diff mbox series

[net-next,12/13] bnxt_en: Modify the NAPI logic for the new P7 chips

Message ID 20231120234405.194542-13-michael.chan@broadcom.com (mailing list archive)
State Accepted
Commit f94471f3ce74a5fbe2dc5d9687748d9127174eca
Delegated to: Netdev Maintainers
Headers show
Series bnxt_en: Prepare to support new P7 chips | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/codegen success Generated files up to date
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1127 this patch: 1127
netdev/cc_maintainers success CCed 4 of 4 maintainers
netdev/build_clang success Errors and warnings before: 1154 this patch: 1154
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 1158 this patch: 1158
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 36 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Michael Chan Nov. 20, 2023, 11:44 p.m. UTC 
Modify the NAPI logic for the new doorbell mechanism on P7 chips.
These changes are compatible with the current P5 chips.

In the current logic, bnxt_poll_p5() services 1 or more CQs for each
MSIX.  Each MSIX has an associated NQ and each NQ has 1 or more
associated CQs.  If any CQ reaches NAPI budget, we'll stay in polling
mode and will unconditionally check and service all CQs until we exit
polling.  We always re-arm all CQs when we exit polling.

To be compatible with the new Toggle bit mechanism in P7 chips, we need
to modify the logic so that we service and re-arm the CQ only if we
receive an NQE notification for work for that CQ.  We add a new
had_nqe_notify bit to the cp_ring_info structure and it gets set when we
see the NQE notification for that CQ anytime during polling.  We'll
service and re-arm only the CQs with the had_nqe_notify bits set.

Reviewed-by: Somnath Kotur <somnath.kotur@broadcom.com>
Reviewed-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
---
 drivers/net/ethernet/broadcom/bnxt/bnxt.c | 10 ++++++++--
 drivers/net/ethernet/broadcom/bnxt/bnxt.h |  2 ++
 2 files changed, 10 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index b2cf42953130..f968bf12989b 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -2854,8 +2854,11 @@  static int __bnxt_poll_cqs(struct bnxt *bp, struct bnxt_napi *bnapi, int budget)
 	for (i = 0; i < cpr->cp_ring_count; i++) {
 		struct bnxt_cp_ring_info *cpr2 = &cpr->cp_ring_arr[i];
 
-		work_done += __bnxt_poll_work(bp, cpr2, budget - work_done);
-		cpr->has_more_work |= cpr2->has_more_work;
+		if (cpr2->had_nqe_notify) {
+			work_done += __bnxt_poll_work(bp, cpr2,
+						      budget - work_done);
+			cpr->has_more_work |= cpr2->has_more_work;
+		}
 	}
 	return work_done;
 }
@@ -2876,6 +2879,8 @@  static void __bnxt_poll_cqs_done(struct bnxt *bp, struct bnxt_napi *bnapi,
 				    DB_RING_IDX(db, cpr2->cp_raw_cons),
 				    db->doorbell);
 			cpr2->had_work_done = 0;
+			if (dbr_type == DBR_TYPE_CQ_ARMALL)
+				cpr2->had_nqe_notify = 0;
 		}
 	}
 	__bnxt_poll_work_done(bp, bnapi, budget);
@@ -2934,6 +2939,7 @@  static int bnxt_poll_p5(struct napi_struct *napi, int budget)
 
 			idx = BNXT_NQ_HDL_IDX(idx);
 			cpr2 = &cpr->cp_ring_arr[idx];
+			cpr2->had_nqe_notify = 1;
 			work_done += __bnxt_poll_work(bp, cpr2,
 						      budget - work_done);
 			cpr->has_more_work |= cpr2->has_more_work;
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.h b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
index 17e1881c8a27..b287e4a9adff 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
@@ -1017,6 +1017,8 @@  struct bnxt_cp_ring_info {
 
 	u8			had_work_done:1;
 	u8			has_more_work:1;
+	u8			had_nqe_notify:1;
+
 	u8			cp_ring_type;
 	u8			cp_idx;