From: Christoph Hellwig <hch@lst.de>
Date: Fri, 22 Dec 2017 13:50:47 +0000 (+0100)
Subject: dma-mapping: warn when there is no coherent_dma_mask
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=205e1b7f51e4;p=openwrt%2Fstaging%2Fblogic.git

dma-mapping: warn when there is no coherent_dma_mask

These days all devices should have a DMA coherent mask, and most dma_ops
implementations rely on that fact.  But just to be sure add an assert to
ring the warning bell if that is not the case.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---

diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index d84951865be7..16add66d5b68 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -513,6 +513,7 @@ static inline void *dma_alloc_attrs(struct device *dev, size_t size,
 	void *cpu_addr;
 
 	BUG_ON(!ops);
+	WARN_ON_ONCE(dev && !dev->coherent_dma_mask);
 
 	if (dma_alloc_from_dev_coherent(dev, size, dma_handle, &cpu_addr))
 		return cpu_addr;