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authorOsama Abboud <osamaabb@amazon.com>2024-08-07 06:24:16 +0000
committerOsama Abboud <osamaabb@FreeBSD.org>2024-10-15 16:54:28 +0000
commit259e904afa237b6b7d3fb5007ef03ea778f68fbd (patch)
tree7bb5dc924bd12f4c5a93b38aa2ead2f7ff63b774
parent0486b8582beda02de680d3c8e604a0ddd86bc638 (diff)
ena: Fix memory barrier comment
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. Approved by: cperciva (mentor) MFC after: 2 weeks Sponsored by: Amazon, Inc.
-rw-r--r--ena_com.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/ena_com.c b/ena_com.c
index 8c065e700726..198302965318 100644
--- a/ena_com.c
+++ b/ena_com.c
@@ -2448,8 +2448,8 @@ 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();