[PATCH net-next 00/14][pull request] Intel Wired LAN Driver Updates 2022-11-30 (ice)

[PATCH net-next 00/14][pull request] Intel Wired LAN Driver Updates 2022-11-30 (ice)

[Tony Nguyen]

Jacob Keller says:

This series of patches primarily consists of changes to fix some corner
cases that can cause Tx timestamp failures. The issues were discovered and
reported by Siddaraju DH and primarily affect E822 hardware, though this
series also includes some improvements that affect E810 hardware as well.

The primary issue is regarding the way that E822 determines when to generate
timestamp interrupts. If the driver reads timestamp indexes which do not
have a valid timestamp, the E822 interrupt tracking logic can get stuck.
This is due to the way that E822 hardware tracks timestamp index reads
internally. I was previously unaware of this behavior as it is significantly
different in E810 hardware.

Most of the fixes target refactors to ensure that the ice driver does not
read timestamp indexes which are not valid on E822 hardware. This is done by
using the Tx timestamp ready bitmap register from the PHY. This register
indicates what timestamp indexes have outstanding timestamps waiting to be
captured.

Care must be taken in all cases where we read the timestamp registers, and
thus all flows which might have read these registers are refactored. The
ice_ptp_tx_tstamp function is modified to consolidate as much of the logic
relating to these registers as possible. It now handles discarding stale
timestamps which are old or which occurred after a PHC time update. This
replaces previously standalone thread functions like the periodic work
function and the ice_ptp_flush_tx_tracker function.

In addition, some minor cleanups noticed while writing these refactors are
included.

The remaining patches refactor the E822 implementation to remove the
"bypass" mode for timestamps. The E822 hardware has the ability to provide a
more precise timestamp by making use of measurements of the precise way that
packets flow through the hardware pipeline. These measurements are known as
"Vernier" calibration. The "bypass" mode disables many of these measurements
in favor of a faster start up time for Tx and Rx timestamping. Instead, once
these measurements were captured, the driver tries to reconfigure the PHY to
enable the vernier calibrations.

Unfortunately this recalibration does not work. Testing indicates that the
PHY simply remains in bypass mode without the increased timestamp precision.
Remove the attempt at recalibration and always use vernier mode. This has
one disadvantage that Tx and Rx timestamps cannot begin until after at least
one packet of that type goes through the hardware pipeline. Because of this,
further refactor the driver to separate Tx and Rx vernier calibration.
Complete the Tx and Rx independently, enabling the appropriate type of
timestamp as soon as the relevant packet has traversed the hardware
pipeline. This was reported by Milena Olech.

Note that although these might be considered "bug fixes", the required
changes in order to appropriately resolve these issues is large. Thus it
does not feel suitable to send this series to net.

The following are changes since commit 91a7de85600d5dfa272cea3cef83052e067dc0ab:
  selftests/net: add csum offload test
and are available in the git repository at:
  git://git.kernel.org/pub/scm/linux/kernel/git/tnguy/next-queue 100GbE

Jacob Keller (10):
  ice: fix misuse of "link err" with "link status"
  ice: always call ice_ptp_link_change and make it void
  ice: handle discarding old Tx requests in ice_ptp_tx_tstamp
  ice: check Tx timestamp memory register for ready timestamps
  ice: protect init and calibrating fields with spinlock
  ice: disable Tx timestamps while link is down
  ice: cleanup allocations in ice_ptp_alloc_tx_tracker
  ice: handle flushing stale Tx timestamps in ice_ptp_tx_tstamp
  ice: only check set bits in ice_ptp_flush_tx_tracker
  ice: reschedule ice_ptp_wait_for_offset_valid during reset

Karol Kolacinski (1):
  ice: Reset TS memory for all quads

Milena Olech (1):
  ice: Remove the E822 vernier "bypass" logic

Sergey Temerkhanov (1):
  ice: Use more generic names for ice_ptp_tx fields

Siddaraju DH (1):
  ice: make Tx and Rx vernier offset calibration independent

 drivers/net/ethernet/intel/ice/ice_main.c   |   9 +-
 drivers/net/ethernet/intel/ice/ice_ptp.c    | 564 ++++++++++----------
 drivers/net/ethernet/intel/ice/ice_ptp.h    |  41 +-
 drivers/net/ethernet/intel/ice/ice_ptp_hw.c | 336 ++++++------
 drivers/net/ethernet/intel/ice/ice_ptp_hw.h |   8 +-
 5 files changed, 490 insertions(+), 468 deletions(-)

-- 
2.35.1

[PATCH net-next 01/14] ice: Use more generic names for ice_ptp_tx fields

[Tony Nguyen]

From: Sergey Temerkhanov <sergey.temerkhanov@intel.com>

Some supported devices have per-port timestamp memory blocks while
others have shared ones within quads. Rename the struct ice_ptp_tx
fields to reflect the block entities it works with

Signed-off-by: Sergey Temerkhanov <sergey.temerkhanov@intel.com>
Tested-by: Gurucharan G <gurucharanx.g@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/ice/ice_ptp.c | 26 ++++++++++++------------
 drivers/net/ethernet/intel/ice/ice_ptp.h | 11 +++++-----
 2 files changed, 19 insertions(+), 18 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.c b/drivers/net/ethernet/intel/ice/ice_ptp.c
index 13e75279e71c..f41f4674cadd 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.c
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.c
@@ -651,14 +651,14 @@ static bool ice_ptp_tx_tstamp(struct ice_ptp_tx *tx)
 
 	for_each_set_bit(idx, tx->in_use, tx->len) {
 		struct skb_shared_hwtstamps shhwtstamps = {};
-		u8 phy_idx = idx + tx->quad_offset;
+		u8 phy_idx = idx + tx->offset;
 		u64 raw_tstamp, tstamp;
 		struct sk_buff *skb;
 		int err;
 
 		ice_trace(tx_tstamp_fw_req, tx->tstamps[idx].skb, idx);
 
-		err = ice_read_phy_tstamp(&pf->hw, tx->quad, phy_idx,
+		err = ice_read_phy_tstamp(&pf->hw, tx->block, phy_idx,
 					  &raw_tstamp);
 		if (err)
 			continue;
@@ -713,7 +713,7 @@ static bool ice_ptp_tx_tstamp(struct ice_ptp_tx *tx)
  * @tx: Tx tracking structure to initialize
  *
  * Assumes that the length has already been initialized. Do not call directly,
- * use the ice_ptp_init_tx_e822 or ice_ptp_init_tx_e810 instead.
+ * use the ice_ptp_init_tx_* instead.
  */
 static int
 ice_ptp_alloc_tx_tracker(struct ice_ptp_tx *tx)
@@ -747,7 +747,7 @@ ice_ptp_flush_tx_tracker(struct ice_pf *pf, struct ice_ptp_tx *tx)
 	u8 idx;
 
 	for (idx = 0; idx < tx->len; idx++) {
-		u8 phy_idx = idx + tx->quad_offset;
+		u8 phy_idx = idx + tx->offset;
 
 		spin_lock(&tx->lock);
 		if (tx->tstamps[idx].skb) {
@@ -760,7 +760,7 @@ ice_ptp_flush_tx_tracker(struct ice_pf *pf, struct ice_ptp_tx *tx)
 
 		/* Clear any potential residual timestamp in the PHY block */
 		if (!pf->hw.reset_ongoing)
-			ice_clear_phy_tstamp(&pf->hw, tx->quad, phy_idx);
+			ice_clear_phy_tstamp(&pf->hw, tx->block, phy_idx);
 	}
 }
 
@@ -801,9 +801,9 @@ ice_ptp_release_tx_tracker(struct ice_pf *pf, struct ice_ptp_tx *tx)
 static int
 ice_ptp_init_tx_e822(struct ice_pf *pf, struct ice_ptp_tx *tx, u8 port)
 {
-	tx->quad = port / ICE_PORTS_PER_QUAD;
-	tx->quad_offset = (port % ICE_PORTS_PER_QUAD) * INDEX_PER_PORT;
-	tx->len = INDEX_PER_PORT;
+	tx->block = port / ICE_PORTS_PER_QUAD;
+	tx->offset = (port % ICE_PORTS_PER_QUAD) * INDEX_PER_PORT_E822;
+	tx->len = INDEX_PER_PORT_E822;
 
 	return ice_ptp_alloc_tx_tracker(tx);
 }
@@ -819,9 +819,9 @@ ice_ptp_init_tx_e822(struct ice_pf *pf, struct ice_ptp_tx *tx, u8 port)
 static int
 ice_ptp_init_tx_e810(struct ice_pf *pf, struct ice_ptp_tx *tx)
 {
-	tx->quad = pf->hw.port_info->lport;
-	tx->quad_offset = 0;
-	tx->len = INDEX_PER_QUAD;
+	tx->block = pf->hw.port_info->lport;
+	tx->offset = 0;
+	tx->len = INDEX_PER_PORT_E810;
 
 	return ice_ptp_alloc_tx_tracker(tx);
 }
@@ -854,7 +854,7 @@ static void ice_ptp_tx_tstamp_cleanup(struct ice_pf *pf, struct ice_ptp_tx *tx)
 			continue;
 
 		/* Read tstamp to be able to use this register again */
-		ice_read_phy_tstamp(hw, tx->quad, idx + tx->quad_offset,
+		ice_read_phy_tstamp(hw, tx->block, idx + tx->offset,
 				    &raw_tstamp);
 
 		spin_lock(&tx->lock);
@@ -2359,7 +2359,7 @@ s8 ice_ptp_request_ts(struct ice_ptp_tx *tx, struct sk_buff *skb)
 	if (idx >= tx->len)
 		return -1;
 	else
-		return idx + tx->quad_offset;
+		return idx + tx->offset;
 }
 
 /**
diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.h b/drivers/net/ethernet/intel/ice/ice_ptp.h
index 028349295b71..ca0fbfd71ed2 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.h
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.h
@@ -108,8 +108,8 @@ struct ice_tx_tstamp {
  * @lock: lock to prevent concurrent write to in_use bitmap
  * @tstamps: array of len to store outstanding requests
  * @in_use: bitmap of len to indicate which slots are in use
- * @quad: which quad the timestamps are captured in
- * @quad_offset: offset into timestamp block of the quad to get the real index
+ * @block: which memory block (quad or port) the timestamps are captured in
+ * @offset: offset into timestamp block to get the real index
  * @len: length of the tstamps and in_use fields.
  * @init: if true, the tracker is initialized;
  * @calibrating: if true, the PHY is calibrating the Tx offset. During this
@@ -119,8 +119,8 @@ struct ice_ptp_tx {
 	spinlock_t lock; /* lock protecting in_use bitmap */
 	struct ice_tx_tstamp *tstamps;
 	unsigned long *in_use;
-	u8 quad;
-	u8 quad_offset;
+	u8 block;
+	u8 offset;
 	u8 len;
 	u8 init;
 	u8 calibrating;
@@ -128,7 +128,8 @@ struct ice_ptp_tx {
 
 /* Quad and port information for initializing timestamp blocks */
 #define INDEX_PER_QUAD			64
-#define INDEX_PER_PORT			(INDEX_PER_QUAD / ICE_PORTS_PER_QUAD)
+#define INDEX_PER_PORT_E822		16
+#define INDEX_PER_PORT_E810		64
 
 /**
  * struct ice_ptp_port - data used to initialize an external port for PTP
-- 
2.35.1

[PATCH net-next 02/14] ice: Remove the E822 vernier "bypass" logic

[Tony Nguyen]

From: Milena Olech <milena.olech@intel.com>

The E822 devices support an extended "vernier" calibration which enables
higher precision timestamps by accounting for delays in the PHY, and
compensating for them. These delays are measured by hardware as part of its
vernier calibration logic.

The driver currently starts the PHY in "bypass" mode which skips
the compensation. Then it later attempts to switch from bypass to vernier.
This unfortunately does not work as expected. Instead of properly
compensating for the delays, the hardware continues operating in bypass
without the improved precision expected.

Because we cannot dynamically switch between bypass and vernier mode,
refactor the driver to always operate in vernier mode. This has a slight
downside: Tx timestamp and Rx timestamp requests that occur as the very
first packet set after link up will not complete properly and may be
reported to applications as missing timestamps.

This occurs frequently in test environments where traffic is light or
targeted specifically at testing PTP. However, in practice most
environments will have transmitted or received some data over the network
before such initial requests are made.

Signed-off-by: Milena Olech <milena.olech@intel.com>
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Gurucharan G <gurucharanx.g@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/ice/ice_ptp.c    |  10 +-
 drivers/net/ethernet/intel/ice/ice_ptp_hw.c | 145 +-------------------
 drivers/net/ethernet/intel/ice/ice_ptp_hw.h |   4 +-
 3 files changed, 14 insertions(+), 145 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.c b/drivers/net/ethernet/intel/ice/ice_ptp.c
index f41f4674cadd..9539d2d37c5b 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.c
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.c
@@ -1252,10 +1252,10 @@ static void ice_ptp_wait_for_offset_valid(struct kthread_work *work)
 		return;
 	}
 
-	/* Offsets are valid, so it is safe to exit bypass mode */
-	err = ice_phy_exit_bypass_e822(hw, port->port_num);
+	/* Offsets are valid, so Vernier mode calculations are started */
+	err = ice_phy_calc_vernier_e822(hw, port->port_num);
 	if (err) {
-		dev_warn(dev, "Failed to exit bypass mode for PHY port %u, err %d\n",
+		dev_warn(dev, "Failed to prepare Vernier mode for PHY port %u, err %d\n",
 			 port->port_num, err);
 		return;
 	}
@@ -1320,8 +1320,8 @@ ice_ptp_port_phy_restart(struct ice_ptp_port *ptp_port)
 	ptp_port->tx.calibrating = true;
 	ptp_port->tx_fifo_busy_cnt = 0;
 
-	/* Start the PHY timer in bypass mode */
-	err = ice_start_phy_timer_e822(hw, port, true);
+	/* Start the PHY timer in Vernier mode */
+	err = ice_start_phy_timer_e822(hw, port);
 	if (err)
 		goto out_unlock;
 
diff --git a/drivers/net/ethernet/intel/ice/ice_ptp_hw.c b/drivers/net/ethernet/intel/ice/ice_ptp_hw.c
index 1f8dd50db524..242c4db65171 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp_hw.c
+++ b/drivers/net/ethernet/intel/ice/ice_ptp_hw.c
@@ -1786,47 +1786,6 @@ static int ice_phy_cfg_tx_offset_e822(struct ice_hw *hw, u8 port)
 	return 0;
 }
 
-/**
- * ice_phy_cfg_fixed_tx_offset_e822 - Configure Tx offset for bypass mode
- * @hw: pointer to the HW struct
- * @port: the PHY port to configure
- *
- * Calculate and program the fixed Tx offset, and indicate that the offset is
- * ready. This can be used when operating in bypass mode.
- */
-static int
-ice_phy_cfg_fixed_tx_offset_e822(struct ice_hw *hw, u8 port)
-{
-	enum ice_ptp_link_spd link_spd;
-	enum ice_ptp_fec_mode fec_mode;
-	u64 total_offset;
-	int err;
-
-	err = ice_phy_get_speed_and_fec_e822(hw, port, &link_spd, &fec_mode);
-	if (err)
-		return err;
-
-	total_offset = ice_calc_fixed_tx_offset_e822(hw, link_spd);
-
-	/* Program the fixed Tx offset into the P_REG_TOTAL_TX_OFFSET_L
-	 * register, then indicate that the Tx offset is ready. After this,
-	 * timestamps will be enabled.
-	 *
-	 * Note that this skips including the more precise offsets generated
-	 * by the Vernier calibration.
-	 */
-	err = ice_write_64b_phy_reg_e822(hw, port, P_REG_TOTAL_TX_OFFSET_L,
-					 total_offset);
-	if (err)
-		return err;
-
-	err = ice_write_phy_reg_e822(hw, port, P_REG_TX_OR, 1);
-	if (err)
-		return err;
-
-	return 0;
-}
-
 /**
  * ice_phy_calc_pmd_adj_e822 - Calculate PMD adjustment for Rx
  * @hw: pointer to the HW struct
@@ -2104,47 +2063,6 @@ static int ice_phy_cfg_rx_offset_e822(struct ice_hw *hw, u8 port)
 	return 0;
 }
 
