ice: Schedule service task in IRQ top half

Schedule service task and EXTTS in the top half to avoid bottom half
scheduling if possible, which significantly reduces timestamping delay.
Co-developed-by: Michal Michalik <michal.michalik@intel.com>
Signed-off-by: Michal Michalik <michal.michalik@intel.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Signed-off-by: Karol Kolacinski <karol.kolacinski@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

@@ -518,7 +518,6 @@ enum ice_pf_flags {
 };
 
 enum ice_misc_thread_tasks {
-	ICE_MISC_THREAD_EXTTS_EVENT,
 	ICE_MISC_THREAD_TX_TSTAMP,
 	ICE_MISC_THREAD_NBITS		/* must be last */
 };

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

@@ -3084,6 +3084,7 @@ static void ice_ena_misc_vector(struct ice_pf *pf)
 static irqreturn_t ice_misc_intr(int __always_unused irq, void *data)
 {
 	struct ice_pf *pf = (struct ice_pf *)data;
+	irqreturn_t ret = IRQ_HANDLED;
 	struct ice_hw *hw = &pf->hw;
 	struct device *dev;
 	u32 oicr, ena_mask;
@@ -3165,8 +3166,10 @@ 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 (ice_ptp_pf_handles_tx_interrupt(pf))
+		if (ice_ptp_pf_handles_tx_interrupt(pf)) {
 			set_bit(ICE_MISC_THREAD_TX_TSTAMP, pf->misc_thread);
+			ret = IRQ_WAKE_THREAD;
+		}
 	}
 
 	if (oicr & PFINT_OICR_TSYN_EVNT_M) {
@@ -3182,7 +3185,7 @@ static irqreturn_t ice_misc_intr(int __always_unused irq, void *data)
 					       GLTSYN_STAT_EVENT1_M |
 					       GLTSYN_STAT_EVENT2_M);
 
-			set_bit(ICE_MISC_THREAD_EXTTS_EVENT, pf->misc_thread);
+			ice_ptp_extts_event(pf);
 		}
 	}
 
@@ -3205,8 +3208,11 @@ static irqreturn_t ice_misc_intr(int __always_unused irq, void *data)
 			set_bit(ICE_PFR_REQ, pf->state);
 		}
 	}
+	ice_service_task_schedule(pf);
+	if (ret == IRQ_HANDLED)
+		ice_irq_dynamic_ena(hw, NULL, NULL);
 
-	return IRQ_WAKE_THREAD;
+	return ret;
 }
 
 /**
@@ -3222,12 +3228,7 @@ static irqreturn_t ice_misc_intr_thread_fn(int __always_unused irq, void *data)
 	hw = &pf->hw;
 
 	if (ice_is_reset_in_progress(pf->state))
-		return IRQ_HANDLED;
-
-	ice_service_task_schedule(pf);
-
-	if (test_and_clear_bit(ICE_MISC_THREAD_EXTTS_EVENT, pf->misc_thread))
-		ice_ptp_extts_event(pf);
+		goto skip_irq;
 
 	if (test_and_clear_bit(ICE_MISC_THREAD_TX_TSTAMP, pf->misc_thread)) {
 		/* Process outstanding Tx timestamps. If there is more work,
@@ -3239,6 +3240,7 @@ static irqreturn_t ice_misc_intr_thread_fn(int __always_unused irq, void *data)
 		}
 	}
 
+skip_irq:
 	ice_irq_dynamic_ena(hw, NULL, NULL);
 
 	return IRQ_HANDLED;