sfc: move some device reset code

The rest of the reset code will be moved later.
Small code styling fixes included.

Signed-off-by: Alexandru-Mihai Maftei <amaftei@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 237 insertions, 0 deletions

diff --git a/drivers/net/ethernet/sfc/efx_common.c b/drivers/net/ethernet/sfc/efx_common.c
index 445340c903b1..813ebdda50f6 100644
--- a/drivers/net/ethernet/sfc/efx_common.c
+++ b/drivers/net/ethernet/sfc/efx_common.c
@@ -429,3 +429,240 @@ int efx_reconfigure_port(struct efx_nic *efx)
 
 	return rc;
 }
+
+/**************************************************************************
+ *
+ * Device reset and suspend
+ *
+ **************************************************************************/
+
+/* Try recovery mechanisms.
+ * For now only EEH is supported.
+ * Returns 0 if the recovery mechanisms are unsuccessful.
+ * Returns a non-zero value otherwise.
+ */
+int efx_try_recovery(struct efx_nic *efx)
+{
+#ifdef CONFIG_EEH
+	/* A PCI error can occur and not be seen by EEH because nothing
+	 * happens on the PCI bus. In this case the driver may fail and
+	 * schedule a 'recover or reset', leading to this recovery handler.
+	 * Manually call the eeh failure check function.
+	 */
+	struct eeh_dev *eehdev = pci_dev_to_eeh_dev(efx->pci_dev);
+	if (eeh_dev_check_failure(eehdev)) {
+		/* The EEH mechanisms will handle the error and reset the
+		 * device if necessary.
+		 */
+		return 1;
+	}
+#endif
+	return 0;
+}
+
+/* Tears down the entire software state and most of the hardware state
+ * before reset.
+ */
+void efx_reset_down(struct efx_nic *efx, enum reset_type method)
+{
+	EFX_ASSERT_RESET_SERIALISED(efx);
+
+	if (method == RESET_TYPE_MCDI_TIMEOUT)
+		efx->type->prepare_flr(efx);
+
+	efx_stop_all(efx);
+	efx_disable_interrupts(efx);
+
+	mutex_lock(&efx->mac_lock);
+	down_write(&efx->filter_sem);
+	mutex_lock(&efx->rss_lock);
+	if (efx->port_initialized && method != RESET_TYPE_INVISIBLE &&
+	    method != RESET_TYPE_DATAPATH)
+		efx->phy_op->fini(efx);
+	efx->type->fini(efx);
+}
+
+/* This function will always ensure that the locks acquired in
+ * efx_reset_down() are released. A failure return code indicates
+ * that we were unable to reinitialise the hardware, and the
+ * driver should be disabled. If ok is false, then the rx and tx
+ * engines are not restarted, pending a RESET_DISABLE.
+ */
+int efx_reset_up(struct efx_nic *efx, enum reset_type method, bool ok)
+{
+	int rc;
+
+	EFX_ASSERT_RESET_SERIALISED(efx);
+
+	if (method == RESET_TYPE_MCDI_TIMEOUT)
+		efx->type->finish_flr(efx);
+
+	/* Ensure that SRAM is initialised even if we're disabling the device */
+	rc = efx->type->init(efx);
+	if (rc) {
+		netif_err(efx, drv, efx->net_dev, "failed to initialise NIC\n");
+		goto fail;
+	}
+
+	if (!ok)
+		goto fail;
+
+	if (efx->port_initialized && method != RESET_TYPE_INVISIBLE &&
+	    method != RESET_TYPE_DATAPATH) {
+		rc = efx->phy_op->init(efx);
+		if (rc)
+			goto fail;
+		rc = efx->phy_op->reconfigure(efx);
+		if (rc && rc != -EPERM)
+			netif_err(efx, drv, efx->net_dev,
+				  "could not restore PHY settings\n");
+	}
+
+	rc = efx_enable_interrupts(efx);
+	if (rc)
+		goto fail;
+
+#ifdef CONFIG_SFC_SRIOV
+	rc = efx->type->vswitching_restore(efx);
+	if (rc) /* not fatal; the PF will still work fine */
+		netif_warn(efx, probe, efx->net_dev,
+			   "failed to restore vswitching rc=%d;"
+			   " VFs may not function\n", rc);
+#endif
+
