[net-next 03/14] i40e: clear all queues and interrupts

[Jeff Kirsher <jeffrey.t.kirsher@intel.com>]

From: Shannon Nelson <shannon.nelson@intel.com>

Per a recent HW designer comment, this code is for ripping through the
queues and interrupts to fully disable them on driver init, specifically
to help clean up after a PXE or other early boot activity.

Change-ID: I32ed452021a1c2b06dace1969976f882a37b9741
Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
---
 drivers/net/ethernet/intel/i40e/i40e_common.c    | 93 ++++++++++++++++++++++++
 drivers/net/ethernet/intel/i40e/i40e_main.c      |  1 +
 drivers/net/ethernet/intel/i40e/i40e_prototype.h |  1 +
 3 files changed, 95 insertions(+)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_common.c b/drivers/net/ethernet/intel/i40e/i40e_common.c
index bbace40..8305c8a 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_common.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_common.c
@@ -811,6 +811,99 @@ i40e_status i40e_pf_reset(struct i40e_hw *hw)
 }
 
 /**
+ * i40e_clear_hw - clear out any left over hw state
+ * @hw: pointer to the hw struct
+ *
+ * Clear queues and interrupts, typically called at init time,
+ * but after the capabilities have been found so we know how many
+ * queues and msix vectors have been allocated.
+ **/
+void i40e_clear_hw(struct i40e_hw *hw)
+{
+	u32 num_queues, base_queue;
+	u32 num_pf_int;
+	u32 num_vf_int;
+	u32 num_vfs;
+	u32 i, j;
+	u32 val;
+	u32 eol = 0x7ff;
+
+	/* get number of interrupts, queues, and vfs */
+	val = rd32(hw, I40E_GLPCI_CNF2);
+	num_pf_int = (val & I40E_GLPCI_CNF2_MSI_X_PF_N_MASK) >>
+		     I40E_GLPCI_CNF2_MSI_X_PF_N_SHIFT;
+	num_vf_int = (val & I40E_GLPCI_CNF2_MSI_X_VF_N_MASK) >>
+		     I40E_GLPCI_CNF2_MSI_X_VF_N_SHIFT;
+
+	val = rd32(hw, I40E_PFLAN_QALLOC);
+	base_queue = (val & I40E_PFLAN_QALLOC_FIRSTQ_MASK) >>
+		     I40E_PFLAN_QALLOC_FIRSTQ_SHIFT;
+	j = (val & I40E_PFLAN_QALLOC_LASTQ_MASK) >>
+	    I40E_PFLAN_QALLOC_LASTQ_SHIFT;
+	if (val & I40E_PFLAN_QALLOC_VALID_MASK)
+		num_queues = (j - base_queue) + 1;
+	else
+		num_queues = 0;
+
+	val = rd32(hw, I40E_PF_VT_PFALLOC);
+	i = (val & I40E_PF_VT_PFALLOC_FIRSTVF_MASK) >>
+	    I40E_PF_VT_PFALLOC_FIRSTVF_SHIFT;
+	j = (val & I40E_PF_VT_PFALLOC_LASTVF_MASK) >>
+	    I40E_PF_VT_PFALLOC_LASTVF_SHIFT;
+	if (val & I40E_PF_VT_PFALLOC_VALID_MASK)
+		num_vfs = (j - i) + 1;
+	else
+		num_vfs = 0;
+
+	/* stop all the interrupts */
+	wr32(hw, I40E_PFINT_ICR0_ENA, 0);
+	val = 0x3 << I40E_PFINT_DYN_CTLN_ITR_INDX_SHIFT;
+	for (i = 0; i < num_pf_int - 2; i++)
+		wr32(hw, I40E_PFINT_DYN_CTLN(i), val);
+
+	/* Set the FIRSTQ_INDX field to 0x7FF in PFINT_LNKLSTx */
+	val = eol << I40E_PFINT_LNKLST0_FIRSTQ_INDX_SHIFT;
+	wr32(hw, I40E_PFINT_LNKLST0, val);
+	for (i = 0; i < num_pf_int - 2; i++)
+		wr32(hw, I40E_PFINT_LNKLSTN(i), val);
+	val = eol << I40E_VPINT_LNKLST0_FIRSTQ_INDX_SHIFT;
+	for (i = 0; i < num_vfs; i++)
+		wr32(hw, I40E_VPINT_LNKLST0(i), val);
+	for (i = 0; i < num_vf_int - 2; i++)
+		wr32(hw, I40E_VPINT_LNKLSTN(i), val);
+
+	/* warn the HW of the coming Tx disables */
+	for (i = 0; i < num_queues; i++) {
+		u32 abs_queue_idx = base_queue + i;
+		u32 reg_block = 0;
+
+		if (abs_queue_idx >= 128) {
+			reg_block = abs_queue_idx / 128;
+			abs_queue_idx %= 128;
+		}
+
+		val = rd32(hw, I40E_GLLAN_TXPRE_QDIS(reg_block));
+		val &= ~I40E_GLLAN_TXPRE_QDIS_QINDX_MASK;
+		val |= (abs_queue_idx << I40E_GLLAN_TXPRE_QDIS_QINDX_SHIFT);
+		val |= I40E_GLLAN_TXPRE_QDIS_SET_QDIS_MASK;
+
+		wr32(hw, I40E_GLLAN_TXPRE_QDIS(reg_block), val);
+	}
+	udelay(400);
+
+	/* stop all the queues */
+	for (i = 0; i < num_queues; i++) {
+		wr32(hw, I40E_QINT_TQCTL(i), 0);
+		wr32(hw, I40E_QTX_ENA(i), 0);
+		wr32(hw, I40E_QINT_RQCTL(i), 0);
+		wr32(hw, I40E_QRX_ENA(i), 0);
+	}
+
+	/* short wait for all queue disables to settle */
+	udelay(50);
+}
+
+/**
  * i40e_clear_pxe_mode - clear pxe operations mode
  * @hw: pointer to the hw struct
  *
diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 17b1295..2c28538 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -8636,6 +8636,7 @@ static int i40e_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	}
 
 	/* Reset here to make sure all is clean and to define PF 'n' */
+	i40e_clear_hw(hw);
 	err = i40e_pf_reset(hw);
 	if (err) {
 		dev_info(&pdev->dev, "Initial pf_reset failed: %d\n", err);
diff --git a/drivers/net/ethernet/intel/i40e/i40e_prototype.h b/drivers/net/ethernet/intel/i40e/i40e_prototype.h
index 3300b99..77c515d 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_prototype.h
+++ b/drivers/net/ethernet/intel/i40e/i40e_prototype.h
@@ -217,6 +217,7 @@ i40e_status i40e_aq_query_switch_comp_bw_config(struct i40e_hw *hw,
 /* i40e_common */
 i40e_status i40e_init_shared_code(struct i40e_hw *hw);
 i40e_status i40e_pf_reset(struct i40e_hw *hw);
+void i40e_clear_hw(struct i40e_hw *hw);
 void i40e_clear_pxe_mode(struct i40e_hw *hw);
 bool i40e_get_link_status(struct i40e_hw *hw);
 i40e_status i40e_get_mac_addr(struct i40e_hw *hw,
-- 
1.9.3