[PATCH 1/9] driver core: add a min_align_mask field to struct device_dma_parameters
From: Christoph Hellwig <hch@lst.de>
Date: 2021-02-07 16:03:43
Also in:
linux-iommu
Subsystem:
dma mapping helpers, driver core, kobjects, debugfs and sysfs, the rest · Maintainers:
Marek Szyprowski, Greg Kroah-Hartman, "Rafael J. Wysocki", Danilo Krummrich, Linus Torvalds
From: Jianxiong Gao <redacted> Some devices rely on the address offset in a page to function correctly (NVMe driver as an example). These devices may use a different page size than the Linux kernel. The address offset has to be preserved upon mapping, and in order to do so, we need to record the page_offset_mask first. Signed-off-by: Jianxiong Gao <redacted> Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- include/linux/device.h | 1 + include/linux/dma-mapping.h | 16 ++++++++++++++++ 2 files changed, 17 insertions(+)
diff --git a/include/linux/device.h b/include/linux/device.h
index 1779f90eeb4cb4..7960bf516dd7fe 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h@@ -291,6 +291,7 @@ struct device_dma_parameters { * sg limitations. */ unsigned int max_segment_size; + unsigned int min_align_mask; unsigned long segment_boundary_mask; };
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 2e49996a8f391a..9c26225754e719 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h@@ -500,6 +500,22 @@ static inline int dma_set_seg_boundary(struct device *dev, unsigned long mask) return -EIO; } +static inline unsigned int dma_get_min_align_mask(struct device *dev) +{ + if (dev->dma_parms) + return dev->dma_parms->min_align_mask; + return 0; +} + +static inline int dma_set_min_align_mask(struct device *dev, + unsigned int min_align_mask) +{ + if (WARN_ON_ONCE(!dev->dma_parms)) + return -EIO; + dev->dma_parms->min_align_mask = min_align_mask; + return 0; +} + static inline int dma_get_cache_alignment(void) { #ifdef ARCH_DMA_MINALIGN
--
2.29.2
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