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 01/23] dma-mapping: provide a generic DMA_MAPPING_ERROR
Date: Fri, 30 Nov 2018 14:22:09 +0100 [thread overview]
Message-ID: <20181130132231.16512-2-hch@lst.de> (raw)
In-Reply-To: <20181130132231.16512-1-hch@lst.de>
Error handling of the dma_map_single and dma_map_page APIs is a little
problematic at the moment, in that we use different encodings in the
returned dma_addr_t to indicate an error. That means we require an
additional indirect call to figure out if a dma mapping call returned
an error, and a lot of boilerplate code to implement these semantics.
Instead return the maximum addressable value as the error. As long
as we don't allow mapping single-byte ranges with single-byte alignment
this value can never be a valid return. Additionaly if drivers do
not check the return value from the dma_map* routines this values means
they will generally not be pointed to actual memory.
Once the default value is added here we can start removing the
various mapping_error methods and just rely on this generic check.
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
include/linux/dma-mapping.h | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 0f81c713f6e9..46bd612d929e 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -133,6 +133,8 @@ struct dma_map_ops {
u64 (*get_required_mask)(struct device *dev);
};
+#define DMA_MAPPING_ERROR (~(dma_addr_t)0)
+
extern const struct dma_map_ops dma_direct_ops;
extern const struct dma_map_ops dma_virt_ops;
@@ -576,6 +578,10 @@ static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
const struct dma_map_ops *ops = get_dma_ops(dev);
debug_dma_mapping_error(dev, dma_addr);
+
+ if (dma_addr == DMA_MAPPING_ERROR)
+ return 1;
+
if (ops->mapping_error)
return ops->mapping_error(dev, dma_addr);
return 0;
--
2.19.1
next prev parent reply other threads:[~2018-11-30 13:25 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-30 13:22 remove the ->mapping_error method from dma_map_ops V3 Christoph Hellwig
2018-11-30 13:22 ` Christoph Hellwig [this message]
2018-12-04 16:41 ` [PATCH 01/23] dma-mapping: provide a generic DMA_MAPPING_ERROR Robin Murphy
2018-12-04 22:33 ` Christoph Hellwig
2018-11-30 13:22 ` [PATCH 02/23] dma-direct: remove the mapping_error dma_map_ops method Christoph Hellwig
2018-11-30 13:22 ` [PATCH 03/23] arm: " Christoph Hellwig
2018-11-30 13:22 ` [PATCH 04/23] powerpc/iommu: " Christoph Hellwig
2018-11-30 13:22 ` [PATCH 05/23] mips/jazz: " Christoph Hellwig
2018-11-30 13:22 ` [PATCH 06/23] s390: " Christoph Hellwig
2018-11-30 13:22 ` [PATCH 07/23] sparc: " Christoph Hellwig
2018-11-30 13:22 ` [PATCH 08/23] parisc/ccio: " Christoph Hellwig
2018-11-30 13:22 ` [PATCH 09/23] parisc/sba_iommu: " Christoph Hellwig
2018-11-30 13:22 ` [PATCH 10/23] arm64: remove the dummy_dma_ops mapping_error method Christoph Hellwig
2018-11-30 13:22 ` [PATCH 11/23] alpha: remove the mapping_error dma_map_ops method Christoph Hellwig
2018-11-30 13:22 ` [PATCH 12/23] ia64/sba_iommu: improve internal map_page users Christoph Hellwig
2018-11-30 13:22 ` [PATCH 13/23] ia64/sba_iommu: remove the mapping_error dma_map_ops method Christoph Hellwig
2018-11-30 13:22 ` [PATCH 14/23] ia64/sn: " Christoph Hellwig
2018-11-30 13:22 ` [PATCH 15/23] x86/amd_gart: " Christoph Hellwig
2018-11-30 13:22 ` [PATCH 16/23] x86/calgary: " Christoph Hellwig
2018-11-30 13:22 ` [PATCH 17/23] iommu: " Christoph Hellwig
2018-11-30 13:22 ` [PATCH 18/23] iommu/intel: small map_page cleanup Christoph Hellwig
2018-11-30 13:22 ` [PATCH 19/23] iommu/vt-d: remove the mapping_error dma_map_ops method Christoph Hellwig
2018-11-30 13:22 ` [PATCH 20/23] iommu/dma-iommu: " Christoph Hellwig
2018-11-30 13:22 ` [PATCH 21/23] xen-swiotlb: " Christoph Hellwig
2018-12-02 12:42 ` Konrad Rzeszutek Wilk
2018-11-30 13:22 ` [PATCH 22/23] dma-mapping: " Christoph Hellwig
2018-11-30 13:22 ` [PATCH 23/23] dma-mapping: return an error code from dma_mapping_error Christoph Hellwig
2018-11-30 18:59 ` remove the ->mapping_error method from dma_map_ops V3 Russell King - ARM Linux
2018-11-30 19:43 ` Linus Torvalds
2018-12-03 17:27 ` Christoph Hellwig
2018-12-06 14:57 ` Christoph Hellwig
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