Commit 06917f75 authored by Dave Jiang's avatar Dave Jiang Committed by Jon Mason

NTB: Improve performance with write combining

Changing the memory window BAR mappings to write combining significantly
boosts the performance.  We will also use memcpy that uses non-temporal
store, which showed performance improvement when doing non-cached
Signed-off-by: default avatarDave Jiang <>
Signed-off-by: default avatarJon Mason <>
parent 0e041fb5
......@@ -58,6 +58,7 @@
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/uaccess.h>
#include "linux/ntb.h"
#include "linux/ntb_transport.h"
......@@ -993,7 +994,7 @@ static int ntb_transport_probe(struct ntb_client *self, struct ntb_dev *ndev)
if (rc)
goto err1;
mw->vbase = ioremap(mw->phys_addr, mw->phys_size);
mw->vbase = ioremap_wc(mw->phys_addr, mw->phys_size);
if (!mw->vbase) {
rc = -ENOMEM;
goto err1;
......@@ -1375,7 +1376,15 @@ static void ntb_tx_copy_callback(void *data)
static void ntb_memcpy_tx(struct ntb_queue_entry *entry, void __iomem *offset)
* Using non-temporal mov to improve performance on non-cached
* writes, even though we aren't actually copying from user space.
__copy_from_user_inatomic_nocache(offset, entry->buf, entry->len);
memcpy_toio(offset, entry->buf, entry->len);
/* Ensure that the data is fully copied out before setting the flags */
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment