common/sfc_efx/base: complete EvQ creation on Riverhead

Client drivers relying on interrupts will fail to complete event
queue creation on Riverhead boards as the latter have no support
for INIT_DONE events which means that it's useless to wait until
initialisation callback is triggered by interrupt-driven polling.

Client drivers which avoid interrupt-driven polling still handle
INIT_DONE events by direct polling and will fail to do so.

Solve this problem by adding an extra poll-once method which
will be called by client drivers after queue creation (probably,
with driver-specific lock being held). The method will invoke
initialisation callback on Riverhead and do nothing on the other
boards. Then the drivers will proceed with normal waiting which
will complete immediately in the case of Riverhead.

Signed-off-by: Ivan Malov <ivan.malov@oktetlabs.ru>
Signed-off-by: Andrew Rybchenko <arybchenko@solarflare.com>
Reviewed-by: Andy Moreton <amoreton@xilinx.com>

drivers/common/sfc_efx/base/efx.h

@@ -1443,6 +1443,7 @@ typedef struct efx_nic_cfg_s {
 	uint32_t		enc_vf;
 	uint32_t		enc_privilege_mask;
 #endif /* EFSYS_OPT_RIVERHEAD || EFX_OPTS_EF10() */
+	boolean_t		enc_evq_init_done_ev_supported;
 	boolean_t		enc_bug26807_workaround;
 	boolean_t		enc_bug35388_workaround;
 	boolean_t		enc_bug41750_workaround;
@@ -2430,6 +2431,13 @@ efx_ev_qprefetch(
 
 #endif	/* EFSYS_OPT_EV_PREFETCH */
 
+LIBEFX_API
+extern			void
+efx_ev_qcreate_check_init_done(
+	__in		efx_evq_t *eep,
+	__in		const efx_ev_callbacks_t *eecp,
+	__in_opt	void *arg);
+
 LIBEFX_API
 extern			void
 efx_ev_qpoll(

drivers/common/sfc_efx/base/efx_ev.c

@@ -423,6 +423,36 @@ efx_ev_qprefetch(
 
 #endif	/* EFSYS_OPT_EV_PREFETCH */
 
+/*
+ * This method is needed to ensure that eec_initialized callback
+ * is invoked after queue creation. The callback will be invoked
+ * on Riverhead boards which have no support for INIT_DONE events
+ * and will do nothing on other boards.
+ *
+ * The client drivers must call this method after calling efx_ev_create().
+ * The call must be done with the same locks being held (if any) which are
+ * normally acquired around efx_ev_qpoll() calls to ensure that
+ * eec_initialized callback is invoked within the same locking context.
+ */
+			void
+efx_ev_qcreate_check_init_done(
+	__in		efx_evq_t *eep,
+	__in		const efx_ev_callbacks_t *eecp,
+	__in_opt	void *arg)
+{
+	const efx_nic_cfg_t *encp;
+
+	EFSYS_ASSERT(eep != NULL);
+	EFSYS_ASSERT3U(eep->ee_magic, ==, EFX_EVQ_MAGIC);
+	EFSYS_ASSERT(eecp != NULL);
+	EFSYS_ASSERT(eecp->eec_initialized != NULL);
+
+	encp = efx_nic_cfg_get(eep->ee_enp);
+
+	if (encp->enc_evq_init_done_ev_supported == B_FALSE)
+		(void) eecp->eec_initialized(arg);
+}
+
 			void
 efx_ev_qpoll(
 	__in		efx_evq_t *eep,

drivers/common/sfc_efx/base/hunt_nic.c

@@ -76,6 +76,12 @@ hunt_board_cfg(
 	uint32_t bandwidth;
 	efx_rc_t rc;
 
+	/*
+	 * Event queue creation is complete when an
+	 * EVQ_INIT_DONE_EV event is received.
+	 */
+	encp->enc_evq_init_done_ev_supported = B_TRUE;
+
 	/*
 	 * Enable firmware workarounds for hardware errata.
 	 * Expected responses are:

drivers/common/sfc_efx/base/medford2_nic.c

@@ -44,6 +44,12 @@ medford2_board_cfg(
 	uint32_t bandwidth;
 	efx_rc_t rc;
 