-/**
- * ice_phy_cfg_fixed_rx_offset_e822 - Configure fixed Rx offset for bypass mode
- * @hw: pointer to the HW struct
- * @port: the PHY port to configure
- *
- * Calculate and program the fixed Rx offset, and indicate that the offset is
- * ready. This can be used when operating in bypass mode.
- */
-static int
-ice_phy_cfg_fixed_rx_offset_e822(struct ice_hw *hw, u8 port)
-{
-	enum ice_ptp_link_spd link_spd;
-	enum ice_ptp_fec_mode fec_mode;
-	u64 total_offset;
-	int err;
-
-	err = ice_phy_get_speed_and_fec_e822(hw, port, &link_spd, &fec_mode);
-	if (err)
-		return err;
-
-	total_offset = ice_calc_fixed_rx_offset_e822(hw, link_spd);
-
-	/* Program the fixed Rx offset into the P_REG_TOTAL_RX_OFFSET_L
-	 * register, then indicate that the Rx offset is ready. After this,
-	 * timestamps will be enabled.
-	 *
-	 * Note that this skips including the more precise offsets generated
-	 * by Vernier calibration.
-	 */
-	err = ice_write_64b_phy_reg_e822(hw, port, P_REG_TOTAL_RX_OFFSET_L,
-					 total_offset);
-	if (err)
-		return err;
-
-	err = ice_write_phy_reg_e822(hw, port, P_REG_RX_OR, 1);
-	if (err)
-		return err;
-
-	return 0;
-}
-
 /**
  * ice_read_phy_and_phc_time_e822 - Simultaneously capture PHC and PHY time
  * @hw: pointer to the HW struct
@@ -2323,20 +2241,14 @@ ice_stop_phy_timer_e822(struct ice_hw *hw, u8 port, bool soft_reset)
  * ice_start_phy_timer_e822 - Start the PHY clock timer
  * @hw: pointer to the HW struct
  * @port: the PHY port to start
- * @bypass: if true, start the PHY in bypass mode
  *
  * Start the clock of a PHY port. This must be done as part of the flow to
  * re-calibrate Tx and Rx timestamping offsets whenever the clock time is
  * initialized or when link speed changes.
  *
- * Bypass mode enables timestamps immediately without waiting for Vernier
- * calibration to complete. Hardware will still continue taking Vernier
- * measurements on Tx or Rx of packets, but they will not be applied to
- * timestamps. Use ice_phy_exit_bypass_e822 to exit bypass mode once hardware
- * has completed offset calculation.
+ * Hardware will take Vernier measurements on Tx or Rx of packets.
  */
-int
-ice_start_phy_timer_e822(struct ice_hw *hw, u8 port, bool bypass)
+int ice_start_phy_timer_e822(struct ice_hw *hw, u8 port)
 {
 	u32 lo, hi, val;
 	u64 incval;
@@ -2414,44 +2326,24 @@ ice_start_phy_timer_e822(struct ice_hw *hw, u8 port, bool bypass)
 	if (err)
 		return err;
 
-	if (bypass) {
-		val |= P_REG_PS_BYPASS_MODE_M;
-		/* Enter BYPASS mode, enabling timestamps immediately. */
-		err = ice_write_phy_reg_e822(hw, port, P_REG_PS, val);
-		if (err)
-			return err;
-
-		/* Program the fixed Tx offset */
-		err = ice_phy_cfg_fixed_tx_offset_e822(hw, port);
-		if (err)
-			return err;
-
-		/* Program the fixed Rx offset */
-		err = ice_phy_cfg_fixed_rx_offset_e822(hw, port);
-		if (err)
-			return err;
-	}
-
 	ice_debug(hw, ICE_DBG_PTP, "Enabled clock on PHY port %u\n", port);
 
 	return 0;
 }
 
 /**
- * ice_phy_exit_bypass_e822 - Exit bypass mode, after vernier calculations
+ * ice_phy_calc_vernier_e822 - Perform vernier calculations
  * @hw: pointer to the HW struct
  * @port: the PHY port to configure
  *
- * After hardware finishes vernier calculations for the Tx and Rx offset, this
- * function can be used to exit bypass mode by updating the total Tx and Rx
- * offsets, and then disabling bypass. This will enable hardware to include
- * the more precise offset calibrations, increasing precision of the generated
- * timestamps.
+ * Perform vernier calculations for the Tx and Rx offset. This will enable
+ * hardware to include the more precise offset calibrations,
+ * increasing precision of the generated timestamps.
  *
  * This cannot be done until hardware has measured the offsets, which requires
  * waiting until at least one packet has been sent and received by the device.
  */
-int ice_phy_exit_bypass_e822(struct ice_hw *hw, u8 port)
+int ice_phy_calc_vernier_e822(struct ice_hw *hw, u8 port)
 {
 	int err;
 	u32 val;
@@ -2496,29 +2388,6 @@ int ice_phy_exit_bypass_e822(struct ice_hw *hw, u8 port)
 		return err;
 	}
 
-	/* Exit bypass mode now that the offset has been updated */
-	err = ice_read_phy_reg_e822(hw, port, P_REG_PS, &val);
-	if (err) {
-		ice_debug(hw, ICE_DBG_PTP, "Failed to read P_REG_PS for port %u, err %d\n",
-			  port, err);
-		return err;
-	}
-
-	if (!(val & P_REG_PS_BYPASS_MODE_M))
-		ice_debug(hw, ICE_DBG_PTP, "Port %u not in bypass mode\n",
-			  port);
-
-	val &= ~P_REG_PS_BYPASS_MODE_M;
-	err = ice_write_phy_reg_e822(hw, port, P_REG_PS, val);
-	if (err) {
-		ice_debug(hw, ICE_DBG_PTP, "Failed to disable bypass for port %u, err %d\n",
-			  port, err);
-		return err;
-	}
-
-	dev_info(ice_hw_to_dev(hw), "Exiting bypass mode on PHY port %u\n",
-		 port);
-
 	return 0;
 }
 
diff --git a/drivers/net/ethernet/intel/ice/ice_ptp_hw.h b/drivers/net/ethernet/intel/ice/ice_ptp_hw.h
index 2bda64c76abc..db4f57cb9ec9 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp_hw.h
+++ b/drivers/net/ethernet/intel/ice/ice_ptp_hw.h
@@ -184,8 +184,8 @@ static inline u64 ice_e822_pps_delay(enum ice_time_ref_freq time_ref)
 
 /* E822 Vernier calibration functions */
 int ice_stop_phy_timer_e822(struct ice_hw *hw, u8 port, bool soft_reset);
-int ice_start_phy_timer_e822(struct ice_hw *hw, u8 port, bool bypass);
-int ice_phy_exit_bypass_e822(struct ice_hw *hw, u8 port);
+int ice_start_phy_timer_e822(struct ice_hw *hw, u8 port);
+int ice_phy_calc_vernier_e822(struct ice_hw *hw, u8 port);
 
 /* E810 family functions */
 int ice_ptp_init_phy_e810(struct ice_hw *hw);
-- 
2.35.1

[PATCH net-next 03/14] ice: Reset TS memory for all quads

[Tony Nguyen]

From: Karol Kolacinski <karol.kolacinski@intel.com>

In E822 products, the owner PF should reset memory for all quads, not
only for the one where assigned lport is.

Signed-off-by: Karol Kolacinski <karol.kolacinski@intel.com>
Tested-by: Gurucharan G <gurucharanx.g@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/ice/ice_ptp.c    | 29 ++--------------
 drivers/net/ethernet/intel/ice/ice_ptp_hw.c | 38 +++++++++++++++++++++
 drivers/net/ethernet/intel/ice/ice_ptp_hw.h |  2 ++
 3 files changed, 42 insertions(+), 27 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.c b/drivers/net/ethernet/intel/ice/ice_ptp.c
index 9539d2d37c5b..f93fa0273252 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.c
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.c
@@ -1059,19 +1059,6 @@ static u64 ice_base_incval(struct ice_pf *pf)
 	return incval;
 }
 
-/**
- * ice_ptp_reset_ts_memory_quad - Reset timestamp memory for one quad
- * @pf: The PF private data structure
- * @quad: The quad (0-4)
- */
-static void ice_ptp_reset_ts_memory_quad(struct ice_pf *pf, int quad)
-{
-	struct ice_hw *hw = &pf->hw;
-
-	ice_write_quad_reg_e822(hw, quad, Q_REG_TS_CTRL, Q_REG_TS_CTRL_M);
-	ice_write_quad_reg_e822(hw, quad, Q_REG_TS_CTRL, ~(u32)Q_REG_TS_CTRL_M);
-}
-
 /**
  * ice_ptp_check_tx_fifo - Check whether Tx FIFO is in an OK state
  * @port: PTP port for which Tx FIFO is checked
@@ -1124,7 +1111,7 @@ static int ice_ptp_check_tx_fifo(struct ice_ptp_port *port)
 		dev_dbg(ice_pf_to_dev(pf),
 			"Port %d Tx FIFO still not empty; resetting quad %d\n",
 			port->port_num, quad);
-		ice_ptp_reset_ts_memory_quad(pf, quad);
+		ice_ptp_reset_ts_memory_quad_e822(hw, quad);
 		port->tx_fifo_busy_cnt = FIFO_OK;
 		return 0;
 	}
@@ -1370,18 +1357,6 @@ int ice_ptp_link_change(struct ice_pf *pf, u8 port, bool linkup)
 	return ice_ptp_port_phy_restart(ptp_port);
 }
 
-/**
- * ice_ptp_reset_ts_memory - Reset timestamp memory for all quads
- * @pf: The PF private data structure
- */
-static void ice_ptp_reset_ts_memory(struct ice_pf *pf)
-{
-	int quad;
-
-	quad = pf->hw.port_info->lport / ICE_PORTS_PER_QUAD;
-	ice_ptp_reset_ts_memory_quad(pf, quad);
-}
-
 /**
  * ice_ptp_tx_ena_intr - Enable or disable the Tx timestamp interrupt
  * @pf: PF private structure
@@ -1397,7 +1372,7 @@ static int ice_ptp_tx_ena_intr(struct ice_pf *pf, bool ena, u32 threshold)
 	int quad;
 	u32 val;
 
-	ice_ptp_reset_ts_memory(pf);
+	ice_ptp_reset_ts_memory(hw);
 
 	for (quad = 0; quad < ICE_MAX_QUAD; quad++) {
 		err = ice_read_quad_reg_e822(hw, quad, Q_REG_TX_MEM_GBL_CFG,
diff --git a/drivers/net/ethernet/intel/ice/ice_ptp_hw.c b/drivers/net/ethernet/intel/ice/ice_ptp_hw.c
index 242c4db65171..6c149b88c235 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp_hw.c
+++ b/drivers/net/ethernet/intel/ice/ice_ptp_hw.c
@@ -655,6 +655,32 @@ ice_clear_phy_tstamp_e822(struct ice_hw *hw, u8 quad, u8 idx)
 	return 0;
 }
 
+/**
+ * ice_ptp_reset_ts_memory_quad_e822 - Clear all timestamps from the quad block
+ * @hw: pointer to the HW struct
+ * @quad: the quad to read from
+ *
+ * Clear all timestamps from the PHY quad block that is shared between the
+ * internal PHYs on the E822 devices.
+ */
+void ice_ptp_reset_ts_memory_quad_e822(struct ice_hw *hw, u8 quad)
+{
+	ice_write_quad_reg_e822(hw, quad, Q_REG_TS_CTRL, Q_REG_TS_CTRL_M);
+	ice_write_quad_reg_e822(hw, quad, Q_REG_TS_CTRL, ~(u32)Q_REG_TS_CTRL_M);
+}
+
+/**
+ * ice_ptp_reset_ts_memory_e822 - Clear all timestamps from all quad blocks
+ * @hw: pointer to the HW struct
+ */
+static void ice_ptp_reset_ts_memory_e822(struct ice_hw *hw)
+{
+	unsigned int quad;
+
+	for (quad = 0; quad < ICE_MAX_QUAD; quad++)
+		ice_ptp_reset_ts_memory_quad_e822(hw, quad);
+}
+
 /**
  * ice_read_cgu_reg_e822 - Read a CGU register
  * @hw: pointer to the HW struct
@@ -3247,6 +3273,18 @@ bool ice_is_pca9575_present(struct ice_hw *hw)
 	return !status && handle;
 }
 
+/**
+ * ice_ptp_reset_ts_memory - Reset timestamp memory for all blocks
+ * @hw: pointer to the HW struct
+ */
+void ice_ptp_reset_ts_memory(struct ice_hw *hw)
+{
+	if (ice_is_e810(hw))
+		return;
+
+	ice_ptp_reset_ts_memory_e822(hw);
+}
+
 /**
  * ice_ptp_init_phc - Initialize PTP hardware clock
  * @hw: pointer to the HW struct
diff --git a/drivers/net/ethernet/intel/ice/ice_ptp_hw.h b/drivers/net/ethernet/intel/ice/ice_ptp_hw.h
index db4f57cb9ec9..b0cd73aaac6b 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp_hw.h
+++ b/drivers/net/ethernet/intel/ice/ice_ptp_hw.h
@@ -133,6 +133,7 @@ int ice_ptp_write_incval_locked(struct ice_hw *hw, u64 incval);
 int ice_ptp_adj_clock(struct ice_hw *hw, s32 adj);
 int ice_read_phy_tstamp(struct ice_hw *hw, u8 block, u8 idx, u64 *tstamp);
 int ice_clear_phy_tstamp(struct ice_hw *hw, u8 block, u8 idx);
+void ice_ptp_reset_ts_memory(struct ice_hw *hw);
 int ice_ptp_init_phc(struct ice_hw *hw);
 
 /* E822 family functions */
@@ -141,6 +142,7 @@ int ice_write_phy_reg_e822(struct ice_hw *hw, u8 port, u16 offset, u32 val);
 int ice_read_quad_reg_e822(struct ice_hw *hw, u8 quad, u16 offset, u32 *val);
 int ice_write_quad_reg_e822(struct ice_hw *hw, u8 quad, u16 offset, u32 val);
 int ice_ptp_prep_port_adj_e822(struct ice_hw *hw, u8 port, s64 time);
+void ice_ptp_reset_ts_memory_quad_e822(struct ice_hw *hw, u8 quad);
 
 /**
  * ice_e822_time_ref - Get the current TIME_REF from capabilities
-- 
2.35.1

[PATCH net-next 04/14] ice: fix misuse of "link err" with "link status"

[Tony Nguyen]

From: Jacob Keller <jacob.e.keller@intel.com>

The ice_ptp_link_change function has a comment which mentions "link
err" when referring to the current link status. We are storing the status
of whether link is up or down, which is not an error.

It is appears that this use of err accidentally got included due to an
overzealous search and replace when removing the ice_status enum and local
status variable.

Fix the wording to use the correct term.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Gurucharan G <gurucharanx.g@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/ice/ice_ptp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.c b/drivers/net/ethernet/intel/ice/ice_ptp.c
index f93fa0273252..5607ec578499 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.c
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.c
@@ -1347,7 +1347,7 @@ int ice_ptp_link_change(struct ice_pf *pf, u8 port, bool linkup)
 	if (ptp_port->port_num != port)
 		return -EINVAL;
 
-	/* Update cached link err for this port immediately */
+	/* Update cached link status for this port immediately */
 	ptp_port->link_up = linkup;
 
 	if (!test_bit(ICE_FLAG_PTP, pf->flags))
-- 
2.35.1

[PATCH net-next 05/14] ice: always call ice_ptp_link_change and make it void

[Tony Nguyen]

From: Jacob Keller <jacob.e.keller@intel.com>

The ice_ptp_link_change function is currently only called for E822 based
hardware. Future changes are going to extend this function to perform
additional tasks on link change.

Always call this function, moving the E810 check from the callers down to
just before we call the E822-specific function required to restart the PHY.

This function also returns an error value, but none of the callers actually
check it. In general, the errors it produces are more likely systemic
problems such as invalid or corrupt port numbers. No caller checks these,
and so no warning is logged.

Re-order the flag checks so that ICE_FLAG_PTP is checked first. Drop the
unnecessary check for ICE_FLAG_PTP_SUPPORTED, as ICE_FLAG_PTP will not be
set except when ICE_FLAG_PTP_SUPPORTED is set.

Convert the port checks to WARN_ON_ONCE, in order to generate a kernel
stack trace when they are hit.

Convert the function to void since no caller actually checks these return
values.

