[PATCH v3 0/5] SAN Congestion Management (SCM) statistics

[PATCH v3 0/5] SAN Congestion Management (SCM) statistics

[Nilesh Javali]

Martin,

Please apply the attached patchset implementing the SAN Congestion
Management (SCM) statistics to the scsi tree at your earliest
convenience.

v2->v3:
Incorporate review comments for patch v2 3/5.
Added Reviewed-by tag for other patches.

v1->v2:
Further break down patches based on functionality.
Remove dependency on LLDs for remote port FPIN statistics.
Optimize fc_find_rport_by_wwpn implementation.
Name changes to multiple variables/structure elements based on review
comments.

Thanks,
Nilesh

Shyam Sundar (5):
  scsi: fc: Update formal FPIN descriptor definitions
  scsi: fc: Add FPIN statistics to fc_host and fc_rport objects
  scsi: fc: Parse FPIN packets and update statistics
  scsi: fc: Add mechanism to update FPIN signal statistics
  scsi: fc: Update documentation of sysfs nodes for FPIN stats

 Documentation/ABI/testing/sysfs-class-fc_host |  23 +
 .../ABI/testing/sysfs-class-fc_remote_ports   |  23 +
 drivers/scsi/scsi_transport_fc.c              | 415 ++++++++++++++++++
 include/scsi/scsi_transport_fc.h              |  36 ++
 include/uapi/scsi/fc/fc_els.h                 | 114 ++++-
 5 files changed, 610 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/ABI/testing/sysfs-class-fc_host
 create mode 100644 Documentation/ABI/testing/sysfs-class-fc_remote_ports


base-commit: 1ef16a407f544408d3559e4de2ed05591df4da75
-- 
2.19.0.rc0

[PATCH v3 1/5] scsi: fc: Update formal FPIN descriptor definitions

[Nilesh Javali]

From: Shyam Sundar <ssundar@marvell.com>

Add Fabric Performance Impact Notification (FPIN) descriptor definition
for the following FPINs:
Delivery Notification Descriptor
Peer Congestion Notification Descriptor
Congestion Notification Descriptor

Signed-off-by: Shyam Sundar <ssundar@marvell.com>
Signed-off-by: Nilesh Javali <njavali@marvell.com>
Reviewed-by: James Smart <james.smart@broadcom.com>
---
 include/uapi/scsi/fc/fc_els.h | 114 +++++++++++++++++++++++++++++++++-
 1 file changed, 113 insertions(+), 1 deletion(-)

diff --git a/include/uapi/scsi/fc/fc_els.h b/include/uapi/scsi/fc/fc_els.h
index 8c704e510e39..91d4be987220 100644
--- a/include/uapi/scsi/fc/fc_els.h
+++ b/include/uapi/scsi/fc/fc_els.h
@@ -916,7 +916,9 @@ enum fc_els_clid_ic {
 	ELS_CLID_IC_LIP =	8,	/* receiving LIP */
 };
 
-
+/*
+ * Link Integrity event types
+ */
 enum fc_fpin_li_event_types {
 	FPIN_LI_UNKNOWN =		0x0,
 	FPIN_LI_LINK_FAILURE =		0x1,
@@ -943,6 +945,54 @@ enum fc_fpin_li_event_types {
 	{ FPIN_LI_DEVICE_SPEC,		"Device Specific" },		\
 }
 
+/*
+ * Delivery event types
+ */
+enum fc_fpin_deli_event_types {
+	FPIN_DELI_UNKNOWN =		0x0,
+	FPIN_DELI_TIMEOUT =		0x1,
+	FPIN_DELI_UNABLE_TO_ROUTE =	0x2,
+	FPIN_DELI_DEVICE_SPEC =		0xF,
+};
+
+/*
+ * Initializer useful for decoding table.
+ * Please keep this in sync with the above definitions.
+ */
+#define FC_FPIN_DELI_EVT_TYPES_INIT {					\
+	{ FPIN_DELI_UNKNOWN,		"Unknown" },			\
+	{ FPIN_DELI_TIMEOUT,		"Timeout" },			\
+	{ FPIN_DELI_UNABLE_TO_ROUTE,	"Unable to Route" },		\
+	{ FPIN_DELI_DEVICE_SPEC,	"Device Specific" },		\
+}
+
+/*
+ * Congestion event types
+ */
+enum fc_fpin_congn_event_types {
+	FPIN_CONGN_CLEAR =		0x0,
+	FPIN_CONGN_LOST_CREDIT =	0x1,
+	FPIN_CONGN_CREDIT_STALL =	0x2,
+	FPIN_CONGN_OVERSUBSCRIPTION =	0x3,
+	FPIN_CONGN_DEVICE_SPEC =	0xF,
+};
+
+/*
+ * Initializer useful for decoding table.
+ * Please keep this in sync with the above definitions.
+ */
+#define FC_FPIN_CONGN_EVT_TYPES_INIT {					\
+	{ FPIN_CONGN_CLEAR,		"Clear" },			\
+	{ FPIN_CONGN_LOST_CREDIT,	"Lost Credit" },		\
+	{ FPIN_CONGN_CREDIT_STALL,	"Credit Stall" },		\
+	{ FPIN_CONGN_OVERSUBSCRIPTION,	"Oversubscription" },		\
+	{ FPIN_CONGN_DEVICE_SPEC,	"Device Specific" },		\
+}
+
+enum fc_fpin_congn_severity_types {
+	FPIN_CONGN_SEVERITY_WARNING =	0xF1,
+	FPIN_CONGN_SEVERITY_ERROR =	0xF7,
+};
 
 /*
  * Link Integrity Notification Descriptor
@@ -974,6 +1024,68 @@ struct fc_fn_li_desc {
 					 */
 };
 
+/*
+ * Delivery Notification Descriptor
+ */
+struct fc_fn_deli_desc {
+	__be32		desc_tag;	/* Descriptor Tag (0x00020002) */
+	__be32		desc_len;	/* Length of Descriptor (in bytes).
+					 * Size of descriptor excluding
+					 * desc_tag and desc_len fields.
+					 */
+	__be64		detecting_wwpn;	/* Port Name that detected event */
+	__be64		attached_wwpn;	/* Port Name of device attached to
+					 * detecting Port Name
+					 */
+	__be32		deli_reason_code;/* see enum fc_fpin_deli_event_types */
+};
+
+/*
+ * Peer Congestion Notification Descriptor
+ */
+struct fc_fn_peer_congn_desc {
+	__be32		desc_tag;	/* Descriptor Tag (0x00020003) */
+	__be32		desc_len;	/* Length of Descriptor (in bytes).
+					 * Size of descriptor excluding
+					 * desc_tag and desc_len fields.
+					 */
+	__be64		detecting_wwpn;	/* Port Name that detected event */
+	__be64		attached_wwpn;	/* Port Name of device attached to
+					 * detecting Port Name
+					 */
+	__be16		event_type;	/* see enum fc_fpin_congn_event_types */
+	__be16		event_modifier;	/* Implementation specific value
+					 * describing the event type
+					 */
+	__be32		event_period;	/* duration (ms) of the detected
+					 * congestion event
+					 */
+	__be32		pname_count;	/* number of portname_list elements */
+	__be64		pname_list[0];	/* list of N_Port_Names accessible
+					 * through the attached port
+					 */
+};
+
+/*
+ * Congestion Notification Descriptor
+ */
+struct fc_fn_congn_desc {
+	__be32		desc_tag;	/* Descriptor Tag (0x00020004) */
+	__be32		desc_len;	/* Length of Descriptor (in bytes).
+					 * Size of descriptor excluding
+					 * desc_tag and desc_len fields.
+					 */
+	__be16		event_type;	/* see enum fc_fpin_congn_event_types */
+	__be16		event_modifier;	/* Implementation specific value
+					 * describing the event type
+					 */
+	__be32		event_period;	/* duration (ms) of the detected
+					 * congestion event
+					 */
+	__u8		severity;	/* command */
+	__u8		resv[3];	/* reserved - must be zero */
+};
+
 /*
  * ELS_FPIN - Fabric Performance Impact Notification
  */
-- 
2.19.0.rc0

