From: Qinxin Xia <xiaqinxin@huawei.com>
Date: Wed, 25 Feb 2026 09:38:00 +0000 (+0800)
Subject: tools/dma: Add dma_map_sg support
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a54302ccfd38afba7b297566f0d414b961ca97bf;p=thirdparty%2Fkernel%2Flinux.git

tools/dma: Add dma_map_sg support

Support for dma_map_sg, add option '-m' to distinguish mode.

i) Users can set option '-m' to select mode:
   DMA_MAP_BENCH_SINGLE_MODE=0, DMA_MAP_BENCH_SG_MODE:=1
   (The mode is also show in the test result).
ii) Users can set option '-g' to set sg_nents
    (total count of entries in scatterlist)
    the maximum number is 1024. Each of sg buf size is PAGE_SIZE.
    e.g
    [root@localhost]# ./dma_map_benchmark -m 1 -g 8 -t 8 -s 30 -d 2
    dma mapping mode: DMA_MAP_BENCH_SG_MODE
    dma mapping benchmark: threads:8 seconds:30 node:-1
    dir:FROM_DEVICE granule/sg_nents: 8
    average map latency(us):1.4 standard deviation:0.3
    average unmap latency(us):1.3 standard deviation:0.3
    [root@localhost]# ./dma_map_benchmark -m 0 -g 8 -t 8 -s 30 -d 2
    dma mapping mode: DMA_MAP_BENCH_SINGLE_MODE
    dma mapping benchmark: threads:8 seconds:30 node:-1
    dir:FROM_DEVICE granule/sg_nents: 8
    average map latency(us):1.0 standard deviation:0.3
    average unmap latency(us):1.3 standard deviation:0.5

Reviewed-by: Barry Song <baohua@kernel.org>
Signed-off-by: Qinxin Xia <xiaqinxin@huawei.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/20260225093800.3625054-4-xiaqinxin@huawei.com
---

diff --git a/tools/dma/dma_map_benchmark.c b/tools/dma/dma_map_benchmark.c
index dd0ed528e6dfc..eab0ac611a23a 100644
--- a/tools/dma/dma_map_benchmark.c
+++ b/tools/dma/dma_map_benchmark.c
@@ -20,12 +20,19 @@ static char *directions[] = {
 	"FROM_DEVICE",
 };
 
+static char *mode[] = {
+	"SINGLE_MODE",
+	"SG_MODE",
+};
+
 int main(int argc, char **argv)
 {
 	struct map_benchmark map;
 	int fd, opt;
 	/* default single thread, run 20 seconds on NUMA_NO_NODE */
 	int threads = 1, seconds = 20, node = -1;
+	/* default single map mode */
+	int map_mode = DMA_MAP_BENCH_SINGLE_MODE;
 	/* default dma mask 32bit, bidirectional DMA */
 	int bits = 32, xdelay = 0, dir = DMA_MAP_BIDIRECTIONAL;
 	/* default granule 1 PAGESIZE */
@@ -33,7 +40,7 @@ int main(int argc, char **argv)
 
 	int cmd = DMA_MAP_BENCHMARK;
 
-	while ((opt = getopt(argc, argv, "t:s:n:b:d:x:g:")) != -1) {
+	while ((opt = getopt(argc, argv, "t:s:n:b:d:x:g:m:")) != -1) {
 		switch (opt) {
 		case 't':
 			threads = atoi(optarg);
@@ -56,11 +63,20 @@ int main(int argc, char **argv)
 		case 'g':
 			granule = atoi(optarg);
 			break;
+		case 'm':
+			map_mode = atoi(optarg);
+			break;
 		default:
 			return -1;
 		}
 	}
 
+	if (map_mode < 0 || map_mode >= DMA_MAP_BENCH_MODE_MAX) {
+		fprintf(stderr, "invalid map mode, SINGLE_MODE:%d, SG_MODE: %d\n",
+			DMA_MAP_BENCH_SINGLE_MODE, DMA_MAP_BENCH_SG_MODE);
+		exit(1);
+	}
+
 	if (threads <= 0 || threads > DMA_MAP_MAX_THREADS) {
 		fprintf(stderr, "invalid number of threads, must be in 1-%d\n",
 			DMA_MAP_MAX_THREADS);
@@ -110,14 +126,15 @@ int main(int argc, char **argv)
 	map.dma_dir = dir;
 	map.dma_trans_ns = xdelay;
 	map.granule = granule;
+	map.map_mode = map_mode;
 
 	if (ioctl(fd, cmd, &map)) {
 		perror("ioctl");
 		exit(1);
 	}
 
-	printf("dma mapping benchmark: threads:%d seconds:%d node:%d dir:%s granule: %d\n",
-			threads, seconds, node, directions[dir], granule);
+	printf("dma mapping benchmark(%s): threads:%d seconds:%d node:%d dir:%s granule:%d\n",
+			mode[map_mode], threads, seconds, node, directions[dir], granule);
 	printf("average map latency(us):%.1f standard deviation:%.1f\n",
 			map.avg_map_100ns/10.0, map.map_stddev/10.0);
 	printf("average unmap latency(us):%.1f standard deviation:%.1f\n",