+	if (efx->type->rx_restore_rss_contexts)
+		efx->type->rx_restore_rss_contexts(efx);
+	mutex_unlock(&efx->rss_lock);
+	efx->type->filter_table_restore(efx);
+	up_write(&efx->filter_sem);
+	if (efx->type->sriov_reset)
+		efx->type->sriov_reset(efx);
+
+	mutex_unlock(&efx->mac_lock);
+
+	efx_start_all(efx);
+
+	if (efx->type->udp_tnl_push_ports)
+		efx->type->udp_tnl_push_ports(efx);
+
+	return 0;
+
+fail:
+	efx->port_initialized = false;
+
+	mutex_unlock(&efx->rss_lock);
+	up_write(&efx->filter_sem);
+	mutex_unlock(&efx->mac_lock);
+
+	return rc;
+}
+
+/* Reset the NIC using the specified method.  Note that the reset may
+ * fail, in which case the card will be left in an unusable state.
+ *
+ * Caller must hold the rtnl_lock.
+ */
+int efx_reset(struct efx_nic *efx, enum reset_type method)
+{
+	bool disabled;
+	int rc, rc2;
+
+	netif_info(efx, drv, efx->net_dev, "resetting (%s)\n",
+		   RESET_TYPE(method));
+
+	efx_device_detach_sync(efx);
+	efx_reset_down(efx, method);
+
+	rc = efx->type->reset(efx, method);
+	if (rc) {
+		netif_err(efx, drv, efx->net_dev, "failed to reset hardware\n");
+		goto out;
+	}
+
+	/* Clear flags for the scopes we covered.  We assume the NIC and
+	 * driver are now quiescent so that there is no race here.
+	 */
+	if (method < RESET_TYPE_MAX_METHOD)
+		efx->reset_pending &= -(1 << (method + 1));
+	else /* it doesn't fit into the well-ordered scope hierarchy */
+		__clear_bit(method, &efx->reset_pending);
+
+	/* Reinitialise bus-mastering, which may have been turned off before
+	 * the reset was scheduled. This is still appropriate, even in the
+	 * RESET_TYPE_DISABLE since this driver generally assumes the hardware
+	 * can respond to requests.
+	 */
+	pci_set_master(efx->pci_dev);
+
+out:
+	/* Leave device stopped if necessary */
+	disabled = rc ||
+		method == RESET_TYPE_DISABLE ||
+		method == RESET_TYPE_RECOVER_OR_DISABLE;
+	rc2 = efx_reset_up(efx, method, !disabled);
+	if (rc2) {
+		disabled = true;
+		if (!rc)
+			rc = rc2;
+	}
+
+	if (disabled) {
+		dev_close(efx->net_dev);
+		netif_err(efx, drv, efx->net_dev, "has been disabled\n");
+		efx->state = STATE_DISABLED;
+	} else {
+		netif_dbg(efx, drv, efx->net_dev, "reset complete\n");
+		efx_device_attach_if_not_resetting(efx);
+	}
+	return rc;
+}
+
+void efx_schedule_reset(struct efx_nic *efx, enum reset_type type)
+{
+	enum reset_type method;
+
+	if (efx->state == STATE_RECOVERY) {
+		netif_dbg(efx, drv, efx->net_dev,
+			  "recovering: skip scheduling %s reset\n",
+			  RESET_TYPE(type));
+		return;
+	}
+
+	switch (type) {
+	case RESET_TYPE_INVISIBLE:
+	case RESET_TYPE_ALL:
+	case RESET_TYPE_RECOVER_OR_ALL:
+	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;
+		netif_dbg(efx, drv, efx->net_dev, "scheduling %s reset\n",
+			  RESET_TYPE(method));
+		break;
+	default:
+		method = efx->type->map_reset_reason(type);
+		netif_dbg(efx, drv, efx->net_dev,
+			  "scheduling %s reset for %s\n",
+			  RESET_TYPE(method), RESET_TYPE(type));
+		break;
+	}
+
+	set_bit(method, &efx->reset_pending);
+	smp_mb(); /* ensure we change reset_pending before checking state */
+
+	/* If we're not READY then just leave the flags set as the cue
+	 * to abort probing or reschedule the reset later.
+	 */
+	if (READ_ONCE(efx->state) != STATE_READY)
+		return;
+
+	/* efx_process_channel() will no longer read events once a
+	 * reset is scheduled. So switch back to poll'd MCDI completions.
+	 */
+	efx_mcdi_mode_poll(efx);
+
+	efx_queue_reset_work(efx);
+}