[PATCH v3 2/5] scsi: fc: Add FPIN statistics to fc_host and fc_rport objects

[Nilesh Javali]

From: Shyam Sundar <ssundar@marvell.com>

- Adds a structure for holding fpin stats for host & rport

- Adds sysfs nodes to maintain FPIN stats:
        /sys/class/fc_host/hostXX/statistics/
        /sys/class/fc_remote_ports/rport-XX\:Y-Z/statistics/

Signed-off-by: Shyam Sundar <ssundar@marvell.com>
Signed-off-by: Nilesh Javali <njavali@marvell.com>
Reviewed-by: James Smart <james.smart@broadcom.com>
---
 drivers/scsi/scsi_transport_fc.c | 117 +++++++++++++++++++++++++++++++
 include/scsi/scsi_transport_fc.h |  32 +++++++++
 2 files changed, 149 insertions(+)

diff --git a/drivers/scsi/scsi_transport_fc.c b/drivers/scsi/scsi_transport_fc.c
index 2ff7f06203da..501e165ae6f1 100644
--- a/drivers/scsi/scsi_transport_fc.c
+++ b/drivers/scsi/scsi_transport_fc.c
@@ -22,6 +22,7 @@
 #include <net/netlink.h>
 #include <scsi/scsi_netlink_fc.h>
 #include <scsi/scsi_bsg_fc.h>
+#include <uapi/scsi/fc/fc_els.h>
 #include "scsi_priv.h"
 
 static int fc_queue_work(struct Scsi_Host *, struct work_struct *);
@@ -419,6 +420,7 @@ static int fc_host_setup(struct transport_container *tc, struct device *dev,
 	fc_host->fabric_name = -1;
 	memset(fc_host->symbolic_name, 0, sizeof(fc_host->symbolic_name));
 	memset(fc_host->system_hostname, 0, sizeof(fc_host->system_hostname));
+	memset(&fc_host->fpin_stats, 0, sizeof(fc_host->fpin_stats));
 
 	fc_host->tgtid_bind_type = FC_TGTID_BIND_BY_WWPN;
 
@@ -991,6 +993,67 @@ store_fc_rport_fast_io_fail_tmo(struct device *dev,
 static FC_DEVICE_ATTR(rport, fast_io_fail_tmo, S_IRUGO | S_IWUSR,
 	show_fc_rport_fast_io_fail_tmo, store_fc_rport_fast_io_fail_tmo);
 
+#define fc_rport_fpin_statistic(name)					\
+static ssize_t fc_rport_fpinstat_##name(struct device *cd,		\
+				  struct device_attribute *attr,	\
+				  char *buf)				\
+{									\
+	struct fc_rport *rport = transport_class_to_rport(cd);		\
+									\
+	return snprintf(buf, 20, "0x%llx\n", rport->fpin_stats.name);	\
+}									\
+static FC_DEVICE_ATTR(rport, fpin_##name, 0444, fc_rport_fpinstat_##name, NULL)
+
+fc_rport_fpin_statistic(dn);
+fc_rport_fpin_statistic(dn_unknown);
+fc_rport_fpin_statistic(dn_timeout);
+fc_rport_fpin_statistic(dn_unable_to_route);
+fc_rport_fpin_statistic(dn_device_specific);
+fc_rport_fpin_statistic(cn);
+fc_rport_fpin_statistic(cn_clear);
+fc_rport_fpin_statistic(cn_lost_credit);
+fc_rport_fpin_statistic(cn_credit_stall);
+fc_rport_fpin_statistic(cn_oversubscription);
+fc_rport_fpin_statistic(cn_device_specific);
+fc_rport_fpin_statistic(li);
+fc_rport_fpin_statistic(li_failure_unknown);
+fc_rport_fpin_statistic(li_link_failure_count);
+fc_rport_fpin_statistic(li_loss_of_sync_count);
+fc_rport_fpin_statistic(li_loss_of_signals_count);
+fc_rport_fpin_statistic(li_prim_seq_err_count);
+fc_rport_fpin_statistic(li_invalid_tx_word_count);
+fc_rport_fpin_statistic(li_invalid_crc_count);
+fc_rport_fpin_statistic(li_device_specific);
+
+static struct attribute *fc_rport_statistics_attrs[] = {
+	&device_attr_rport_fpin_dn.attr,
+	&device_attr_rport_fpin_dn_unknown.attr,
+	&device_attr_rport_fpin_dn_timeout.attr,
+	&device_attr_rport_fpin_dn_unable_to_route.attr,
+	&device_attr_rport_fpin_dn_device_specific.attr,
+	&device_attr_rport_fpin_li.attr,
+	&device_attr_rport_fpin_li_failure_unknown.attr,
+	&device_attr_rport_fpin_li_link_failure_count.attr,
+	&device_attr_rport_fpin_li_loss_of_sync_count.attr,
+	&device_attr_rport_fpin_li_loss_of_signals_count.attr,
+	&device_attr_rport_fpin_li_prim_seq_err_count.attr,
+	&device_attr_rport_fpin_li_invalid_tx_word_count.attr,
+	&device_attr_rport_fpin_li_invalid_crc_count.attr,
+	&device_attr_rport_fpin_li_device_specific.attr,
+	&device_attr_rport_fpin_cn.attr,
+	&device_attr_rport_fpin_cn_clear.attr,
+	&device_attr_rport_fpin_cn_lost_credit.attr,
+	&device_attr_rport_fpin_cn_credit_stall.attr,
+	&device_attr_rport_fpin_cn_oversubscription.attr,
+	&device_attr_rport_fpin_cn_device_specific.attr,
+	NULL
+};
+
+static struct attribute_group fc_rport_statistics_group = {
+	.name = "statistics",
+	.attrs = fc_rport_statistics_attrs,
+};
+
 
 /*
  * FC SCSI Target Attribute Management
@@ -1745,6 +1808,39 @@ fc_host_statistic(fc_xid_busy);
 fc_host_statistic(fc_seq_not_found);
 fc_host_statistic(fc_non_bls_resp);
 
