i40e: add support for triggering EMPR

Allow debugfs to trigger a reset called EMPR.

Change-Id: I2f6600a8242759ec60c8198d03f70c2b774e0740
Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Kavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/i40e/i40e.h

@@ -130,6 +130,7 @@ enum i40e_state_t {
 	__I40E_PF_RESET_REQUESTED,
 	__I40E_CORE_RESET_REQUESTED,
 	__I40E_GLOBAL_RESET_REQUESTED,
+	__I40E_EMP_RESET_REQUESTED,
 	__I40E_FILTER_OVERFLOW_PROMISC,
 };
 

drivers/net/ethernet/intel/i40e/i40e_debugfs.c

@@ -1472,6 +1472,10 @@ static ssize_t i40e_dbg_command_write(struct file *filp,
 		dev_info(&pf->pdev->dev, "forcing GlobR\n");
 		i40e_do_reset(pf, (1 << __I40E_GLOBAL_RESET_REQUESTED));
 
+	} else if (strncmp(cmd_buf, "empr", 4) == 0) {
+		dev_info(&pf->pdev->dev, "forcing EMPR\n");
+		i40e_do_reset(pf, (1 << __I40E_EMP_RESET_REQUESTED));
+
 	} else if (strncmp(cmd_buf, "read", 4) == 0) {
 		u32 address;
 		u32 value;

drivers/net/ethernet/intel/i40e/i40e_main.c

@@ -4056,6 +4056,24 @@ void i40e_do_reset(struct i40e_pf *pf, u32 reset_flags)
 		wr32(&pf->hw, I40E_GLGEN_RTRIG, val);
 		i40e_flush(&pf->hw);
 
+	} else if (reset_flags & (1 << __I40E_EMP_RESET_REQUESTED)) {
+
+		/* Request a Firmware Reset
+		 *
+		 * Same as Global reset, plus restarting the
+		 * embedded firmware engine.
+		 */
+		/* enable EMP Reset */
+		val = rd32(&pf->hw, I40E_GLGEN_RSTENA_EMP);
+		val |= I40E_GLGEN_RSTENA_EMP_EMP_RST_ENA_MASK;
+		wr32(&pf->hw, I40E_GLGEN_RSTENA_EMP, val);
+
+		/* force the reset */
+		val = rd32(&pf->hw, I40E_GLGEN_RTRIG);
+		val |= I40E_GLGEN_RTRIG_EMPFWR_MASK;
+		wr32(&pf->hw, I40E_GLGEN_RTRIG, val);
+		i40e_flush(&pf->hw);
+
 	} else if (reset_flags & (1 << __I40E_PF_RESET_REQUESTED)) {
 
 		/* Request a PF Reset