Co-developed-by: Dave Ertman <david.m.ertman@intel.com>
Signed-off-by: Dave Ertman <david.m.ertman@intel.com>
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Gurucharan G <gurucharanx.g@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/ice/ice_main.c |  9 +++------
 drivers/net/ethernet/intel/ice/ice_ptp.c  | 24 +++++++++++------------
 drivers/net/ethernet/intel/ice/ice_ptp.h  |  7 ++++---
 3 files changed, 19 insertions(+), 21 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
index 2b23b4714a26..a9a7f8b52140 100644
--- a/drivers/net/ethernet/intel/ice/ice_main.c
+++ b/drivers/net/ethernet/intel/ice/ice_main.c
@@ -1111,8 +1111,7 @@ ice_link_event(struct ice_pf *pf, struct ice_port_info *pi, bool link_up,
 	if (link_up == old_link && link_speed == old_link_speed)
 		return 0;
 
-	if (!ice_is_e810(&pf->hw))
-		ice_ptp_link_change(pf, pf->hw.pf_id, link_up);
+	ice_ptp_link_change(pf, pf->hw.pf_id, link_up);
 
 	if (ice_is_dcb_active(pf)) {
 		if (test_bit(ICE_FLAG_DCB_ENA, pf->flags))
@@ -6340,8 +6339,7 @@ static int ice_up_complete(struct ice_vsi *vsi)
 		ice_print_link_msg(vsi, true);
 		netif_tx_start_all_queues(vsi->netdev);
 		netif_carrier_on(vsi->netdev);
-		if (!ice_is_e810(&pf->hw))
-			ice_ptp_link_change(pf, pf->hw.pf_id, true);
+		ice_ptp_link_change(pf, pf->hw.pf_id, true);
 	}
 
 	/* Perform an initial read of the statistics registers now to
@@ -6773,8 +6771,7 @@ int ice_down(struct ice_vsi *vsi)
 
 	if (vsi->netdev && vsi->type == ICE_VSI_PF) {
 		vlan_err = ice_vsi_del_vlan_zero(vsi);
-		if (!ice_is_e810(&vsi->back->hw))
-			ice_ptp_link_change(vsi->back, vsi->back->hw.pf_id, false);
+		ice_ptp_link_change(vsi->back, vsi->back->hw.pf_id, false);
 		netif_carrier_off(vsi->netdev);
 		netif_tx_disable(vsi->netdev);
 	} else if (vsi->type == ICE_VSI_SWITCHDEV_CTRL) {
diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.c b/drivers/net/ethernet/intel/ice/ice_ptp.c
index 5607ec578499..1564c72189bf 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.c
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.c
@@ -1328,33 +1328,33 @@ ice_ptp_port_phy_restart(struct ice_ptp_port *ptp_port)
 }
 
 /**
- * ice_ptp_link_change - Set or clear port registers for timestamping
+ * ice_ptp_link_change - Reconfigure PTP after link status change
  * @pf: Board private structure
  * @port: Port for which the PHY start is set
  * @linkup: Link is up or down
  */
-int ice_ptp_link_change(struct ice_pf *pf, u8 port, bool linkup)
+void ice_ptp_link_change(struct ice_pf *pf, u8 port, bool linkup)
 {
 	struct ice_ptp_port *ptp_port;
 
-	if (!test_bit(ICE_FLAG_PTP_SUPPORTED, pf->flags))
-		return 0;
+	if (!test_bit(ICE_FLAG_PTP, pf->flags))
+		return;
 
-	if (port >= ICE_NUM_EXTERNAL_PORTS)
-		return -EINVAL;
+	if (WARN_ON_ONCE(port >= ICE_NUM_EXTERNAL_PORTS))
+		return;
 
 	ptp_port = &pf->ptp.port;
-	if (ptp_port->port_num != port)
-		return -EINVAL;
+	if (WARN_ON_ONCE(ptp_port->port_num != port))
+		return;
 
 	/* Update cached link status for this port immediately */
 	ptp_port->link_up = linkup;
 
-	if (!test_bit(ICE_FLAG_PTP, pf->flags))
-		/* PTP is not setup */
-		return -EAGAIN;
+	/* E810 devices do not need to reconfigure the PHY */
+	if (ice_is_e810(&pf->hw))
+		return;
 
-	return ice_ptp_port_phy_restart(ptp_port);
+	ice_ptp_port_phy_restart(ptp_port);
 }
 
 /**
diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.h b/drivers/net/ethernet/intel/ice/ice_ptp.h
index ca0fbfd71ed2..39cab020f1af 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.h
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.h
@@ -257,7 +257,7 @@ void ice_ptp_reset(struct ice_pf *pf);
 void ice_ptp_prepare_for_reset(struct ice_pf *pf);
 void ice_ptp_init(struct ice_pf *pf);
 void ice_ptp_release(struct ice_pf *pf);
-int ice_ptp_link_change(struct ice_pf *pf, u8 port, bool linkup);
+void ice_ptp_link_change(struct ice_pf *pf, u8 port, bool linkup);
 #else /* IS_ENABLED(CONFIG_PTP_1588_CLOCK) */
 static inline int ice_ptp_set_ts_config(struct ice_pf *pf, struct ifreq *ifr)
 {
@@ -292,7 +292,8 @@ static inline void ice_ptp_reset(struct ice_pf *pf) { }
 static inline void ice_ptp_prepare_for_reset(struct ice_pf *pf) { }
 static inline void ice_ptp_init(struct ice_pf *pf) { }
 static inline void ice_ptp_release(struct ice_pf *pf) { }
-static inline int ice_ptp_link_change(struct ice_pf *pf, u8 port, bool linkup)
-{ return 0; }
+static inline void ice_ptp_link_change(struct ice_pf *pf, u8 port, bool linkup)
+{
+}
 #endif /* IS_ENABLED(CONFIG_PTP_1588_CLOCK) */
 #endif /* _ICE_PTP_H_ */
-- 
2.35.1

[PATCH net-next 06/14] ice: handle discarding old Tx requests in ice_ptp_tx_tstamp

[Tony Nguyen]

From: Jacob Keller <jacob.e.keller@intel.com>

Currently the driver uses the PTP kthread to process handling and
discarding of stale Tx timestamp requests. The function
ice_ptp_tx_tstamp_cleanup is used for this.

A separate thread creates complications for the driver as we now have both
the main Tx timestamp processing IRQ checking timestamps as well as the
kthread.

Rather than using the kthread to handle this, simply check for stale
timestamps within the ice_ptp_tx_tstamp function. This function must
already process the timestamps anyways.

If a Tx timestamp has been waiting for 2 seconds we simply clear the bit
and discard the SKB. This avoids the complication of having separate
threads polling, reducing overall CPU work.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Gurucharan G <gurucharanx.g@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/ice/ice_ptp.c | 106 ++++++++++-------------
 1 file changed, 45 insertions(+), 61 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.c b/drivers/net/ethernet/intel/ice/ice_ptp.c
index 1564c72189bf..58e527f202c0 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.c
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.c
@@ -626,15 +626,32 @@ static u64 ice_ptp_extend_40b_ts(struct ice_pf *pf, u64 in_tstamp)
  * Note that we only take the tracking lock when clearing the bit and when
  * checking if we need to re-queue this task. The only place where bits can be
  * set is the hard xmit routine where an SKB has a request flag set. The only
- * places where we clear bits are this work function, or the periodic cleanup
- * thread. If the cleanup thread clears a bit we're processing we catch it
- * when we lock to clear the bit and then grab the SKB pointer. If a Tx thread
- * starts a new timestamp, we might not begin processing it right away but we
- * will notice it at the end when we re-queue the task. If a Tx thread starts
- * a new timestamp just after this function exits without re-queuing,
- * the interrupt when the timestamp finishes should trigger. Avoiding holding
- * the lock for the entire function is important in order to ensure that Tx
- * threads do not get blocked while waiting for the lock.
+ * places where we clear bits are this work function, or when flushing the Tx
+ * timestamp tracker.
+ *
+ * If the Tx tracker gets flushed while we're processing a packet, we catch
+ * this because we grab the SKB pointer under lock. If the SKB is NULL we know
+ * that another thread already discarded the SKB and we can avoid passing it
+ * up to the stack.
+ *
+ * If a Tx thread starts a new timestamp, we might not begin processing it
+ * right away but we will notice it at the end when we re-queue the task.
+ *
+ * If a Tx thread starts a new timestamp just after this function exits, the
+ * interrupt for that timestamp should re-trigger this function once
+ * a timestamp is ready.
+ *
+ * Note that minimizing the time we hold the lock is important. If we held the
+ * lock for the entire function we would unnecessarily block the Tx hot path
+ * which needs to set the timestamp index. Limiting how long we hold the lock
+ * ensures we do not block Tx threads.
+ *
+ * If a Tx packet has been waiting for more than 2 seconds, it is not possible
+ * to correctly extend the timestamp using the cached PHC time. It is
+ * extremely unlikely that a packet will ever take this long to timestamp. If
+ * we detect a Tx timestamp request that has waited for this long we assume
+ * the packet will never be sent by hardware and discard it without reading
+ * the timestamp register.
  */
 static bool ice_ptp_tx_tstamp(struct ice_ptp_tx *tx)
 {
@@ -653,9 +670,20 @@ static bool ice_ptp_tx_tstamp(struct ice_ptp_tx *tx)
 		struct skb_shared_hwtstamps shhwtstamps = {};
 		u8 phy_idx = idx + tx->offset;
 		u64 raw_tstamp, tstamp;
+		bool drop_ts = false;
 		struct sk_buff *skb;
 		int err;
 
+		/* Drop packets which have waited for more than 2 seconds */
+		if (time_is_before_jiffies(tx->tstamps[idx].start + 2 * HZ)) {
+			drop_ts = true;
+
+			/* Count the number of Tx timestamps that timed out */
+			pf->ptp.tx_hwtstamp_timeouts++;
+
+			goto skip_ts_read;
+		}
+
 		ice_trace(tx_tstamp_fw_req, tx->tstamps[idx].skb, idx);
 
 		err = ice_read_phy_tstamp(&pf->hw, tx->block, phy_idx,
@@ -670,9 +698,7 @@ static bool ice_ptp_tx_tstamp(struct ice_ptp_tx *tx)
 		    raw_tstamp == tx->tstamps[idx].cached_tstamp)
 			continue;
 
-		/* The timestamp is valid, so we'll go ahead and clear this
-		 * index and then send the timestamp up to the stack.
-		 */
+skip_ts_read:
 		spin_lock(&tx->lock);
 		tx->tstamps[idx].cached_tstamp = raw_tstamp;
 		clear_bit(idx, tx->in_use);
@@ -680,12 +706,17 @@ static bool ice_ptp_tx_tstamp(struct ice_ptp_tx *tx)
 		tx->tstamps[idx].skb = NULL;
 		spin_unlock(&tx->lock);
 
-		/* it's (unlikely but) possible we raced with the cleanup
-		 * thread for discarding old timestamp requests.
+		/* It is unlikely but possible that the SKB will have been
+		 * flushed at this point due to link change or teardown.
 		 */
 		if (!skb)
 			continue;
 
+		if (drop_ts) {
+			dev_kfree_skb_any(skb);
+			continue;
+		}
+
 		/* Extend the timestamp using cached PHC time */
 		tstamp = ice_ptp_extend_40b_ts(pf, raw_tstamp);
 		if (tstamp) {
@@ -826,51 +857,6 @@ ice_ptp_init_tx_e810(struct ice_pf *pf, struct ice_ptp_tx *tx)
 	return ice_ptp_alloc_tx_tracker(tx);
 }
 
-/**
- * ice_ptp_tx_tstamp_cleanup - Cleanup old timestamp requests that got dropped
- * @pf: pointer to the PF struct
- * @tx: PTP Tx tracker to clean up
- *
- * Loop through the Tx timestamp requests and see if any of them have been
- * waiting for a long time. Discard any SKBs that have been waiting for more
- * than 2 seconds. This is long enough to be reasonably sure that the
- * timestamp will never be captured. This might happen if the packet gets
- * discarded before it reaches the PHY timestamping block.
- */
-static void ice_ptp_tx_tstamp_cleanup(struct ice_pf *pf, struct ice_ptp_tx *tx)
-{
-	struct ice_hw *hw = &pf->hw;
-	u8 idx;
-
-	if (!tx->init)
-		return;
-
-	for_each_set_bit(idx, tx->in_use, tx->len) {
-		struct sk_buff *skb;
-		u64 raw_tstamp;
-
-		/* Check if this SKB has been waiting for too long */
-		if (time_is_after_jiffies(tx->tstamps[idx].start + 2 * HZ))
-			continue;
-
-		/* Read tstamp to be able to use this register again */
-		ice_read_phy_tstamp(hw, tx->block, idx + tx->offset,
-				    &raw_tstamp);
-
-		spin_lock(&tx->lock);
-		skb = tx->tstamps[idx].skb;
-		tx->tstamps[idx].skb = NULL;
-		clear_bit(idx, tx->in_use);
-		spin_unlock(&tx->lock);
-
-		/* Count the number of Tx timestamps which have timed out */
-		pf->ptp.tx_hwtstamp_timeouts++;
-
-		/* Free the SKB after we've cleared the bit */
-		dev_kfree_skb_any(skb);
-	}
-}
-
 /**
  * ice_ptp_update_cached_phctime - Update the cached PHC time values
  * @pf: Board specific private structure
@@ -2359,8 +2345,6 @@ static void ice_ptp_periodic_work(struct kthread_work *work)
 
 	err = ice_ptp_update_cached_phctime(pf);
 
-	ice_ptp_tx_tstamp_cleanup(pf, &pf->ptp.port.tx);
-
 	/* Run twice a second or reschedule if phc update failed */
 	kthread_queue_delayed_work(ptp->kworker, &ptp->work,
 				   msecs_to_jiffies(err ? 10 : 500));
-- 
2.35.1

Re: [PATCH net-next 06/14] ice: handle discarding old Tx requests in ice_ptp_tx_tstamp

[Paolo Abeni]

On Wed, 2022-11-30 at 11:43 -0800, Tony Nguyen wrote:
> From: Jacob Keller <jacob.e.keller@intel.com>
> 
> Currently the driver uses the PTP kthread to process handling and
> discarding of stale Tx timestamp requests. The function
> ice_ptp_tx_tstamp_cleanup is used for this.
> 
> A separate thread creates complications for the driver as we now have both
> the main Tx timestamp processing IRQ checking timestamps as well as the
> kthread.
> 
> Rather than using the kthread to handle this, simply check for stale
> timestamps within the ice_ptp_tx_tstamp function. This function must
> already process the timestamps anyways.
> 
> If a Tx timestamp has been waiting for 2 seconds we simply clear the bit
> and discard the SKB. This avoids the complication of having separate
> threads polling, reducing overall CPU work.
> 
> Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
> Tested-by: Gurucharan G <gurucharanx.g@intel.com> (A Contingent worker at Intel)
> Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
> ---
>  drivers/net/ethernet/intel/ice/ice_ptp.c | 106 ++++++++++-------------
>  1 file changed, 45 insertions(+), 61 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.c b/drivers/net/ethernet/intel/ice/ice_ptp.c
> index 1564c72189bf..58e527f202c0 100644
> --- a/drivers/net/ethernet/intel/ice/ice_ptp.c
> +++ b/drivers/net/ethernet/intel/ice/ice_ptp.c
> @@ -626,15 +626,32 @@ static u64 ice_ptp_extend_40b_ts(struct ice_pf *pf, u64 in_tstamp)
>   * Note that we only take the tracking lock when clearing the bit and when
>   * checking if we need to re-queue this task. The only place where bits can be
>   * set is the hard xmit routine where an SKB has a request flag set. The only
> - * places where we clear bits are this work function, or the periodic cleanup
> - * thread. If the cleanup thread clears a bit we're processing we catch it
> - * when we lock to clear the bit and then grab the SKB pointer. If a Tx thread
> - * starts a new timestamp, we might not begin processing it right away but we
> - * will notice it at the end when we re-queue the task. If a Tx thread starts
> - * a new timestamp just after this function exits without re-queuing,
> - * the interrupt when the timestamp finishes should trigger. Avoiding holding
> - * the lock for the entire function is important in order to ensure that Tx
> - * threads do not get blocked while waiting for the lock.
> + * places where we clear bits are this work function, or when flushing the Tx
> + * timestamp tracker.
> + *
> + * If the Tx tracker gets flushed while we're processing a packet, we catch
> + * this because we grab the SKB pointer under lock. If the SKB is NULL we know
> + * that another thread already discarded the SKB and we can avoid passing it
> + * up to the stack.
> + *
> + * If a Tx thread starts a new timestamp, we might not begin processing it
> + * right away but we will notice it at the end when we re-queue the task.
> + *
> + * If a Tx thread starts a new timestamp just after this function exits, the
> + * interrupt for that timestamp should re-trigger this function once
> + * a timestamp is ready.
> + *
> + * Note that minimizing the time we hold the lock is important. If we held the
> + * lock for the entire function we would unnecessarily block the Tx hot path
> + * which needs to set the timestamp index. Limiting how long we hold the lock
> + * ensures we do not block Tx threads.
> + *
> + * If a Tx packet has been waiting for more than 2 seconds, it is not possible
> + * to correctly extend the timestamp using the cached PHC time. It is
> + * extremely unlikely that a packet will ever take this long to timestamp. If
> + * we detect a Tx timestamp request that has waited for this long we assume
> + * the packet will never be sent by hardware and discard it without reading
> + * the timestamp register.
>   */
>  static bool ice_ptp_tx_tstamp(struct ice_ptp_tx *tx)
>  {
> @@ -653,9 +670,20 @@ static bool ice_ptp_tx_tstamp(struct ice_ptp_tx *tx)
>  		struct skb_shared_hwtstamps shhwtstamps = {};
>  		u8 phy_idx = idx + tx->offset;
>  		u64 raw_tstamp, tstamp;
> +		bool drop_ts = false;
>  		struct sk_buff *skb;
>  		int err;
>  
> +		/* Drop packets which have waited for more than 2 seconds */
> +		if (time_is_before_jiffies(tx->tstamps[idx].start + 2 * HZ)) {
> +			drop_ts = true;
> +
> +			/* Count the number of Tx timestamps that timed out */
> +			pf->ptp.tx_hwtstamp_timeouts++;
> +
> +			goto skip_ts_read;

This skips raw_tstamp initialization and causes later compiler warning
when accessing raw_tstamp.

