From: Christoph Hellwig <hch@lst.de>
To: iommu@lists.linux-foundation.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Jon Mason <jdmason@kudzu.us>, Joerg Roedel <joro@8bytes.org>,
David Woodhouse <dwmw2@infradead.org>,
Marek Szyprowski <m.szyprowski@samsung.com>,
Robin Murphy <robin.murphy@arm.com>,
x86@kernel.org, linux-alpha@vger.kernel.org,
linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org,
linux-parisc@vger.kernel.org, xen-devel@lists.xenproject.org,
linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 01/24] dma-direct: Make DIRECT_MAPPING_ERROR viable for SWIOTLB
Date: Thu, 22 Nov 2018 15:02:57 +0100 [thread overview]
Message-ID: <20181122140320.24080-2-hch@lst.de> (raw)
In-Reply-To: <20181122140320.24080-1-hch@lst.de>
From: Robin Murphy <robin.murphy@arm.com>
With the overflow buffer removed, we no longer have a unique address
which is guaranteed not to be a valid DMA target to use as an error
token. The DIRECT_MAPPING_ERROR value of 0 tries to at least represent
an unlikely DMA target, but unfortunately there are already SWIOTLB
users with DMA-able memory at physical address 0 which now gets falsely
treated as a mapping failure and leads to all manner of misbehaviour.
The best we can do to mitigate that is flip DIRECT_MAPPING_ERROR to the
other commonly-used error value of all-bits-set, since the last single
byte of memory is by far the least-likely-valid DMA target.
Fixes: dff8d6c1ed58 ("swiotlb: remove the overflow buffer")
Reported-by: John Stultz <john.stultz@linaro.org>
Tested-by: John Stultz <john.stultz@linaro.org>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
include/linux/dma-direct.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/dma-direct.h b/include/linux/dma-direct.h
index bd73e7a91410..9e66bfe369aa 100644
--- a/include/linux/dma-direct.h
+++ b/include/linux/dma-direct.h
@@ -5,7 +5,7 @@
#include <linux/dma-mapping.h>
#include <linux/mem_encrypt.h>
-#define DIRECT_MAPPING_ERROR 0
+#define DIRECT_MAPPING_ERROR (~(dma_addr_t)0)
#ifdef CONFIG_ARCH_HAS_PHYS_TO_DMA
#include <asm/dma-direct.h>
--
2.19.1
next prev parent reply other threads:[~2018-11-22 14:06 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-22 14:02 remove the ->mapping_error method from dma_map_ops V2 Christoph Hellwig
2018-11-22 14:02 ` Christoph Hellwig [this message]
2018-11-22 14:02 ` [PATCH 02/24] swiotlb: Skip cache maintenance on map error Christoph Hellwig
2018-11-22 14:02 ` [PATCH 03/24] dma-mapping: provide a generic DMA_MAPPING_ERROR Christoph Hellwig
2018-11-22 14:03 ` [PATCH 04/24] dma-direct: remove the mapping_error dma_map_ops method Christoph Hellwig
2018-11-22 14:03 ` [PATCH 05/24] arm: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 06/24] powerpc/iommu: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 07/24] mips/jazz: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 08/24] s390: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 09/24] sparc: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 10/24] parisc/ccio: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 11/24] parisc/sba_iommu: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 12/24] arm64: remove the dummy_dma_ops mapping_error method Christoph Hellwig
2018-11-22 14:03 ` [PATCH 13/24] alpha: remove the mapping_error dma_map_ops method Christoph Hellwig
2018-11-22 14:03 ` [PATCH 14/24] ia64/sba_iommu: improve internal map_page users Christoph Hellwig
2018-11-22 14:03 ` [PATCH 15/24] ia64/sba_iommu: remove the mapping_error dma_map_ops method Christoph Hellwig
2018-11-22 14:03 ` [PATCH 16/24] ia64/sn: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 17/24] x86/amd_gart: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 18/24] x86/calgary: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 19/24] iommu: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 20/24] iommu/intel: small map_page cleanup Christoph Hellwig
2018-11-22 14:03 ` [PATCH 21/24] iommu/vt-d: remove the mapping_error dma_map_ops method Christoph Hellwig
2018-11-22 14:03 ` [PATCH 22/24] iommu/dma-iommu: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 23/24] xen-swiotlb: " Christoph Hellwig
2018-11-22 14:03 ` [PATCH 24/24] dma-mapping: " Christoph Hellwig
2018-11-22 16:50 ` remove the ->mapping_error method from dma_map_ops V2 Linus Torvalds
2018-11-22 17:07 ` Russell King - ARM Linux
2018-11-22 17:09 ` Linus Torvalds
2018-11-22 17:14 ` Russell King - ARM Linux
2018-11-22 17:52 ` Robin Murphy
2018-11-22 17:55 ` Linus Torvalds
2018-11-22 18:05 ` Russell King - ARM Linux
2018-11-23 6:57 ` Christoph Hellwig
2018-11-23 6:55 ` Christoph Hellwig
2018-11-28 7:41 ` Christoph Hellwig
2018-11-28 16:47 ` Linus Torvalds
2018-11-28 17:45 ` Russell King - ARM Linux
2018-11-28 18:00 ` Linus Torvalds
2018-11-28 18:08 ` Russell King - ARM Linux
2018-11-28 19:23 ` Russell King - ARM Linux
[not found] ` <CAHk-=whcbiSxSUprsKjVPEdN5-+o8WnTGiKxEV-+HbKNDs=iNA@mail.gmail.com>
2018-11-28 19:31 ` Russell King - ARM Linux
2018-11-29 16:23 ` Christoph Hellwig
2018-11-29 17:44 ` Linus Torvalds
2018-11-29 18:31 ` Christoph Hellwig
2018-11-29 18:53 ` Linus Torvalds
2018-11-29 18:55 ` Christoph Hellwig
2018-11-28 19:27 ` David Miller
2018-11-28 19:47 ` Russell King - ARM Linux
2018-11-28 23:01 ` Shuah Khan
2018-11-23 10:49 ` Joerg Roedel
2018-11-23 11:01 ` Russell King - ARM Linux
2018-11-23 13:03 ` Joerg Roedel
2018-11-23 13:20 ` Russell King - ARM Linux
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