[PATCH net] bnxt_en: Fix the resource check condition for RSS contexts

[Michael Chan <michael.chan@broadcom.com>]

[-- Attachment #1: Type: text/plain, Size: 2194 bytes --]

From: Pavan Chebbi <pavan.chebbi@broadcom.com>

While creating a new RSS context, bnxt_rfs_capable() currently
makes a strict check to see if the required VNICs are already
available.  If the current VNICs are not what is required,
either too many or not enough, it will call the firmware to
reserve the exact number required.

There is a bug in the firmware when the driver tries to
relinquish some reserved VNICs and RSS contexts.  It will
cause the default VNIC to lose its RSS configuration and
cause receive packets to be placed incorrectly.

Workaround this problem by skipping the resource reduction.
The driver will not reduce the VNIC and RSS context reservations
when a context is deleted.  The resources will be available for
use when new contexts are created later.

Potentially, this workaround can cause us to run out of VNIC
and RSS contexts if there are a lot of VF functions creating
and deleting RSS contexts.  In the future, we will conditionally
disable this workaround when the firmware fix is available.

Fixes: 438ba39b25fe ("bnxt_en: Improve RSS context reservation infrastructure")
Reported-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/netdev/20240625010210.2002310-1-kuba@kernel.org/
Reviewed-by: Andy Gospodarek <andrew.gospodarek@broadcom.com>
Signed-off-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
---
 drivers/net/ethernet/broadcom/bnxt/bnxt.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index a6d69a45fa01..53085058100c 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -12669,7 +12669,11 @@ bool bnxt_rfs_capable(struct bnxt *bp, bool new_rss_ctx)
 	if (!BNXT_NEW_RM(bp))
 		return true;
 
-	if (hwr.vnic == bp->hw_resc.resv_vnics &&
+	/* Do not reduce VNIC and RSS ctx reservations.  There is a FW
+	 * issue that will mess up the default VNIC if we reduce the
+	 * reservations.
+	 */
+	if (hwr.vnic <= bp->hw_resc.resv_vnics &&
 	    hwr.rss_ctx <= bp->hw_resc.resv_rsscos_ctxs)
 		return true;
 
-- 
2.30.1


[-- Attachment #2: S/MIME Cryptographic Signature --]
[-- Type: application/pkcs7-signature, Size: 4209 bytes --]