+#define fc_host_fpin_statistic(name)					\
+static ssize_t fc_host_fpinstat_##name(struct device *cd,		\
+				  struct device_attribute *attr,	\
+				  char *buf)				\
+{									\
+	struct Scsi_Host *shost = transport_class_to_shost(cd);		\
+	struct fc_host_attrs *fc_host = shost_to_fc_host(shost);	\
+									\
+	return snprintf(buf, 20, "0x%llx\n", fc_host->fpin_stats.name);	\
+}									\
+static FC_DEVICE_ATTR(host, fpin_##name, 0444, fc_host_fpinstat_##name, NULL)
+
+fc_host_fpin_statistic(dn);
+fc_host_fpin_statistic(dn_unknown);
+fc_host_fpin_statistic(dn_timeout);
+fc_host_fpin_statistic(dn_unable_to_route);
+fc_host_fpin_statistic(dn_device_specific);
+fc_host_fpin_statistic(cn);
+fc_host_fpin_statistic(cn_clear);
+fc_host_fpin_statistic(cn_lost_credit);
+fc_host_fpin_statistic(cn_credit_stall);
+fc_host_fpin_statistic(cn_oversubscription);
+fc_host_fpin_statistic(cn_device_specific);
+fc_host_fpin_statistic(li);
+fc_host_fpin_statistic(li_failure_unknown);
+fc_host_fpin_statistic(li_link_failure_count);
+fc_host_fpin_statistic(li_loss_of_sync_count);
+fc_host_fpin_statistic(li_loss_of_signals_count);
+fc_host_fpin_statistic(li_prim_seq_err_count);
+fc_host_fpin_statistic(li_invalid_tx_word_count);
+fc_host_fpin_statistic(li_invalid_crc_count);
+fc_host_fpin_statistic(li_device_specific);
+
 static ssize_t
 fc_reset_statistics(struct device *dev, struct device_attribute *attr,
 		    const char *buf, size_t count)
@@ -1794,6 +1890,26 @@ static struct attribute *fc_statistics_attrs[] = {
 	&device_attr_host_fc_seq_not_found.attr,
 	&device_attr_host_fc_non_bls_resp.attr,
 	&device_attr_host_reset_statistics.attr,
+	&device_attr_host_fpin_dn.attr,
+	&device_attr_host_fpin_dn_unknown.attr,
+	&device_attr_host_fpin_dn_timeout.attr,
+	&device_attr_host_fpin_dn_unable_to_route.attr,
+	&device_attr_host_fpin_dn_device_specific.attr,
+	&device_attr_host_fpin_li.attr,
+	&device_attr_host_fpin_li_failure_unknown.attr,
+	&device_attr_host_fpin_li_link_failure_count.attr,
+	&device_attr_host_fpin_li_loss_of_sync_count.attr,
+	&device_attr_host_fpin_li_loss_of_signals_count.attr,
+	&device_attr_host_fpin_li_prim_seq_err_count.attr,
+	&device_attr_host_fpin_li_invalid_tx_word_count.attr,
+	&device_attr_host_fpin_li_invalid_crc_count.attr,
+	&device_attr_host_fpin_li_device_specific.attr,
+	&device_attr_host_fpin_cn.attr,
+	&device_attr_host_fpin_cn_clear.attr,
+	&device_attr_host_fpin_cn_lost_credit.attr,
+	&device_attr_host_fpin_cn_credit_stall.attr,
+	&device_attr_host_fpin_cn_oversubscription.attr,
+	&device_attr_host_fpin_cn_device_specific.attr,
 	NULL
 };
 
@@ -2177,6 +2293,7 @@ fc_attach_transport(struct fc_function_template *ft)
 	i->rport_attr_cont.ac.attrs = &i->rport_attrs[0];
 	i->rport_attr_cont.ac.class = &fc_rport_class.class;
 	i->rport_attr_cont.ac.match = fc_rport_match;
+	i->rport_attr_cont.statistics = &fc_rport_statistics_group;
 	transport_container_register(&i->rport_attr_cont);
 
 	i->vport_attr_cont.ac.attrs = &i->vport_attrs[0];
diff --git a/include/scsi/scsi_transport_fc.h b/include/scsi/scsi_transport_fc.h
index 1c7dd35cb7a0..487a403ee51e 100644
--- a/include/scsi/scsi_transport_fc.h
+++ b/include/scsi/scsi_transport_fc.h
@@ -285,6 +285,36 @@ struct fc_rport_identifiers {
 	u32 roles;
 };
 
+/*
+ * Fabric Performance Impact Notification Statistics
+ */
+struct fc_fpin_stats {
+	/* Delivery */
+	u64 dn;
+	u64 dn_unknown;
+	u64 dn_timeout;
+	u64 dn_unable_to_route;
+	u64 dn_device_specific;
+
+	/* Link Integrity */
+	u64 li;
+	u64 li_failure_unknown;
+	u64 li_link_failure_count;
+	u64 li_loss_of_sync_count;
+	u64 li_loss_of_signals_count;
+	u64 li_prim_seq_err_count;
+	u64 li_invalid_tx_word_count;
+	u64 li_invalid_crc_count;
+	u64 li_device_specific;
+
+	/* Congestion/Peer Congestion */
+	u64 cn;
+	u64 cn_clear;
+	u64 cn_lost_credit;
+	u64 cn_credit_stall;
+	u64 cn_oversubscription;
+	u64 cn_device_specific;
+};
 
 /* Macro for use in defining Remote Port attributes */
 #define FC_RPORT_ATTR(_name,_mode,_show,_store)				\
@@ -326,6 +356,7 @@ struct fc_rport {	/* aka fc_starget_attrs */
 
 	/* Dynamic Attributes */
 	u32 dev_loss_tmo;	/* Remote Port loss timeout in seconds. */
+	struct fc_fpin_stats fpin_stats;
 
 	/* Private (Transport-managed) Attributes */
 	u64 node_name;
@@ -516,6 +547,7 @@ struct fc_host_attrs {
 	char symbolic_name[FC_SYMBOLIC_NAME_SIZE];
 	char system_hostname[FC_SYMBOLIC_NAME_SIZE];
 	u32 dev_loss_tmo;
+	struct fc_fpin_stats fpin_stats;
 
 	/* Private (Transport-managed) Attributes */
 	enum fc_tgtid_binding_type  tgtid_bind_type;
-- 
2.19.0.rc0

[PATCH v3 3/5] scsi: fc: Parse FPIN packets and update statistics

[Nilesh Javali]

From: Shyam Sundar <ssundar@marvell.com>

Parse the incoming FPIN packets and update the host and rport FPIN
statistics based on the FPINs.

