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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 <baohua@kernel.org>
Signed-off-by: Qinxin Xia <xiaqinxin@huawei.com>
Reported-by: Barry Song <baohua@kernel.org>
Closes: https://lore.kernel.org/lkml/CAGsJ_4waiZ2+NBJG+SCnbNk+nQ_ZF13_Q5FHJqZyxyJTcEop2A@mail.gmail.com/
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/20251028120900.2265511-2-xiaqinxin@huawei.com
33 lines
1.1 KiB
C
33 lines
1.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* Copyright (C) 2022 HiSilicon Limited.
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*/
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#ifndef _KERNEL_DMA_BENCHMARK_H
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#define _KERNEL_DMA_BENCHMARK_H
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#define DMA_MAP_BENCHMARK _IOWR('d', 1, struct map_benchmark)
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#define DMA_MAP_MAX_THREADS 1024
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#define DMA_MAP_MAX_SECONDS 300
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#define DMA_MAP_MAX_TRANS_DELAY (10 * NSEC_PER_MSEC)
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#define DMA_MAP_BIDIRECTIONAL 0
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#define DMA_MAP_TO_DEVICE 1
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#define DMA_MAP_FROM_DEVICE 2
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struct map_benchmark {
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__u64 avg_map_100ns; /* average map latency in 100ns */
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__u64 map_stddev; /* standard deviation of map latency */
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__u64 avg_unmap_100ns; /* as above */
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__u64 unmap_stddev;
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__u32 threads; /* how many threads will do map/unmap in parallel */
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__u32 seconds; /* how long the test will last */
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__s32 node; /* which numa node this benchmark will run on */
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__u32 dma_bits; /* DMA addressing capability */
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__u32 dma_dir; /* DMA data direction */
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__u32 dma_trans_ns; /* time for DMA transmission in ns */
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__u32 granule; /* how many PAGE_SIZE will do map/unmap once a time */
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__u8 expansion[76]; /* For future use */
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};
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#endif /* _KERNEL_DMA_BENCHMARK_H */
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