From: Krzysztof Kozlowski <k.kozlowski@samsung.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org, hch@infradead.org,
Krzysztof Kozlowski <k.kozlowski@samsung.com>,
Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Subject: [PATCH v6 46/46] dma-mapping: Document the DMA attributes next to the declaration
Date: Wed, 13 Jul 2016 10:41:37 +0200 [thread overview]
Message-ID: <1468399300-5399-46-git-send-email-k.kozlowski@samsung.com> (raw)
In-Reply-To: <1468399300-5399-45-git-send-email-k.kozlowski@samsung.com>
Copy documentation abstract about each DMA attribute from
Documentation/DMA-attributes.txt to the place with declaration.
Suggested-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
---
include/linux/dma-mapping.h | 33 +++++++++++++++++++++++++++++++++
1 file changed, 33 insertions(+)
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index d8fb67783cb7..66533e18276c 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -14,14 +14,47 @@
/**
* List of possible attributes associated with a DMA mapping. The semantics
* of each attribute should be defined in Documentation/DMA-attributes.txt.
+ *
+ * DMA_ATTR_WRITE_BARRIER: DMA to a memory region with this attribute
+ * forces all pending DMA writes to complete.
*/
#define DMA_ATTR_WRITE_BARRIER (1UL << 0)
+/*
+ * DMA_ATTR_WEAK_ORDERING: Specifies that reads and writes to the mapping
+ * may be weakly ordered, that is that reads and writes may pass each other.
+ */
#define DMA_ATTR_WEAK_ORDERING (1UL << 1)
+/*
+ * DMA_ATTR_WRITE_COMBINE: Specifies that writes to the mapping may be
+ * buffered to improve performance.
+ */
#define DMA_ATTR_WRITE_COMBINE (1UL << 2)
+/*
+ * DMA_ATTR_NON_CONSISTENT: Lets the platform to choose to return either
+ * consistent or non-consistent memory as it sees fit.
+ */
#define DMA_ATTR_NON_CONSISTENT (1UL << 3)
+/*
+ * DMA_ATTR_NO_KERNEL_MAPPING: Lets the platform to avoid creating a kernel
+ * virtual mapping for the allocated buffer.
+ */
#define DMA_ATTR_NO_KERNEL_MAPPING (1UL << 4)
+/*
+ * DMA_ATTR_SKIP_CPU_SYNC: Allows platform code to skip synchronization of
+ * the CPU cache for the given buffer assuming that it has been already
+ * transferred to 'device' domain.
+ */
#define DMA_ATTR_SKIP_CPU_SYNC (1UL << 5)
+/*
+ * DMA_ATTR_FORCE_CONTIGUOUS: Forces contiguous allocation of the buffer
+ * in physical memory.
+ */
#define DMA_ATTR_FORCE_CONTIGUOUS (1UL << 6)
+/*
+ * DMA_ATTR_ALLOC_SINGLE_PAGES: This is a hint to the DMA-mapping subsystem
+ * that it's probably not worth the time to try to allocate memory to in a way
+ * that gives better TLB efficiency.
+ */
#define DMA_ATTR_ALLOC_SINGLE_PAGES (1UL << 7)
/*
--
1.9.1
next prev parent reply other threads:[~2016-07-13 8:43 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-07-13 8:39 [PATCH v6 00/46] dma-mapping: Use unsigned long for dma_attrs Krzysztof Kozlowski
2016-07-13 8:40 ` [PATCH v6 01/46] [media] mtk-vcodec: Remove unused dma_attrs Krzysztof Kozlowski
2016-07-13 8:40 ` [PATCH v6 02/46] dma-mapping: Use unsigned long for dma_attrs Krzysztof Kozlowski
2016-07-13 8:40 ` [PATCH v6 03/46] alpha: " Krzysztof Kozlowski
2016-07-13 8:40 ` [PATCH v6 04/46] arc: " Krzysztof Kozlowski
2016-07-13 8:40 ` [PATCH v6 05/46] ARM: " Krzysztof Kozlowski