Signed-off-by: Shyam Sundar <ssundar@marvell.com>
Signed-off-by: Nilesh Javali <njavali@marvell.com>
---
 drivers/scsi/scsi_transport_fc.c | 293 +++++++++++++++++++++++++++++++
 include/scsi/scsi_transport_fc.h |   1 +
 2 files changed, 294 insertions(+)

diff --git a/drivers/scsi/scsi_transport_fc.c b/drivers/scsi/scsi_transport_fc.c
index 501e165ae6f1..4dfa0e40d8e5 100644
--- a/drivers/scsi/scsi_transport_fc.c
+++ b/drivers/scsi/scsi_transport_fc.c
@@ -34,6 +34,11 @@ static int fc_bsg_hostadd(struct Scsi_Host *, struct fc_host_attrs *);
 static int fc_bsg_rportadd(struct Scsi_Host *, struct fc_rport *);
 static void fc_bsg_remove(struct request_queue *);
 static void fc_bsg_goose_queue(struct fc_rport *);
+static void fc_li_stats_update(struct fc_fn_li_desc *li_desc,
+			       struct fc_fpin_stats *stats);
+static void fc_delivery_stats_update(u32 reason_code,
+				     struct fc_fpin_stats *stats);
+static void fc_cn_stats_update(u16 event_type, struct fc_fpin_stats *stats);
 
 /*
  * Module Parameters
@@ -630,6 +635,262 @@ fc_host_post_vendor_event(struct Scsi_Host *shost, u32 event_number,
 }
 EXPORT_SYMBOL(fc_host_post_vendor_event);
 
