ice: support immediate firmware activation via devlink reload

The ice hardware contains an embedded chip with firmware which can be
updated using devlink flash. The firmware which runs on this chip is
referred to as the Embedded Management Processor firmware (EMP
firmware).

Activating the new firmware image currently requires that the system be
rebooted. This is not ideal as rebooting the system can cause unwanted
downtime.

In practical terms, activating the firmware does not always require a
full system reboot. In many cases it is possible to activate the EMP
firmware immediately. There are a couple of different scenarios to
cover.

 * The EMP firmware itself can be reloaded by issuing a special update
   to the device called an Embedded Management Processor reset (EMP
   reset). This reset causes the device to reset and reload the EMP
   firmware.

 * PCI configuration changes are only reloaded after a cold PCIe reset.
   Unfortunately there is no generic way to trigger this for a PCIe
   device without a system reboot.

When performing a flash update, firmware is capable of responding with
some information about the specific update requirements.

The driver updates the flash by programming a secondary inactive bank
with the contents of the new image, and then issuing a command to
request to switch the active bank starting from the next load.

The response to the final command for updating the inactive NVM flash
bank includes an indication of the minimum reset required to fully
update the device. This can be one of the following:

 * A full power on is required
 * A cold PCIe reset is required
 * An EMP reset is required

The response to the command to switch flash banks includes an indication
of whether or not the firmware will allow an EMP reset request.

For most updates, an EMP reset is sufficient to load the new EMP
firmware without issues. In some cases, this reset is not sufficient
because the PCI configuration space has changed. When this could cause
incompatibility with the new EMP image, the firmware is capable of
rejecting the EMP reset request.

Add logic to ice_fw_update.c to handle the response data flash update
AdminQ commands.

For the reset level, issue a devlink status notification informing the
user of how to complete the update with a simple suggestion like
"Activate new firmware by rebooting the system".

Cache the status of whether or not firmware will restrict the EMP reset
for use in implementing devlink reload.

Implement support for devlink reload with the "fw_activate" flag. This
allows user space to request the firmware be activated immediately.

For the .reload_down handler, we will issue a request for the EMP reset
using the appropriate firmware AdminQ command. If we know that the
firmware will not allow an EMP reset, simply exit with a suitable
netlink extended ACK message indicating that the EMP reset is not
available.

For the .reload_up handler, simply wait until the driver has finished
resetting. Logic to handle processing of an EMP reset already exists in
the driver as part of its reset and rebuild flows.

Implement support for the devlink reload interface with the
"fw_activate" action. This allows userspace to request activation of
firmware without a reboot.

Note that support for indicating the required reset and EMP reset
restriction is not supported on old versions of firmware. The driver can
determine if the two features are supported by checking the device
capabilities report. I confirmed support has existed since at least
version 5.5.2 as reported by the 'fw.mgmt' version. Support to issue the
EMP reset request has existed in all version of the EMP firmware for the
ice hardware.

Check the device capabilities report to determine whether or not the
indications are reported by the running firmware. If the reset
requirement indication is not supported, always assume a full power on
is necessary. If the reset restriction capability is not supported,
always assume the EMP reset is available.

Users can verify if the EMP reset has activated the firmware by using
the devlink info report to check that the 'running' firmware version has
updated. For example a user might do the following:

 # Check current version
 $ devlink dev info

 # Update the device
 $ devlink dev flash pci/0000:af:00.0 file firmware.bin

 # Confirm stored version updated
 $ devlink dev info

 # Reload to activate new firmware
 $ devlink dev reload pci/0000:af:00.0 action fw_activate

 # Confirm running version updated
 $ devlink dev info

Finally, this change does *not* implement basic driver-only reload
support. I did look into trying to do this. However, it requires
significant refactor of how the ice driver probes and loads everything.
The ice driver probe and allocation flows were not designed with such
a reload in mind. Refactoring the flow to support this is beyond the
scope of this change.

Signed-off-by: Jacob Keller <[email protected]>
Tested-by: Gurucharan G <[email protected]>
Signed-off-by: Tony Nguyen <[email protected]>

Author: jacob-keller

Documentation/networking/devlink/ice.rst

@@ -26,8 +26,10 @@ The ``ice`` driver reports the following versions
     * - ``fw.mgmt``
       - running
       - 2.1.7
-      - 3-digit version number of the management firmware that controls the
-        PHY, link, etc.
+      - 3-digit version number of the management firmware running on the
+        Embedded Management Processor of the device. It controls the PHY,
+        link, access to device resources, etc. Intel documentation refers to
+        this as the EMP firmware.
     * - ``fw.mgmt.api``
       - running
       - 1.5.1
@@ -119,6 +121,24 @@ preserving settings, and thus ``DEVLINK_FLASH_OVERWRITE_IDENTIFIERS`` on its
 own will be rejected. If no overwrite mask is provided, the firmware will be
 instructed to preserve all settings and identifying fields when updating.
 
