sfc:On MCDI timeout, issue an FLR (and mark MCDI to fail-fast)

When an MCDI command times out (whether or not we find it
completed when we poll), call efx_mcdi_abandon(), which tells
all subsequent MCDI calls to fail-fast, and queues up an FLR.

Because an FLR doesn't lead to receiving any reboot even from
the MC (unlike most other types of reset), we have to call
efx_ef10_reset_mc_allocations.
In efx_start_all(), if a reset (of any kind) is pending, we
bail out.
Without this, attempts to reconfigure (e.g. change mtu) can
cause driver/mc state inconsistency if the first MCDI call
triggers an FLR.

For similar reasons, on EF10, in
efx_reset_down(method=RESET_TYPE_MCDI_TIMEOUT), set the number
of active queues to zero before calling efx_stop_all().
And, on farch, in efx_reset_up(method=RESET_TYPE_MCDI_TIMEOUT),
set active_queues and flushes pending & outstanding to zero.

efx_mcdi_mode_{poll,event}() should not take us out of fail-fast
 mode. Instead, this is done by efx_mcdi_reset() after the FLR
completes.

The new FLR reset_type RESET_TYPE_MCDI_TIMEOUT doesn't really
fit into the hierarchy of reset 'scopes' whereby efx_reset()
decides some resets subsume others.  Thus, it uses separate logic.

Also, fixed up some inconsistency around RESET_TYPE_MC_BIST,
which was in the wrong place in that hierarchy.

Signed-off-by: Shradha Shah <sshah@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 16 insertions, 7 deletions

diff --git a/drivers/net/ethernet/sfc/enum.h b/drivers/net/ethernet/sfc/enum.h
index 75ef7ef6450b..d1dbb5fb31bb 100644
--- a/drivers/net/ethernet/sfc/enum.h
+++ b/drivers/net/ethernet/sfc/enum.h
@@ -143,6 +143,7 @@ enum efx_loopback_mode {
  * @RESET_TYPE_WORLD: Reset as much as possible
  * @RESET_TYPE_RECOVER_OR_DISABLE: Try to recover. Apply RESET_TYPE_DISABLE if
  * unsuccessful.
+ * @RESET_TYPE_MC_BIST: MC entering BIST mode.
  * @RESET_TYPE_DISABLE: Reset datapath, MAC and PHY; leave NIC disabled
  * @RESET_TYPE_TX_WATCHDOG: reset due to TX watchdog
  * @RESET_TYPE_INT_ERROR: reset due to internal error
@@ -150,14 +151,16 @@ enum efx_loopback_mode {
  * @RESET_TYPE_DMA_ERROR: DMA error
  * @RESET_TYPE_TX_SKIP: hardware completed empty tx descriptors
  * @RESET_TYPE_MC_FAILURE: MC reboot/assertion
+ * @RESET_TYPE_MCDI_TIMEOUT: MCDI timeout.
  */
 enum reset_type {
-	RESET_TYPE_INVISIBLE = 0,
-	RESET_TYPE_RECOVER_OR_ALL = 1,
-	RESET_TYPE_ALL = 2,
-	RESET_TYPE_WORLD = 3,
-	RESET_TYPE_RECOVER_OR_DISABLE = 4,
-	RESET_TYPE_DISABLE = 5,
+	RESET_TYPE_INVISIBLE,
+	RESET_TYPE_RECOVER_OR_ALL,
+	RESET_TYPE_ALL,
+	RESET_TYPE_WORLD,
+	RESET_TYPE_RECOVER_OR_DISABLE,
+	RESET_TYPE_MC_BIST,
+	RESET_TYPE_DISABLE,
 	RESET_TYPE_MAX_METHOD,
 	RESET_TYPE_TX_WATCHDOG,
 	RESET_TYPE_INT_ERROR,
@@ -165,7 +168,13 @@ enum reset_type {
 	RESET_TYPE_DMA_ERROR,
 	RESET_TYPE_TX_SKIP,
 	RESET_TYPE_MC_FAILURE,
-	RESET_TYPE_MC_BIST,
+	/* RESET_TYPE_MCDI_TIMEOUT is actually a method, not just a reason, but
+	 * it doesn't fit the scope hierarchy (not well-ordered by inclusion).
+	 * We encode this by having its enum value be greater than
+	 * RESET_TYPE_MAX_METHOD. This also prevents issuing it with
+	 * efx_ioctl_reset.
+	 */
+	RESET_TYPE_MCDI_TIMEOUT,
 	RESET_TYPE_MAX,
 };