[dpdk-dev] [PATCH 49/60] common/sfc_efx/base: introduce states for UDP tunnel entries

[Andrew Rybchenko <arybchenko@solarflare.com>]

From: Igor Romanov <igor.romanov@oktetlabs.ru>

UDP tunnel reconfigure operation takes UDP tunnel table, which contains
entries that need to be applied to HW. This approach does not retain
information about what entries were removed or added, which is required
for Riverhead.

Add states to the table entries to indicate add or remove operations.
On tunnel reconfiguration added and removed entries become busy to
indicate that the entries are currently configured and to prevent add or
remove operations from other threads. After tunnel reconfiguration is
complete, the states are reset - added entries become applied and
removed entries are purged from the table.

Signed-off-by: Igor Romanov <igor.romanov@oktetlabs.ru>
Signed-off-by: Andrew Rybchenko <arybchenko@solarflare.com>
Reviewed-by: Andy Moreton <amoreton@xilinx.com>
---
 drivers/common/sfc_efx/base/efx.h        |   9 +-
 drivers/common/sfc_efx/base/efx_impl.h   |   9 +
 drivers/common/sfc_efx/base/efx_tunnel.c | 276 +++++++++++++++++++++--
 3 files changed, 269 insertions(+), 25 deletions(-)

diff --git a/drivers/common/sfc_efx/base/efx.h b/drivers/common/sfc_efx/base/efx.h
index f6dd9db301..b603e263e6 100644
--- a/drivers/common/sfc_efx/base/efx.h
+++ b/drivers/common/sfc_efx/base/efx.h
@@ -3659,6 +3659,9 @@ efx_tunnel_config_udp_add(
 	__in		uint16_t port /* host/cpu-endian */,
 	__in		efx_tunnel_protocol_t protocol);
 
+/*
+ * Returns EBUSY if reconfiguration of the port is in progress in other thread.
+ */
 LIBEFX_API
 extern	__checkReturn	efx_rc_t
 efx_tunnel_config_udp_remove(
@@ -3666,8 +3669,12 @@ efx_tunnel_config_udp_remove(
 	__in		uint16_t port /* host/cpu-endian */,
 	__in		efx_tunnel_protocol_t protocol);
 
+/*
+ * Returns EBUSY if reconfiguration of any of the tunnel entries
+ * is in progress in other thread.
+ */
 LIBEFX_API
-extern			void
+extern	__checkReturn	efx_rc_t
 efx_tunnel_config_clear(
 	__in		efx_nic_t *enp);
 
diff --git a/drivers/common/sfc_efx/base/efx_impl.h b/drivers/common/sfc_efx/base/efx_impl.h
index 64156de884..1ae4eeaf88 100644
--- a/drivers/common/sfc_efx/base/efx_impl.h
+++ b/drivers/common/sfc_efx/base/efx_impl.h
@@ -489,9 +489,18 @@ siena_filter_tbl_clear(
 
 #if EFSYS_OPT_TUNNEL
 
+/* State of a UDP tunnel table entry */
+typedef enum efx_tunnel_udp_entry_state_e {
+	EFX_TUNNEL_UDP_ENTRY_ADDED, /* Tunnel addition is requested */
+	EFX_TUNNEL_UDP_ENTRY_REMOVED, /* Tunnel removal is requested */
+	EFX_TUNNEL_UDP_ENTRY_APPLIED, /* Tunnel is applied by HW */
+} efx_tunnel_udp_entry_state_t;
+
 typedef struct efx_tunnel_udp_entry_s {
 	uint16_t			etue_port; /* host/cpu-endian */
 	uint16_t			etue_protocol;
+	boolean_t			etue_busy;
+	efx_tunnel_udp_entry_state_t	etue_state;
 } efx_tunnel_udp_entry_t;
 
 typedef struct efx_tunnel_cfg_s {
diff --git a/drivers/common/sfc_efx/base/efx_tunnel.c b/drivers/common/sfc_efx/base/efx_tunnel.c
index 5f2186c4c8..204871e00d 100644
--- a/drivers/common/sfc_efx/base/efx_tunnel.c
+++ b/drivers/common/sfc_efx/base/efx_tunnel.c
@@ -7,6 +7,43 @@
 #include "efx.h"
 #include "efx_impl.h"
 
