[PATCH 1/2] soc: fsl: dpio: Add prefetch instruction

From: Ioana Ciocoi Radulescu
Date: Fri Dec 14 2018 - 11:04:11 EST


In dpaa2_io_store_next(), if the current dequeue entry is not
the last, prefetch the next one as most likely it will be
requested shortly by the consumer driver.

This brings a ~3% improvement for dpaa2 ethernet driver
IP forwarding with small size frames.

Signed-off-by: Ioana Radulescu <ruxandra.radulescu@xxxxxxx>
---
drivers/soc/fsl/dpio/dpio-service.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/soc/fsl/dpio/dpio-service.c b/drivers/soc/fsl/dpio/dpio-service.c
index 5583d28..56a35c0 100644
--- a/drivers/soc/fsl/dpio/dpio-service.c
+++ b/drivers/soc/fsl/dpio/dpio-service.c
@@ -613,6 +613,7 @@ struct dpaa2_dq *dpaa2_io_store_next(struct dpaa2_io_store *s, int *is_last)
if (!(dpaa2_dq_flags(ret) & DPAA2_DQ_STAT_VALIDFRAME))
ret = NULL;
} else {
+ prefetch(&s->vaddr[s->idx]);
*is_last = 0;
}

--
2.7.4