[Intel-wired-lan] [PATCH net v1] i40e: Fix for failed to init adminq while VF reset

[Mateusz Palczewski <mateusz.palczewski@intel.com>]

Fix for failed to init adminq: -53 while VF is resetting via MAC
address changing procedure.
Added sync module to avoid reading deadbeef value in reinit adminq
during software reset.
Without this patch it is possible to trigger VF reset procedure
during reinit adminq. This resulted in an incorrect reading of
value from the AQP registers and generated the -53 error.

Fixes: 9dc2e417383815"(i40e: split some code in i40e_reset_vf into helpers")
Signed-off-by: Grzegorz Szczurek <grzegorzx.szczurek@intel.com>
Signed-off-by: Mateusz Palczewski <mateusz.palczewski@intel.com>
Reviewed-by: Jaroslaw Gawin <jaroslawx.gawin@intel.com>
Reviewed-by: Slawomir Laba <slawomirx.laba@intel.com>
Reviewed-by: Karen Sornek <karen.sornek@intel.com>
Reviewed-by: Grzegorz Siwik <grzegorz.siwik@intel.com>
Reviewed-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
---
 .../ethernet/intel/i40e/i40e_virtchnl_pf.c    | 46 ++++++++++++++++++-
 .../ethernet/intel/i40e/i40e_virtchnl_pf.h    |  2 +
 2 files changed, 46 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
index 21ee564..afccbbc 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c
@@ -1297,6 +1297,32 @@ static i40e_status i40e_config_vf_promiscuous_mode(struct i40e_vf *vf,
 	return aq_ret;
 }
 
+/**
+* i40e_sync_vfr_reset
+* @hw: pointer to hw struct
+* @vf_id: VF identifier
+*
+* Before trigger hardware reset, we need to know if no other process has
+* reserved the hardware for any reset operations. This check is done by
+* examining the status of the ADMINQ bit in VF interrupt register.
+**/
+static int i40e_sync_vfr_reset(struct i40e_hw *hw, int vf_id)
+{
+	u32 reg;
+	int i;
+
+	for (i = 0; i < I40E_VFR_WAIT_COUNT; i++) {
+		reg = rd32(hw, I40E_VFINT_ICR0_ENA(vf_id)) &
+			   I40E_VFINT_ICR0_ADMINQ_MASK;
+		if (reg)
+			return 0;
+
+		usleep_range(10, 200);
+	}
+
+	return -EAGAIN;
+}
+
 /**
  * i40e_trigger_vf_reset
  * @vf: pointer to the VF structure
@@ -1311,9 +1337,11 @@ static void i40e_trigger_vf_reset(struct i40e_vf *vf, bool flr)
 	struct i40e_pf *pf = vf->pf;
 	struct i40e_hw *hw = &pf->hw;
 	u32 reg, reg_idx, bit_idx;
+	bool vf_active;
+	u32 radq;
 
 	/* warn the VF */
-	clear_bit(I40E_VF_STATE_ACTIVE, &vf->vf_states);
+	vf_active = test_and_clear_bit(I40E_VF_STATE_ACTIVE, &vf->vf_states);
 
 	/* Disable VF's configuration API during reset. The flag is re-enabled
 	 * in i40e_alloc_vf_res(), when it's safe again to access VF's VSI.
@@ -1327,7 +1355,19 @@ static void i40e_trigger_vf_reset(struct i40e_vf *vf, bool flr)
 	 * just need to clean up, so don't hit the VFRTRIG register.
 	 */
 	if (!flr) {
-		/* reset VF using VPGEN_VFRTRIG reg */
+		/* Sync VFR reset before trigger next one */
+		radq = rd32(hw, I40E_VFINT_ICR0_ENA(vf->vf_id)) &
+			    I40E_VFINT_ICR0_ADMINQ_MASK;
+		if (vf_active && !radq)
+			/* waiting for finish reset by virtual driver */
+			if (i40e_sync_vfr_reset(hw, vf->vf_id))
+				dev_info(&pf->pdev->dev,
+					 "Reset VF %d never finished\n",
+					 vf->vf_id);
+
+		/* Reset VF using VPGEN_VFRTRIG reg. It is also setting
+		 * in progress state in rstat1 register.
+		 */
 		reg = rd32(hw, I40E_VPGEN_VFRTRIG(vf->vf_id));
 		reg |= I40E_VPGEN_VFRTRIG_VFSWR_MASK;
 		wr32(hw, I40E_VPGEN_VFRTRIG(vf->vf_id), reg);
@@ -1457,6 +1497,7 @@ bool i40e_reset_vf(struct i40e_vf *vf, bool flr)
 	i40e_cleanup_reset_vf(vf);
 
 	i40e_flush(hw);
+	usleep_range(20000, 40000);
 	clear_bit(__I40E_VF_DISABLE, pf->state);
 
 	return true;
@@ -1561,6 +1602,7 @@ bool i40e_reset_all_vfs(struct i40e_pf *pf, bool flr)
 		i40e_cleanup_reset_vf(&pf->vf[v]);
 
 	i40e_flush(hw);
+	usleep_range(20000, 40000);
 	clear_bit(__I40E_VF_DISABLE, pf->state);
 
 	return true;
diff --git a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.h b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.h
index 5491215..fb4f5db 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.h
+++ b/drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.h
@@ -18,6 +18,8 @@
 
 #define I40E_MAX_VF_PROMISC_FLAGS	3
 
+#define I40E_VFR_WAIT_COUNT		100
+
 /* Various queue ctrls */
 enum i40e_queue_ctrl {
 	I40E_QUEUE_CTRL_UNKNOWN = 0,
-- 
2.17.1

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