+/*
+ * State diagram of the UDP tunnel table entries
+ * (efx_tunnel_udp_entry_state_t and busy flag):
+ *
+ *                             +---------+
+ *                    +--------| APPLIED |<-------+
+ *                    |        +---------+        |
+ *                    |                           |
+ *                    |                efx_tunnel_reconfigure (end)
+ *   efx_tunnel_config_udp_remove                 |
+ *                    |                    +------------+
+ *                    v                    | BUSY ADDED |
+ *               +---------+               +------------+
+ *               | REMOVED |                      ^
+ *               +---------+                      |
+ *                    |               efx_tunnel_reconfigure (begin)
+ *  efx_tunnel_reconfigure (begin)                |
+ *                    |                           |
+ *                    v                     +-----------+
+ *            +--------------+              |   ADDED   |<---------+
+ *            | BUSY REMOVED |              +-----------+          |
+ *            +--------------+                    |                |
+ *                    |              efx_tunnel_config_udp_remove  |
+ *  efx_tunnel_reconfigure (end)                  |                |
+ *                    |                           |                |
+ *                    |        +---------+        |                |
+ *                    |        |+-------+|        |                |
+ *                    +------->|| empty ||<-------+                |
+ *                             |+-------+|                         |
+ *                             +---------+        efx_tunnel_config_udp_add
+ *                                  |                              |
+ *                                  +------------------------------+
+ *
+ * Note that there is no BUSY APPLIED state since removing an applied entry
+ * should not be blocked by ongoing reconfiguration in another thread -
+ * reconfiguration will remove only busy entries.
+ */
 
 #if EFSYS_OPT_TUNNEL
 
@@ -36,6 +73,24 @@ static const efx_tunnel_ops_t	__efx_tunnel_ef10_ops = {
 };
 #endif /* EFSYS_OPT_MEDFORD || EFSYS_OPT_MEDFORD2 */
 
+/* Indicates that an entry is to be set */
+static	__checkReturn		boolean_t
+ef10_entry_staged(
+	__in			efx_tunnel_udp_entry_t *entry)
+{
+	switch (entry->etue_state) {
+	case EFX_TUNNEL_UDP_ENTRY_ADDED:
+		return (entry->etue_busy);
+	case EFX_TUNNEL_UDP_ENTRY_REMOVED:
+		return (!entry->etue_busy);
+	case EFX_TUNNEL_UDP_ENTRY_APPLIED:
+		return (B_TRUE);
+	default:
+		EFSYS_ASSERT(0);
+		return (B_FALSE);
+	}
+}
+
 static	__checkReturn		efx_rc_t
 efx_mcdi_set_tunnel_encap_udp_ports(
 	__in			efx_nic_t *enp,
@@ -51,11 +106,17 @@ efx_mcdi_set_tunnel_encap_udp_ports(
 	efx_rc_t rc;
 	unsigned int i;
 	unsigned int entries_num;
+	unsigned int entry;
 
-	if (etcp == NULL)
-		entries_num = 0;
-	else
-		entries_num = etcp->etc_udp_entries_num;
+	entries_num = 0;
+	if (etcp != NULL) {
+		for (i = 0; i < etcp->etc_udp_entries_num; i++) {
+			if (ef10_entry_staged(&etcp->etc_udp_entries[i]) !=
+			    B_FALSE) {
+				entries_num++;
+			}
+		}
+	}
 
 	req.emr_cmd = MC_CMD_SET_TUNNEL_ENCAP_UDP_PORTS;
 	req.emr_in_buf = payload;
@@ -73,9 +134,12 @@ efx_mcdi_set_tunnel_encap_udp_ports(
 	MCDI_IN_SET_WORD(req, SET_TUNNEL_ENCAP_UDP_PORTS_IN_NUM_ENTRIES,
 	    entries_num);
 
