From 0cc848a75b742c3f9800e643cd2c03b9cfdc3d69 Mon Sep 17 00:00:00 2001
From: Christian König <christian.koenig@amd.com>
Date: Tue, 9 Nov 2021 11:08:18 +0100
Subject: dma-buf: add DMA_RESV_USAGE_BOOKKEEP v3
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Add an usage for submissions independent of implicit sync but still
interesting for memory management.

v2: cleanup the kerneldoc a bit
v3: separate amdgpu changes from this

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20220407085946.744568-10-christian.koenig@amd.com
---
 include/linux/dma-resv.h | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

(limited to 'include')

diff --git a/include/linux/dma-resv.h b/include/linux/dma-resv.h
index a749f229ae91..1db759eacc98 100644
--- a/include/linux/dma-resv.h
+++ b/include/linux/dma-resv.h
@@ -55,7 +55,7 @@ struct dma_resv_list;
  * This enum describes the different use cases for a dma_resv object and
  * controls which fences are returned when queried.
  *
- * An important fact is that there is the order KERNEL<WRITE<READ and
+ * An important fact is that there is the order KERNEL<WRITE<READ<BOOKKEEP and
  * when the dma_resv object is asked for fences for one use case the fences
  * for the lower use case are returned as well.
  *
@@ -93,6 +93,17 @@ enum dma_resv_usage {
 	 * an implicit read dependency.
 	 */
 	DMA_RESV_USAGE_READ,
+
+	/**
+	 * @DMA_RESV_USAGE_BOOKKEEP: No implicit sync.
+	 *
+	 * This should be used by submissions which don't want to participate in
+	 * implicit synchronization.
+	 *
+	 * The most common case are preemption fences as well as page table
+	 * updates and their TLB flushes.
+	 */
+	DMA_RESV_USAGE_BOOKKEEP
 };
 
 /**
-- 
cgit v1.2.3