ice: Auxbus devices & driver for E822 TS

There is a problem in HW in E822-based devices leading to race
condition.
It might happen that, in order:
- PF0 (which owns the PHC) requests few timestamps,
- PF1 requests a timestamp,
- interrupt is being triggered and both PF0 and PF1 threads are woken
up,
- PF0 got one timestamp, still waiting for others so not going to sleep,
- PF1 gets it's timestamp, process it and go to sleep,
- PF1 requests a timestamp again,
- just before PF0 goes to sleep timestamp of PF1 appear,
- PF0 finishes all it's timestamps and go to sleep (PF1 also sleeping).
That leaves PF1 timestamp memory not read, which lead to blocking the
next interrupt from arriving.

Fix it by adding auxiliary devices and only one driver to handle all the
timestamps for all PF's by PHC owner. In the past each PF requested it's
own timestamps and process it from the start till the end which causes
problem described above. Currently each PF requests the timestamps as
before, but the actual reading of the completed timestamps is being done
by the PTP auxiliary driver, which is registered by the PF which owns PHC.

Additionally, the newly introduced auxiliary driver/devices for PTP clock
owner will be used for other features in all products (including E810).
Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Signed-off-by: Karol Kolacinski <karol.kolacinski@intel.com>
Signed-off-by: Michal Michalik <michal.michalik@intel.com>
Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

drivers/net/ethernet/intel/ice/ice.h

@@ -673,6 +673,18 @@ static inline bool ice_vector_ch_enabled(struct ice_q_vector *qv)
 	return !!qv->ch; /* Enable it to run with TC */
 }
 
+/**
+ * ice_ptp_pf_handles_tx_interrupt - Check if PF handles Tx interrupt
+ * @pf: Board private structure
+ *
+ * Return true if this PF should respond to the Tx timestamp interrupt
+ * indication in the miscellaneous OICR interrupt handler.
+ */
+static inline bool ice_ptp_pf_handles_tx_interrupt(struct ice_pf *pf)
+{
+	return pf->ptp.tx_interrupt_mode != ICE_PTP_TX_INTERRUPT_NONE;
+}
+
 /**
  * ice_irq_dynamic_ena - Enable default interrupt generation settings
  * @hw: pointer to HW struct

drivers/net/ethernet/intel/ice/ice_hw_autogen.h

@@ -231,6 +231,7 @@
 #define PFINT_SB_CTL				0x0016B600
 #define PFINT_SB_CTL_MSIX_INDX_M		ICE_M(0x7FF, 0)
 #define PFINT_SB_CTL_CAUSE_ENA_M		BIT(30)
+#define PFINT_TSYN_MSK				0x0016C980
 #define QINT_RQCTL(_QRX)			(0x00150000 + ((_QRX) * 4))
 #define QINT_RQCTL_MSIX_INDX_S			0
 #define QINT_RQCTL_MSIX_INDX_M			ICE_M(0x7FF, 0)

drivers/net/ethernet/intel/ice/ice_main.c

@@ -3149,7 +3149,7 @@ static irqreturn_t ice_misc_intr(int __always_unused irq, void *data)
 
 	if (oicr & PFINT_OICR_TSYN_TX_M) {
 		ena_mask &= ~PFINT_OICR_TSYN_TX_M;
-		if (!hw->reset_ongoing)
+		if (!hw->reset_ongoing && ice_ptp_pf_handles_tx_interrupt(pf))
 			set_bit(ICE_MISC_THREAD_TX_TSTAMP, pf->misc_thread);
 	}
 
@@ -7375,8 +7375,13 @@ static void ice_rebuild(struct ice_pf *pf, enum ice_reset_req reset_type)
 	}
 
 	/* configure PTP timestamping after VSI rebuild */
-	if (test_bit(ICE_FLAG_PTP_SUPPORTED, pf->flags))
-		ice_ptp_cfg_timestamp(pf, false);
+	if (test_bit(ICE_FLAG_PTP_SUPPORTED, pf->flags)) {
+		if (pf->ptp.tx_interrupt_mode == ICE_PTP_TX_INTERRUPT_SELF)
+			ice_ptp_cfg_timestamp(pf, false);
+		else if (pf->ptp.tx_interrupt_mode == ICE_PTP_TX_INTERRUPT_ALL)
+			/* for E82x PHC owner always need to have interrupts */
+			ice_ptp_cfg_timestamp(pf, true);
+	}
 
 	err = ice_vsi_rebuild_by_type(pf, ICE_VSI_SWITCHDEV_CTRL);
 	if (err) {

drivers/net/ethernet/intel/ice/ice_ptp.h

@@ -157,7 +157,9 @@ struct ice_ptp_tx {
  * ready for PTP functionality. It is used to track the port initialization
  * and determine when the port's PHY offset is valid.
  *
+ * @list_member: list member structure of auxiliary device
  * @tx: Tx timestamp tracking for this port
+ * @aux_dev: auxiliary device associated with this port
  * @ov_work: delayed work task for tracking when PHY offset is valid
  * @ps_lock: mutex used to protect the overall PTP PHY start procedure
  * @link_up: indicates whether the link is up
@@ -165,7 +167,9 @@ struct ice_ptp_tx {
  * @port_num: the port number this structure represents
  */
 struct ice_ptp_port {
+	struct list_head list_member;
 	struct ice_ptp_tx tx;
+	struct auxiliary_device aux_dev;
 	struct kthread_delayed_work ov_work;
 	struct mutex ps_lock; /* protects overall PTP PHY start procedure */
 	bool link_up;
@@ -173,11 +177,35 @@ struct ice_ptp_port {
 	u8 port_num;
 };
 
+enum ice_ptp_tx_interrupt {
+	ICE_PTP_TX_INTERRUPT_NONE = 0,
+	ICE_PTP_TX_INTERRUPT_SELF,
+	ICE_PTP_TX_INTERRUPT_ALL,
+};
+
+/**
+ * struct ice_ptp_port_owner - data used to handle the PTP clock owner info
+ *
+ * This structure contains data necessary for the PTP clock owner to correctly
+ * handle the timestamping feature for all attached ports.
+ *
+ * @aux_driver: the structure carring the auxiliary driver information
+ * @ports: list of porst handled by this port owner
+ * @lock: protect access to ports list
+ */
+struct ice_ptp_port_owner {
+	struct auxiliary_driver aux_driver;
+	struct list_head ports;
+	struct mutex lock;
+};
+
 #define GLTSYN_TGT_H_IDX_MAX		4
 
 /**
  * struct ice_ptp - data used for integrating with CONFIG_PTP_1588_CLOCK
+ * @tx_interrupt_mode: the TX interrupt mode for the PTP clock
  * @port: data for the PHY port initialization procedure
+ * @ports_owner: data for the auxiliary driver owner
  * @work: delayed work function for periodic tasks
  * @cached_phc_time: a cached copy of the PHC time for timestamp extension
  * @cached_phc_jiffies: jiffies when cached_phc_time was last updated
@@ -197,7 +225,9 @@ struct ice_ptp_port {
  * @late_cached_phc_updates: number of times cached PHC update is late
  */
 struct ice_ptp {
+	enum ice_ptp_tx_interrupt tx_interrupt_mode;
 	struct ice_ptp_port port;
+	struct ice_ptp_port_owner ports_owner;
 	struct kthread_delayed_work work;
 	u64 cached_phc_time;
 	unsigned long cached_phc_jiffies;