-	for (i = 0; i < entries_num; ++i) {
+	for (i = 0, entry = 0; entry < entries_num; ++entry, ++i) {
 		uint16_t mcdi_udp_protocol;
 
+		while (ef10_entry_staged(&etcp->etc_udp_entries[i]) == B_FALSE)
+			i++;
+
 		switch (etcp->etc_udp_entries[i].etue_protocol) {
 		case EFX_TUNNEL_PROTOCOL_VXLAN:
 			mcdi_udp_protocol = TUNNEL_ENCAP_UDP_PORT_ENTRY_VXLAN;
@@ -97,7 +161,7 @@ efx_mcdi_set_tunnel_encap_udp_ports(
 		    TUNNEL_ENCAP_UDP_PORT_ENTRY_LEN);
 		EFX_POPULATE_DWORD_2(
 		    MCDI_IN2(req, efx_dword_t,
-			SET_TUNNEL_ENCAP_UDP_PORTS_IN_ENTRIES)[i],
+			SET_TUNNEL_ENCAP_UDP_PORTS_IN_ENTRIES)[entry],
 		    TUNNEL_ENCAP_UDP_PORT_ENTRY_UDP_PORT,
 		    etcp->etc_udp_entries[i].etue_port,
 		    TUNNEL_ENCAP_UDP_PORT_ENTRY_PROTOCOL,
@@ -230,7 +294,8 @@ efx_tunnel_config_find_udp_tunnel_entry(
 	for (i = 0; i < etcp->etc_udp_entries_num; ++i) {
 		efx_tunnel_udp_entry_t *p = &etcp->etc_udp_entries[i];
 
-		if (p->etue_port == port) {
+		if (p->etue_port == port &&
+		    p->etue_state != EFX_TUNNEL_UDP_ENTRY_REMOVED) {
 			*entryp = i;
 			return (0);
 		}
@@ -281,6 +346,8 @@ efx_tunnel_config_udp_add(
 	etcp->etc_udp_entries[etcp->etc_udp_entries_num].etue_port = port;
 	etcp->etc_udp_entries[etcp->etc_udp_entries_num].etue_protocol =
 	    protocol;
+	etcp->etc_udp_entries[etcp->etc_udp_entries_num].etue_state =
+	    EFX_TUNNEL_UDP_ENTRY_ADDED;
 
 	etcp->etc_udp_entries_num++;
 
@@ -304,6 +371,61 @@ efx_tunnel_config_udp_add(
 	return (rc);
 }
 
+/*
+ * Returns the index of the entry after the deleted one,
+ * or one past the last entry.
+ */
+static			unsigned int
+efx_tunnel_config_udp_do_remove(
+	__in		efx_tunnel_cfg_t *etcp,
+	__in		unsigned int entry)
+{
+	EFSYS_ASSERT3U(etcp->etc_udp_entries_num, >, 0);
+	etcp->etc_udp_entries_num--;
+
+	if (entry < etcp->etc_udp_entries_num) {
+		memmove(&etcp->etc_udp_entries[entry],
+		    &etcp->etc_udp_entries[entry + 1],
+		    (etcp->etc_udp_entries_num - entry) *
+		    sizeof (etcp->etc_udp_entries[0]));
+	}
+
+	memset(&etcp->etc_udp_entries[etcp->etc_udp_entries_num], 0,
+	    sizeof (etcp->etc_udp_entries[0]));
+
+	return (entry);
+}
+
+/*
+ * Returns the index of the entry after the specified one,
+ * or one past the last entry. The index is correct whether
+ * the specified entry was removed or not.
+ */
+static			unsigned int
+efx_tunnel_config_udp_remove_prepare(
+	__in		efx_tunnel_cfg_t *etcp,
+	__in		unsigned int entry)
+{
+	unsigned int next = entry + 1;
+
+	switch (etcp->etc_udp_entries[entry].etue_state) {
+	case EFX_TUNNEL_UDP_ENTRY_ADDED:
+		next = efx_tunnel_config_udp_do_remove(etcp, entry);
+		break;
+	case EFX_TUNNEL_UDP_ENTRY_REMOVED:
+		break;
+	case EFX_TUNNEL_UDP_ENTRY_APPLIED:
+		etcp->etc_udp_entries[entry].etue_state =
+		    EFX_TUNNEL_UDP_ENTRY_REMOVED;
+		break;
+	default:
+		EFSYS_ASSERT(0);
+		break;
+	}
+
+	return (next);
+}
+
 	__checkReturn	efx_rc_t
 efx_tunnel_config_udp_remove(
 	__in		efx_nic_t *enp,
@@ -323,28 +445,25 @@ efx_tunnel_config_udp_remove(
 	if (rc != 0)
 		goto fail1;
 
