Commit 4aae9777 authored by Logan Gunthorpe's avatar Logan Gunthorpe Committed by Jon Mason

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: default avatarLogan Gunthorpe <>
Acked-by: default avatarDave Jiang <>
Signed-off-by: default avatarJon Mason <>
parent a754a8fc
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);
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