You probably need to duplicate/factor out a bit of later code to fix
this.

Cheers,

Paolo

Re: [PATCH net-next 06/14] ice: handle discarding old Tx requests in ice_ptp_tx_tstamp

[Paolo Abeni]

On Thu, 2022-12-01 at 15:58 +0100, Paolo Abeni wrote:
> On Wed, 2022-11-30 at 11:43 -0800, Tony Nguyen wrote:
> > From: Jacob Keller <jacob.e.keller@intel.com>
> > 
> > Currently the driver uses the PTP kthread to process handling and
> > discarding of stale Tx timestamp requests. The function
> > ice_ptp_tx_tstamp_cleanup is used for this.
> > 
> > A separate thread creates complications for the driver as we now have both
> > the main Tx timestamp processing IRQ checking timestamps as well as the
> > kthread.
> > 
> > Rather than using the kthread to handle this, simply check for stale
> > timestamps within the ice_ptp_tx_tstamp function. This function must
> > already process the timestamps anyways.
> > 
> > If a Tx timestamp has been waiting for 2 seconds we simply clear the bit
> > and discard the SKB. This avoids the complication of having separate
> > threads polling, reducing overall CPU work.
> > 
> > Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
> > Tested-by: Gurucharan G <gurucharanx.g@intel.com> (A Contingent worker at Intel)
> > Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
> > ---
> >  drivers/net/ethernet/intel/ice/ice_ptp.c | 106 ++++++++++-------------
> >  1 file changed, 45 insertions(+), 61 deletions(-)
> > 
> > diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.c b/drivers/net/ethernet/intel/ice/ice_ptp.c
> > index 1564c72189bf..58e527f202c0 100644
> > --- a/drivers/net/ethernet/intel/ice/ice_ptp.c
> > +++ b/drivers/net/ethernet/intel/ice/ice_ptp.c
> > @@ -626,15 +626,32 @@ static u64 ice_ptp_extend_40b_ts(struct ice_pf *pf, u64 in_tstamp)
> >   * Note that we only take the tracking lock when clearing the bit and when
> >   * checking if we need to re-queue this task. The only place where bits can be
> >   * set is the hard xmit routine where an SKB has a request flag set. The only
> > - * places where we clear bits are this work function, or the periodic cleanup
> > - * thread. If the cleanup thread clears a bit we're processing we catch it
> > - * when we lock to clear the bit and then grab the SKB pointer. If a Tx thread
> > - * starts a new timestamp, we might not begin processing it right away but we
> > - * will notice it at the end when we re-queue the task. If a Tx thread starts
> > - * a new timestamp just after this function exits without re-queuing,
> > - * the interrupt when the timestamp finishes should trigger. Avoiding holding
> > - * the lock for the entire function is important in order to ensure that Tx
> > - * threads do not get blocked while waiting for the lock.
> > + * places where we clear bits are this work function, or when flushing the Tx
> > + * timestamp tracker.
> > + *
> > + * If the Tx tracker gets flushed while we're processing a packet, we catch
> > + * this because we grab the SKB pointer under lock. If the SKB is NULL we know
> > + * that another thread already discarded the SKB and we can avoid passing it
> > + * up to the stack.
> > + *
> > + * If a Tx thread starts a new timestamp, we might not begin processing it
> > + * right away but we will notice it at the end when we re-queue the task.
> > + *
> > + * If a Tx thread starts a new timestamp just after this function exits, the
> > + * interrupt for that timestamp should re-trigger this function once
> > + * a timestamp is ready.
> > + *
> > + * Note that minimizing the time we hold the lock is important. If we held the
> > + * lock for the entire function we would unnecessarily block the Tx hot path
> > + * which needs to set the timestamp index. Limiting how long we hold the lock
> > + * ensures we do not block Tx threads.
> > + *
> > + * If a Tx packet has been waiting for more than 2 seconds, it is not possible
> > + * to correctly extend the timestamp using the cached PHC time. It is
> > + * extremely unlikely that a packet will ever take this long to timestamp. If
> > + * we detect a Tx timestamp request that has waited for this long we assume
> > + * the packet will never be sent by hardware and discard it without reading
> > + * the timestamp register.
> >   */
> >  static bool ice_ptp_tx_tstamp(struct ice_ptp_tx *tx)
> >  {
> > @@ -653,9 +670,20 @@ static bool ice_ptp_tx_tstamp(struct ice_ptp_tx *tx)
> >  		struct skb_shared_hwtstamps shhwtstamps = {};
> >  		u8 phy_idx = idx + tx->offset;
> >  		u64 raw_tstamp, tstamp;
> > +		bool drop_ts = false;
> >  		struct sk_buff *skb;
> >  		int err;
> >  
> > +		/* Drop packets which have waited for more than 2 seconds */
> > +		if (time_is_before_jiffies(tx->tstamps[idx].start + 2 * HZ)) {
> > +			drop_ts = true;
> > +
> > +			/* Count the number of Tx timestamps that timed out */
> > +			pf->ptp.tx_hwtstamp_timeouts++;
> > +
> > +			goto skip_ts_read;
> 
> This skips raw_tstamp initialization and causes later compiler warning
> when accessing raw_tstamp.
> 
> You probably need to duplicate/factor out a bit of later code to fix
> this.

Ah, I see the warning is resolved in the next patch. Perhaps it's
worthy to move the relevant chunk here?

Thanks,

Paolo

Re: [PATCH net-next 06/14] ice: handle discarding old Tx requests in ice_ptp_tx_tstamp

[Jacob Keller]

On 12/1/2022 7:04 AM, Paolo Abeni wrote:
> On Thu, 2022-12-01 at 15:58 +0100, Paolo Abeni wrote:
>> On Wed, 2022-11-30 at 11:43 -0800, Tony Nguyen wrote:
>>> From: Jacob Keller <jacob.e.keller@intel.com>
>>>
>>> Currently the driver uses the PTP kthread to process handling and
>>> discarding of stale Tx timestamp requests. The function
>>> ice_ptp_tx_tstamp_cleanup is used for this.
>>>
>>> A separate thread creates complications for the driver as we now have both
>>> the main Tx timestamp processing IRQ checking timestamps as well as the
>>> kthread.
>>>
>>> Rather than using the kthread to handle this, simply check for stale
>>> timestamps within the ice_ptp_tx_tstamp function. This function must
>>> already process the timestamps anyways.
>>>
>>> If a Tx timestamp has been waiting for 2 seconds we simply clear the bit
>>> and discard the SKB. This avoids the complication of having separate
>>> threads polling, reducing overall CPU work.
>>>
>>> Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
>>> Tested-by: Gurucharan G <gurucharanx.g@intel.com> (A Contingent worker at Intel)
>>> Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
>>> ---
>>>   drivers/net/ethernet/intel/ice/ice_ptp.c | 106 ++++++++++-------------
>>>   1 file changed, 45 insertions(+), 61 deletions(-)
>>>
>>> diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.c b/drivers/net/ethernet/intel/ice/ice_ptp.c
>>> index 1564c72189bf..58e527f202c0 100644
>>> --- a/drivers/net/ethernet/intel/ice/ice_ptp.c
>>> +++ b/drivers/net/ethernet/intel/ice/ice_ptp.c
>>> @@ -626,15 +626,32 @@ static u64 ice_ptp_extend_40b_ts(struct ice_pf *pf, u64 in_tstamp)
>>>    * Note that we only take the tracking lock when clearing the bit and when
>>>    * checking if we need to re-queue this task. The only place where bits can be
>>>    * set is the hard xmit routine where an SKB has a request flag set. The only
>>> - * places where we clear bits are this work function, or the periodic cleanup
>>> - * thread. If the cleanup thread clears a bit we're processing we catch it
>>> - * when we lock to clear the bit and then grab the SKB pointer. If a Tx thread
>>> - * starts a new timestamp, we might not begin processing it right away but we
>>> - * will notice it at the end when we re-queue the task. If a Tx thread starts
>>> - * a new timestamp just after this function exits without re-queuing,
>>> - * the interrupt when the timestamp finishes should trigger. Avoiding holding
>>> - * the lock for the entire function is important in order to ensure that Tx
>>> - * threads do not get blocked while waiting for the lock.
>>> + * places where we clear bits are this work function, or when flushing the Tx
>>> + * timestamp tracker.
>>> + *
>>> + * If the Tx tracker gets flushed while we're processing a packet, we catch
>>> + * this because we grab the SKB pointer under lock. If the SKB is NULL we know
>>> + * that another thread already discarded the SKB and we can avoid passing it
>>> + * up to the stack.
>>> + *
>>> + * If a Tx thread starts a new timestamp, we might not begin processing it
>>> + * right away but we will notice it at the end when we re-queue the task.
>>> + *
>>> + * If a Tx thread starts a new timestamp just after this function exits, the
>>> + * interrupt for that timestamp should re-trigger this function once
>>> + * a timestamp is ready.
>>> + *
>>> + * Note that minimizing the time we hold the lock is important. If we held the
>>> + * lock for the entire function we would unnecessarily block the Tx hot path
>>> + * which needs to set the timestamp index. Limiting how long we hold the lock
>>> + * ensures we do not block Tx threads.
>>> + *
>>> + * If a Tx packet has been waiting for more than 2 seconds, it is not possible
>>> + * to correctly extend the timestamp using the cached PHC time. It is
>>> + * extremely unlikely that a packet will ever take this long to timestamp. If
>>> + * we detect a Tx timestamp request that has waited for this long we assume
>>> + * the packet will never be sent by hardware and discard it without reading
>>> + * the timestamp register.
>>>    */
>>>   static bool ice_ptp_tx_tstamp(struct ice_ptp_tx *tx)
>>>   {
>>> @@ -653,9 +670,20 @@ static bool ice_ptp_tx_tstamp(struct ice_ptp_tx *tx)
>>>   		struct skb_shared_hwtstamps shhwtstamps = {};
>>>   		u8 phy_idx = idx + tx->offset;
>>>   		u64 raw_tstamp, tstamp;
>>> +		bool drop_ts = false;
>>>   		struct sk_buff *skb;
>>>   		int err;
>>>   
>>> +		/* Drop packets which have waited for more than 2 seconds */
>>> +		if (time_is_before_jiffies(tx->tstamps[idx].start + 2 * HZ)) {
>>> +			drop_ts = true;
>>> +
>>> +			/* Count the number of Tx timestamps that timed out */
>>> +			pf->ptp.tx_hwtstamp_timeouts++;
>>> +
>>> +			goto skip_ts_read;
>>
>> This skips raw_tstamp initialization and causes later compiler warning
>> when accessing raw_tstamp.
>>
>> You probably need to duplicate/factor out a bit of later code to fix
>> this.
> 
> Ah, I see the warning is resolved in the next patch. Perhaps it's
> worthy to move the relevant chunk here?
> 
> Thanks,
> 
> Paolo
> 

Ah. Its probably a failed rebase. I re-ordered patches a bunch while 
trying to decide what order made the most sense. Yea we should move the 
hunk from the later patch into this one.

Thanks,
Jake

[PATCH net-next 07/14] ice: check Tx timestamp memory register for ready timestamps

[Tony Nguyen]

From: Jacob Keller <jacob.e.keller@intel.com>

The PHY for E822 based hardware has a register which indicates which
timestamps are valid in the PHY timestamp memory block. Each bit in the
register indicates whether the associated index in the timestamp memory is
valid.

Hardware sets this bit when the timestamp is captured, and clears the bit
when the timestamp is read. Use of this register is important as reading
timestamp registers can impact the way that hardware generates timestamp
interrupts.

This occurs because the PHY has an internal value which is incremented
when hardware captures a timestamp and decremented when software reads a
timestamp. Reading timestamps which are not marked as valid still decrement
the internal value and can result in the Tx timestamp interrupt not
triggering in the future.

To prevent this, use the timestamp memory value to determine which
timestamps are ready to be read. The ice_get_phy_tx_tstamp_ready function
reads this value. For E810 devices, this just always returns with all bits
set.

Skip any timestamp which is not set in this bitmap, avoiding reading extra
timestamps on E822 devices.

The stale check against a cached timestamp value is no longer necessary for
PHYs which support the timestamp ready bitmap properly. E810 devices still
need this. Introduce a new verify_cached flag to the ice_ptp_tx structure.
Use this to determine if we need to perform the verification against the
cached timestamp value. Set this to 1 for the E810 Tx tracker init
function. Notice that many of the fields in ice_ptp_tx are simple 1 bit
flags. Save some structure space by using bitfields of length 1 for these
values.

Modify the ICE_PTP_TS_VALID check to simply drop the timestamp immediately
so that in an event of getting such an invalid timestamp the driver does
not attempt to re-read the timestamp again in a future poll of the
register.

With these changes, the driver now reads each timestamp register exactly
once, and does not attempt any re-reads. This ensures the interrupt
tracking logic in the PHY will not get stuck.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Gurucharan G <gurucharanx.g@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/ice/ice_ptp.c    | 49 ++++++++++++--
 drivers/net/ethernet/intel/ice/ice_ptp.h    | 17 +++--
 drivers/net/ethernet/intel/ice/ice_ptp_hw.c | 72 +++++++++++++++++++++
 drivers/net/ethernet/intel/ice/ice_ptp_hw.h |  1 +
 4 files changed, 127 insertions(+), 12 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.c b/drivers/net/ethernet/intel/ice/ice_ptp.c
index 58e527f202c0..a7d950dd1264 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.c
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.c
@@ -658,6 +658,9 @@ static bool ice_ptp_tx_tstamp(struct ice_ptp_tx *tx)
 	struct ice_ptp_port *ptp_port;
 	bool ts_handled = true;
 	struct ice_pf *pf;
+	struct ice_hw *hw;
+	u64 tstamp_ready;
+	int err;
 	u8 idx;
 
 	if (!tx->init)
@@ -665,6 +668,12 @@ static bool ice_ptp_tx_tstamp(struct ice_ptp_tx *tx)
 
 	ptp_port = container_of(tx, struct ice_ptp_port, tx);
 	pf = ptp_port_to_pf(ptp_port);
+	hw = &pf->hw;
+
+	/* Read the Tx ready status first */
+	err = ice_get_phy_tx_tstamp_ready(hw, tx->block, &tstamp_ready);
+	if (err)
+		return false;
 
 	for_each_set_bit(idx, tx->in_use, tx->len) {
 		struct skb_shared_hwtstamps shhwtstamps = {};
@@ -672,7 +681,6 @@ static bool ice_ptp_tx_tstamp(struct ice_ptp_tx *tx)
 		u64 raw_tstamp, tstamp;
 		bool drop_ts = false;
 		struct sk_buff *skb;
-		int err;
 
 		/* Drop packets which have waited for more than 2 seconds */
 		if (time_is_before_jiffies(tx->tstamps[idx].start + 2 * HZ)) {
@@ -680,27 +688,48 @@ static bool ice_ptp_tx_tstamp(struct ice_ptp_tx *tx)
 
 			/* Count the number of Tx timestamps that timed out */
 			pf->ptp.tx_hwtstamp_timeouts++;
+		}
 
-			goto skip_ts_read;
+		/* Only read a timestamp from the PHY if its marked as ready
+		 * by the tstamp_ready register. This avoids unnecessary
+		 * reading of timestamps which are not yet valid. This is
+		 * important as we must read all timestamps which are valid
+		 * and only timestamps which are valid during each interrupt.
+		 * If we do not, the hardware logic for generating a new
+		 * interrupt can get stuck on some devices.
+		 */
+		if (!(tstamp_ready & BIT_ULL(phy_idx))) {
+			if (drop_ts)
+				goto skip_ts_read;
+
+			continue;
 		}
 
 		ice_trace(tx_tstamp_fw_req, tx->tstamps[idx].skb, idx);
 
-		err = ice_read_phy_tstamp(&pf->hw, tx->block, phy_idx,
-					  &raw_tstamp);
+		err = ice_read_phy_tstamp(hw, tx->block, phy_idx, &raw_tstamp);
 		if (err)
 			continue;
 
 		ice_trace(tx_tstamp_fw_done, tx->tstamps[idx].skb, idx);
 
