Commit 1a931c4f authored by Christopher S M Hall's avatar Christopher S M Hall Committed by Tony Nguyen
Browse files

igc: add lock preventing multiple simultaneous PTM transactions 



Add a mutex around the PTM transaction to prevent multiple transactors

Multiple processes try to initiate a PTM transaction, one or all may
fail. This can be reproduced by running two instances of the
following:

$ sudo phc2sys -O 0 -i tsn0 -m

PHC2SYS exits with:

"ioctl PTP_OFFSET_PRECISE: Connection timed out" when the PTM transaction
 fails

Note: Normally two instance of PHC2SYS will not run, but one process
 should not break another.

Fixes: a90ec848 ("igc: Add support for PTP getcrosststamp()")
Signed-off-by: default avatarChristopher S M Hall <christopher.s.hall@intel.com>
Reviewed-by: default avatarCorinna Vinschen <vinschen@redhat.com>
Signed-off-by: default avatarJacob Keller <jacob.e.keller@intel.com>
Tested-by: default avatarMor Bar-Gabay <morx.bar.gabay@intel.com>
Acked-by: default avatarVinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: default avatarTony Nguyen <anthony.l.nguyen@intel.com>
parent 1f025759

drivers/net/ethernet/intel/igc/igc.h

+1 −0
Original line number Diff line number Diff line
@@ -319,6 +319,7 @@ struct igc_adapter { 
	struct timespec64 prev_ptp_time; /* Pre-reset PTP clock */

	ktime_t ptp_reset_start; /* Reset time in clock mono */

	struct system_time_snapshot snapshot;

	struct mutex ptm_lock; /* Only allow one PTM transaction at a time */



	char fw_version[32];

drivers/net/ethernet/intel/igc/igc_ptp.c

+18 −2
Original line number Diff line number Diff line
@@ -974,6 +974,7 @@ static void igc_ptm_log_error(struct igc_adapter *adapter, u32 ptm_stat) 
	}

}



/* The PTM lock: adapter->ptm_lock must be held when calling igc_ptm_trigger() */

static void igc_ptm_trigger(struct igc_hw *hw)

{

	u32 ctrl;
@@ -990,6 +991,7 @@ static void igc_ptm_trigger(struct igc_hw *hw) 
	wrfl();

}



/* The PTM lock: adapter->ptm_lock must be held when calling igc_ptm_reset() */

static void igc_ptm_reset(struct igc_hw *hw)

{

	u32 ctrl;
@@ -1068,9 +1070,16 @@ static int igc_ptp_getcrosststamp(struct ptp_clock_info *ptp, 
{

	struct igc_adapter *adapter = container_of(ptp, struct igc_adapter,

						   ptp_caps);

	int ret;



	return get_device_system_crosststamp(igc_phc_get_syncdevicetime,

	/* This blocks until any in progress PTM transactions complete */

	mutex_lock(&adapter->ptm_lock);



	ret = get_device_system_crosststamp(igc_phc_get_syncdevicetime,

					    adapter, &adapter->snapshot, cts);

	mutex_unlock(&adapter->ptm_lock);



	return ret;

}



static int igc_ptp_getcyclesx64(struct ptp_clock_info *ptp,
@@ -1169,6 +1178,7 @@ void igc_ptp_init(struct igc_adapter *adapter) 
	spin_lock_init(&adapter->ptp_tx_lock);

	spin_lock_init(&adapter->free_timer_lock);

	spin_lock_init(&adapter->tmreg_lock);

	mutex_init(&adapter->ptm_lock);



	adapter->tstamp_config.rx_filter = HWTSTAMP_FILTER_NONE;

	adapter->tstamp_config.tx_type = HWTSTAMP_TX_OFF;
@@ -1181,6 +1191,7 @@ void igc_ptp_init(struct igc_adapter *adapter) 
	if (IS_ERR(adapter->ptp_clock)) {

		adapter->ptp_clock = NULL;

		netdev_err(netdev, "ptp_clock_register failed\n");

		mutex_destroy(&adapter->ptm_lock);

	} else if (adapter->ptp_clock) {

		netdev_info(netdev, "PHC added\n");

		adapter->ptp_flags |= IGC_PTP_ENABLED;
@@ -1210,10 +1221,12 @@ static void igc_ptm_stop(struct igc_adapter *adapter) 
	struct igc_hw *hw = &adapter->hw;

	u32 ctrl;



	mutex_lock(&adapter->ptm_lock);

	ctrl = rd32(IGC_PTM_CTRL);

	ctrl &= ~IGC_PTM_CTRL_EN;



	wr32(IGC_PTM_CTRL, ctrl);

	mutex_unlock(&adapter->ptm_lock);

}



/**
@@ -1255,6 +1268,7 @@ void igc_ptp_stop(struct igc_adapter *adapter) 
		netdev_info(adapter->netdev, "PHC removed\n");

		adapter->ptp_flags &= ~IGC_PTP_ENABLED;

	}

	mutex_destroy(&adapter->ptm_lock);

}



/**
@@ -1294,6 +1308,7 @@ void igc_ptp_reset(struct igc_adapter *adapter) 
		if (!igc_is_crosststamp_supported(adapter))

			break;



		mutex_lock(&adapter->ptm_lock);

		wr32(IGC_PCIE_DIG_DELAY, IGC_PCIE_DIG_DELAY_DEFAULT);

		wr32(IGC_PCIE_PHY_DELAY, IGC_PCIE_PHY_DELAY_DEFAULT);
@@ -1317,6 +1332,7 @@ void igc_ptp_reset(struct igc_adapter *adapter) 
			netdev_err(adapter->netdev, "Timeout reading IGC_PTM_STAT register\n");



		igc_ptm_reset(hw);

		mutex_unlock(&adapter->ptm_lock);

		break;

	default:

		/* No work to do. */