From 23ee8a2563a0f24cf4964685ced23c32be444ab8 Mon Sep 17 00:00:00 2001 From: Qinxin Xia Date: Tue, 28 Oct 2025 20:08:59 +0800 Subject: dma-mapping: benchmark: Restore padding to ensure uABI remained consistent The padding field in the structure was previously reserved to maintain a stable interface for potential new fields, ensuring compatibility with user-space shared data structures. However,it was accidentally removed by tiantao in a prior commit, which may lead to incompatibility between user space and the kernel. This patch reinstates the padding to restore the original structure layout and preserve compatibility. Fixes: 8ddde07a3d28 ("dma-mapping: benchmark: extract a common header file for map_benchmark definition") Cc: stable@vger.kernel.org Acked-by: Barry Song Signed-off-by: Qinxin Xia Reported-by: Barry Song Closes: https://lore.kernel.org/lkml/CAGsJ_4waiZ2+NBJG+SCnbNk+nQ_ZF13_Q5FHJqZyxyJTcEop2A@mail.gmail.com/ Reviewed-by: Jonathan Cameron Signed-off-by: Marek Szyprowski Link: https://lore.kernel.org/r/20251028120900.2265511-2-xiaqinxin@huawei.com --- include/linux/map_benchmark.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/map_benchmark.h b/include/linux/map_benchmark.h index 62674c83bde4..48e2ff95332f 100644 --- a/include/linux/map_benchmark.h +++ b/include/linux/map_benchmark.h @@ -27,5 +27,6 @@ struct map_benchmark { __u32 dma_dir; /* DMA data direction */ __u32 dma_trans_ns; /* time for DMA transmission in ns */ __u32 granule; /* how many PAGE_SIZE will do map/unmap once a time */ + __u8 expansion[76]; /* For future use */ }; #endif /* _KERNEL_DMA_BENCHMARK_H */ -- cgit v1.2.3 From a50f7456f853ec3a6f07cbe1d16ad8a8b2501320 Mon Sep 17 00:00:00 2001 From: James Clark Date: Thu, 30 Oct 2025 14:05:27 +0000 Subject: dma-mapping: Allow use of DMA_BIT_MASK(64) in global scope Clang doesn't like that (1ULL<<(64)) overflows when initializing a global scope variable, even if that part of the ternary isn't used when n = 64. The same initialization can be done without warnings in function scopes, and GCC doesn't mind either way. The build failure that highlighted this was already fixed in a different way [1], which also has detailed links to the Clang issues. However it's not going to be long before the same thing happens again, so it's better to fix the root cause. Fix it by using GENMASK_ULL() which does exactly the same thing, is much more readable anyway, and doesn't have a shift that overflows. [1]: https://lore.kernel.org/all/20250918-mmp-pdma-simplify-dma-addressing-v1-1-5c2be2b85696@riscstar.com/ Signed-off-by: James Clark Reviewed-by: Nathan Chancellor Signed-off-by: Marek Szyprowski Link: https://lore.kernel.org/r/20251030-james-fix-dma_bit_mask-v1-1-ad1ce7cfab6e@linaro.org --- include/linux/dma-mapping.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index 8248ff9363ee..2ceda49c609f 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -90,7 +90,7 @@ */ #define DMA_MAPPING_ERROR (~(dma_addr_t)0) -#define DMA_BIT_MASK(n) (((n) == 64) ? ~0ULL : ((1ULL<<(n))-1)) +#define DMA_BIT_MASK(n) GENMASK_ULL(n - 1, 0) struct dma_iova_state { dma_addr_t addr; -- cgit v1.2.3