-		/* Check if the timestamp is invalid or stale */
-		if (!(raw_tstamp & ICE_PTP_TS_VALID) ||
+		/* For PHYs which don't implement a proper timestamp ready
+		 * bitmap, verify that the timestamp value is different
+		 * from the last cached timestamp. If it is not, skip this for
+		 * now assuming it hasn't yet been captured by hardware.
+		 */
+		if (!drop_ts && tx->verify_cached &&
 		    raw_tstamp == tx->tstamps[idx].cached_tstamp)
 			continue;
 
+		/* Discard any timestamp value without the valid bit set */
+		if (!(raw_tstamp & ICE_PTP_TS_VALID))
+			drop_ts = true;
+
 skip_ts_read:
 		spin_lock(&tx->lock);
-		tx->tstamps[idx].cached_tstamp = raw_tstamp;
+		if (tx->verify_cached)
+			tx->tstamps[idx].cached_tstamp = raw_tstamp;
 		clear_bit(idx, tx->in_use);
 		skb = tx->tstamps[idx].skb;
 		tx->tstamps[idx].skb = NULL;
@@ -835,6 +864,7 @@ ice_ptp_init_tx_e822(struct ice_pf *pf, struct ice_ptp_tx *tx, u8 port)
 	tx->block = port / ICE_PORTS_PER_QUAD;
 	tx->offset = (port % ICE_PORTS_PER_QUAD) * INDEX_PER_PORT_E822;
 	tx->len = INDEX_PER_PORT_E822;
+	tx->verify_cached = 0;
 
 	return ice_ptp_alloc_tx_tracker(tx);
 }
@@ -853,6 +883,11 @@ ice_ptp_init_tx_e810(struct ice_pf *pf, struct ice_ptp_tx *tx)
 	tx->block = pf->hw.port_info->lport;
 	tx->offset = 0;
 	tx->len = INDEX_PER_PORT_E810;
+	/* The E810 PHY does not provide a timestamp ready bitmap. Instead,
+	 * verify new timestamps against cached copy of the last read
+	 * timestamp.
+	 */
+	tx->verify_cached = 1;
 
 	return ice_ptp_alloc_tx_tracker(tx);
 }
diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.h b/drivers/net/ethernet/intel/ice/ice_ptp.h
index 39cab020f1af..5052fc41bed3 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.h
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.h
@@ -93,9 +93,14 @@ struct ice_perout_channel {
  * we discard old requests that were not fulfilled within a 2 second time
  * window.
  * Timestamp values in the PHY are read only and do not get cleared except at
- * hardware reset or when a new timestamp value is captured. The cached_tstamp
- * field is used to detect the case where a new timestamp has not yet been
- * captured, ensuring that we avoid sending stale timestamp data to the stack.
+ * hardware reset or when a new timestamp value is captured.
+ *
+ * Some PHY types do not provide a "ready" bitmap indicating which timestamp
+ * indexes are valid. In these cases, we use a cached_tstamp to keep track of
+ * the last timestamp we read for a given index. If the current timestamp
+ * value is the same as the cached value, we assume a new timestamp hasn't
+ * been captured. This avoids reporting stale timestamps to the stack. This is
+ * only done if the verify_cached flag is set in ice_ptp_tx structure.
  */
 struct ice_tx_tstamp {
 	struct sk_buff *skb;
@@ -114,6 +119,7 @@ struct ice_tx_tstamp {
  * @init: if true, the tracker is initialized;
  * @calibrating: if true, the PHY is calibrating the Tx offset. During this
  *               window, timestamps are temporarily disabled.
+ * @verify_cached: if true, verify new timestamp differs from last read value
  */
 struct ice_ptp_tx {
 	spinlock_t lock; /* lock protecting in_use bitmap */
@@ -122,8 +128,9 @@ struct ice_ptp_tx {
 	u8 block;
 	u8 offset;
 	u8 len;
-	u8 init;
-	u8 calibrating;
+	u8 init : 1;
+	u8 calibrating : 1;
+	u8 verify_cached : 1;
 };
 
 /* Quad and port information for initializing timestamp blocks */
diff --git a/drivers/net/ethernet/intel/ice/ice_ptp_hw.c b/drivers/net/ethernet/intel/ice/ice_ptp_hw.c
index 6c149b88c235..d5d51427580a 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp_hw.c
+++ b/drivers/net/ethernet/intel/ice/ice_ptp_hw.c
@@ -2417,6 +2417,41 @@ int ice_phy_calc_vernier_e822(struct ice_hw *hw, u8 port)
 	return 0;
 }
 
+/**
+ * ice_get_phy_tx_tstamp_ready_e822 - Read Tx memory status register
+ * @hw: pointer to the HW struct
+ * @quad: the timestamp quad to read from
+ * @tstamp_ready: contents of the Tx memory status register
+ *
+ * Read the Q_REG_TX_MEMORY_STATUS register indicating which timestamps in
+ * the PHY are ready. A set bit means the corresponding timestamp is valid and
+ * ready to be captured from the PHY timestamp block.
+ */
+static int
+ice_get_phy_tx_tstamp_ready_e822(struct ice_hw *hw, u8 quad, u64 *tstamp_ready)
+{
+	u32 hi, lo;
+	int err;
+
+	err = ice_read_quad_reg_e822(hw, quad, Q_REG_TX_MEMORY_STATUS_U, &hi);
+	if (err) {
+		ice_debug(hw, ICE_DBG_PTP, "Failed to read TX_MEMORY_STATUS_U for quad %u, err %d\n",
+			  quad, err);
+		return err;
+	}
+
+	err = ice_read_quad_reg_e822(hw, quad, Q_REG_TX_MEMORY_STATUS_L, &lo);
+	if (err) {
+		ice_debug(hw, ICE_DBG_PTP, "Failed to read TX_MEMORY_STATUS_L for quad %u, err %d\n",
+			  quad, err);
+		return err;
+	}
+
+	*tstamp_ready = (u64)hi << 32 | (u64)lo;
+
+	return 0;
+}
+
 /* E810 functions
  *
  * The following functions operate on the E810 series devices which use
@@ -3091,6 +3126,22 @@ int ice_clear_phy_tstamp(struct ice_hw *hw, u8 block, u8 idx)
 		return ice_clear_phy_tstamp_e822(hw, block, idx);
 }
 
+/**
+ * ice_get_phy_tx_tstamp_ready_e810 - Read Tx memory status register
+ * @hw: pointer to the HW struct
+ * @port: the PHY port to read
+ * @tstamp_ready: contents of the Tx memory status register
+ *
+ * E810 devices do not use a Tx memory status register. Instead simply
+ * indicate that all timestamps are currently ready.
+ */
+static int
+ice_get_phy_tx_tstamp_ready_e810(struct ice_hw *hw, u8 port, u64 *tstamp_ready)
+{
+	*tstamp_ready = 0xFFFFFFFFFFFFFFFF;
+	return 0;
+}
+
 /* E810T SMA functions
  *
  * The following functions operate specifically on E810T hardware and are used
@@ -3306,3 +3357,24 @@ int ice_ptp_init_phc(struct ice_hw *hw)
 	else
 		return ice_ptp_init_phc_e822(hw);
 }
+
+/**
+ * ice_get_phy_tx_tstamp_ready - Read PHY Tx memory status indication
+ * @hw: pointer to the HW struct
+ * @block: the timestamp block to check
+ * @tstamp_ready: storage for the PHY Tx memory status information
+ *
+ * Check the PHY for Tx timestamp memory status. This reports a 64 bit value
+ * which indicates which timestamps in the block may be captured. A set bit
+ * means the timestamp can be read. An unset bit means the timestamp is not
+ * ready and software should avoid reading the register.
+ */
+int ice_get_phy_tx_tstamp_ready(struct ice_hw *hw, u8 block, u64 *tstamp_ready)
+{
+	if (ice_is_e810(hw))
+		return ice_get_phy_tx_tstamp_ready_e810(hw, block,
+							tstamp_ready);
+	else
+		return ice_get_phy_tx_tstamp_ready_e822(hw, block,
+							tstamp_ready);
+}
diff --git a/drivers/net/ethernet/intel/ice/ice_ptp_hw.h b/drivers/net/ethernet/intel/ice/ice_ptp_hw.h
index b0cd73aaac6b..b781dadf5a39 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp_hw.h
+++ b/drivers/net/ethernet/intel/ice/ice_ptp_hw.h
@@ -135,6 +135,7 @@ int ice_read_phy_tstamp(struct ice_hw *hw, u8 block, u8 idx, u64 *tstamp);
 int ice_clear_phy_tstamp(struct ice_hw *hw, u8 block, u8 idx);
 void ice_ptp_reset_ts_memory(struct ice_hw *hw);
 int ice_ptp_init_phc(struct ice_hw *hw);
+int ice_get_phy_tx_tstamp_ready(struct ice_hw *hw, u8 block, u64 *tstamp_ready);
 
 /* E822 family functions */
 int ice_read_phy_reg_e822(struct ice_hw *hw, u8 port, u16 offset, u32 *val);
-- 
2.35.1

[PATCH net-next 08/14] ice: protect init and calibrating fields with spinlock

[Tony Nguyen]

From: Jacob Keller <jacob.e.keller@intel.com>

Ensure that the init and calibrating fields of the PTP Tx timestamp tracker
structure are only modified under the spin lock. This ensures that the
accesses are consistent and that new timestamp requests will either begin
completely or get ignored.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Gurucharan G <gurucharanx.g@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/ice/ice_ptp.c | 55 ++++++++++++++++++++++--
 drivers/net/ethernet/intel/ice/ice_ptp.h |  2 +-
 2 files changed, 52 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.c b/drivers/net/ethernet/intel/ice/ice_ptp.c
index a7d950dd1264..0e39fed7cfca 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.c
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.c
@@ -599,6 +599,42 @@ static u64 ice_ptp_extend_40b_ts(struct ice_pf *pf, u64 in_tstamp)
 				     (in_tstamp >> 8) & mask);
 }
 
+/**
+ * ice_ptp_is_tx_tracker_init - Check if the Tx tracker is initialized
+ * @tx: the PTP Tx timestamp tracker to check
+ *
+ * Check that a given PTP Tx timestamp tracker is initialized. Acquires the
+ * tx->lock spinlock.
+ */
+static bool
+ice_ptp_is_tx_tracker_init(struct ice_ptp_tx *tx)
+{
+	bool init;
+
+	spin_lock(&tx->lock);
+	init = tx->init;
+	spin_unlock(&tx->lock);
+
+	return init;
+}
+
+/**
+ * ice_ptp_is_tx_tracker_up - Check if Tx tracker is ready for new timestamps
+ * @tx: the PTP Tx timestamp tracker to check
+ *
+ * Check that a given PTP Tx timestamp tracker is up, i.e. that it is ready
+ * to accept new timestamp requests.
+ *
+ * Assumes the tx->lock spinlock is already held.
+ */
+static bool
+ice_ptp_is_tx_tracker_up(struct ice_ptp_tx *tx)
+{
+	lockdep_assert_held(&tx->lock);
+
+	return tx->init && !tx->calibrating;
+}
+
 /**
  * ice_ptp_tx_tstamp - Process Tx timestamps for a port
  * @tx: the PTP Tx timestamp tracker
@@ -663,7 +699,7 @@ static bool ice_ptp_tx_tstamp(struct ice_ptp_tx *tx)
 	int err;
 	u8 idx;
 
-	if (!tx->init)
+	if (!ice_ptp_is_tx_tracker_init(tx))
 		return true;
 
 	ptp_port = container_of(tx, struct ice_ptp_port, tx);
@@ -791,7 +827,9 @@ ice_ptp_alloc_tx_tracker(struct ice_ptp_tx *tx)
 
 	spin_lock_init(&tx->lock);
 
+	spin_lock(&tx->lock);
 	tx->init = 1;
+	spin_unlock(&tx->lock);
 
 	return 0;
 }
@@ -834,7 +872,9 @@ ice_ptp_flush_tx_tracker(struct ice_pf *pf, struct ice_ptp_tx *tx)
 static void
 ice_ptp_release_tx_tracker(struct ice_pf *pf, struct ice_ptp_tx *tx)
 {
+	spin_lock(&tx->lock);
 	tx->init = 0;
+	spin_unlock(&tx->lock);
 
 	ice_ptp_flush_tx_tracker(pf, tx);
 
@@ -1325,7 +1365,9 @@ ice_ptp_port_phy_restart(struct ice_ptp_port *ptp_port)
 	kthread_cancel_delayed_work_sync(&ptp_port->ov_work);
 
 	/* temporarily disable Tx timestamps while calibrating PHY offset */
+	spin_lock(&ptp_port->tx.lock);
 	ptp_port->tx.calibrating = true;
+	spin_unlock(&ptp_port->tx.lock);
 	ptp_port->tx_fifo_busy_cnt = 0;
 
 	/* Start the PHY timer in Vernier mode */
@@ -1334,7 +1376,9 @@ ice_ptp_port_phy_restart(struct ice_ptp_port *ptp_port)
 		goto out_unlock;
 
 	/* Enable Tx timestamps right away */
+	spin_lock(&ptp_port->tx.lock);
 	ptp_port->tx.calibrating = false;
+	spin_unlock(&ptp_port->tx.lock);
 
 	kthread_queue_delayed_work(pf->ptp.kworker, &ptp_port->ov_work, 0);
 
@@ -2328,11 +2372,14 @@ s8 ice_ptp_request_ts(struct ice_ptp_tx *tx, struct sk_buff *skb)
 {
 	u8 idx;
 
-	/* Check if this tracker is initialized */
-	if (!tx->init || tx->calibrating)
+	spin_lock(&tx->lock);
+
+	/* Check that this tracker is accepting new timestamp requests */
+	if (!ice_ptp_is_tx_tracker_up(tx)) {
+		spin_unlock(&tx->lock);
 		return -1;
+	}
 
-	spin_lock(&tx->lock);
 	/* Find and set the first available index */
 	idx = find_first_zero_bit(tx->in_use, tx->len);
 	if (idx < tx->len) {
diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.h b/drivers/net/ethernet/intel/ice/ice_ptp.h
index 5052fc41bed3..0bfafaaab6c7 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.h
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.h
@@ -110,7 +110,7 @@ struct ice_tx_tstamp {
 
 /**
  * struct ice_ptp_tx - Tracking structure for all Tx timestamp requests on a port
- * @lock: lock to prevent concurrent write to in_use bitmap
+ * @lock: lock to prevent concurrent access to fields of this struct
  * @tstamps: array of len to store outstanding requests
  * @in_use: bitmap of len to indicate which slots are in use
  * @block: which memory block (quad or port) the timestamps are captured in
-- 
2.35.1

Re: [PATCH net-next 08/14] ice: protect init and calibrating fields with spinlock

[Leon Romanovsky]

On Wed, Nov 30, 2022 at 11:43:24AM -0800, Tony Nguyen wrote:
> From: Jacob Keller <jacob.e.keller@intel.com>
> 
> Ensure that the init and calibrating fields of the PTP Tx timestamp tracker
> structure are only modified under the spin lock. This ensures that the
> accesses are consistent and that new timestamp requests will either begin
> completely or get ignored.
> 
> Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
> Tested-by: Gurucharan G <gurucharanx.g@intel.com> (A Contingent worker at Intel)
> Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
> ---
>  drivers/net/ethernet/intel/ice/ice_ptp.c | 55 ++++++++++++++++++++++--
>  drivers/net/ethernet/intel/ice/ice_ptp.h |  2 +-
>  2 files changed, 52 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.c b/drivers/net/ethernet/intel/ice/ice_ptp.c
> index a7d950dd1264..0e39fed7cfca 100644
> --- a/drivers/net/ethernet/intel/ice/ice_ptp.c
> +++ b/drivers/net/ethernet/intel/ice/ice_ptp.c
> @@ -599,6 +599,42 @@ static u64 ice_ptp_extend_40b_ts(struct ice_pf *pf, u64 in_tstamp)
>  				     (in_tstamp >> 8) & mask);
>  }
>  
> +/**
> + * ice_ptp_is_tx_tracker_init - Check if the Tx tracker is initialized
> + * @tx: the PTP Tx timestamp tracker to check
> + *
> + * Check that a given PTP Tx timestamp tracker is initialized. Acquires the
> + * tx->lock spinlock.
> + */
> +static bool
> +ice_ptp_is_tx_tracker_init(struct ice_ptp_tx *tx)
> +{
> +	bool init;
> +
> +	spin_lock(&tx->lock);
> +	init = tx->init;
> +	spin_unlock(&tx->lock);
> +
> +	return init;

How this type of locking can be correct?
It doesn't protect anything and equal to do not have locking at all.