+Reload
+======
+
+The ``ice`` driver supports activating new firmware after a flash update
+using ``DEVLINK_CMD_RELOAD`` with the ``DEVLINK_RELOAD_ACTION_FW_ACTIVATE``
+action.
+
+.. code:: shell
+
+    $ devlink dev reload pci/0000:01:00.0 reload action fw_activate
+
+The new firmware is activated by issuing a device specific Embedded
+Management Processor reset which requests the device to reset and reload the
+EMP firmware image.
+
+The driver does not currently support reloading the driver via
+``DEVLINK_RELOAD_ACTION_DRIVER_REINIT``.
+
 Regions
 =======
 

drivers/net/ethernet/intel/ice/ice.h

@@ -553,6 +553,7 @@ struct ice_pf {
 	spinlock_t aq_wait_lock;
 	struct hlist_head aq_wait_list;
 	wait_queue_head_t aq_wait_queue;
+	bool fw_emp_reset_disabled;
 
 	wait_queue_head_t reset_wait_queue;
 

drivers/net/ethernet/intel/ice/ice_adminq_cmd.h

@@ -117,6 +117,8 @@ struct ice_aqc_list_caps_elem {
 #define ICE_AQC_CAPS_NET_VER				0x004C
 #define ICE_AQC_CAPS_PENDING_NET_VER			0x004D
 #define ICE_AQC_CAPS_RDMA				0x0051
+#define ICE_AQC_CAPS_PCIE_RESET_AVOIDANCE		0x0076
+#define ICE_AQC_CAPS_POST_UPDATE_RESET_RESTRICT		0x0077
 #define ICE_AQC_CAPS_NVM_MGMT				0x0080
 
 	u8 major_ver;
@@ -1408,6 +1410,11 @@ struct ice_aqc_nvm {
 #define ICE_AQC_NVM_REVERT_LAST_ACTIV	BIT(6) /* Write Activate only */
 #define ICE_AQC_NVM_ACTIV_SEL_MASK	ICE_M(0x7, 3)
 #define ICE_AQC_NVM_FLASH_ONLY		BIT(7)
+#define ICE_AQC_NVM_RESET_LVL_M		ICE_M(0x3, 0) /* Write reply only */
+#define ICE_AQC_NVM_POR_FLAG		0
+#define ICE_AQC_NVM_PERST_FLAG		1
+#define ICE_AQC_NVM_EMPR_FLAG		2
+#define ICE_AQC_NVM_EMPR_ENA		BIT(0) /* Write Activate reply only */
 	__le16 module_typeid;
 	__le16 length;
 #define ICE_AQC_NVM_ERASE_LEN	0xFFFF

drivers/net/ethernet/intel/ice/ice_common.c

@@ -2068,6 +2068,18 @@ ice_parse_common_caps(struct ice_hw *hw, struct ice_hw_common_caps *caps,
 		ice_debug(hw, ICE_DBG_INIT, "%s: max_mtu = %d\n",
 			  prefix, caps->max_mtu);
 		break;
+	case ICE_AQC_CAPS_PCIE_RESET_AVOIDANCE:
+		caps->pcie_reset_avoidance = (number > 0);
+		ice_debug(hw, ICE_DBG_INIT,
+			  "%s: pcie_reset_avoidance = %d\n", prefix,
+			  caps->pcie_reset_avoidance);
+		break;
+	case ICE_AQC_CAPS_POST_UPDATE_RESET_RESTRICT:
+		caps->reset_restrict_support = (number == 1);
+		ice_debug(hw, ICE_DBG_INIT,
+			  "%s: reset_restrict_support = %d\n", prefix,
+			  caps->reset_restrict_support);
+		break;
 	default:
 		/* Not one of the recognized common capabilities */
 		found = false;

drivers/net/ethernet/intel/ice/ice_devlink.c

@@ -370,8 +370,106 @@ static int ice_devlink_info_get(struct devlink *devlink,
 	return err;
 }
 
