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, 4 insertions, 0 deletions

diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h
index 8a400a0595eb..5bdae8ed7c57 100644
--- a/drivers/net/ethernet/sfc/net_driver.h
+++ b/drivers/net/ethernet/sfc/net_driver.h
@@ -972,6 +972,8 @@ struct efx_mtd_partition {
  *	(for Falcon architecture)
  * @finish_flush: Clean up after flushing the DMA queues (for Falcon
  *	architecture)
+ * @prepare_flr: Prepare for an FLR
+ * @finish_flr: Clean up after an FLR
  * @describe_stats: Describe statistics for ethtool
  * @update_stats: Update statistics not provided by event handling.
  *	Either argument may be %NULL.
@@ -1100,6 +1102,8 @@ struct efx_nic_type {
 	int (*fini_dmaq)(struct efx_nic *efx);
 	void (*prepare_flush)(struct efx_nic *efx);
 	void (*finish_flush)(struct efx_nic *efx);
+	void (*prepare_flr)(struct efx_nic *efx);
+	void (*finish_flr)(struct efx_nic *efx);
 	size_t (*describe_stats)(struct efx_nic *efx, u8 *names);
 	size_t (*update_stats)(struct efx_nic *efx, u64 *full_stats,
 			       struct rtnl_link_stats64 *core_stats);