Thanks

Re: [PATCH net-next 08/14] ice: protect init and calibrating fields with spinlock

[Jacob Keller]

On 12/1/2022 1:18 AM, Leon Romanovsky wrote:
> On Wed, Nov 30, 2022 at 11:43:24AM -0800, Tony Nguyen wrote:
>> From: Jacob Keller <jacob.e.keller@intel.com>
>>
>> Ensure that the init and calibrating fields of the PTP Tx timestamp tracker
>> structure are only modified under the spin lock. This ensures that the
>> accesses are consistent and that new timestamp requests will either begin
>> completely or get ignored.
>>
>> Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
>> Tested-by: Gurucharan G <gurucharanx.g@intel.com> (A Contingent worker at Intel)
>> Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
>> ---
>>   drivers/net/ethernet/intel/ice/ice_ptp.c | 55 ++++++++++++++++++++++--
>>   drivers/net/ethernet/intel/ice/ice_ptp.h |  2 +-
>>   2 files changed, 52 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.c b/drivers/net/ethernet/intel/ice/ice_ptp.c
>> index a7d950dd1264..0e39fed7cfca 100644
>> --- a/drivers/net/ethernet/intel/ice/ice_ptp.c
>> +++ b/drivers/net/ethernet/intel/ice/ice_ptp.c
>> @@ -599,6 +599,42 @@ static u64 ice_ptp_extend_40b_ts(struct ice_pf *pf, u64 in_tstamp)
>>   				     (in_tstamp >> 8) & mask);
>>   }
>>   
>> +/**
>> + * ice_ptp_is_tx_tracker_init - Check if the Tx tracker is initialized
>> + * @tx: the PTP Tx timestamp tracker to check
>> + *
>> + * Check that a given PTP Tx timestamp tracker is initialized. Acquires the
>> + * tx->lock spinlock.
>> + */
>> +static bool
>> +ice_ptp_is_tx_tracker_init(struct ice_ptp_tx *tx)
>> +{
>> +	bool init;
>> +
>> +	spin_lock(&tx->lock);
>> +	init = tx->init;
>> +	spin_unlock(&tx->lock);
>> +
>> +	return init;
> 
> How this type of locking can be correct?
> It doesn't protect anything and equal to do not have locking at all.
> 
> Thanks

The init field is used to by the Tx timestamp work item to have it exit 
if it is executed after the Tx tracker starts being de-initialized. I 
guess technically reading the value would be atomic.. Though using a 
spinlock also ensures the appropriate memory barriers are in place 
around reading the value, preventing re-ordering.

We clear the init field and then the Tx timestamp thread will stop 
re-arming itself. We used to have a kthread item which we would then 
call flush to ensure the last queued instance of the work item was 
removed... but ugh now that we're using a threaded interrupt I am not 
sure if we have any way to guarantee that the Tx work has completed. I 
am not sure how to address that now with a threaded interrupt. Hmm.

We can't hold a spin lock for the entire duration of the Tx timestamp 
work because it might sleep while checking for an outstanding Tx 
timestamp via the device Admin queue interface to read the PHY timestamp.

The goal is to ensure that

a) timestamp requests guarantee that they each get unique indexes or 
fail to start. This is covered by the fact that timestamp requests all 
hold the lock over the duration of checking that requests are being 
accepted, picking the index, and setting that index's in_use bit

b) timestamp completions are reported only once. The only place that 
processes timestamp completions is the threaded interrupt function, 
which can only have one instance executing at a time. This function 
doesn't hold the spin lock while iterating the in_use bitmap, but it 
does hold the lock when it reports the timestamp and before doing so it 
rechecks the in_use bit in case the timestamp got flushed. We used to 
have a separate thread that handled discarding old timestamps after 2 
seconds but we now do that from within the same threaded function. Its 
possible that a request thread might execute while this function is 
processing and *set* a new in_use bit. In this case, either the function 
will see the update when iterating the in_use bitmap, in which case it 
will check the PHY register and process the timestamp if it happened to 
be completed. Or, it will miss the timestamp in that run. At the end of 
the loop, the lock is re-acquired and we check if any timestamp requests 
are outstanding. If so, we exit such that the threaded interrupt 
function will re-execute the Tx timestamp thread shortly to check again.

c) In previous versions we had a kthread task which was used to run the 
Tx timestamp function. In that version we used kthread flush after 
clearing the init flag to ensure that the threaded function was 
completed. I think this is a gap since the commit that introduced a 
threaded interrupt instead. We need some way for the tear down to ensure 
that no more timestamp processing will occur. There is a small window 
after we clear init that we could race with tearing down and removing 
the Tx tracker memory now :(

I am not sure what the best way to fix c) is. Perhaps an additional flag 
of some sort which indicates that the timestamp thread function is 
processing so that tear down can wait until after the interrupt function 
completes. Once init is cleared, the function will stop re-executing, 
but we need a way to wait until it has stopped. That method in tear down 
can't hold the lock or else we'd potentially deadlock... Maybe an 
additional "processing" flag which is set under lock only if the init 
flag is set? and then cleared when the function exits. Then the tear 
down can check and wait for the processing to be complete? Hmm.

I realize this whole scheme is rather complicated. The biggest problem 
is that while reading timestamps we need to interact with firmware over 
the Admin queue, but we also need to safely be able to set new timestamp 
requests from the hot path with minimal disruption. If we locked over 
the entire Tx timestamp read process it would block hot path.

I think there's a gap now with the threaded interrupt needing a way to 
ensure that no new Tx timestamp interrupts will be processed since we 
can no longer use kthread flushing to handle that. I believe the other 
parts are correct.

Thanks,
Jake

Re: [PATCH net-next 08/14] ice: protect init and calibrating fields with spinlock

[Jacob Keller]

On 12/2/2022 10:36 AM, Jacob Keller wrote:
> I am not sure what the best way to fix c) is. Perhaps an additional flag 
> of some sort which indicates that the timestamp thread function is 
> processing so that tear down can wait until after the interrupt function 
> completes. Once init is cleared, the function will stop re-executing, 
> but we need a way to wait until it has stopped. That method in tear down 
> can't hold the lock or else we'd potentially deadlock... Maybe an 
> additional "processing" flag which is set under lock only if the init 
> flag is set? and then cleared when the function exits. Then the tear 
> down can check and wait for the processing to be complete? Hmm.
> 

For what its worth, I think this is an issue regardless of whether this 
series is applied, since the change from kthread to threaded IRQ was 
done a while ago.

Re: [PATCH net-next 08/14] ice: protect init and calibrating fields with spinlock

[Leon Romanovsky]

On Fri, Dec 02, 2022 at 03:07:16PM -0800, Jacob Keller wrote:
> 
> 
> On 12/2/2022 10:36 AM, Jacob Keller wrote:
> > I am not sure what the best way to fix c) is. Perhaps an additional flag
> > of some sort which indicates that the timestamp thread function is
> > processing so that tear down can wait until after the interrupt function
> > completes. Once init is cleared, the function will stop re-executing,
> > but we need a way to wait until it has stopped. That method in tear down
> > can't hold the lock or else we'd potentially deadlock... Maybe an
> > additional "processing" flag which is set under lock only if the init
> > flag is set? and then cleared when the function exits. Then the tear
> > down can check and wait for the processing to be complete? Hmm.
> > 
> 
> For what its worth, I think this is an issue regardless of whether this
> series is applied, since the change from kthread to threaded IRQ was done a
> while ago.

Sorry, I can't say anything clear without deep dive into ice code. But this specific
patch is not correct.

Thanks

Re: [PATCH net-next 08/14] ice: protect init and calibrating fields with spinlock

[Jacob Keller]

On 12/4/2022 5:30 AM, Leon Romanovsky wrote:
> On Fri, Dec 02, 2022 at 03:07:16PM -0800, Jacob Keller wrote:
>>
>>
>> On 12/2/2022 10:36 AM, Jacob Keller wrote:
>>> I am not sure what the best way to fix c) is. Perhaps an additional flag
>>> of some sort which indicates that the timestamp thread function is
>>> processing so that tear down can wait until after the interrupt function
>>> completes. Once init is cleared, the function will stop re-executing,
>>> but we need a way to wait until it has stopped. That method in tear down
>>> can't hold the lock or else we'd potentially deadlock... Maybe an
>>> additional "processing" flag which is set under lock only if the init
>>> flag is set? and then cleared when the function exits. Then the tear
>>> down can check and wait for the processing to be complete? Hmm.
>>>
>>
>> For what its worth, I think this is an issue regardless of whether this
>> series is applied, since the change from kthread to threaded IRQ was done a
>> while ago.
> 
> Sorry, I can't say anything clear without deep dive into ice code. But this specific
> patch is not correct.
> 
> Thanks

I understand. Its rather complicated :( I appreciate the review. I've 
got a new version we're testing now that drops the changes around 
tx->init for the ice_ptp_tx_tstamp function and adds a call to 
synchronize_irq in the teardown path to ensure that we wait for any 
outstanding interrupt before continuing teardown. I believe that should 
address your concerns. Hopefully we can send a fixed version of the 
series soon once it completes some internal testing.

Thanks,
Jake

[PATCH net-next 09/14] ice: disable Tx timestamps while link is down

[Tony Nguyen]

From: Jacob Keller <jacob.e.keller@intel.com>

Introduce a new link_down field for the Tx tracker which indicates whether
the link is down for a given port.

Use this bit to prevent any Tx timestamp requests from starting while link
is down. This ensures that we do not try to start new timestamp requests
until after link has been restored.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Gurucharan G <gurucharanx.g@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/ice/ice_ptp.c | 11 ++++++++++-
 drivers/net/ethernet/intel/ice/ice_ptp.h |  2 ++
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.c b/drivers/net/ethernet/intel/ice/ice_ptp.c
index 0e39fed7cfca..17883974c31e 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.c
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.c
@@ -632,7 +632,7 @@ ice_ptp_is_tx_tracker_up(struct ice_ptp_tx *tx)
 {
 	lockdep_assert_held(&tx->lock);
 
-	return tx->init && !tx->calibrating;
+	return tx->init && !tx->calibrating && !tx->link_down;
 }
 
 /**
@@ -829,6 +829,8 @@ ice_ptp_alloc_tx_tracker(struct ice_ptp_tx *tx)
 
 	spin_lock(&tx->lock);
 	tx->init = 1;
+	tx->link_down = 0;
+	tx->calibrating = 0;
 	spin_unlock(&tx->lock);
 
 	return 0;
@@ -1415,6 +1417,13 @@ void ice_ptp_link_change(struct ice_pf *pf, u8 port, bool linkup)
 	/* Update cached link status for this port immediately */
 	ptp_port->link_up = linkup;
 
+	/* Set the link status of the Tx tracker. While link is down, all Tx
+	 * timestamp requests will be ignored.
+	 */
+	spin_lock(&ptp_port->tx.lock);
+	ptp_port->tx.link_down = !linkup;
+	spin_unlock(&ptp_port->tx.lock);
+
 	/* E810 devices do not need to reconfigure the PHY */
 	if (ice_is_e810(&pf->hw))
 		return;
diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.h b/drivers/net/ethernet/intel/ice/ice_ptp.h
index 0bfafaaab6c7..75dcab8e1124 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.h
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.h
@@ -119,6 +119,7 @@ struct ice_tx_tstamp {
  * @init: if true, the tracker is initialized;
  * @calibrating: if true, the PHY is calibrating the Tx offset. During this
  *               window, timestamps are temporarily disabled.
+ * @link_down: if true, the link is down and timestamp requests are disabled
  * @verify_cached: if true, verify new timestamp differs from last read value
  */
 struct ice_ptp_tx {
@@ -130,6 +131,7 @@ struct ice_ptp_tx {
 	u8 len;
 	u8 init : 1;
 	u8 calibrating : 1;
+	u8 link_down : 1;
 	u8 verify_cached : 1;
 };
 
-- 
2.35.1

[PATCH net-next 10/14] ice: cleanup allocations in ice_ptp_alloc_tx_tracker

[Tony Nguyen]

From: Jacob Keller <jacob.e.keller@intel.com>

The ice_ptp_alloc_tx_tracker function must allocate the timestamp array and
the bitmap for tracking the currently in use indexes. A future change is
going to add yet another allocation to this function.

If these allocations fail we need to ensure that we properly cleanup and
ensure that the pointers in the ice_ptp_tx structure are NULL.

Simplify this logic by allocating to local variables first. If any
allocation fails, then free everything and exit. Only update the ice_ptp_tx
structure if all allocations succeed.

This ensures that we have no side effects on the Tx structure unless all
allocations have succeeded. Thus, no code will see an invalid pointer and
we don't need to re-assign NULL on cleanup.

This is safe because kernel "free" functions are designed to be NULL safe
and perform no action if passed a NULL pointer. Thus its safe to simply
always call kfree or bitmap_free even if one of those pointers was NULL.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Gurucharan G <gurucharanx.g@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/ice/ice_ptp.c | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.c b/drivers/net/ethernet/intel/ice/ice_ptp.c
index 17883974c31e..5a8c866f2412 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.c
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.c
@@ -814,17 +814,22 @@ static bool ice_ptp_tx_tstamp(struct ice_ptp_tx *tx)
 static int
 ice_ptp_alloc_tx_tracker(struct ice_ptp_tx *tx)
 {
-	tx->tstamps = kcalloc(tx->len, sizeof(*tx->tstamps), GFP_KERNEL);
-	if (!tx->tstamps)
-		return -ENOMEM;
+	struct ice_tx_tstamp *tstamps;
+	unsigned long *in_use;
+
+	tstamps = kcalloc(tx->len, sizeof(*tstamps), GFP_KERNEL);
+	in_use = bitmap_zalloc(tx->len, GFP_KERNEL);
+
+	if (!tstamps || !in_use) {
+		kfree(tstamps);
+		bitmap_free(in_use);
 
-	tx->in_use = bitmap_zalloc(tx->len, GFP_KERNEL);
-	if (!tx->in_use) {
-		kfree(tx->tstamps);
-		tx->tstamps = NULL;
 		return -ENOMEM;
 	}
 
+	tx->tstamps = tstamps;
+	tx->in_use = in_use;
+
 	spin_lock_init(&tx->lock);
 
 	spin_lock(&tx->lock);
-- 
2.35.1

[PATCH net-next 11/14] ice: handle flushing stale Tx timestamps in ice_ptp_tx_tstamp

[Tony Nguyen]

From: Jacob Keller <jacob.e.keller@intel.com>

In the event of a PTP clock time change due to .adjtime or .settime, the
ice driver needs to update the cached copy of the PHC time and also discard
any outstanding Tx timestamps.

This is required because otherwise the wrong copy of the PHC time will be
used when extending the Tx timestamp. This could result in reporting
incorrect timestamps to the stack.

The current approach taken to handle this is to call
ice_ptp_flush_tx_tracker, which will discard any timestamps which are not
yet complete.

This is problematic for two reasons:

1) it could lead to a potential race condition where the wrong timestamp is
   associated with a future packet.

   This can occur with the following flow:

   1. Thread A gets request to transmit a timestamped packet, and picks an
      index and transmits the packet

   2. Thread B calls ice_ptp_flush_tx_tracker and sees the index in use,
      marking is as disarded. No timestamp read occurs because the status
      bit is not set, but the index is released for re-use

   3. Thread A gets a new request to transmit another timestamped packet,
      picks the same (now unused) index and transmits that packet.

   4. The PHY transmits the first packet and updates the timestamp slot and
      generates an interrupt.

   5. The ice_ptp_tx_tstamp thread executes and sees the interrupt and a
      valid timestamp but associates it with the new Tx SKB and not the one
      that actual timestamp for the packet as expected.

   This could result in the previous timestamp being assigned to a new
   packet producing incorrect timestamps and leading to incorrect behavior
   in PTP applications.

   This is most likely to occur when the packet rate for Tx timestamp
   requests is very high.

2) on E822 hardware, we must avoid reading a timestamp index more than once
   each time its status bit is set and an interrupt is generated by
   hardware.

   We do have some extensive checks for the unread flag to ensure that only
   one of either the ice_ptp_flush_tx_tracker or ice_ptp_tx_tstamp threads
   read the timestamp. However, even with this we can still have cases
   where we "flush" a timestamp that was actually completed in hardware.
   This can lead to cases where we don't read the timestamp index as
   appropriate.

To fix both of these issues, we must avoid calling ice_ptp_flush_tx_tracker
outside of the teardown path.

Rather than using ice_ptp_flush_tx_tracker, introduce a new state bitmap,
the stale bitmap. Start this as cleared when we begin a new timestamp
request. When we're about to extend a timestamp and send it up to the
stack, first check to see if that stale bit was set. If so, drop the
timestamp without sending it to the stack.

