dma-mapping: benchmark: Add support for multi-pages map/unmap

Currently it only support one page map/unmap once a time for dma-map
benchmark, but there are some other scenaries which need to support for
multi-page map/unmap: for those multi-pages interfaces such as
dma_alloc_coherent() and dma_map_sg(), the time spent on multi-pages
map/unmap is not the time of a single page * npages (not linear) as it
may use block description instead of page description when it is satified
with the size such as 2M/1G, and also it can send a single TLB invalidation
command to invalidate multi-pages instead of multi-times when RIL is
enabled (which will short the time of unmap). So it is necessary to add
support for multi-pages map/unmap.

Add a parameter "-g" to support multi-pages map/unmap.

Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Acked-by: Barry Song <song.bao.hua@hisilicon.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

1 files changed, 14 insertions, 7 deletions

diff --git a/kernel/dma/map_benchmark.c b/kernel/dma/map_benchmark.c
index 00d6549a5495..9b9af1bd6be3 100644
--- a/kernel/dma/map_benchmark.c
+++ b/kernel/dma/map_benchmark.c
@@ -38,7 +38,8 @@ struct map_benchmark {
 	__u32 dma_bits; /* DMA addressing capability */
 	__u32 dma_dir; /* DMA data direction */
 	__u32 dma_trans_ns; /* time for DMA transmission in ns */
-	__u8 expansion[80];	/* For future use */
+	__u32 granule;	/* how many PAGE_SIZE will do map/unmap once a time */
+	__u8 expansion[76];	/* For future use */
 };
 
 struct map_benchmark_data {
@@ -58,9 +59,11 @@ static int map_benchmark_thread(void *data)
 	void *buf;
 	dma_addr_t dma_addr;
 	struct map_benchmark_data *map = data;
+	int npages = map->bparam.granule;
+	u64 size = npages * PAGE_SIZE;
 	int ret = 0;
 
-	buf = (void *)__get_free_page(GFP_KERNEL);
+	buf = alloc_pages_exact(size, GFP_KERNEL);
 	if (!buf)
 		return -ENOMEM;
 
@@ -76,10 +79,10 @@ static int map_benchmark_thread(void *data)
 		 * 66 means evertything goes well! 66 is lucky.
 		 */
 		if (map->dir != DMA_FROM_DEVICE)
-			memset(buf, 0x66, PAGE_SIZE);
+			memset(buf, 0x66, size);
 
 		map_stime = ktime_get();
-		dma_addr = dma_map_single(map->dev, buf, PAGE_SIZE, map->dir);
+		dma_addr = dma_map_single(map->dev, buf, size, map->dir);
 		if (unlikely(dma_mapping_error(map->dev, dma_addr))) {
 			pr_err("dma_map_single failed on %s\n",
 				dev_name(map->dev));
@@ -93,7 +96,7 @@ static int map_benchmark_thread(void *data)
 		ndelay(map->bparam.dma_trans_ns);
 
 		unmap_stime = ktime_get();
-		dma_unmap_single(map->dev, dma_addr, PAGE_SIZE, map->dir);
+		dma_unmap_single(map->dev, dma_addr, size, map->dir);
 		unmap_etime = ktime_get();
 		unmap_delta = ktime_sub(unmap_etime, unmap_stime);
 
@@ -112,7 +115,7 @@ static int map_benchmark_thread(void *data)
 	}
 
 out:
-	free_page((unsigned long)buf);
+	free_pages_exact(buf, size);
 	return ret;
 }
 
@@ -203,7 +206,6 @@ static long map_benchmark_ioctl(struct file *file, unsigned int cmd,
 	struct map_benchmark_data *map = file->private_data;
 	void __user *argp = (void __user *)arg;
 	u64 old_dma_mask;
-
 	int ret;
 
 	if (copy_from_user(&map->bparam, argp, sizeof(map->bparam)))
@@ -234,6 +236,11 @@ static long map_benchmark_ioctl(struct file *file, unsigned int cmd,
 			return -EINVAL;
 		}
 
+		if (map->bparam.granule < 1 || map->bparam.granule > 1024) {
+			pr_err("invalid granule size\n");
+			return -EINVAL;
+		}
+
 		switch (map->bparam.dma_dir) {
 		case DMA_MAP_BIDIRECTIONAL:
 			map->dir = DMA_BIDIRECTIONAL;