sfc: Change entity reset on MC reboot to a new datapath-only reset.

Currently we do an entity reset when we detect an MC reboot.
This messes up SRIOV because it leaves VFs orphaned. The extra
reset is rather redundant anyway, since the MC reboot will have
basically reset everything.

This change replaces the entity reset after MC reboot with a
simpler datapath reset that reallocates resources but doesn't
perform the entity reset.

Signed-off-by: Shradha Shah <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/ethernet/sfc/ef10.c

···
 	nic_data->rx_rss_context = EFX_EF10_RSS_CONTEXT_INVALID;
 }
 
+static enum reset_type efx_ef10_map_reset_reason(enum reset_type reason)
+{
+	if (reason == RESET_TYPE_MC_FAILURE)
+		return RESET_TYPE_DATAPATH;
+
+	return efx_mcdi_map_reset_reason(reason);
+}
+
 static int efx_ef10_map_reset_flags(u32 *flags)
 {
 	enum {
···
 	.dimension_resources = efx_ef10_dimension_resources,
 	.init = efx_ef10_init_nic,
 	.fini = efx_port_dummy_op_void,
-	.map_reset_reason = efx_mcdi_map_reset_reason,
+	.map_reset_reason = efx_ef10_map_reset_reason,
 	.map_reset_flags = efx_ef10_map_reset_flags,
 	.reset = efx_ef10_reset,
 	.probe_port = efx_mcdi_port_probe,
···
 	.dimension_resources = efx_ef10_dimension_resources,
 	.init = efx_ef10_init_nic,
 	.fini = efx_port_dummy_op_void,
-	.map_reset_reason = efx_mcdi_map_reset_reason,
+	.map_reset_reason = efx_ef10_map_reset_reason,
 	.map_reset_flags = efx_ef10_map_reset_flags,
 	.reset = efx_ef10_reset,
 	.probe_port = efx_mcdi_port_probe,

drivers/net/ethernet/sfc/efx.c

···
 	[RESET_TYPE_RECOVER_OR_ALL]     = "RECOVER_OR_ALL",
 	[RESET_TYPE_WORLD]              = "WORLD",
 	[RESET_TYPE_RECOVER_OR_DISABLE] = "RECOVER_OR_DISABLE",
+	[RESET_TYPE_DATAPATH]           = "DATAPATH",
 	[RESET_TYPE_MC_BIST]		= "MC_BIST",
 	[RESET_TYPE_DISABLE]            = "DISABLE",
 	[RESET_TYPE_TX_WATCHDOG]        = "TX_WATCHDOG",
···
 	efx_disable_interrupts(efx);
 
 	mutex_lock(&efx->mac_lock);
-	if (efx->port_initialized && method != RESET_TYPE_INVISIBLE)
+	if (efx->port_initialized && method != RESET_TYPE_INVISIBLE &&
+	    method != RESET_TYPE_DATAPATH)
 		efx->phy_op->fini(efx);
 	efx->type->fini(efx);
 }
···
 	if (!ok)
 		goto fail;
 
-	if (efx->port_initialized && method != RESET_TYPE_INVISIBLE) {
+	if (efx->port_initialized && method != RESET_TYPE_INVISIBLE &&
+	    method != RESET_TYPE_DATAPATH) {
 		rc = efx->phy_op->init(efx);
 		if (rc)
 			goto fail;
···
 	case RESET_TYPE_WORLD:
 	case RESET_TYPE_DISABLE:
 	case RESET_TYPE_RECOVER_OR_DISABLE:
+	case RESET_TYPE_DATAPATH:
 	case RESET_TYPE_MC_BIST:
 	case RESET_TYPE_MCDI_TIMEOUT:
 		method = type;

drivers/net/ethernet/sfc/enum.h

···
  * @RESET_TYPE_WORLD: Reset as much as possible
  * @RESET_TYPE_RECOVER_OR_DISABLE: Try to recover. Apply RESET_TYPE_DISABLE if
  * unsuccessful.
+ * @RESET_TYPE_DATAPATH: Reset datapath only.
  * @RESET_TYPE_MC_BIST: MC entering BIST mode.
  * @RESET_TYPE_DISABLE: Reset datapath, MAC and PHY; leave NIC disabled
  * @RESET_TYPE_TX_WATCHDOG: reset due to TX watchdog
···
 	RESET_TYPE_ALL,
 	RESET_TYPE_WORLD,
 	RESET_TYPE_RECOVER_OR_DISABLE,
+	RESET_TYPE_DATAPATH,
 	RESET_TYPE_MC_BIST,
 	RESET_TYPE_DISABLE,
 	RESET_TYPE_MAX_METHOD,

drivers/net/ethernet/sfc/mcdi.c

···
 	if (rc)
 		return rc;
 
-	if (method == RESET_TYPE_WORLD)
+	if (method == RESET_TYPE_DATAPATH)
+		return 0;
+	else if (method == RESET_TYPE_WORLD)
 		return efx_mcdi_reset_mc(efx);
 	else
 		return efx_mcdi_reset_func(efx);