When we need to update the cached PHC timestamp out of band, just mark all
currently outstanding timestamps as stale. This will ensure that once
hardware completes the timestamp we'll ignore it correctly and avoid
reporting bogus timestamps to userspace.

With this change, we fix potential issues caused  by calling
ice_ptp_flush_tx_tracker during normal operation.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Gurucharan G <gurucharanx.g@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/ice/ice_ptp.c | 104 +++++++++++++++--------
 drivers/net/ethernet/intel/ice/ice_ptp.h |   2 +
 2 files changed, 70 insertions(+), 36 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.c b/drivers/net/ethernet/intel/ice/ice_ptp.c
index 5a8c866f2412..b293c88202cc 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.c
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.c
@@ -644,11 +644,13 @@ ice_ptp_is_tx_tracker_up(struct ice_ptp_tx *tx)
  *
  * If a given index has a valid timestamp, perform the following steps:
  *
- * 1) copy the timestamp out of the PHY register
- * 4) clear the timestamp valid bit in the PHY register
- * 5) unlock the index by clearing the associated in_use bit.
- * 2) extend the 40b timestamp value to get a 64bit timestamp
- * 3) send that timestamp to the stack
+ * 1) check that the timestamp request is not stale
+ * 2) check that a timestamp is ready and available in the PHY memory bank
+ * 3) read and copy the timestamp out of the PHY register
+ * 4) unlock the index by clearing the associated in_use bit
+ * 5) check if the timestamp is stale, and discard if so
+ * 6) extend the 40 bit timestamp value to get a 64 bit timestamp value
+ * 7) send this 64 bit timestamp to the stack
  *
  * Returns true if all timestamps were handled, and false if any slots remain
  * without a timestamp.
@@ -659,16 +661,16 @@ ice_ptp_is_tx_tracker_up(struct ice_ptp_tx *tx)
  * interrupt. In some cases hardware might not interrupt us again when the
  * timestamp is captured.
  *
- * Note that we only take the tracking lock when clearing the bit and when
- * checking if we need to re-queue this task. The only place where bits can be
- * set is the hard xmit routine where an SKB has a request flag set. The only
- * places where we clear bits are this work function, or when flushing the Tx
- * timestamp tracker.
+ * Note that we do not hold the tracking lock while reading the Tx timestamp.
+ * This is because reading the timestamp requires taking a mutex that might
+ * sleep.
  *
- * If the Tx tracker gets flushed while we're processing a packet, we catch
- * this because we grab the SKB pointer under lock. If the SKB is NULL we know
- * that another thread already discarded the SKB and we can avoid passing it
- * up to the stack.
+ * The only place where we set in_use is when a new timestamp is initiated
+ * with a slot index. This is only called in the hard xmit routine where an
+ * SKB has a request flag set. The only places where we clear this bit is this
+ * function, or during teardown when the Tx timestamp tracker is being
+ * removed. A timestamp index will never be re-used until the in_use bit for
+ * that index is cleared.
  *
  * If a Tx thread starts a new timestamp, we might not begin processing it
  * right away but we will notice it at the end when we re-queue the task.
@@ -677,10 +679,11 @@ ice_ptp_is_tx_tracker_up(struct ice_ptp_tx *tx)
  * interrupt for that timestamp should re-trigger this function once
  * a timestamp is ready.
  *
- * Note that minimizing the time we hold the lock is important. If we held the
- * lock for the entire function we would unnecessarily block the Tx hot path
- * which needs to set the timestamp index. Limiting how long we hold the lock
- * ensures we do not block Tx threads.
+ * In cases where the PTP hardware clock was directly adjusted, some
+ * timestamps may not be able to safely use the timestamp extension math. In
+ * this case, software will set the stale bit for any outstanding Tx
+ * timestamps when the clock is adjusted. Then this function will discard
+ * those captured timestamps instead of sending them to the stack.
  *
  * If a Tx packet has been waiting for more than 2 seconds, it is not possible
  * to correctly extend the timestamp using the cached PHC time. It is
@@ -769,6 +772,8 @@ static bool ice_ptp_tx_tstamp(struct ice_ptp_tx *tx)
 		clear_bit(idx, tx->in_use);
 		skb = tx->tstamps[idx].skb;
 		tx->tstamps[idx].skb = NULL;
+		if (test_and_clear_bit(idx, tx->stale))
+			drop_ts = true;
 		spin_unlock(&tx->lock);
 
 		/* It is unlikely but possible that the SKB will have been
@@ -814,21 +819,24 @@ static bool ice_ptp_tx_tstamp(struct ice_ptp_tx *tx)
 static int
 ice_ptp_alloc_tx_tracker(struct ice_ptp_tx *tx)
 {
+	unsigned long *in_use, *stale;
 	struct ice_tx_tstamp *tstamps;
-	unsigned long *in_use;
 
 	tstamps = kcalloc(tx->len, sizeof(*tstamps), GFP_KERNEL);
 	in_use = bitmap_zalloc(tx->len, GFP_KERNEL);
+	stale = bitmap_zalloc(tx->len, GFP_KERNEL);
 
-	if (!tstamps || !in_use) {
+	if (!tstamps || !in_use || !stale) {
 		kfree(tstamps);
 		bitmap_free(in_use);
+		bitmap_free(stale);
 
 		return -ENOMEM;
 	}
 
 	tx->tstamps = tstamps;
 	tx->in_use = in_use;
+	tx->stale = stale;
 
 	spin_lock_init(&tx->lock);
 
@@ -861,6 +869,7 @@ ice_ptp_flush_tx_tracker(struct ice_pf *pf, struct ice_ptp_tx *tx)
 			pf->ptp.tx_hwtstamp_flushed++;
 		}
 		clear_bit(idx, tx->in_use);
+		clear_bit(idx, tx->stale);
 		spin_unlock(&tx->lock);
 
 		/* Clear any potential residual timestamp in the PHY block */
@@ -869,6 +878,28 @@ ice_ptp_flush_tx_tracker(struct ice_pf *pf, struct ice_ptp_tx *tx)
 	}
 }
 
+/**
+ * ice_ptp_mark_tx_tracker_stale - Mark unfinished timestamps as stale
+ * @tx: the tracker to mark
+ *
+ * Mark currently outstanding Tx timestamps as stale. This prevents sending
+ * their timestamp value to the stack. This is required to prevent extending
+ * the 40bit hardware timestamp incorrectly.
+ *
+ * This should be called when the PTP clock is modified such as after a set
+ * time request.
+ */
+static void
+ice_ptp_mark_tx_tracker_stale(struct ice_ptp_tx *tx)
+{
+	u8 idx;
+
+	spin_lock(&tx->lock);
+	for_each_set_bit(idx, tx->in_use, tx->len)
+		set_bit(idx, tx->stale);
+	spin_unlock(&tx->lock);
+}
+
 /**
  * ice_ptp_release_tx_tracker - Release allocated memory for Tx tracker
  * @pf: Board private structure
@@ -891,6 +922,9 @@ ice_ptp_release_tx_tracker(struct ice_pf *pf, struct ice_ptp_tx *tx)
 	bitmap_free(tx->in_use);
 	tx->in_use = NULL;
 
+	bitmap_free(tx->stale);
+	tx->stale = NULL;
+
 	tx->len = 0;
 }
 
@@ -1009,20 +1043,13 @@ static int ice_ptp_update_cached_phctime(struct ice_pf *pf)
  * @pf: Board specific private structure
  *
  * This function must be called when the cached PHC time is no longer valid,
- * such as after a time adjustment. It discards any outstanding Tx timestamps,
- * and updates the cached PHC time for both the PF and Rx rings. If updating
- * the PHC time cannot be done immediately, a warning message is logged and
- * the work item is scheduled.
- *
- * These steps are required in order to ensure that we do not accidentally
- * report a timestamp extended by the wrong PHC cached copy. Note that we
- * do not directly update the cached timestamp here because it is possible
- * this might produce an error when ICE_CFG_BUSY is set. If this occurred, we
- * would have to try again. During that time window, timestamps might be
- * requested and returned with an invalid extension. Thus, on failure to
- * immediately update the cached PHC time we would need to zero the value
- * anyways. For this reason, we just zero the value immediately and queue the
- * update work item.
+ * such as after a time adjustment. It marks any currently outstanding Tx
+ * timestamps as stale and updates the cached PHC time for both the PF and Rx
+ * rings.
+ *
+ * If updating the PHC time cannot be done immediately, a warning message is
+ * logged and the work item is scheduled immediately to minimize the window
+ * with a wrong cached timestamp.
  */
 static void ice_ptp_reset_cached_phctime(struct ice_pf *pf)
 {
@@ -1046,8 +1073,12 @@ static void ice_ptp_reset_cached_phctime(struct ice_pf *pf)
 					   msecs_to_jiffies(10));
 	}
 
-	/* Flush any outstanding Tx timestamps */
-	ice_ptp_flush_tx_tracker(pf, &pf->ptp.port.tx);
+	/* Mark any outstanding timestamps as stale, since they might have
+	 * been captured in hardware before the time update. This could lead
+	 * to us extending them with the wrong cached value resulting in
+	 * incorrect timestamp values.
+	 */
+	ice_ptp_mark_tx_tracker_stale(&pf->ptp.port.tx);
 }
 
 /**
@@ -2402,6 +2433,7 @@ s8 ice_ptp_request_ts(struct ice_ptp_tx *tx, struct sk_buff *skb)
 		 * requests.
 		 */
 		set_bit(idx, tx->in_use);
+		clear_bit(idx, tx->stale);
 		tx->tstamps[idx].start = jiffies;
 		tx->tstamps[idx].skb = skb_get(skb);
 		skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.h b/drivers/net/ethernet/intel/ice/ice_ptp.h
index 75dcab8e1124..c03849dc7941 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.h
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.h
@@ -113,6 +113,7 @@ struct ice_tx_tstamp {
  * @lock: lock to prevent concurrent access to fields of this struct
  * @tstamps: array of len to store outstanding requests
  * @in_use: bitmap of len to indicate which slots are in use
+ * @stale: bitmap of len to indicate slots which have stale timestamps
  * @block: which memory block (quad or port) the timestamps are captured in
  * @offset: offset into timestamp block to get the real index
  * @len: length of the tstamps and in_use fields.
@@ -126,6 +127,7 @@ struct ice_ptp_tx {
 	spinlock_t lock; /* lock protecting in_use bitmap */
 	struct ice_tx_tstamp *tstamps;
 	unsigned long *in_use;
+	unsigned long *stale;
 	u8 block;
 	u8 offset;
 	u8 len;
-- 
2.35.1

[PATCH net-next 12/14] ice: only check set bits in ice_ptp_flush_tx_tracker

[Tony Nguyen]

From: Jacob Keller <jacob.e.keller@intel.com>

The ice_ptp_flush_tx_tracker function is called to clear all outstanding Tx
timestamp requests when the port is being brought down. This function
iterates over the entire list, but this is unnecessary. We only need to
check the bits which are actually set in the ready bitmap.

Replace this logic with for_each_set_bit, and follow a similar flow as in
ice_ptp_tx_tstamp_cleanup. Note that it is safe to call dev_kfree_skb_any
on a NULL pointer as it will perform a no-op so we do not need to verify
that the skb is actually NULL.

The new implementation also avoids clearing (and thus reading!) the PHY
timestamp unless the index is marked as having a valid timestamp in the
timestamp status bitmap. This ensures that we properly clear the status
registers as appropriate.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Gurucharan G <gurucharanx.g@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/ice/ice_ptp.c | 38 ++++++++++++++++++------
 1 file changed, 29 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.c b/drivers/net/ethernet/intel/ice/ice_ptp.c
index b293c88202cc..a572c3c2bdd4 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.c
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.c
@@ -853,28 +853,48 @@ ice_ptp_alloc_tx_tracker(struct ice_ptp_tx *tx)
  * ice_ptp_flush_tx_tracker - Flush any remaining timestamps from the tracker
  * @pf: Board private structure
  * @tx: the tracker to flush
+ *
+ * Called during teardown when a Tx tracker is being removed.
  */
 static void
 ice_ptp_flush_tx_tracker(struct ice_pf *pf, struct ice_ptp_tx *tx)
 {
+	struct ice_hw *hw = &pf->hw;
+	u64 tstamp_ready;
+	int err;
 	u8 idx;
 
-	for (idx = 0; idx < tx->len; idx++) {
+	err = ice_get_phy_tx_tstamp_ready(hw, tx->block, &tstamp_ready);
+	if (err) {
+		dev_dbg(ice_pf_to_dev(pf), "Failed to get the Tx tstamp ready bitmap for block %u, err %d\n",
+			tx->block, err);
+
+		/* If we fail to read the Tx timestamp ready bitmap just
+		 * skip clearing the PHY timestamps.
+		 */
+		tstamp_ready = 0;
+	}
+
+	for_each_set_bit(idx, tx->in_use, tx->len) {
 		u8 phy_idx = idx + tx->offset;
+		struct sk_buff *skb;
+
+		/* In case this timestamp is ready, we need to clear it. */
+		if (!hw->reset_ongoing && (tstamp_ready & BIT_ULL(phy_idx)))
+			ice_clear_phy_tstamp(hw, tx->block, phy_idx);
 
 		spin_lock(&tx->lock);
-		if (tx->tstamps[idx].skb) {
-			dev_kfree_skb_any(tx->tstamps[idx].skb);
-			tx->tstamps[idx].skb = NULL;
-			pf->ptp.tx_hwtstamp_flushed++;
-		}
+		skb = tx->tstamps[idx].skb;
+		tx->tstamps[idx].skb = NULL;
 		clear_bit(idx, tx->in_use);
 		clear_bit(idx, tx->stale);
 		spin_unlock(&tx->lock);
 
-		/* Clear any potential residual timestamp in the PHY block */
-		if (!pf->hw.reset_ongoing)
-			ice_clear_phy_tstamp(&pf->hw, tx->block, phy_idx);
+		/* Count the number of Tx timestamps flushed */
+		pf->ptp.tx_hwtstamp_flushed++;
+
+		/* Free the SKB after we've cleared the bit */
+		dev_kfree_skb_any(skb);
 	}
 }
 
-- 
2.35.1

[PATCH net-next 13/14] ice: make Tx and Rx vernier offset calibration independent

[Tony Nguyen]

From: Siddaraju DH <siddaraju.dh@intel.com>

The Tx and Rx calibration and timestamp generation blocks are independent.
However, the ice driver waits until both blocks are ready before
configuring either block.

This can result in delay of configuring one block because we have not yet
received a packet in the other block.

There is no reason to wait to finish programming Tx just because we haven't
received a packet. Similarly there is no reason to wait to program Rx just
because we haven't transmitted a packet.

Instead of checking both offset status before programming either block,
refactor the ice_phy_cfg_tx_offset_e822 and ice_phy_cfg_rx_offset_e822
functions so that they perform their own offset status checks.
Additionally, make them also check the offset ready bit to determine if
the offset values have already been programmed.

Call the individual configure functions directly in
ice_ptp_wait_for_offset_valid. The functions will now correctly check
status, and program the offsets if ready. Once the offset is programmed,
the functions will exit quickly after just checking the offset ready
register.

Remove the ice_phy_calc_vernier_e822 in ice_ptp_hw.c, as well as the offset
valid check functions in ice_ptp.c entirely as they are no longer
necessary.

With this change, the Tx and Rx blocks will each be enabled as soon as
possible without waiting for the other block to complete calibration. This
can enable timestamps faster in setups which have a low rate of transmitted
or received packets. In particular, it can stop a situation where one port
never receives traffic, and thus never finishes calibration of the Tx
block, resulting in continuous faults reported by the ptp4l daemon
application.

