ice: add ability to read and configure FW log data

Once logging is enabled the user should read the data from the 'data'
file. The data is in the form of a binary blob that can be sent to Intel
for decoding. To read the data use a command like:

  # cat /sys/kernel/debug/ice/0000\:18\:00.0/fwlog/data > log_data.bin

If the user wants to clear the FW log data that has been stored in the
driver then they can write any value to the 'data' file and that will clear
the data. An example is:

  # echo 34 > /sys/kernel/debug/ice/0000\:18\:00.0/fwlog/data

In addition to being able to read the data the user can configure how
much memory is used to store FW log data. This allows the user to
increase/decrease the amount of memory based on the users situation.
The data is stored such that if the memory fills up then the oldest data
will get overwritten in a circular manner. To change the amount of
memory the user can write to the 'log_size' file like this:

  # echo <value> > /sys/kernel/debug/ice/0000\:18\:00.0/fwlog/log_size

Where <value> is one of 128K, 256K, 512K, 1M, and 2M. The default value
is 1M.

The user can see the current value of 'log_size' by reading the file:

  # cat /sys/kernel/debug/ice/0000\:18\:00.0/fwlog/log_size

Signed-off-by: Paul M Stillwell Jr <[email protected]>
Tested-by: Pucha Himasekhar Reddy <[email protected]> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <[email protected]>

1 files changed, 29 insertions, 0 deletions

diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
index 4b2d3d27cdbb..9b0c04d595ce 100644
--- a/drivers/net/ethernet/intel/ice/ice_main.c
+++ b/drivers/net/ethernet/intel/ice/ice_main.c
@@ -1253,6 +1253,32 @@ ice_handle_link_event(struct ice_pf *pf, struct ice_rq_event_info *event)
 }
 
 /**
+ * ice_get_fwlog_data - copy the FW log data from ARQ event
+ * @pf: PF that the FW log event is associated with
+ * @event: event structure containing FW log data
+ */
+static void
+ice_get_fwlog_data(struct ice_pf *pf, struct ice_rq_event_info *event)
+{
+	struct ice_fwlog_data *fwlog;
+	struct ice_hw *hw = &pf->hw;
+
+	fwlog = &hw->fwlog_ring.rings[hw->fwlog_ring.tail];
+
+	memset(fwlog->data, 0, PAGE_SIZE);
+	fwlog->data_size = le16_to_cpu(event->desc.datalen);
+
+	memcpy(fwlog->data, event->msg_buf, fwlog->data_size);
+	ice_fwlog_ring_increment(&hw->fwlog_ring.tail, hw->fwlog_ring.size);
+
+	if (ice_fwlog_ring_full(&hw->fwlog_ring)) {
+		/* the rings are full so bump the head to create room */
+		ice_fwlog_ring_increment(&hw->fwlog_ring.head,
+					 hw->fwlog_ring.size);
+	}
+}
+
+/**
  * ice_aq_prep_for_event - Prepare to wait for an AdminQ event from firmware
  * @pf: pointer to the PF private structure
  * @task: intermediate helper storage and identifier for waiting
@@ -1533,6 +1559,9 @@ static int __ice_clean_ctrlq(struct ice_pf *pf, enum ice_ctl_q q_type)
 
 			ice_vc_process_vf_msg(pf, &event, &data);
 			break;
+		case ice_aqc_opc_fw_logs_event:
+			ice_get_fwlog_data(pf, &event);
+			break;
 		case ice_aqc_opc_lldp_set_mib_change:
 			ice_dcb_process_lldp_set_mib_change(pf, &event);
 			break;