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authorLogan Gunthorpe <logang@deltatee.com>2016-06-03 14:50:31 -0600
committerJon Mason <jdmason@kudzu.us>2016-08-05 10:21:06 -0400
commit4aae977721f0367809cdc94584b6945073d9fe10 (patch)
tree2ed434a025160326c1bfc04b61269ad867b5cc51 /drivers/ntb
parenta754a8fcaf383be3c5fcc6c3c08e36d9f3005988 (diff)
downloadlinux-4aae977721f0367809cdc94584b6945073d9fe10.tar.gz
ntb_perf: Allow limiting the size of the memory windows
On my system, dma_alloc_coherent won't produce memory anywhere
near the size of the BAR. So I needed a way to limit this.

It's pretty much copied straight from ntb_transport.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Acked-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
Diffstat (limited to 'drivers/ntb')
-rw-r--r--drivers/ntb/test/ntb_perf.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/ntb/test/ntb_perf.c b/drivers/ntb/test/ntb_perf.c
index 8dfce9c9aad0..30635c89320c 100644
--- a/drivers/ntb/test/ntb_perf.c
+++ b/drivers/ntb/test/ntb_perf.c
@@ -83,6 +83,10 @@ MODULE_DESCRIPTION(DRIVER_DESCRIPTION);
 
 static struct dentry *perf_debugfs_dir;
 
+static unsigned long max_mw_size;
+module_param(max_mw_size, ulong, 0644);
+MODULE_PARM_DESC(max_mw_size, "Limit size of large memory windows");
+
 static unsigned int seg_order = 19; /* 512K */
 module_param(seg_order, uint, 0644);
 MODULE_PARM_DESC(seg_order, "size order [n^2] of buffer segment for testing");
@@ -472,6 +476,10 @@ static void perf_link_work(struct work_struct *work)
 	dev_dbg(&perf->ntb->pdev->dev, "%s called\n", __func__);
 
 	size = perf->mw.phys_size;
+
+	if (max_mw_size && size > max_mw_size)
+		size = max_mw_size;
+
 	ntb_peer_spad_write(ndev, MW_SZ_HIGH, upper_32_bits(size));
 	ntb_peer_spad_write(ndev, MW_SZ_LOW, lower_32_bits(size));
 	ntb_peer_spad_write(ndev, VERSION, PERF_VERSION);