i40e: ATR policy change to flush the table to clean stale ATR rules

Instead of disabling ATR when we get a programming error, we now
will wait it out to see if some room gets created by ATR rule deletion.
If we still have too many errors and ATR filter count did not change
much, its time to flush and replay. We no more auto-disable ATR when
we have errors in programming.
The disabling of ATR when we get programming error was buggy and
was still adding new rules and causing continuous errors. With this
policy change we flush instead when we see too many errors.
ATR is still disabled if we add a SB rule for TCP/IPv4 flow type,
more logic is added to re-enable it once all SB TCP/IPv4 rules are gone.

Change-ID: I77edcbeab9500c72a7e0bd7b5c5b113ced133a9c
Signed-off-by: Anjali Singhai Jain <anjali.singhai@intel.com>
Tested-by: Jim Young <jamesx.m.young@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 86 insertions, 10 deletions

diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index eddec6ba095..cab9c9e3e69 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -4483,8 +4483,16 @@ static int i40e_up_complete(struct i40e_vsi *vsi)
 	}
 
 	/* replay FDIR SB filters */
-	if (vsi->type == I40E_VSI_FDIR)
+	if (vsi->type == I40E_VSI_FDIR) {
+		/* reset fd counters */
+		pf->fd_add_err = pf->fd_atr_cnt = 0;
+		if (pf->fd_tcp_rule > 0) {
+			pf->flags &= ~I40E_FLAG_FD_ATR_ENABLED;
+			dev_info(&pf->pdev->dev, "Forcing ATR off, sideband rules for TCP/IPv4 exist\n");
+			pf->fd_tcp_rule = 0;
+		}
 		i40e_fdir_filter_restore(vsi);
+	}
 	i40e_service_event_schedule(pf);
 
 	return 0;
@@ -5125,6 +5133,7 @@ int i40e_get_current_fd_count(struct i40e_pf *pf)
 		      I40E_PFQF_FDSTAT_BEST_CNT_SHIFT);
 	return fcnt_prog;
 }
+
 /**
  * i40e_fdir_check_and_reenable - Function to reenabe FD ATR or SB if disabled
  * @pf: board private structure
@@ -5133,15 +5142,17 @@ void i40e_fdir_check_and_reenable(struct i40e_pf *pf)
 {
 	u32 fcnt_prog, fcnt_avail;
 
+	if (test_bit(__I40E_FD_FLUSH_REQUESTED, &pf->state))
+		return;
+
 	/* Check if, FD SB or ATR was auto disabled and if there is enough room
 	 * to re-enable
 	 */
-	if ((pf->flags & I40E_FLAG_FD_ATR_ENABLED) &&
-	    (pf->flags & I40E_FLAG_FD_SB_ENABLED))
-		return;
 	fcnt_prog = i40e_get_cur_guaranteed_fd_count(pf);
 	fcnt_avail = pf->fdir_pf_filter_count;
-	if (fcnt_prog < (fcnt_avail - I40E_FDIR_BUFFER_HEAD_ROOM)) {
+	if ((fcnt_prog < (fcnt_avail - I40E_FDIR_BUFFER_HEAD_ROOM)) ||
+	    (pf->fd_add_err == 0) ||
+	    (i40e_get_current_atr_cnt(pf) < pf->fd_atr_cnt)) {
 		if ((pf->flags & I40E_FLAG_FD_SB_ENABLED) &&
 		    (pf->auto_disable_flags & I40E_FLAG_FD_SB_ENABLED)) {
 			pf->auto_disable_flags &= ~I40E_FLAG_FD_SB_ENABLED;
@@ -5158,23 +5169,83 @@ void i40e_fdir_check_and_reenable(struct i40e_pf *pf)
 	}
 }
 