+/**
+ * fc_find_rport_by_wwpn - find the fc_rport pointer for a given wwpn
+ * @shost:		host the fc_rport is associated with
+ * @wwpn:		wwpn of the fc_rport device
+ *
+ * Notes:
+ *	This routine assumes no locks are held on entry.
+ */
+struct fc_rport *
+fc_find_rport_by_wwpn(struct Scsi_Host *shost, u64 wwpn)
+{
+	struct fc_rport *rport;
+	unsigned long flags;
+
+	spin_lock_irqsave(shost->host_lock, flags);
+
+	list_for_each_entry(rport, &fc_host_rports(shost), peers) {
+		if (rport->port_state != FC_PORTSTATE_ONLINE)
+			continue;
+
+		if (rport->port_name == wwpn) {
+			spin_unlock_irqrestore(shost->host_lock, flags);
+			return rport;
+		}
+	}
+
+	spin_unlock_irqrestore(shost->host_lock, flags);
+	return NULL;
+}
+EXPORT_SYMBOL(fc_find_rport_by_wwpn);
+
+static void
+fc_li_stats_update(struct fc_fn_li_desc *li_desc,
+		   struct fc_fpin_stats *stats)
+{
+	stats->li += be32_to_cpu(li_desc->event_count);
+	switch (be16_to_cpu(li_desc->event_type)) {
+	case FPIN_LI_UNKNOWN:
+		stats->li_failure_unknown +=
+		    be32_to_cpu(li_desc->event_count);
+		break;
+	case FPIN_LI_LINK_FAILURE:
+		stats->li_link_failure_count +=
+		    be32_to_cpu(li_desc->event_count);
+		break;
+	case FPIN_LI_LOSS_OF_SYNC:
+		stats->li_loss_of_sync_count +=
+		    be32_to_cpu(li_desc->event_count);
+		break;
+	case FPIN_LI_LOSS_OF_SIG:
+		stats->li_loss_of_signals_count +=
+		    be32_to_cpu(li_desc->event_count);
+		break;
+	case FPIN_LI_PRIM_SEQ_ERR:
+		stats->li_prim_seq_err_count +=
+		    be32_to_cpu(li_desc->event_count);
+		break;
+	case FPIN_LI_INVALID_TX_WD:
+		stats->li_invalid_tx_word_count +=
+		    be32_to_cpu(li_desc->event_count);
+		break;
+	case FPIN_LI_INVALID_CRC:
+		stats->li_invalid_crc_count +=
+		    be32_to_cpu(li_desc->event_count);
+		break;
+	case FPIN_LI_DEVICE_SPEC:
+		stats->li_device_specific +=
+		    be32_to_cpu(li_desc->event_count);
+		break;
+	}
+}
+
+static void
+fc_delivery_stats_update(u32 reason_code, struct fc_fpin_stats *stats)
+{
+	stats->dn++;
+	switch (reason_code) {
+	case FPIN_DELI_UNKNOWN:
+		stats->dn_unknown++;
+		break;
+	case FPIN_DELI_TIMEOUT:
+		stats->dn_timeout++;
+		break;
+	case FPIN_DELI_UNABLE_TO_ROUTE:
+		stats->dn_unable_to_route++;
+		break;
+	case FPIN_DELI_DEVICE_SPEC:
+		stats->dn_device_specific++;
+		break;
+	}
+}
+
+static void
+fc_cn_stats_update(u16 event_type, struct fc_fpin_stats *stats)
+{
+	stats->cn++;
+	switch (event_type) {
+	case FPIN_CONGN_CLEAR:
+		stats->cn_clear++;
+		break;
+	case FPIN_CONGN_LOST_CREDIT:
+		stats->cn_lost_credit++;
+		break;
+	case FPIN_CONGN_CREDIT_STALL:
+		stats->cn_credit_stall++;
+		break;
+	case FPIN_CONGN_OVERSUBSCRIPTION:
+		stats->cn_oversubscription++;
+		break;
+	case FPIN_CONGN_DEVICE_SPEC:
+		stats->cn_device_specific++;
+	}
+}
+
+/*
+ * fc_fpin_li_stats_update - routine to update Link Integrity
+ * event statistics.
+ * @shost:		host the FPIN was received on
+ * @tlv:		pointer to link integrity descriptor
+ *
+ */
+static void
+fc_fpin_li_stats_update(struct Scsi_Host *shost, struct fc_tlv_desc *tlv)
+{
+	u8 i;
+	struct fc_rport *rport = NULL;
+	struct fc_rport *attach_rport = NULL;
+	struct fc_host_attrs *fc_host = shost_to_fc_host(shost);
+	struct fc_fn_li_desc *li_desc = (struct fc_fn_li_desc *)tlv;
+	u64 wwpn;
+
+	rport = fc_find_rport_by_wwpn(shost,
+				      be64_to_cpu(li_desc->attached_wwpn));
+	if (rport &&
+	    (rport->roles & FC_PORT_ROLE_FCP_TARGET ||
+	     rport->roles & FC_PORT_ROLE_NVME_TARGET)) {
+		attach_rport = rport;
+		fc_li_stats_update(li_desc, &attach_rport->fpin_stats);
+	}
+
+	if (be32_to_cpu(li_desc->pname_count) > 0) {
+		for (i = 0;
+		    i < be32_to_cpu(li_desc->pname_count);
+		    i++) {
+			wwpn = be64_to_cpu(li_desc->pname_list[i]);
+			rport = fc_find_rport_by_wwpn(shost, wwpn);
+			if (rport &&
+			    (rport->roles & FC_PORT_ROLE_FCP_TARGET ||
+			    rport->roles & FC_PORT_ROLE_NVME_TARGET)) {
+				if (rport == attach_rport)
+					continue;
+				fc_li_stats_update(li_desc,
+						   &rport->fpin_stats);
+			}
+		}
+	}
+
+	if (fc_host->port_name == be64_to_cpu(li_desc->attached_wwpn))
+		fc_li_stats_update(li_desc, &fc_host->fpin_stats);
+}
+
+/*
+ * fc_fpin_delivery_stats_update - routine to update Delivery Notification
+ * event statistics.
+ * @shost:		host the FPIN was received on
+ * @tlv:		pointer to delivery descriptor
+ *
+ */
+static void
+fc_fpin_delivery_stats_update(struct Scsi_Host *shost,
+			      struct fc_tlv_desc *tlv)
+{
+	struct fc_rport *rport = NULL;
+	struct fc_rport *attach_rport = NULL;
+	struct fc_host_attrs *fc_host = shost_to_fc_host(shost);
+	struct fc_fn_deli_desc *dn_desc = (struct fc_fn_deli_desc *)tlv;
+	u32 reason_code = be32_to_cpu(dn_desc->deli_reason_code);
+
+	rport = fc_find_rport_by_wwpn(shost,
+				      be64_to_cpu(dn_desc->attached_wwpn));
+	if (rport &&
+	    (rport->roles & FC_PORT_ROLE_FCP_TARGET ||
+	     rport->roles & FC_PORT_ROLE_NVME_TARGET)) {
+		attach_rport = rport;
+		fc_delivery_stats_update(reason_code,
+					 &attach_rport->fpin_stats);
+	}
+
+	if (fc_host->port_name == be64_to_cpu(dn_desc->attached_wwpn))
+		fc_delivery_stats_update(reason_code, &fc_host->fpin_stats);
+}
+
+/*
+ * fc_fpin_peer_congn_stats_update - routine to update Peer Congestion
+ * event statistics.
+ * @shost:		host the FPIN was received on
+ * @tlv:		pointer to peer congestion descriptor
+ *
+ */
+static void
+fc_fpin_peer_congn_stats_update(struct Scsi_Host *shost,
+				struct fc_tlv_desc *tlv)
+{
+	u8 i;
+	struct fc_rport *rport = NULL;
+	struct fc_rport *attach_rport = NULL;
+	struct fc_fn_peer_congn_desc *pc_desc =
+	    (struct fc_fn_peer_congn_desc *)tlv;
+	u16 event_type = be16_to_cpu(pc_desc->event_type);
+	u64 wwpn;
+
+	rport = fc_find_rport_by_wwpn(shost,
+				      be64_to_cpu(pc_desc->attached_wwpn));
+	if (rport &&
+	    (rport->roles & FC_PORT_ROLE_FCP_TARGET ||
+	     rport->roles & FC_PORT_ROLE_NVME_TARGET)) {
+		attach_rport = rport;
+		fc_cn_stats_update(event_type, &attach_rport->fpin_stats);
+	}
+
+	if (be32_to_cpu(pc_desc->pname_count) > 0) {
+		for (i = 0;
+		    i < be32_to_cpu(pc_desc->pname_count);
+		    i++) {
+			wwpn = be64_to_cpu(pc_desc->pname_list[i]);
+			rport = fc_find_rport_by_wwpn(shost, wwpn);
+			if (rport &&
+			    (rport->roles & FC_PORT_ROLE_FCP_TARGET ||
+			     rport->roles & FC_PORT_ROLE_NVME_TARGET)) {
+				if (rport == attach_rport)
+					continue;
+				fc_cn_stats_update(event_type,
+						   &rport->fpin_stats);
+			}
+		}
+	}
+}
+
+/*
+ * fc_fpin_congn_stats_update - routine to update Congestion
+ * event statistics.
+ * @shost:		host the FPIN was received on
+ * @tlv:		pointer to congestion descriptor
+ *
+ */
+static void
+fc_fpin_congn_stats_update(struct Scsi_Host *shost,
+			   struct fc_tlv_desc *tlv)
+{
+	struct fc_host_attrs *fc_host = shost_to_fc_host(shost);
+	struct fc_fn_congn_desc *congn = (struct fc_fn_congn_desc *)tlv;
+
+	fc_cn_stats_update(be16_to_cpu(congn->event_type),
+			   &fc_host->fpin_stats);
+}
+
 /**
  * fc_host_rcv_fpin - routine to process a received FPIN.
  * @shost:		host the FPIN was received on
@@ -642,6 +903,38 @@ EXPORT_SYMBOL(fc_host_post_vendor_event);
 void
 fc_host_fpin_rcv(struct Scsi_Host *shost, u32 fpin_len, char *fpin_buf)
 {
+	struct fc_els_fpin *fpin = (struct fc_els_fpin *)fpin_buf;
+	struct fc_tlv_desc *tlv;
+	u32 desc_cnt = 0, bytes_remain;
+	u32 dtag;
+
+	/* Update Statistics */
+	tlv = (struct fc_tlv_desc *)&fpin->fpin_desc[0];
+	bytes_remain = fpin_len - offsetof(struct fc_els_fpin, fpin_desc);
+	bytes_remain = min_t(u32, bytes_remain, be32_to_cpu(fpin->desc_len));
+
+	while (bytes_remain >= FC_TLV_DESC_HDR_SZ &&
+	       bytes_remain >= FC_TLV_DESC_SZ_FROM_LENGTH(tlv)) {
+		dtag = be32_to_cpu(tlv->desc_tag);
+		switch (dtag) {
+		case ELS_DTAG_LNK_INTEGRITY:
+			fc_fpin_li_stats_update(shost, tlv);
+			break;
+		case ELS_DTAG_DELIVERY:
+			fc_fpin_delivery_stats_update(shost, tlv);
+			break;
+		case ELS_DTAG_PEER_CONGEST:
+			fc_fpin_peer_congn_stats_update(shost, tlv);
+			break;
+		case ELS_DTAG_CONGESTION:
+			fc_fpin_congn_stats_update(shost, tlv);
+		}
+
+		desc_cnt++;
+		bytes_remain -= FC_TLV_DESC_SZ_FROM_LENGTH(tlv);
+		tlv = fc_tlv_next_desc(tlv);
+	}
+
 	fc_host_post_fc_event(shost, fc_get_event_number(),
 				FCH_EVT_LINK_FPIN, fpin_len, fpin_buf, 0);
 }
diff --git a/include/scsi/scsi_transport_fc.h b/include/scsi/scsi_transport_fc.h
index 487a403ee51e..a636c1986e22 100644
--- a/include/scsi/scsi_transport_fc.h
+++ b/include/scsi/scsi_transport_fc.h
@@ -819,6 +819,7 @@ void fc_host_post_event(struct Scsi_Host *shost, u32 event_number,
 		enum fc_host_event_code event_code, u32 event_data);
 void fc_host_post_vendor_event(struct Scsi_Host *shost, u32 event_number,
 		u32 data_len, char *data_buf, u64 vendor_id);
+struct fc_rport *fc_find_rport_by_wwpn(struct Scsi_Host *shost, u64 wwpn);
 void fc_host_post_fc_event(struct Scsi_Host *shost, u32 event_number,
 		enum fc_host_event_code event_code,
 		u32 data_len, char *data_buf, u64 vendor_id);
-- 
2.19.0.rc0

[PATCH v3 4/5] scsi: fc: Add mechanism to update FPIN signal statistics

[Nilesh Javali]

From: Shyam Sundar <ssundar@marvell.com>

Add statistics for Congestion Signals that are delivered to the host as
interrupt signals, under fc_host_statistics.

