linux-kernel - [PATCH v3 3/6] dma-mapping: Remove dma_check

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Message-Id: <20190718032858.28744-4-bauerman@linux.ibm.com>
Date:   Thu, 18 Jul 2019 00:28:55 -0300
From:   Thiago Jung Bauermann <bauerman@...ux.ibm.com>
To:     x86@...nel.org
Cc:     iommu@...ts.linux-foundation.org, linux-fsdevel@...r.kernel.org,
        linuxppc-dev@...ts.ozlabs.org, linux-s390@...r.kernel.org,
        linux-kernel@...r.kernel.org, Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        "H. Peter Anvin" <hpa@...or.com>, Christoph Hellwig <hch@....de>,
        Marek Szyprowski <m.szyprowski@...sung.com>,
        Robin Murphy <robin.murphy@....com>,
        Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>,
        Alexey Dobriyan <adobriyan@...il.com>,
        Thomas Lendacky <Thomas.Lendacky@....com>,
        Halil Pasic <pasic@...ux.ibm.com>,
        Mike Anderson <andmike@...ux.ibm.com>,
        Ram Pai <linuxram@...ibm.com>,
        Thiago Jung Bauermann <bauerman@...ux.ibm.com>
Subject: [PATCH v3 3/6] dma-mapping: Remove dma_check_mask()

sme_active() is an x86-specific function so it's better not to call it from
generic code. Christoph Hellwig mentioned that "There is no reason why we
should have a special debug printk just for one specific reason why there
is a requirement for a large DMA mask.", so just remove dma_check_mask().

Signed-off-by: Thiago Jung Bauermann <bauerman@...ux.ibm.com>
---
 kernel/dma/mapping.c | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c
index 1f628e7ac709..61eeefbfcb36 100644
--- a/kernel/dma/mapping.c
+++ b/kernel/dma/mapping.c
@@ -291,12 +291,6 @@ void dma_free_attrs(struct device *dev, size_t size, void *cpu_addr,
 }
 EXPORT_SYMBOL(dma_free_attrs);
 
-static inline void dma_check_mask(struct device *dev, u64 mask)
-{
-	if (sme_active() && (mask < (((u64)sme_get_me_mask() << 1) - 1)))
-		dev_warn(dev, "SME is active, device will require DMA bounce buffers\n");
-}
-
 int dma_supported(struct device *dev, u64 mask)
 {
 	const struct dma_map_ops *ops = get_dma_ops(dev);
@@ -327,7 +321,6 @@ int dma_set_mask(struct device *dev, u64 mask)
 		return -EIO;
 
 	arch_dma_set_mask(dev, mask);
-	dma_check_mask(dev, mask);
 	*dev->dma_mask = mask;
 	return 0;
 }
@@ -345,7 +338,6 @@ int dma_set_coherent_mask(struct device *dev, u64 mask)
 	if (!dma_supported(dev, mask))
 		return -EIO;
 
-	dma_check_mask(dev, mask);
 	dev->coherent_dma_mask = mask;
 	return 0;
 }