2peer: true if the importer can handle peer resources without pages.
  * @priv: exporter specific attachment data.
  * @importer_ops: importer operations for this attachment, if provided
  * dma_buf_map/unmap_attachment() must be called with the dma_resv lock held.
@@ -381,6 +390,7 @@ struct dma_buf_attachment {
 	struct list_head node;
 	struct sg_table *sgt;
 	enum dma_data_direction dir;
+	bool peer2peer;
 	const struct dma_buf_attach_ops *importer_ops;
 	void *importer_priv;
 	void *priv;
-- 
2.28.0