Commit f0fe51a0 authored by Vadim Fedorenko's avatar Vadim Fedorenko Committed by Jakub Kicinski
Browse files

bnxt_en: add unlocked version of bnxt_refclk_read 



Serialization of PHC read with FW reset mechanism uses ptp_lock which
also protects timecounter updates. This means we cannot grab it when
called from bnxt_cc_read(). Let's move locking into different function.

Fixes: 6c0828d0 ("bnxt_en: replace PTP spinlock with seqlock")
Signed-off-by: default avatarVadim Fedorenko <vadfed@meta.com>
Reviewed-by: default avatarPavan Chebbi <pavan.chebbi@broadcom.com>
Link: https://patch.msgid.link/20241107214917.2980976-1-vadfed@meta.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 5ffb7ac0

drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c

+24 −11
Original line number Diff line number Diff line
@@ -73,19 +73,15 @@ static int bnxt_ptp_settime(struct ptp_clock_info *ptp_info, 
	return 0;

}



static int bnxt_refclk_read(struct bnxt *bp, struct ptp_system_timestamp *sts,

/* Caller holds ptp_lock */

static int __bnxt_refclk_read(struct bnxt *bp, struct ptp_system_timestamp *sts,

			      u64 *ns)

{

	struct bnxt_ptp_cfg *ptp = bp->ptp_cfg;

	u32 high_before, high_now, low;

	unsigned long flags;



	/* We have to serialize reg access and FW reset */

	read_seqlock_excl_irqsave(&ptp->ptp_lock, flags);

	if (test_bit(BNXT_STATE_IN_FW_RESET, &bp->state)) {

		read_sequnlock_excl_irqrestore(&ptp->ptp_lock, flags);

	if (test_bit(BNXT_STATE_IN_FW_RESET, &bp->state))

		return -EIO;

	}



	high_before = readl(bp->bar0 + ptp->refclk_mapped_regs[1]);

	ptp_read_system_prets(sts);
@@ -97,12 +93,25 @@ static int bnxt_refclk_read(struct bnxt *bp, struct ptp_system_timestamp *sts, 
		low = readl(bp->bar0 + ptp->refclk_mapped_regs[0]);

		ptp_read_system_postts(sts);

	}

	read_sequnlock_excl_irqrestore(&ptp->ptp_lock, flags);

	*ns = ((u64)high_now << 32) | low;



	return 0;

}



static int bnxt_refclk_read(struct bnxt *bp, struct ptp_system_timestamp *sts,

			    u64 *ns)

{

	struct bnxt_ptp_cfg *ptp = bp->ptp_cfg;

	unsigned long flags;

	int rc;



	/* We have to serialize reg access and FW reset */

	read_seqlock_excl_irqsave(&ptp->ptp_lock, flags);

	rc = __bnxt_refclk_read(bp, sts, ns);

	read_sequnlock_excl_irqrestore(&ptp->ptp_lock, flags);

	return rc;

}



static void bnxt_ptp_get_current_time(struct bnxt *bp)

{

	struct bnxt_ptp_cfg *ptp = bp->ptp_cfg;
@@ -674,7 +683,7 @@ static u64 bnxt_cc_read(const struct cyclecounter *cc) 
	struct bnxt_ptp_cfg *ptp = container_of(cc, struct bnxt_ptp_cfg, cc);

	u64 ns = 0;



	bnxt_refclk_read(ptp->bp, NULL, &ns);

	__bnxt_refclk_read(ptp->bp, NULL, &ns);

	return ns;

}
@@ -936,6 +945,7 @@ static bool bnxt_pps_config_ok(struct bnxt *bp) 
static void bnxt_ptp_timecounter_init(struct bnxt *bp, bool init_tc)

{

	struct bnxt_ptp_cfg *ptp = bp->ptp_cfg;

	unsigned long flags;



	if (!ptp->ptp_clock) {

		memset(&ptp->cc, 0, sizeof(ptp->cc));
@@ -952,8 +962,11 @@ static void bnxt_ptp_timecounter_init(struct bnxt *bp, bool init_tc) 
		}

		ptp->next_overflow_check = jiffies + BNXT_PHC_OVERFLOW_PERIOD;

	}

	if (init_tc)

	if (init_tc) {

		write_seqlock_irqsave(&ptp->ptp_lock, flags);

		timecounter_init(&ptp->tc, &ptp->cc, ktime_to_ns(ktime_get_real()));

		write_sequnlock_irqrestore(&ptp->ptp_lock, flags);

	}

}



/* Caller holds ptp_lock */