From: <shaibran@amazon.com>
To: <ferruh.yigit@amd.com>
Cc: <dev@dpdk.org>, Shai Brandes <shaibran@amazon.com>
Subject: [PATCH 21/33] net/ena/hal: modify memory barrier comment
Date: Mon, 4 Mar 2024 11:01:24 +0200 [thread overview]
Message-ID: <20240304090136.861-22-shaibran@amazon.com> (raw)
In-Reply-To: <20240304090136.861-1-shaibran@amazon.com>
From: Shai Brandes <shaibran@amazon.com>
The dma_rmb() memory barrier guarantees that the device set the
phase bit before continuing to read the rest of the descriptor.
Because the phase bit and the rest of the descriptor are in the same
cache line this ensures coherency of the data from the descriptor.
Signed-off-by: Shai Brandes <shaibran@amazon.com>
Reviewed-by: Amit Bernstein <amitbern@amazon.com>
---
drivers/net/ena/hal/ena_com.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ena/hal/ena_com.c b/drivers/net/ena/hal/ena_com.c
index 7a23881667..7f0e0b2449 100644
--- a/drivers/net/ena/hal/ena_com.c
+++ b/drivers/net/ena/hal/ena_com.c
@@ -2412,8 +2412,8 @@ void ena_com_aenq_intr_handler(struct ena_com_dev *ena_dev, void *data)
/* Go over all the events */
while ((READ_ONCE8(aenq_common->flags) &
ENA_ADMIN_AENQ_COMMON_DESC_PHASE_MASK) == phase) {
- /* Make sure the phase bit (ownership) is as expected before
- * reading the rest of the descriptor.
+ /* Make sure the device finished writing the rest of the descriptor
+ * before reading it.
*/
dma_rmb();
--
2.17.1
next prev parent reply other threads:[~2024-03-04 9:05 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-04 9:01 [PATCH 00/33] net/ena: v2.9.0 driver release shaibran
2024-03-04 9:01 ` [PATCH 01/33] net/ena: rework the metrics multi-process functions shaibran
2024-03-04 9:01 ` [PATCH 02/33] net/ena: report new supported link speed capabilities shaibran
2024-03-04 9:01 ` [PATCH 03/33] net/ena: update imissed stat with Rx overruns shaibran
2024-03-04 9:01 ` [PATCH 04/33] net/ena: sub-optimal configuration notifications support shaibran
2024-03-04 9:01 ` [PATCH 05/33] net/ena: fix fast mbuf free shaibran
2024-03-04 9:01 ` [PATCH 06/33] net/ena: rename base folder to hal shaibran
2024-03-04 9:01 ` [PATCH 07/33] net/ena: restructure the llq policy setting process shaibran
2024-03-04 9:01 ` [PATCH 08/33] net/ena/hal: exponential backoff exp limit shaibran
2024-03-04 9:01 ` [PATCH 09/33] net/ena/hal: add a new csum offload bit shaibran
2024-03-04 9:01 ` [PATCH 10/33] net/ena/hal: added a bus parameter to ena memcpy macro shaibran
2024-03-04 9:01 ` [PATCH 11/33] net/ena/hal: optimize Rx ring submission queue shaibran
2024-03-04 9:01 ` [PATCH 12/33] net/ena/hal: rename fields in completion descriptors shaibran
2024-03-04 9:01 ` [PATCH 13/33] net/ena/hal: use correct read once on u8 field shaibran
2024-03-04 9:01 ` [PATCH 14/33] net/ena/hal: add completion descriptor corruption check shaibran
2024-03-04 9:01 ` [PATCH 15/33] net/ena/hal: malformed Tx descriptor error reason shaibran
2024-03-04 9:01 ` [PATCH 16/33] net/ena/hal: phc feature modifications shaibran
2024-03-04 9:01 ` [PATCH 17/33] net/ena/hal: restructure interrupt handling shaibran
2024-03-04 9:01 ` [PATCH 18/33] net/ena/hal: add unlikely to error checks shaibran
2024-03-04 9:01 ` [PATCH 19/33] net/ena/hal: missing admin interrupt reset reason shaibran
2024-03-04 9:01 ` [PATCH 20/33] net/ena/hal: check for existing keep alive notification shaibran
2024-03-04 9:01 ` shaibran [this message]
2024-03-04 9:01 ` [PATCH 22/33] net/ena/hal: rework Rx ring submission queue shaibran
2024-03-04 9:01 ` [PATCH 23/33] net/ena/hal: remove operating system type enum shaibran
2024-03-04 9:01 ` [PATCH 24/33] net/ena/hal: handle command abort shaibran
2024-03-04 9:01 ` [PATCH 25/33] net/ena/hal: add support for device reset request shaibran
2024-03-04 9:01 ` [PATCH 26/33] net/ena: cosmetic changes shaibran
2024-03-04 9:01 ` [PATCH 27/33] net/ena/hal: modify customer metrics memory management shaibran
2024-03-04 9:01 ` [PATCH 28/33] net/ena/hal: cosmetic changes shaibran
2024-03-04 9:01 ` [PATCH 29/33] net/ena: update device-preferred size of rings shaibran
2024-03-04 9:01 ` [PATCH 30/33] net/ena: exhaust interrupt callbacks in device close shaibran
2024-03-04 9:01 ` [PATCH 31/33] net/ena: support max large llq depth from the device shaibran
2024-03-04 9:01 ` [PATCH 32/33] net/ena: control path pure polling mode shaibran
2024-03-04 9:01 ` [PATCH 33/33] net/ena: upgrade driver version to 2.9.0 shaibran
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