@@ -106,7 +106,7 @@ static void bnxt_ptp_get_current_time(struct bnxt *bp)
if (!ptp)
return;
spin_lock_irqsave(&ptp->ptp_lock, flags);
- WRITE_ONCE(ptp->old_time, ptp->current_time);
+ WRITE_ONCE(ptp->old_time, (u32)(ptp->current_time >> BNXT_HI_TIMER_SHIFT));
bnxt_refclk_read(bp, NULL, &ptp->current_time);
spin_unlock_irqrestore(&ptp->ptp_lock, flags);
}
@@ -174,7 +174,7 @@ void bnxt_ptp_update_current_time(struct bnxt *bp)
struct bnxt_ptp_cfg *ptp = bp->ptp_cfg;
bnxt_refclk_read(ptp->bp, NULL, &ptp->current_time);
- WRITE_ONCE(ptp->old_time, ptp->current_time);
+ WRITE_ONCE(ptp->old_time, (u32)(ptp->current_time >> BNXT_HI_TIMER_SHIFT));
}
static int bnxt_ptp_adjphc(struct bnxt_ptp_cfg *ptp, s64 delta)
@@ -813,7 +813,7 @@ int bnxt_get_rx_ts_p5(struct bnxt *bp, u64 *ts, u32 pkt_ts)
if (!ptp)
return -ENODEV;
- BNXT_READ_TIME64(ptp, time, ptp->old_time);
+ time = (u64)(READ_ONCE(ptp->old_time) << BNXT_HI_TIMER_SHIFT);
*ts = (time & BNXT_HI_TIMER_MASK) | pkt_ts;
if (pkt_ts < (time & BNXT_LO_TIMER_MASK))
*ts += BNXT_LO_TIMER_MASK + 1;
@@ -1079,7 +1079,7 @@ int bnxt_ptp_init(struct bnxt *bp, bool phc_cfg)
spin_lock_irqsave(&ptp->ptp_lock, flags);
bnxt_refclk_read(bp, NULL, &ptp->current_time);
- WRITE_ONCE(ptp->old_time, ptp->current_time);
+ WRITE_ONCE(ptp->old_time, (u32)(ptp->current_time >> BNXT_HI_TIMER_SHIFT));
spin_unlock_irqrestore(&ptp->ptp_lock, flags);
ptp_schedule_worker(ptp->ptp_clock, 0);
}
@@ -21,6 +21,7 @@
#define BNXT_DEVCLK_FREQ 1000000
#define BNXT_LO_TIMER_MASK 0x0000ffffffffUL
#define BNXT_HI_TIMER_MASK 0xffff00000000UL
+#define BNXT_HI_TIMER_SHIFT 24
#define BNXT_PTP_DFLT_TX_TMO 1000 /* ms */
#define BNXT_PTP_QTS_TIMEOUT 1000
@@ -106,10 +107,11 @@ struct bnxt_ptp_cfg {
/* serialize ts tx request queuing */
spinlock_t ptp_tx_lock;
u64 current_time;
- u64 old_time;
unsigned long next_period;
unsigned long next_overflow_check;
u32 cmult;
+ /* cache of upper 24 bits of cyclecoutner. 8 bits are used to check for roll-over */
+ u32 old_time;
/* a 23b shift cyclecounter will overflow in ~36 mins. Check overflow every 18 mins. */
#define BNXT_PHC_OVERFLOW_PERIOD (18 * 60 * HZ)
@@ -145,20 +147,6 @@ struct bnxt_ptp_cfg {
struct bnxt_ptp_stats stats;
};
-#if BITS_PER_LONG == 32
-#define BNXT_READ_TIME64(ptp, dst, src) \
-do { \
- unsigned long flags; \
- \
- spin_lock_irqsave(&(ptp)->ptp_lock, flags); \
- (dst) = (src); \
- spin_unlock_irqrestore(&(ptp)->ptp_lock, flags); \
-} while (0)
-#else
-#define BNXT_READ_TIME64(ptp, dst, src) \
- ((dst) = READ_ONCE(src))
-#endif
-
#define BNXT_PTP_INC_TX_AVAIL(ptp) \
do { \
spin_lock_bh(&(ptp)->ptp_tx_lock); \
This hardware can provide only 48 bits of cycle counter. We can leave only 24 bits in the cache to extend RX timestamps from 32 bits to 48 bits. Lower 8 bits of the cached value will be used to check for roll-over while extending to full 48 bits. This change makes cache writes atomic even on 32 bit platforms and we can simply use READ_ONCE()/WRITE_ONCE() pair and remove spinlock. The configuration structure will be also reduced by 4 bytes. Signed-off-by: Vadim Fedorenko <vadfed@meta.com> --- v2 -> v3: * define BNXT_HI_TIMER_SHIFT for shift * add comment explaining that 8 bits of cahced value will be used to check for roll-over --- drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c | 8 ++++---- drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.h | 18 +++--------------- 2 files changed, 7 insertions(+), 19 deletions(-)