be2net: Support UE recovery in BEx/Skyhawk adapters

This patch supports recovery from UEs caused due to Transient Parity
Errors (TPE), in BE2, BE3 and Skyhawk adapters. This change avoids
system reboot when such errors occur. The driver recovers from these
errors such that the adapter resumes full operational status as prior
to the UE.

Following is the list of changes in the driver to support this:

o The driver registers its UE recoverable capability with ARM FW at init
time. This also allows the driver to know if the feature is supported in
the FW.

o As the UE recovery requires precise time bound processing, the driver
creates its own error recovery work queue with a single worker thread (per
module, shared across functions).

o Each function runs an error detection task at an interval of 1 second as
required by the FW. The error detection logic already exists for BEx/SH,
but it now runs in the context of a separate worker thread.

o When an error is detected by the task, if it is recoverable, the PF0
driver instance initiates a soft reset, while other PF driver instances
wait for the reset to complete and the chip to become ready. Once
the chip is ready, all driver instances including PF0, resume to
reinitialize the respective functions.

o The PF0 driver checks for some recovery criteria, to determine if the
recovery can be initiated. If the criteria is not met, the PF0 driver does
not initiate a soft reset, it retains the existing behavior to stop
further processing and requires a reboot to get the chip to operational
state again.

o To allow each function to share the workq, while also making progress in
its recovery process, a per-function recovery state machine is used.
The per-function tasks avoid blocking operations like msleep() while in
this state machine (until reinit state) and instead reschedule for the
required delay.

o With these changes, the existing error recovery code for Lancer also
runs in the context of the new worker thread.

Signed-off-by: Sriharsha Basavapatna <sriharsha.basavapatna@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 52 insertions, 1 deletions

diff --git a/drivers/net/ethernet/emulex/benet/be_cmds.c b/drivers/net/ethernet/emulex/benet/be_cmds.c
index fa11a5a8c354..92794f345bcb 100644
--- a/drivers/net/ethernet/emulex/benet/be_cmds.c
+++ b/drivers/net/ethernet/emulex/benet/be_cmds.c
@@ -705,7 +705,7 @@ static int be_mbox_notify_wait(struct be_adapter *adapter)
 	return 0;
 }
 
-static u16 be_POST_stage_get(struct be_adapter *adapter)
+u16 be_POST_stage_get(struct be_adapter *adapter)
 {
 	u32 sem;
 
@@ -4954,6 +4954,57 @@ int be_cmd_set_logical_link_config(struct be_adapter *adapter,
 							  1, domain);
 	return status;
 }
+
+int be_cmd_set_features(struct be_adapter *adapter)
+{
+	struct be_cmd_resp_set_features *resp;
+	struct be_cmd_req_set_features *req;
+	struct be_mcc_wrb *wrb;
+	int status;
+
+	if (mutex_lock_interruptible(&adapter->mcc_lock))
+		return -1;
+
+	wrb = wrb_from_mccq(adapter);
+	if (!wrb) {
+		status = -EBUSY;
+		goto err;
+	}
+
+	req = embedded_payload(wrb);
+
+	be_wrb_cmd_hdr_prepare(&req->hdr, CMD_SUBSYSTEM_COMMON,
+			       OPCODE_COMMON_SET_FEATURES,
+			       sizeof(*req), wrb, NULL);
+
+	req->features = cpu_to_le32(BE_FEATURE_UE_RECOVERY);
+	req->parameter_len = cpu_to_le32(sizeof(struct be_req_ue_recovery));
+	req->parameter.req.uer = cpu_to_le32(BE_UE_RECOVERY_UER_MASK);
+
+	status = be_mcc_notify_wait(adapter);
+	if (status)
+		goto err;
+
+	resp = embedded_payload(wrb);
+
+	adapter->error_recovery.ue_to_poll_time =
+		le16_to_cpu(resp->parameter.resp.ue2rp);
+	adapter->error_recovery.ue_to_reset_time =
+		le16_to_cpu(resp->parameter.resp.ue2sr);
+	adapter->error_recovery.recovery_supported = true;
+err:
+	/* Checking "MCC_STATUS_INVALID_LENGTH" for SKH as FW
+	 * returns this error in older firmware versions
+	 */
+	if (base_status(status) == MCC_STATUS_ILLEGAL_REQUEST ||
+	    base_status(status) == MCC_STATUS_INVALID_LENGTH)
+		dev_info(&adapter->pdev->dev,
+			 "Adapter does not support HW error recovery\n");
+
+	mutex_unlock(&adapter->mcc_lock);
+	return status;
+}
+
 int be_roce_mcc_cmd(void *netdev_handle, void *wrb_payload,
 		    int wrb_payload_size, u16 *cmd_status, u16 *ext_status)
 {