-	if (etcp->etc_udp_entries[entry].etue_protocol != protocol) {
-		rc = EINVAL;
+	if (etcp->etc_udp_entries[entry].etue_busy != B_FALSE) {
+		rc = EBUSY;
 		goto fail2;
 	}
 
-	EFSYS_ASSERT3U(etcp->etc_udp_entries_num, >, 0);
-	etcp->etc_udp_entries_num--;
-
-	if (entry < etcp->etc_udp_entries_num) {
-		memmove(&etcp->etc_udp_entries[entry],
-		    &etcp->etc_udp_entries[entry + 1],
-		    (etcp->etc_udp_entries_num - entry) *
-		    sizeof (etcp->etc_udp_entries[0]));
+	if (etcp->etc_udp_entries[entry].etue_protocol != protocol) {
+		rc = EINVAL;
+		goto fail3;
 	}
 
-	memset(&etcp->etc_udp_entries[etcp->etc_udp_entries_num], 0,
-	    sizeof (etcp->etc_udp_entries[0]));
+	(void) efx_tunnel_config_udp_remove_prepare(etcp, entry);
 
 	EFSYS_UNLOCK(enp->en_eslp, state);
 
 	return (0);
 
+fail3:
+	EFSYS_PROBE(fail3);
+
 fail2:
 	EFSYS_PROBE(fail2);
 
@@ -355,21 +474,51 @@ efx_tunnel_config_udp_remove(
 	return (rc);
 }
 
-			void
+static			boolean_t
+efx_tunnel_table_all_available(
+	__in			efx_tunnel_cfg_t *etcp)
+{
+	unsigned int i;
+
+	for (i = 0; i < etcp->etc_udp_entries_num; i++) {
+		if (etcp->etc_udp_entries[i].etue_busy != B_FALSE)
+			return (B_FALSE);
+	}
+
+	return (B_TRUE);
+}
+
+	__checkReturn	efx_rc_t
 efx_tunnel_config_clear(
 	__in			efx_nic_t *enp)
 {
 	efx_tunnel_cfg_t *etcp = &enp->en_tunnel_cfg;
 	efsys_lock_state_t state;
+	unsigned int i;
+	efx_rc_t rc;
 
 	EFSYS_ASSERT3U(enp->en_mod_flags, &, EFX_MOD_TUNNEL);
 
 	EFSYS_LOCK(enp->en_eslp, state);
 
-	etcp->etc_udp_entries_num = 0;
-	memset(etcp->etc_udp_entries, 0, sizeof (etcp->etc_udp_entries));
+	if (efx_tunnel_table_all_available(etcp) == B_FALSE) {
+		rc = EBUSY;
+		goto fail1;
+	}
+
+	i = 0;
+	while (i < etcp->etc_udp_entries_num)
+		i = efx_tunnel_config_udp_remove_prepare(etcp, i);
 
 	EFSYS_UNLOCK(enp->en_eslp, state);
+
+	return (0);
+
+fail1:
+	EFSYS_PROBE1(fail1, efx_rc_t, rc);
+	EFSYS_UNLOCK(enp->en_eslp, state);
+
+	return (rc);
 }
 
