From 36950f2da1ea4cb683be174f6f581e25b2d33e71 Mon Sep 17 00:00:00 2001 From: Jianxiong Gao Date: Mon, 1 Feb 2021 10:30:15 -0800 Subject: [PATCH] driver core: add a min_align_mask field to struct device_dma_parameters 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 Signed-off-by: Christoph Hellwig Acked-by: Greg Kroah-Hartman Signed-off-by: Konrad Rzeszutek Wilk --- 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 1779f90eeb4c..7960bf516dd7 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 2e49996a8f39..9c26225754e7 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