+/**
+ * ice_devlink_reload_empr_start - Start EMP reset to activate new firmware
+ * @devlink: pointer to the devlink instance to reload
+ * @netns_change: if true, the network namespace is changing
+ * @action: the action to perform. Must be DEVLINK_RELOAD_ACTION_FW_ACTIVATE
+ * @limit: limits on what reload should do, such as not resetting
+ * @extack: netlink extended ACK structure
+ *
+ * Allow user to activate new Embedded Management Processor firmware by
+ * issuing device specific EMP reset. Called in response to
+ * a DEVLINK_CMD_RELOAD with the DEVLINK_RELOAD_ACTION_FW_ACTIVATE.
+ *
+ * Note that teardown and rebuild of the driver state happens automatically as
+ * part of an interrupt and watchdog task. This is because all physical
+ * functions on the device must be able to reset when an EMP reset occurs from
+ * any source.
+ */
+static int
+ice_devlink_reload_empr_start(struct devlink *devlink, bool netns_change,
+			      enum devlink_reload_action action,
+			      enum devlink_reload_limit limit,
+			      struct netlink_ext_ack *extack)
+{
+	struct ice_pf *pf = devlink_priv(devlink);
+	struct device *dev = ice_pf_to_dev(pf);
+	struct ice_hw *hw = &pf->hw;
+	u8 pending;
+	int err;
+
+	err = ice_get_pending_updates(pf, &pending, extack);
+	if (err)
+		return err;
+
+	/* pending is a bitmask of which flash banks have a pending update,
+	 * including the main NVM bank, the Option ROM bank, and the netlist
+	 * bank. If any of these bits are set, then there is a pending update
+	 * waiting to be activated.
+	 */
+	if (!pending) {
+		NL_SET_ERR_MSG_MOD(extack, "No pending firmware update");
+		return -ECANCELED;
+	}
+
+	if (pf->fw_emp_reset_disabled) {
+		NL_SET_ERR_MSG_MOD(extack, "EMP reset is not available. To activate firmware, a reboot or power cycle is needed");
+		return -ECANCELED;
+	}
+
+	dev_dbg(dev, "Issuing device EMP reset to activate firmware\n");
+
+	err = ice_aq_nvm_update_empr(hw);
+	if (err) {
+		dev_err(dev, "Failed to trigger EMP device reset to reload firmware, err %d aq_err %s\n",
+			err, ice_aq_str(hw->adminq.sq_last_status));
+		NL_SET_ERR_MSG_MOD(extack, "Failed to trigger EMP device reset to reload firmware");
+		return err;
+	}
+
+	return 0;
+}
+
+/**
+ * ice_devlink_reload_empr_finish - Wait for EMP reset to finish
+ * @devlink: pointer to the devlink instance reloading
+ * @action: the action requested
+ * @limit: limits imposed by userspace, such as not resetting
+ * @actions_performed: on return, indicate what actions actually performed
+ * @extack: netlink extended ACK structure
+ *
+ * Wait for driver to finish rebuilding after EMP reset is completed. This
+ * includes time to wait for both the actual device reset as well as the time
+ * for the driver's rebuild to complete.
+ */
+static int
+ice_devlink_reload_empr_finish(struct devlink *devlink,
+			       enum devlink_reload_action action,
+			       enum devlink_reload_limit limit,
+			       u32 *actions_performed,
+			       struct netlink_ext_ack *extack)
+{
+	struct ice_pf *pf = devlink_priv(devlink);
+	int err;
+
+	*actions_performed = BIT(DEVLINK_RELOAD_ACTION_FW_ACTIVATE);
+
+	err = ice_wait_for_reset(pf, 60 * HZ);
+	if (err) {
+		NL_SET_ERR_MSG_MOD(extack, "Device still resetting after 1 minute");
+		return err;
+	}
+
+	return 0;
+}
+
 static const struct devlink_ops ice_devlink_ops = {
 	.supported_flash_update_params = DEVLINK_SUPPORT_FLASH_UPDATE_OVERWRITE_MASK,
+	.reload_actions = BIT(DEVLINK_RELOAD_ACTION_FW_ACTIVATE),
+	/* The ice driver currently does not support driver reinit */
+	.reload_down = ice_devlink_reload_empr_start,
+	.reload_up = ice_devlink_reload_empr_finish,
 	.eswitch_mode_get = ice_eswitch_mode_get,
 	.eswitch_mode_set = ice_eswitch_mode_set,
 	.info_get = ice_devlink_info_get,
@@ -532,6 +630,7 @@ void ice_devlink_register(struct ice_pf *pf)
 {
 	struct devlink *devlink = priv_to_devlink(pf);
 
+	devlink_set_features(devlink, DEVLINK_F_RELOAD);
 	devlink_register(devlink);
 }