 	__checkReturn	efx_rc_t
@@ -377,6 +526,12 @@ efx_tunnel_reconfigure(
 	__in		efx_nic_t *enp)
 {
 	const efx_tunnel_ops_t *etop = enp->en_etop;
+	efx_tunnel_cfg_t *etcp = &enp->en_tunnel_cfg;
+	efx_tunnel_udp_entry_t *entry;
+	boolean_t locked = B_FALSE;
+	efsys_lock_state_t state;
+	boolean_t resetting;
+	unsigned int i;
 	efx_rc_t rc;
 
 	EFSYS_ASSERT3U(enp->en_mod_flags, &, EFX_MOD_TUNNEL);
@@ -386,16 +541,89 @@ efx_tunnel_reconfigure(
 		goto fail1;
 	}
 
-	if ((rc = enp->en_etop->eto_reconfigure(enp)) != 0)
+	EFSYS_LOCK(enp->en_eslp, state);
+	locked = B_TRUE;
+
+	if (efx_tunnel_table_all_available(etcp) == B_FALSE) {
+		rc = EBUSY;
 		goto fail2;
+	}
 
-	return (0);
+	for (i = 0; i < etcp->etc_udp_entries_num; i++) {
+		entry = &etcp->etc_udp_entries[i];
+		if (entry->etue_state != EFX_TUNNEL_UDP_ENTRY_APPLIED)
+			entry->etue_busy = B_TRUE;
+	}
+
+	EFSYS_UNLOCK(enp->en_eslp, state);
+	locked = B_FALSE;
+
+	rc = enp->en_etop->eto_reconfigure(enp);
+	if (rc != 0 && rc != EAGAIN)
+		goto fail3;
+
+	resetting = (rc == EAGAIN) ? B_TRUE : B_FALSE;
+
+	EFSYS_LOCK(enp->en_eslp, state);
+	locked = B_TRUE;
+
+	/*
+	 * Delete entries marked for removal since they are no longer
+	 * needed after successful NIC-specific reconfiguration.
+	 * Added entries become applied because they are installed in
+	 * the hardware.
+	 */
+
+	i = 0;
+	while (i < etcp->etc_udp_entries_num) {
+		unsigned int next = i + 1;
+
+		entry = &etcp->etc_udp_entries[i];
+		if (entry->etue_busy != B_FALSE) {
+			entry->etue_busy = B_FALSE;
+
+			switch (entry->etue_state) {
+			case EFX_TUNNEL_UDP_ENTRY_APPLIED:
+				break;
+			case EFX_TUNNEL_UDP_ENTRY_ADDED:
+				entry->etue_state =
+				    EFX_TUNNEL_UDP_ENTRY_APPLIED;
+				break;
+			case EFX_TUNNEL_UDP_ENTRY_REMOVED:
+				next = efx_tunnel_config_udp_do_remove(etcp, i);
+				break;
+			default:
+				EFSYS_ASSERT(0);
+				break;
+			}
+		}
+
+		i = next;
+	}
+
+	EFSYS_UNLOCK(enp->en_eslp, state);
+	locked = B_FALSE;
+
+	return ((resetting == B_FALSE) ? 0 : EAGAIN);
+
+fail3:
+	EFSYS_PROBE(fail3);
+
+	EFSYS_ASSERT(locked == B_FALSE);
+	EFSYS_LOCK(enp->en_eslp, state);
+
+	for (i = 0; i < etcp->etc_udp_entries_num; i++)
+		etcp->etc_udp_entries[i].etue_busy = B_FALSE;
+
+	EFSYS_UNLOCK(enp->en_eslp, state);
 
 fail2:
 	EFSYS_PROBE(fail2);
 
 fail1:
 	EFSYS_PROBE1(fail1, efx_rc_t, rc);
+	if (locked)
+		EFSYS_UNLOCK(enp->en_eslp, state);
 
 	return (rc);
 }
-- 
2.17.1