2016-07-13 8:40 ` [PATCH v6 06/46] arm64: " Krzysztof Kozlowski
2016-07-13 8:40 ` [PATCH v6 07/46] avr32: " Krzysztof Kozlowski
2016-07-13 8:40 ` [PATCH v6 08/46] blackfin: " Krzysztof Kozlowski
2016-07-13 8:41 ` [PATCH v6 09/46] c6x: " Krzysztof Kozlowski
2016-07-13 8:41 ` [PATCH v6 10/46] cris: " Krzysztof Kozlowski
2016-07-13 8:41 ` [PATCH v6 11/46] frv: " Krzysztof Kozlowski
2016-07-13 8:41 ` [PATCH v6 12/46] drm/exynos: " Krzysztof Kozlowski
2016-07-13 8:41 ` [PATCH v6 13/46] drm/mediatek: " Krzysztof Kozlowski
2016-07-13 8:41 ` [PATCH v6 14/46] drm/msm: " Krzysztof Kozlowski
2016-07-13 8:41 ` [PATCH v6 15/46] drm/nouveau: " Krzysztof Kozlowski
2016-07-13 8:41 ` [PATCH v6 16/46] drm/rockship: " Krzysztof Kozlowski
2016-07-13 8:41 ` [PATCH v6 17/46] infiniband: " Krzysztof Kozlowski
2016-07-13 8:41 ` [PATCH v6 18/46] iommu: " Krzysztof Kozlowski
2016-07-13 8:41 ` [PATCH v6 19/46] [media] " Krzysztof Kozlowski
2016-07-13 8:41 ` [PATCH v6 20/46] xen: " Krzysztof Kozlowski
2016-07-13 8:41 ` [PATCH v6 21/46] swiotlb: " Krzysztof Kozlowski
2016-07-13 8:41 ` [PATCH v6 22/46] powerpc: " Krzysztof Kozlowski
2016-07-13 8:41 ` [PATCH v6 23/46] video: " Krzysztof Kozlowski
2016-07-13 8:41 ` [PATCH v6 24/46] x86: " Krzysztof Kozlowski
2016-07-13 8:41 ` [PATCH v6 25/46] iommu: intel: " Krzysztof Kozlowski
2016-07-13 8:41 ` [PATCH v6 26/46] h8300: " Krzysztof Kozlowski
2016-07-13 8:41 ` [PATCH v6 27/46] hexagon: " Krzysztof Kozlowski
2016-07-13 8:41 ` [PATCH v6 28/46] ia64: " Krzysztof Kozlowski
2016-07-13 8:41 ` [PATCH v6 29/46] m68k: " Krzysztof Kozlowski
2016-07-13 8:41 ` [PATCH v6 30/46] metag: " Krzysztof Kozlowski
2016-07-13 8:41 ` [PATCH v6 31/46] microblaze: " Krzysztof Kozlowski
2016-07-13 8:41 ` [PATCH v6 32/46] mips: " Krzysztof Kozlowski
2016-07-13 8:41 ` [PATCH v6 33/46] mn10300: " Krzysztof Kozlowski
2016-07-13 8:41 ` [PATCH v6 34/46] nios2: " Krzysztof Kozlowski
2016-07-13 8:41 ` [PATCH v6 35/46] openrisc: " Krzysztof Kozlowski
2016-07-13 8:41 ` [PATCH v6 36/46] parisc: " Krzysztof Kozlowski
2016-07-13 8:41 ` [PATCH v6 37/46] misc: mic: " Krzysztof Kozlowski
2016-07-13 8:41 ` [PATCH v6 38/46] s390: " Krzysztof Kozlowski
2016-07-13 8:41 ` [PATCH v6 39/46] sh: " Krzysztof Kozlowski
2016-07-13 8:41 ` [PATCH v6 40/46] sparc: " Krzysztof Kozlowski
2016-07-13 8:41 ` [PATCH v6 41/46] tile: " Krzysztof Kozlowski
2016-07-13 8:41 ` [PATCH v6 42/46] unicore32: " Krzysztof Kozlowski
2016-07-13 8:41 ` [PATCH v6 43/46] xtensa: " Krzysztof Kozlowski
2016-07-13 8:41 ` [PATCH v6 44/46] remoteproc: qcom: " Krzysztof Kozlowski
2016-07-13 8:41 ` [PATCH v6 45/46] dma-mapping: Remove dma_get_attr Krzysztof Kozlowski
2016-07-13 8:41 ` Krzysztof Kozlowski [this message]
2016-07-13 16:51 ` [PATCH v6 44/46] remoteproc: qcom: Use unsigned long for dma_attrs Bjorn Andersson
2016-07-13 10:37 ` [PATCH v6 17/46] infiniband: dma-mapping: " Bart Van Assche
2016-07-13 10:47 ` Krzysztof Kozlowski
2016-07-13 10:56 ` Bart Van Assche
2016-07-13 11:03 ` Krzysztof Kozlowski
2016-07-13 11:14 ` [PATCH v6.1] " Krzysztof Kozlowski
2016-07-13 11:17 ` Krzysztof Kozlowski
2016-07-13 11:56 ` [PATCH v6.2] " Krzysztof Kozlowski
2016-07-13 12:29 ` Bart Van Assche
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