From 42ed64524d846b96afaa8b3f9ba045bcaf11ab0f Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Fri, 2 Feb 2018 09:51:14 +0100
Subject: [PATCH] dma-direct: comment the dma_direct_free calling convention
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
lib/dma-direct.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/lib/dma-direct.c b/lib/dma-direct.c
index fdc733cf9e30..c9e8e21cb334 100644
--- a/lib/dma-direct.c
+++ b/lib/dma-direct.c
@@ -84,6 +84,10 @@ void *dma_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
return page_address(page);
}
+/*
+ * NOTE: this function must never look at the dma_addr argument, because we want
+ * to be able to use it as a helper for iommu implementations as well.
+ */
void dma_direct_free(struct device *dev, size_t size, void *cpu_addr,
dma_addr_t dma_addr, unsigned long attrs)
{
--
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