+	/*
+	 * Event queue creation is complete when an
+	 * EVQ_INIT_DONE_EV event is received.
+	 */
+	encp->enc_evq_init_done_ev_supported = B_TRUE;
+
 	/*
 	 * Enable firmware workarounds for hardware errata.
 	 * Expected responses are:

drivers/common/sfc_efx/base/medford_nic.c

@@ -42,6 +42,12 @@ medford_board_cfg(
 	uint32_t bandwidth;
 	efx_rc_t rc;
 
+	/*
+	 * Event queue creation is complete when an
+	 * EVQ_INIT_DONE_EV event is received.
+	 */
+	encp->enc_evq_init_done_ev_supported = B_TRUE;
+
 	/*
 	 * Enable firmware workarounds for hardware errata.
 	 * Expected responses are:

drivers/common/sfc_efx/base/rhead_nic.c

@@ -51,6 +51,12 @@ rhead_board_cfg(
 
 	encp->enc_buftbl_limit = UINT32_MAX;
 
+	/*
+	 * Riverhead event queue creation completes
+	 * immediately (no initial event).
+	 */
+	encp->enc_evq_init_done_ev_supported = B_FALSE;
+
 	/*
 	 * Enable firmware workarounds for hardware errata.
 	 * Expected responses are:

drivers/common/sfc_efx/base/siena_nic.c

@@ -135,6 +135,12 @@ siena_board_cfg(
 	encp->enc_rx_scale_additional_modes_supported = B_FALSE;
 #endif /* EFSYS_OPT_RX_SCALE */
 
+	/*
+	 * Event queue creation is complete when an
+	 * EVQ_INIT_DONE_EV event is received.
+	 */
+	encp->enc_evq_init_done_ev_supported = B_TRUE;
+
 	encp->enc_tx_dma_desc_size_max = EFX_MASK32(FSF_AZ_TX_KER_BYTE_COUNT);
 	/* Fragments must not span 4k boundaries. */
 	encp->enc_tx_dma_desc_boundary = 4096;

drivers/common/sfc_efx/rte_common_sfc_efx_version.map

@@ -6,6 +6,7 @@ INTERNAL {
 	efx_ev_fini;
 	efx_ev_init;
 	efx_ev_qcreate;
+	efx_ev_qcreate_check_init_done;
 	efx_ev_qdestroy;
 	efx_ev_qmoderate;
 	efx_ev_qpending;

drivers/net/sfc/sfc_ev.c

@@ -608,6 +608,8 @@ sfc_ev_qstart(struct sfc_evq *evq, unsigned int hw_index)
 	else
 		evq_flags |= EFX_EVQ_FLAGS_NOTIFY_DISABLED;
 
+	evq->init_state = SFC_EVQ_STARTING;
+
 	/* Create the common code event queue */
 	rc = efx_ev_qcreate(sa->nic, hw_index, esmp, evq->entries,
 			    0 /* unused on EF10 */, 0, evq_flags,
@@ -632,7 +634,13 @@ sfc_ev_qstart(struct sfc_evq *evq, unsigned int hw_index)
 		evq->callbacks = &sfc_ev_callbacks;
 	}
 
-	evq->init_state = SFC_EVQ_STARTING;
+	/*
+	 * Poll once to ensure that eec_initialized callback is invoked in
+	 * case if the hardware does not support INIT_DONE events. If the
+	 * hardware supports INIT_DONE events, this will do nothing, and the
+	 * corresponding event will be processed by sfc_ev_qpoll() below.
+	 */
+	efx_ev_qcreate_check_init_done(evq->common, evq->callbacks, evq);
 
 	/* Wait for the initialization event */
 	total_delay_us = 0;
@@ -665,10 +673,10 @@ done:
 	return 0;
 
 fail_timedout:
-	evq->init_state = SFC_EVQ_INITIALIZED;
 	efx_ev_qdestroy(evq->common);
 
 fail_ev_qcreate:
+	evq->init_state = SFC_EVQ_INITIALIZED;
 	sfc_log_init(sa, "failed %d", rc);
 	return rc;
 }