Signed-off-by: Shyam Sundar <ssundar@marvell.com>
Signed-off-by: Nilesh Javali <njavali@marvell.com>
Reviewed-by: James Smart <james.smart@broadcom.com>
---
 drivers/scsi/scsi_transport_fc.c | 5 +++++
 include/scsi/scsi_transport_fc.h | 3 +++
 2 files changed, 8 insertions(+)

diff --git a/drivers/scsi/scsi_transport_fc.c b/drivers/scsi/scsi_transport_fc.c
index 4dfa0e40d8e5..3f816ab1d845 100644
--- a/drivers/scsi/scsi_transport_fc.c
+++ b/drivers/scsi/scsi_transport_fc.c
@@ -2100,6 +2100,9 @@ fc_host_statistic(fc_xid_not_found);
 fc_host_statistic(fc_xid_busy);
 fc_host_statistic(fc_seq_not_found);
 fc_host_statistic(fc_non_bls_resp);
+fc_host_statistic(cn_sig_warn);
+fc_host_statistic(cn_sig_alarm);
+
 
 #define fc_host_fpin_statistic(name)					\
 static ssize_t fc_host_fpinstat_##name(struct device *cd,		\
@@ -2182,6 +2185,8 @@ static struct attribute *fc_statistics_attrs[] = {
 	&device_attr_host_fc_xid_busy.attr,
 	&device_attr_host_fc_seq_not_found.attr,
 	&device_attr_host_fc_non_bls_resp.attr,
+	&device_attr_host_cn_sig_warn.attr,
+	&device_attr_host_cn_sig_alarm.attr,
 	&device_attr_host_reset_statistics.attr,
 	&device_attr_host_fpin_dn.attr,
 	&device_attr_host_fpin_dn_unknown.attr,
diff --git a/include/scsi/scsi_transport_fc.h b/include/scsi/scsi_transport_fc.h
index a636c1986e22..c759b29e46c7 100644
--- a/include/scsi/scsi_transport_fc.h
+++ b/include/scsi/scsi_transport_fc.h
@@ -468,6 +468,9 @@ struct fc_host_statistics {
 	u64 fc_seq_not_found;		/* seq is not found for exchange */
 	u64 fc_non_bls_resp;		/* a non BLS response frame with
 					   a sequence responder in new exch */
+	/* Host Congestion Signals */
+	u64 cn_sig_warn;
+	u64 cn_sig_alarm;
 };
 
 
-- 
2.19.0.rc0

[PATCH v3 5/5] scsi: fc: Update documentation of sysfs nodes for FPIN stats

[Nilesh Javali]

From: Shyam Sundar <ssundar@marvell.com>

Update documentation for sysfs nodes within,
       /sys/class/fc_host
       /sys/class/fc_remote_ports

Signed-off-by: Shyam Sundar <ssundar@marvell.com>
Signed-off-by: Nilesh Javali <njavali@marvell.com>
Reviewed-by: James Smart <james.smart@broadcom.com>
---
 Documentation/ABI/testing/sysfs-class-fc_host | 23 +++++++++++++++++++
 .../ABI/testing/sysfs-class-fc_remote_ports   | 23 +++++++++++++++++++
 2 files changed, 46 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-class-fc_host
 create mode 100644 Documentation/ABI/testing/sysfs-class-fc_remote_ports

diff --git a/Documentation/ABI/testing/sysfs-class-fc_host b/Documentation/ABI/testing/sysfs-class-fc_host
new file mode 100644
index 000000000000..0a696cbd8232
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-fc_host
@@ -0,0 +1,23 @@
+What:		/sys/class/fc_host/hostX/statistics/fpin_cn_yyy
+Date:		July 2020
+Contact:	Shyam Sundar <ssundar@marvell.com>
+Description:
+		These files contain the number of congestion notification
+		events recorded by the F_Port, reported using fabric
+		performance impact notification (FPIN) event.
+
+What:		/sys/class/fc_host/hostX/statistics/fpin_li_yyy
+Date:		July 2020
+Contact:	Shyam Sundar <ssundar@marvell.com>
+Description:
+		These files contain the number of link integrity error
+		events recorded by the F_Port/Nx_Port, reported using fabric
+		performance impact notification (FPIN) event.
+
+What:		/sys/class/fc_host/hostX/statistics/fpin_dn_yyy
+Date:		July 2020
+Contact:	Shyam Sundar <ssundar@marvell.com>
+Description:
+		These files contain the number of delivery related errors
+		recorded by the F_Port/Nx_Port, reported using fabric
+		performance impact notification (FPIN) event.
diff --git a/Documentation/ABI/testing/sysfs-class-fc_remote_ports b/Documentation/ABI/testing/sysfs-class-fc_remote_ports
new file mode 100644
index 000000000000..55a951529e03
--- /dev/null
+++ b/Documentation/ABI/testing/sysfs-class-fc_remote_ports
@@ -0,0 +1,23 @@
+What:		/sys/class/fc_remote_ports/rport-X:Y-Z/statistics/fpin_cn_yyy
+Date:		July 2020
+Contact:	Shyam Sundar <ssundar@marvell.com>
+Description:
+		These files contain the number of congestion notification
+		events recorded by the F_Port/Nx_Port, reported using fabric
+		performance impact notification (FPIN) event.
+
+What:		/sys/class/fc_remote_ports/rport-X:Y-Z/statistics/fpin_li_yyy
+Date:		July 2020
+Contact:	Shyam Sundar <ssundar@marvell.com>
+Description:
+		These files contain the number of link integrity error
+		events recorded by the F_Port/Nx_Port, reported using fabric
+		performance impact notification (FPIN) event.
+
+What:		/sys/class/fc_remote_ports/rport-X:Y-Z/statistics/fpin_dn_yyy
+Date:		July 2020
+Contact:	Shyam Sundar <ssundar@marvell.com>
+Description:
+		These files contain the number of delivery related errors
+		recorded by the F_Port/Nx_Port, reported using fabric
+		performance impact notification (FPIN) event.
-- 
2.19.0.rc0

Re: [PATCH v3 1/5] scsi: fc: Update formal FPIN descriptor definitions

[Himanshu Madhani]