Signed-off-by: Siddaraju DH <siddaraju.dh@intel.com>
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Gurucharan G <gurucharanx.g@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/ice/ice_ptp.c    | 128 ++++---------------
 drivers/net/ethernet/intel/ice/ice_ptp_hw.c | 133 ++++++++++----------
 drivers/net/ethernet/intel/ice/ice_ptp_hw.h |   3 +-
 3 files changed, 91 insertions(+), 173 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.c b/drivers/net/ethernet/intel/ice/ice_ptp.c
index a572c3c2bdd4..bb3f5f952667 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.c
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.c
@@ -1239,132 +1239,46 @@ static int ice_ptp_check_tx_fifo(struct ice_ptp_port *port)
 }
 
 /**
- * ice_ptp_check_tx_offset_valid - Check if the Tx PHY offset is valid
- * @port: the PTP port to check
- *
- * Checks whether the Tx offset for the PHY associated with this port is
- * valid. Returns 0 if the offset is valid, and a non-zero error code if it is
- * not.
- */
-static int ice_ptp_check_tx_offset_valid(struct ice_ptp_port *port)
-{
-	struct ice_pf *pf = ptp_port_to_pf(port);
-	struct device *dev = ice_pf_to_dev(pf);
-	struct ice_hw *hw = &pf->hw;
-	u32 val;
-	int err;
-
-	err = ice_ptp_check_tx_fifo(port);
-	if (err)
-		return err;
-
-	err = ice_read_phy_reg_e822(hw, port->port_num, P_REG_TX_OV_STATUS,
-				    &val);
-	if (err) {
-		dev_err(dev, "Failed to read TX_OV_STATUS for port %d, err %d\n",
-			port->port_num, err);
-		return -EAGAIN;
-	}
-
-	if (!(val & P_REG_TX_OV_STATUS_OV_M))
-		return -EAGAIN;
-
-	return 0;
-}
-
-/**
- * ice_ptp_check_rx_offset_valid - Check if the Rx PHY offset is valid
- * @port: the PTP port to check
- *
- * Checks whether the Rx offset for the PHY associated with this port is
- * valid. Returns 0 if the offset is valid, and a non-zero error code if it is
- * not.
- */
-static int ice_ptp_check_rx_offset_valid(struct ice_ptp_port *port)
-{
-	struct ice_pf *pf = ptp_port_to_pf(port);
-	struct device *dev = ice_pf_to_dev(pf);
-	struct ice_hw *hw = &pf->hw;
-	int err;
-	u32 val;
-
-	err = ice_read_phy_reg_e822(hw, port->port_num, P_REG_RX_OV_STATUS,
-				    &val);
-	if (err) {
-		dev_err(dev, "Failed to read RX_OV_STATUS for port %d, err %d\n",
-			port->port_num, err);
-		return err;
-	}
-
-	if (!(val & P_REG_RX_OV_STATUS_OV_M))
-		return -EAGAIN;
-
-	return 0;
-}
-
-/**
- * ice_ptp_check_offset_valid - Check port offset valid bit
- * @port: Port for which offset valid bit is checked
- *
- * Returns 0 if both Tx and Rx offset are valid, and -EAGAIN if one of the
- * offset is not ready.
- */
-static int ice_ptp_check_offset_valid(struct ice_ptp_port *port)
-{
-	int tx_err, rx_err;
-
-	/* always check both Tx and Rx offset validity */
-	tx_err = ice_ptp_check_tx_offset_valid(port);
-	rx_err = ice_ptp_check_rx_offset_valid(port);
-
-	if (tx_err || rx_err)
-		return -EAGAIN;
-
-	return 0;
-}
-
-/**
- * ice_ptp_wait_for_offset_valid - Check for valid Tx and Rx offsets
+ * ice_ptp_wait_for_offsets - Check for valid Tx and Rx offsets
  * @work: Pointer to the kthread_work structure for this task
  *
- * Check whether both the Tx and Rx offsets are valid for enabling the vernier
- * calibration.
+ * Check whether hardware has completed measuring the Tx and Rx offset values
+ * used to configure and enable vernier timestamp calibration.
+ *
+ * Once the offset in either direction is measured, configure the associated
+ * registers with the calibrated offset values and enable timestamping. The Tx
+ * and Rx directions are configured independently as soon as their associated
+ * offsets are known.
  *
- * Once we have valid offsets from hardware, update the total Tx and Rx
- * offsets, and exit bypass mode. This enables more precise timestamps using
- * the extra data measured during the vernier calibration process.
+ * This function reschedules itself until both Tx and Rx calibration have
+ * completed.
  */
-static void ice_ptp_wait_for_offset_valid(struct kthread_work *work)
+static void ice_ptp_wait_for_offsets(struct kthread_work *work)
 {
 	struct ice_ptp_port *port;
-	int err;
-	struct device *dev;
 	struct ice_pf *pf;
 	struct ice_hw *hw;
+	int tx_err;
+	int rx_err;
 
 	port = container_of(work, struct ice_ptp_port, ov_work.work);
 	pf = ptp_port_to_pf(port);
 	hw = &pf->hw;
-	dev = ice_pf_to_dev(pf);
 
 	if (ice_is_reset_in_progress(pf->state))
 		return;
 
-	if (ice_ptp_check_offset_valid(port)) {
-		/* Offsets not ready yet, try again later */
+	tx_err = ice_ptp_check_tx_fifo(port);
+	if (!tx_err)
+		tx_err = ice_phy_cfg_tx_offset_e822(hw, port->port_num);
+	rx_err = ice_phy_cfg_rx_offset_e822(hw, port->port_num);
+	if (tx_err || rx_err) {
+		/* Tx and/or Rx offset not yet configured, try again later */
 		kthread_queue_delayed_work(pf->ptp.kworker,
 					   &port->ov_work,
 					   msecs_to_jiffies(100));
 		return;
 	}
-
-	/* Offsets are valid, so Vernier mode calculations are started */
-	err = ice_phy_calc_vernier_e822(hw, port->port_num);
-	if (err) {
-		dev_warn(dev, "Failed to prepare Vernier mode for PHY port %u, err %d\n",
-			 port->port_num, err);
-		return;
-	}
 }
 
 /**
@@ -2569,7 +2483,7 @@ void ice_ptp_reset(struct ice_pf *pf)
 		err = ice_ptp_init_tx_e810(pf, &ptp->port.tx);
 	} else {
 		kthread_init_delayed_work(&ptp->port.ov_work,
-					  ice_ptp_wait_for_offset_valid);
+					  ice_ptp_wait_for_offsets);
 		err = ice_ptp_init_tx_e822(pf, &ptp->port.tx,
 					   ptp->port.port_num);
 	}
@@ -2732,7 +2646,7 @@ static int ice_ptp_init_port(struct ice_pf *pf, struct ice_ptp_port *ptp_port)
 		return ice_ptp_init_tx_e810(pf, &ptp_port->tx);
 
 	kthread_init_delayed_work(&ptp_port->ov_work,
-				  ice_ptp_wait_for_offset_valid);
+				  ice_ptp_wait_for_offsets);
 	return ice_ptp_init_tx_e822(pf, &ptp_port->tx, ptp_port->port_num);
 }
 
diff --git a/drivers/net/ethernet/intel/ice/ice_ptp_hw.c b/drivers/net/ethernet/intel/ice/ice_ptp_hw.c
index d5d51427580a..a38614d21ea8 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp_hw.c
+++ b/drivers/net/ethernet/intel/ice/ice_ptp_hw.c
@@ -1741,21 +1741,48 @@ ice_calc_fixed_tx_offset_e822(struct ice_hw *hw, enum ice_ptp_link_spd link_spd)
  * adjust Tx timestamps by. This is calculated by combining some known static
  * latency along with the Vernier offset computations done by hardware.
  *
- * This function must be called only after the offset registers are valid,
- * i.e. after the Vernier calibration wait has passed, to ensure that the PHY
- * has measured the offset.
+ * This function will not return successfully until the Tx offset calculations
+ * have been completed, which requires waiting until at least one packet has
+ * been transmitted by the device. It is safe to call this function
+ * periodically until calibration succeeds, as it will only program the offset
+ * once.
  *
  * To avoid overflow, when calculating the offset based on the known static
  * latency values, we use measurements in 1/100th of a nanosecond, and divide
  * the TUs per second up front. This avoids overflow while allowing
  * calculation of the adjustment using integer arithmetic.
+ *
+ * Returns zero on success, -EBUSY if the hardware vernier offset
+ * calibration has not completed, or another error code on failure.
  */
-static int ice_phy_cfg_tx_offset_e822(struct ice_hw *hw, u8 port)
+int ice_phy_cfg_tx_offset_e822(struct ice_hw *hw, u8 port)
 {
 	enum ice_ptp_link_spd link_spd;
 	enum ice_ptp_fec_mode fec_mode;
 	u64 total_offset, val;
 	int err;
+	u32 reg;
+
+	/* Nothing to do if we've already programmed the offset */
+	err = ice_read_phy_reg_e822(hw, port, P_REG_TX_OR, &reg);
+	if (err) {
+		ice_debug(hw, ICE_DBG_PTP, "Failed to read TX_OR for port %u, err %d\n",
+			  port, err);
+		return err;
+	}
+
+	if (reg)
+		return 0;
+
+	err = ice_read_phy_reg_e822(hw, port, P_REG_TX_OV_STATUS, &reg);
+	if (err) {
+		ice_debug(hw, ICE_DBG_PTP, "Failed to read TX_OV_STATUS for port %u, err %d\n",
+			  port, err);
+		return err;
+	}
+
+	if (!(reg & P_REG_TX_OV_STATUS_OV_M))
+		return -EBUSY;
 
 	err = ice_phy_get_speed_and_fec_e822(hw, port, &link_spd, &fec_mode);
 	if (err)
@@ -1809,6 +1836,9 @@ static int ice_phy_cfg_tx_offset_e822(struct ice_hw *hw, u8 port)
 	if (err)
 		return err;
 
+	dev_info(ice_hw_to_dev(hw), "Port=%d Tx vernier offset calibration complete\n",
+		 port);
+
 	return 0;
 }
 
@@ -2011,6 +2041,11 @@ ice_calc_fixed_rx_offset_e822(struct ice_hw *hw, enum ice_ptp_link_spd link_spd)
  * measurements taken in hardware with some data about known fixed delay as
  * well as adjusting for multi-lane alignment delay.
  *
+ * This function will not return successfully until the Rx offset calculations
+ * have been completed, which requires waiting until at least one packet has
+ * been received by the device. It is safe to call this function periodically
+ * until calibration succeeds, as it will only program the offset once.
+ *
  * This function must be called only after the offset registers are valid,
  * i.e. after the Vernier calibration wait has passed, to ensure that the PHY
  * has measured the offset.
@@ -2019,13 +2054,38 @@ ice_calc_fixed_rx_offset_e822(struct ice_hw *hw, enum ice_ptp_link_spd link_spd)
  * latency values, we use measurements in 1/100th of a nanosecond, and divide
  * the TUs per second up front. This avoids overflow while allowing
  * calculation of the adjustment using integer arithmetic.
+ *
+ * Returns zero on success, -EBUSY if the hardware vernier offset
+ * calibration has not completed, or another error code on failure.
  */
-static int ice_phy_cfg_rx_offset_e822(struct ice_hw *hw, u8 port)
+int ice_phy_cfg_rx_offset_e822(struct ice_hw *hw, u8 port)
 {
 	enum ice_ptp_link_spd link_spd;
 	enum ice_ptp_fec_mode fec_mode;
 	u64 total_offset, pmd, val;
 	int err;
+	u32 reg;
+
+	/* Nothing to do if we've already programmed the offset */
+	err = ice_read_phy_reg_e822(hw, port, P_REG_RX_OR, &reg);
+	if (err) {
+		ice_debug(hw, ICE_DBG_PTP, "Failed to read RX_OR for port %u, err %d\n",
+			  port, err);
+		return err;
+	}
+
+	if (reg)
+		return 0;
+
+	err = ice_read_phy_reg_e822(hw, port, P_REG_RX_OV_STATUS, &reg);
+	if (err) {
+		ice_debug(hw, ICE_DBG_PTP, "Failed to read RX_OV_STATUS for port %u, err %d\n",
+			  port, err);
+		return err;
+	}
+
+	if (!(reg & P_REG_RX_OV_STATUS_OV_M))
+		return -EBUSY;
 
 	err = ice_phy_get_speed_and_fec_e822(hw, port, &link_spd, &fec_mode);
 	if (err)
@@ -2086,6 +2146,9 @@ static int ice_phy_cfg_rx_offset_e822(struct ice_hw *hw, u8 port)
 	if (err)
 		return err;
 
+	dev_info(ice_hw_to_dev(hw), "Port=%d Rx vernier offset calibration complete\n",
+		 port);
+
 	return 0;
 }
 
@@ -2357,66 +2420,6 @@ int ice_start_phy_timer_e822(struct ice_hw *hw, u8 port)
 	return 0;
 }
 
-/**
- * ice_phy_calc_vernier_e822 - Perform vernier calculations
- * @hw: pointer to the HW struct
- * @port: the PHY port to configure
- *
- * Perform vernier calculations for the Tx and Rx offset. This will enable
- * hardware to include the more precise offset calibrations,
- * increasing precision of the generated timestamps.
- *
- * This cannot be done until hardware has measured the offsets, which requires
- * waiting until at least one packet has been sent and received by the device.
- */
-int ice_phy_calc_vernier_e822(struct ice_hw *hw, u8 port)
-{
-	int err;
-	u32 val;
-
-	err = ice_read_phy_reg_e822(hw, port, P_REG_TX_OV_STATUS, &val);
-	if (err) {
-		ice_debug(hw, ICE_DBG_PTP, "Failed to read TX_OV_STATUS for port %u, err %d\n",
-			  port, err);
-		return err;
-	}
-
-	if (!(val & P_REG_TX_OV_STATUS_OV_M)) {
-		ice_debug(hw, ICE_DBG_PTP, "Tx offset is not yet valid for port %u\n",
-			  port);
-		return -EBUSY;
-	}
-
-	err = ice_read_phy_reg_e822(hw, port, P_REG_RX_OV_STATUS, &val);
-	if (err) {
-		ice_debug(hw, ICE_DBG_PTP, "Failed to read RX_OV_STATUS for port %u, err %d\n",
-			  port, err);
-		return err;
-	}
-
-	if (!(val & P_REG_TX_OV_STATUS_OV_M)) {
-		ice_debug(hw, ICE_DBG_PTP, "Rx offset is not yet valid for port %u\n",
-			  port);
-		return -EBUSY;
-	}
-
-	err = ice_phy_cfg_tx_offset_e822(hw, port);
-	if (err) {
-		ice_debug(hw, ICE_DBG_PTP, "Failed to program total Tx offset for port %u, err %d\n",
-			  port, err);
-		return err;
-	}
-
-	err = ice_phy_cfg_rx_offset_e822(hw, port);
-	if (err) {
-		ice_debug(hw, ICE_DBG_PTP, "Failed to program total Rx offset for port %u, err %d\n",
-			  port, err);
-		return err;
-	}
-
-	return 0;
-}
-
 /**
  * ice_get_phy_tx_tstamp_ready_e822 - Read Tx memory status register
  * @hw: pointer to the HW struct
diff --git a/drivers/net/ethernet/intel/ice/ice_ptp_hw.h b/drivers/net/ethernet/intel/ice/ice_ptp_hw.h
index b781dadf5a39..3b68cb91bd81 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp_hw.h
+++ b/drivers/net/ethernet/intel/ice/ice_ptp_hw.h
@@ -188,7 +188,8 @@ static inline u64 ice_e822_pps_delay(enum ice_time_ref_freq time_ref)
 /* E822 Vernier calibration functions */
 int ice_stop_phy_timer_e822(struct ice_hw *hw, u8 port, bool soft_reset);
 int ice_start_phy_timer_e822(struct ice_hw *hw, u8 port);
-int ice_phy_calc_vernier_e822(struct ice_hw *hw, u8 port);
+int ice_phy_cfg_tx_offset_e822(struct ice_hw *hw, u8 port);
+int ice_phy_cfg_rx_offset_e822(struct ice_hw *hw, u8 port);
 
 /* E810 family functions */
 int ice_ptp_init_phy_e810(struct ice_hw *hw);
-- 
2.35.1

[PATCH net-next 14/14] ice: reschedule ice_ptp_wait_for_offset_valid during reset

[Tony Nguyen]

From: Jacob Keller <jacob.e.keller@intel.com>

If the ice_ptp_wait_for_offest_valid function is scheduled to run while the
driver is resetting, it will exit without completing calibration. The work
function gets scheduled by ice_ptp_port_phy_restart which will be called as
part of the reset recovery process.

It is possible for the first execution to occur before the driver has
completely cleared its resetting flags. Ensure calibration completes by
rescheduling the task until reset is fully completed.

Reported-by: Siddaraju DH <siddaraju.dh@intel.com>
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Gurucharan G <gurucharanx.g@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/ice/ice_ptp.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_ptp.c b/drivers/net/ethernet/intel/ice/ice_ptp.c
index bb3f5f952667..4b43d6f6279a 100644
--- a/drivers/net/ethernet/intel/ice/ice_ptp.c
+++ b/drivers/net/ethernet/intel/ice/ice_ptp.c
@@ -1265,8 +1265,13 @@ static void ice_ptp_wait_for_offsets(struct kthread_work *work)
 	pf = ptp_port_to_pf(port);
 	hw = &pf->hw;
 
-	if (ice_is_reset_in_progress(pf->state))
+	if (ice_is_reset_in_progress(pf->state)) {
+		/* wait for device driver to complete reset */
+		kthread_queue_delayed_work(pf->ptp.kworker,
+					   &port->ov_work,
+					   msecs_to_jiffies(100));
 		return;
+	}
 
 	tx_err = ice_ptp_check_tx_fifo(port);
 	if (!tx_err)
-- 
2.35.1