+#define I40E_MIN_FD_FLUSH_INTERVAL 10
+/**
+ * i40e_fdir_flush_and_replay - Function to flush all FD filters and replay SB
+ * @pf: board private structure
+ **/
+static void i40e_fdir_flush_and_replay(struct i40e_pf *pf)
+{
+	int flush_wait_retry = 50;
+	int reg;
+
+	if (time_after(jiffies, pf->fd_flush_timestamp +
+				(I40E_MIN_FD_FLUSH_INTERVAL * HZ))) {
+		set_bit(__I40E_FD_FLUSH_REQUESTED, &pf->state);
+		pf->fd_flush_timestamp = jiffies;
+		pf->auto_disable_flags |= I40E_FLAG_FD_SB_ENABLED;
+		pf->flags &= ~I40E_FLAG_FD_ATR_ENABLED;
+		/* flush all filters */
+		wr32(&pf->hw, I40E_PFQF_CTL_1,
+		     I40E_PFQF_CTL_1_CLEARFDTABLE_MASK);
+		i40e_flush(&pf->hw);
+		pf->fd_add_err = 0;
+		do {
+			/* Check FD flush status every 5-6msec */
+			usleep_range(5000, 6000);
+			reg = rd32(&pf->hw, I40E_PFQF_CTL_1);
+			if (!(reg & I40E_PFQF_CTL_1_CLEARFDTABLE_MASK))
+				break;
+		} while (flush_wait_retry--);
+		if (reg & I40E_PFQF_CTL_1_CLEARFDTABLE_MASK) {
+			dev_warn(&pf->pdev->dev, "FD table did not flush, needs more time\n");
+		} else {
+			/* replay sideband filters */
+			i40e_fdir_filter_restore(pf->vsi[pf->lan_vsi]);
+
+			pf->flags |= I40E_FLAG_FD_ATR_ENABLED;
+			pf->auto_disable_flags &= ~I40E_FLAG_FD_ATR_ENABLED;
+			pf->auto_disable_flags &= ~I40E_FLAG_FD_SB_ENABLED;
+			clear_bit(__I40E_FD_FLUSH_REQUESTED, &pf->state);
+			dev_info(&pf->pdev->dev, "FD Filter table flushed and FD-SB replayed.\n");
+		}
+	}
+}
+
+/**
+ * i40e_get_current_atr_count - Get the count of total FD ATR filters programmed
+ * @pf: board private structure
+ **/
+int i40e_get_current_atr_cnt(struct i40e_pf *pf)
+{
+	return i40e_get_current_fd_count(pf) - pf->fdir_pf_active_filters;
+}
+
+/* We can see up to 256 filter programming desc in transit if the filters are
+ * being applied really fast; before we see the first
+ * filter miss error on Rx queue 0. Accumulating enough error messages before
+ * reacting will make sure we don't cause flush too often.
+ */
+#define I40E_MAX_FD_PROGRAM_ERROR 256
+
 /**
  * i40e_fdir_reinit_subtask - Worker thread to reinit FDIR filter table
  * @pf: board private structure
  **/
 static void i40e_fdir_reinit_subtask(struct i40e_pf *pf)
 {
-	if (!(pf->flags & I40E_FLAG_FDIR_REQUIRES_REINIT))
-		return;
 
 	/* if interface is down do nothing */
 	if (test_bit(__I40E_DOWN, &pf->state))
 		return;
+
+	if ((pf->fd_add_err >= I40E_MAX_FD_PROGRAM_ERROR) &&
+	    (i40e_get_current_atr_cnt(pf) >= pf->fd_atr_cnt) &&
+	    (i40e_get_current_atr_cnt(pf) > pf->fdir_pf_filter_count))
+		i40e_fdir_flush_and_replay(pf);
+
 	i40e_fdir_check_and_reenable(pf);
 
-	if ((pf->flags & I40E_FLAG_FD_ATR_ENABLED) &&
-	    (pf->flags & I40E_FLAG_FD_SB_ENABLED))
-		pf->flags &= ~I40E_FLAG_FDIR_REQUIRES_REINIT;
 }
 
 /**
@@ -7086,6 +7157,11 @@ bool i40e_set_ntuple(struct i40e_pf *pf, netdev_features_t features)
 		}
 		pf->flags &= ~I40E_FLAG_FD_SB_ENABLED;
 		pf->auto_disable_flags &= ~I40E_FLAG_FD_SB_ENABLED;
+		/* reset fd counters */
+		pf->fd_add_err = pf->fd_atr_cnt = pf->fd_tcp_rule = 0;
+		pf->fdir_pf_active_filters = 0;
+		pf->flags |= I40E_FLAG_FD_ATR_ENABLED;
+		dev_info(&pf->pdev->dev, "ATR re-enabled.\n");
 		/* if ATR was auto disabled it can be re-enabled. */
 		if ((pf->flags & I40E_FLAG_FD_ATR_ENABLED) &&
 		    (pf->auto_disable_flags & I40E_FLAG_FD_ATR_ENABLED))