> On Oct 21, 2020, at 4:27 AM, Nilesh Javali <njavali@marvell.com> wrote:
> 
> From: Shyam Sundar <ssundar@marvell.com>
> 
> Add Fabric Performance Impact Notification (FPIN) descriptor definition
> for the following FPINs:
> Delivery Notification Descriptor
> Peer Congestion Notification Descriptor
> Congestion Notification Descriptor
> 
> Signed-off-by: Shyam Sundar <ssundar@marvell.com>
> Signed-off-by: Nilesh Javali <njavali@marvell.com>
> Reviewed-by: James Smart <james.smart@broadcom.com>
> ---
> include/uapi/scsi/fc/fc_els.h | 114 +++++++++++++++++++++++++++++++++-
> 1 file changed, 113 insertions(+), 1 deletion(-)
> 
> diff --git a/include/uapi/scsi/fc/fc_els.h b/include/uapi/scsi/fc/fc_els.h
> index 8c704e510e39..91d4be987220 100644
> --- a/include/uapi/scsi/fc/fc_els.h
> +++ b/include/uapi/scsi/fc/fc_els.h
> @@ -916,7 +916,9 @@ enum fc_els_clid_ic {
> 	ELS_CLID_IC_LIP =	8,	/* receiving LIP */
> };
> 
> -
> +/*
> + * Link Integrity event types
> + */
> enum fc_fpin_li_event_types {
> 	FPIN_LI_UNKNOWN =		0x0,
> 	FPIN_LI_LINK_FAILURE =		0x1,
> @@ -943,6 +945,54 @@ enum fc_fpin_li_event_types {
> 	{ FPIN_LI_DEVICE_SPEC,		"Device Specific" },		\
> }
> 
> +/*
> + * Delivery event types
> + */
> +enum fc_fpin_deli_event_types {
> +	FPIN_DELI_UNKNOWN =		0x0,
> +	FPIN_DELI_TIMEOUT =		0x1,
> +	FPIN_DELI_UNABLE_TO_ROUTE =	0x2,
> +	FPIN_DELI_DEVICE_SPEC =		0xF,
> +};
> +
> +/*
> + * Initializer useful for decoding table.
> + * Please keep this in sync with the above definitions.
> + */
> +#define FC_FPIN_DELI_EVT_TYPES_INIT {					\
> +	{ FPIN_DELI_UNKNOWN,		"Unknown" },			\
> +	{ FPIN_DELI_TIMEOUT,		"Timeout" },			\
> +	{ FPIN_DELI_UNABLE_TO_ROUTE,	"Unable to Route" },		\
> +	{ FPIN_DELI_DEVICE_SPEC,	"Device Specific" },		\
> +}
> +
> +/*
> + * Congestion event types
> + */
> +enum fc_fpin_congn_event_types {
> +	FPIN_CONGN_CLEAR =		0x0,
> +	FPIN_CONGN_LOST_CREDIT =	0x1,
> +	FPIN_CONGN_CREDIT_STALL =	0x2,
> +	FPIN_CONGN_OVERSUBSCRIPTION =	0x3,
> +	FPIN_CONGN_DEVICE_SPEC =	0xF,
> +};
> +
> +/*
> + * Initializer useful for decoding table.
> + * Please keep this in sync with the above definitions.
> + */
> +#define FC_FPIN_CONGN_EVT_TYPES_INIT {					\
> +	{ FPIN_CONGN_CLEAR,		"Clear" },			\
> +	{ FPIN_CONGN_LOST_CREDIT,	"Lost Credit" },		\
> +	{ FPIN_CONGN_CREDIT_STALL,	"Credit Stall" },		\
> +	{ FPIN_CONGN_OVERSUBSCRIPTION,	"Oversubscription" },		\
> +	{ FPIN_CONGN_DEVICE_SPEC,	"Device Specific" },		\
> +}
> +
> +enum fc_fpin_congn_severity_types {
> +	FPIN_CONGN_SEVERITY_WARNING =	0xF1,
> +	FPIN_CONGN_SEVERITY_ERROR =	0xF7,
> +};
> 
> /*
>  * Link Integrity Notification Descriptor
> @@ -974,6 +1024,68 @@ struct fc_fn_li_desc {
> 					 */
> };
> 
> +/*
> + * Delivery Notification Descriptor
> + */
> +struct fc_fn_deli_desc {
> +	__be32		desc_tag;	/* Descriptor Tag (0x00020002) */
> +	__be32		desc_len;	/* Length of Descriptor (in bytes).
> +					 * Size of descriptor excluding
> +					 * desc_tag and desc_len fields.
> +					 */
> +	__be64		detecting_wwpn;	/* Port Name that detected event */
> +	__be64		attached_wwpn;	/* Port Name of device attached to
> +					 * detecting Port Name
> +					 */
> +	__be32		deli_reason_code;/* see enum fc_fpin_deli_event_types */
> +};
> +
> +/*
> + * Peer Congestion Notification Descriptor
> + */
> +struct fc_fn_peer_congn_desc {
> +	__be32		desc_tag;	/* Descriptor Tag (0x00020003) */
> +	__be32		desc_len;	/* Length of Descriptor (in bytes).
> +					 * Size of descriptor excluding
> +					 * desc_tag and desc_len fields.
> +					 */
> +	__be64		detecting_wwpn;	/* Port Name that detected event */
> +	__be64		attached_wwpn;	/* Port Name of device attached to
> +					 * detecting Port Name
> +					 */
> +	__be16		event_type;	/* see enum fc_fpin_congn_event_types */
> +	__be16		event_modifier;	/* Implementation specific value
> +					 * describing the event type
> +					 */
> +	__be32		event_period;	/* duration (ms) of the detected
> +					 * congestion event
> +					 */
> +	__be32		pname_count;	/* number of portname_list elements */
> +	__be64		pname_list[0];	/* list of N_Port_Names accessible
> +					 * through the attached port
> +					 */
> +};
> +
> +/*
> + * Congestion Notification Descriptor
> + */
> +struct fc_fn_congn_desc {
> +	__be32		desc_tag;	/* Descriptor Tag (0x00020004) */
> +	__be32		desc_len;	/* Length of Descriptor (in bytes).
> +					 * Size of descriptor excluding
> +					 * desc_tag and desc_len fields.
> +					 */
> +	__be16		event_type;	/* see enum fc_fpin_congn_event_types */
> +	__be16		event_modifier;	/* Implementation specific value
> +					 * describing the event type
> +					 */
> +	__be32		event_period;	/* duration (ms) of the detected
> +					 * congestion event
> +					 */
> +	__u8		severity;	/* command */
> +	__u8		resv[3];	/* reserved - must be zero */
> +};
> +
> /*
>  * ELS_FPIN - Fabric Performance Impact Notification
>  */
> -- 
> 2.19.0.rc0
> 

Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>

--
Himanshu Madhani	 Oracle Linux Engineering

Re: [PATCH v3 2/5] scsi: fc: Add FPIN statistics to fc_host and fc_rport objects

[Himanshu Madhani]

