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, 13 insertions, 0 deletions

diff --git a/drivers/net/ethernet/sfc/mcdi.h b/drivers/net/ethernet/sfc/mcdi.h
index 52931aebf3c3..56465f7465a2 100644
--- a/drivers/net/ethernet/sfc/mcdi.h
+++ b/drivers/net/ethernet/sfc/mcdi.h
@@ -28,9 +28,16 @@ enum efx_mcdi_state {
 	MCDI_STATE_COMPLETED,
 };
 
+/**
+ * enum efx_mcdi_mode - MCDI transaction mode
+ * @MCDI_MODE_POLL: poll for MCDI completion, until timeout
+ * @MCDI_MODE_EVENTS: wait for an mcdi_event.  On timeout, poll once
+ * @MCDI_MODE_FAIL: we think MCDI is dead, so fail-fast all calls
+ */
 enum efx_mcdi_mode {
 	MCDI_MODE_POLL,
 	MCDI_MODE_EVENTS,
+	MCDI_MODE_FAIL,
 };
 
 /**
@@ -104,6 +111,12 @@ struct efx_mcdi_data {
 	u32 fn_flags;
 };
 
+static inline struct efx_mcdi_iface *efx_mcdi(struct efx_nic *efx)
+{
+	EFX_BUG_ON_PARANOID(!efx->mcdi);
+	return &efx->mcdi->iface;
+}
+
 #ifdef CONFIG_SFC_MCDI_MON
 static inline struct efx_mcdi_mon *efx_mcdi_mon(struct efx_nic *efx)
 {