ice: wait for reset before reporting devlink info

Requesting device firmware information while the device is busy cleaning
up after a reset can result in an unexpected failure:

This occurs because the command is attempting to access the device
AdminQ while it is down. Resolve this by having the command wait for
a while until the reset is complete. To do this, introduce
a reset_wait_queue and associated helper function "ice_wait_for_reset".

This helper will use the wait queue to sleep until the driver is done
rebuilding. Use of a wait queue is preferred because the potential sleep
duration can be several seconds.

To ensure that the thread wakes up properly, a new wake_up call is added
during all code paths which clear the reset state bits associated with
the driver rebuild flow.

Using this ensures that tools can request device information without
worrying about whether the driver is cleaning up from a reset.
Specifically, it is expected that a flash update could result in
a device reset, and it is better to delay the response for information
until the reset is complete rather than exit with an immediate failure.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Tony Brelinski <tonyx.brelinski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

1 files changed, 28 insertions, 0 deletions

diff --git a/drivers/net/ethernet/intel/ice/ice_lib.c b/drivers/net/ethernet/intel/ice/ice_lib.c
index 357c5d39913d..1c636f4bb4fc 100644
--- a/drivers/net/ethernet/intel/ice/ice_lib.c
+++ b/drivers/net/ethernet/intel/ice/ice_lib.c
@@ -3218,6 +3218,34 @@ bool ice_is_reset_in_progress(unsigned long *state)
 	       test_bit(ICE_GLOBR_REQ, state);
 }
 
+/**
+ * ice_wait_for_reset - Wait for driver to finish reset and rebuild
+ * @pf: pointer to the PF structure
+ * @timeout: length of time to wait, in jiffies
+ *
+ * Wait (sleep) for a short time until the driver finishes cleaning up from
+ * a device reset. The caller must be able to sleep. Use this to delay
+ * operations that could fail while the driver is cleaning up after a device
+ * reset.
+ *
+ * Returns 0 on success, -EBUSY if the reset is not finished within the
+ * timeout, and -ERESTARTSYS if the thread was interrupted.
+ */
+int ice_wait_for_reset(struct ice_pf *pf, unsigned long timeout)
+{
+	long ret;
+
+	ret = wait_event_interruptible_timeout(pf->reset_wait_queue,
+					       !ice_is_reset_in_progress(pf->state),
+					       timeout);
+	if (ret < 0)
+		return ret;
+	else if (!ret)
+		return -EBUSY;
+	else
+		return 0;
+}
+
 #ifdef CONFIG_DCB
 /**
  * ice_vsi_update_q_map - update our copy of the VSI info with new queue map