[PATCH net-next] bnxt_en: Fix 64-bit doorbell operation on 32-bit kernels
From: Michael Chan <michael.chan@broadcom.com>
Date: 2021-08-31 22:29:00
The driver requires 64-bit doorbell writes to be atomic on 32-bit
architectures. So we redefined writeq as a new macro with spinlock
protection on 32-bit architectures. This created a new warning when
we added a new file in a recent patchset. writeq is defined on many
32-bit architectures to do the memory write non-atomically and it
generated a new macro redefined warning. This warning was fixed
incorrectly in the recent patch.
Fix this properly by adding a new bnxt_writeq() function that will
do the non-atomic write under spinlock on 32-bit systems. All callers
in the driver will now call bnxt_writeq() instead.
Reported-by: kernel test robot <redacted>
Fixes: f9ff578251dc ("bnxt_en: introduce new firmware message API based on DMA pools")
Reviewed-by: Edwin Peer <redacted>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
---
drivers/net/ethernet/broadcom/bnxt/bnxt.c | 14 +++++-----
drivers/net/ethernet/broadcom/bnxt/bnxt.h | 33 ++++++++++++++---------
2 files changed, 29 insertions(+), 18 deletions(-)
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 627f85ee3922..5b145077d21a 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c@@ -305,13 +305,15 @@ static bool bnxt_vf_pciid(enum board_idx idx) writel(DB_CP_FLAGS | RING_CMP(idx), (db)->doorbell) #define BNXT_DB_NQ_P5(db, idx) \ - writeq((db)->db_key64 | DBR_TYPE_NQ | RING_CMP(idx), (db)->doorbell) + bnxt_writeq((db)->db_key64 | DBR_TYPE_NQ | RING_CMP(idx), \ + (db)->doorbell) #define BNXT_DB_CQ_ARM(db, idx) \ writel(DB_CP_REARM_FLAGS | RING_CMP(idx), (db)->doorbell) #define BNXT_DB_NQ_ARM_P5(db, idx) \ - writeq((db)->db_key64 | DBR_TYPE_NQ_ARM | RING_CMP(idx), (db)->doorbell) + bnxt_writeq((db)->db_key64 | DBR_TYPE_NQ_ARM | RING_CMP(idx), \ + (db)->doorbell) static void bnxt_db_nq(struct bnxt *bp, struct bnxt_db_info *db, u32 idx) {
@@ -332,8 +334,8 @@ static void bnxt_db_nq_arm(struct bnxt *bp, struct bnxt_db_info *db, u32 idx) static void bnxt_db_cq(struct bnxt *bp, struct bnxt_db_info *db, u32 idx) { if (bp->flags & BNXT_FLAG_CHIP_P5) - writeq(db->db_key64 | DBR_TYPE_CQ_ARMALL | RING_CMP(idx), - db->doorbell); + bnxt_writeq(db->db_key64 | DBR_TYPE_CQ_ARMALL | RING_CMP(idx), + db->doorbell); else BNXT_DB_CQ(db, idx); }
@@ -2638,8 +2640,8 @@ static void __bnxt_poll_cqs_done(struct bnxt *bp, struct bnxt_napi *bnapi, if (cpr2 && cpr2->had_work_done) { db = &cpr2->cp_db; - writeq(db->db_key64 | dbr_type | - RING_CMP(cpr2->cp_raw_cons), db->doorbell); + bnxt_writeq(db->db_key64 | dbr_type | + RING_CMP(cpr2->cp_raw_cons), db->doorbell); cpr2->had_work_done = 0; } }
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.h b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
index a8212dcdad5f..e69d4a1d0c63 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h@@ -1981,7 +1981,7 @@ struct bnxt { struct mutex sriov_lock; #endif -#ifndef writeq +#if BITS_PER_LONG == 32 /* ensure atomic 64-bit doorbell writes on 32-bit systems. */ spinlock_t db_lock; #endif
@@ -2110,24 +2110,33 @@ static inline u32 bnxt_tx_avail(struct bnxt *bp, struct bnxt_tx_ring_info *txr) ((txr->tx_prod - txr->tx_cons) & bp->tx_ring_mask); } -#ifndef writeq -#define writeq(val64, db) \ -do { \ - spin_lock(&bp->db_lock); \ - writel((val64) & 0xffffffff, db); \ - writel((val64) >> 32, (db) + 4); \ - spin_unlock(&bp->db_lock); \ -} while (0) +static inline void bnxt_writeq(u64 val, volatile void __iomem *addr) +{ +#if BITS_PER_LONG == 32 + spin_lock(&bp->db_lock); + writel(val & 0xffffffff, addr); + writel(val >> 32, addr + 4); + spin_unlock(&bp->db_lock); +#else + writeq(val, addr); +#endif +} -#define writeq_relaxed writeq +static inline void bnxt_writeq_relaxed(u64 val, volatile void __iomem *addr) +{ +#if BITS_PER_LONG == 32 + bnxt_writeq(val, addr); +#else + writeq_relaxed(val, addr); #endif +} /* For TX and RX ring doorbells with no ordering guarantee*/ static inline void bnxt_db_write_relaxed(struct bnxt *bp, struct bnxt_db_info *db, u32 idx) { if (bp->flags & BNXT_FLAG_CHIP_P5) { - writeq_relaxed(db->db_key64 | idx, db->doorbell); + bnxt_writeq_relaxed(db->db_key64 | idx, db->doorbell); } else { u32 db_val = db->db_key32 | idx;
@@ -2142,7 +2151,7 @@ static inline void bnxt_db_write(struct bnxt *bp, struct bnxt_db_info *db, u32 idx) { if (bp->flags & BNXT_FLAG_CHIP_P5) { - writeq(db->db_key64 | idx, db->doorbell); + bnxt_writeq(db->db_key64 | idx, db->doorbell); } else { u32 db_val = db->db_key32 | idx;
--
2.18.1