> On Oct 21, 2020, at 4:27 AM, Nilesh Javali <njavali@marvell.com> wrote:
> 
> From: Shyam Sundar <ssundar@marvell.com>
> 
> - Adds a structure for holding fpin stats for host & rport
> 
> - Adds sysfs nodes to maintain FPIN stats:
>        /sys/class/fc_host/hostXX/statistics/
>        /sys/class/fc_remote_ports/rport-XX\:Y-Z/statistics/
> 
> Signed-off-by: Shyam Sundar <ssundar@marvell.com>
> Signed-off-by: Nilesh Javali <njavali@marvell.com>
> Reviewed-by: James Smart <james.smart@broadcom.com>
> ---
> drivers/scsi/scsi_transport_fc.c | 117 +++++++++++++++++++++++++++++++
> include/scsi/scsi_transport_fc.h |  32 +++++++++
> 2 files changed, 149 insertions(+)
> 
> diff --git a/drivers/scsi/scsi_transport_fc.c b/drivers/scsi/scsi_transport_fc.c
> index 2ff7f06203da..501e165ae6f1 100644
> --- a/drivers/scsi/scsi_transport_fc.c
> +++ b/drivers/scsi/scsi_transport_fc.c
> @@ -22,6 +22,7 @@
> #include <net/netlink.h>
> #include <scsi/scsi_netlink_fc.h>
> #include <scsi/scsi_bsg_fc.h>
> +#include <uapi/scsi/fc/fc_els.h>
> #include "scsi_priv.h"
> 
> static int fc_queue_work(struct Scsi_Host *, struct work_struct *);
> @@ -419,6 +420,7 @@ static int fc_host_setup(struct transport_container *tc, struct device *dev,
> 	fc_host->fabric_name = -1;
> 	memset(fc_host->symbolic_name, 0, sizeof(fc_host->symbolic_name));
> 	memset(fc_host->system_hostname, 0, sizeof(fc_host->system_hostname));
> +	memset(&fc_host->fpin_stats, 0, sizeof(fc_host->fpin_stats));
> 
> 	fc_host->tgtid_bind_type = FC_TGTID_BIND_BY_WWPN;
> 
> @@ -991,6 +993,67 @@ store_fc_rport_fast_io_fail_tmo(struct device *dev,
> static FC_DEVICE_ATTR(rport, fast_io_fail_tmo, S_IRUGO | S_IWUSR,
> 	show_fc_rport_fast_io_fail_tmo, store_fc_rport_fast_io_fail_tmo);
> 
> +#define fc_rport_fpin_statistic(name)					\
> +static ssize_t fc_rport_fpinstat_##name(struct device *cd,		\
> +				  struct device_attribute *attr,	\
> +				  char *buf)				\
> +{									\
> +	struct fc_rport *rport = transport_class_to_rport(cd);		\
> +									\
> +	return snprintf(buf, 20, "0x%llx\n", rport->fpin_stats.name);	\
> +}									\
> +static FC_DEVICE_ATTR(rport, fpin_##name, 0444, fc_rport_fpinstat_##name, NULL)
> +
> +fc_rport_fpin_statistic(dn);
> +fc_rport_fpin_statistic(dn_unknown);
> +fc_rport_fpin_statistic(dn_timeout);
> +fc_rport_fpin_statistic(dn_unable_to_route);
> +fc_rport_fpin_statistic(dn_device_specific);
> +fc_rport_fpin_statistic(cn);
> +fc_rport_fpin_statistic(cn_clear);
> +fc_rport_fpin_statistic(cn_lost_credit);
> +fc_rport_fpin_statistic(cn_credit_stall);
> +fc_rport_fpin_statistic(cn_oversubscription);
> +fc_rport_fpin_statistic(cn_device_specific);
> +fc_rport_fpin_statistic(li);
> +fc_rport_fpin_statistic(li_failure_unknown);
> +fc_rport_fpin_statistic(li_link_failure_count);
> +fc_rport_fpin_statistic(li_loss_of_sync_count);
> +fc_rport_fpin_statistic(li_loss_of_signals_count);
> +fc_rport_fpin_statistic(li_prim_seq_err_count);
> +fc_rport_fpin_statistic(li_invalid_tx_word_count);
> +fc_rport_fpin_statistic(li_invalid_crc_count);
> +fc_rport_fpin_statistic(li_device_specific);
> +
> +static struct attribute *fc_rport_statistics_attrs[] = {
> +	&device_attr_rport_fpin_dn.attr,
> +	&device_attr_rport_fpin_dn_unknown.attr,
> +	&device_attr_rport_fpin_dn_timeout.attr,
> +	&device_attr_rport_fpin_dn_unable_to_route.attr,
> +	&device_attr_rport_fpin_dn_device_specific.attr,
> +	&device_attr_rport_fpin_li.attr,
> +	&device_attr_rport_fpin_li_failure_unknown.attr,
> +	&device_attr_rport_fpin_li_link_failure_count.attr,
> +	&device_attr_rport_fpin_li_loss_of_sync_count.attr,
> +	&device_attr_rport_fpin_li_loss_of_signals_count.attr,
> +	&device_attr_rport_fpin_li_prim_seq_err_count.attr,
> +	&device_attr_rport_fpin_li_invalid_tx_word_count.attr,
> +	&device_attr_rport_fpin_li_invalid_crc_count.attr,
> +	&device_attr_rport_fpin_li_device_specific.attr,
> +	&device_attr_rport_fpin_cn.attr,
> +	&device_attr_rport_fpin_cn_clear.attr,
> +	&device_attr_rport_fpin_cn_lost_credit.attr,
> +	&device_attr_rport_fpin_cn_credit_stall.attr,
> +	&device_attr_rport_fpin_cn_oversubscription.attr,
> +	&device_attr_rport_fpin_cn_device_specific.attr,
> +	NULL
> +};
> +
> +static struct attribute_group fc_rport_statistics_group = {
> +	.name = "statistics",
> +	.attrs = fc_rport_statistics_attrs,
> +};
> +
> 
> /*
>  * FC SCSI Target Attribute Management
> @@ -1745,6 +1808,39 @@ fc_host_statistic(fc_xid_busy);
> fc_host_statistic(fc_seq_not_found);
> fc_host_statistic(fc_non_bls_resp);
> 
> +#define fc_host_fpin_statistic(name)					\
> +static ssize_t fc_host_fpinstat_##name(struct device *cd,		\
> +				  struct device_attribute *attr,	\
> +				  char *buf)				\
> +{									\
> +	struct Scsi_Host *shost = transport_class_to_shost(cd);		\
> +	struct fc_host_attrs *fc_host = shost_to_fc_host(shost);	\
> +									\
> +	return snprintf(buf, 20, "0x%llx\n", fc_host->fpin_stats.name);	\
> +}									\
> +static FC_DEVICE_ATTR(host, fpin_##name, 0444, fc_host_fpinstat_##name, NULL)
> +
> +fc_host_fpin_statistic(dn);
> +fc_host_fpin_statistic(dn_unknown);
> +fc_host_fpin_statistic(dn_timeout);
> +fc_host_fpin_statistic(dn_unable_to_route);
> +fc_host_fpin_statistic(dn_device_specific);
> +fc_host_fpin_statistic(cn);
> +fc_host_fpin_statistic(cn_clear);
> +fc_host_fpin_statistic(cn_lost_credit);
> +fc_host_fpin_statistic(cn_credit_stall);
> +fc_host_fpin_statistic(cn_oversubscription);
> +fc_host_fpin_statistic(cn_device_specific);
> +fc_host_fpin_statistic(li);
> +fc_host_fpin_statistic(li_failure_unknown);
> +fc_host_fpin_statistic(li_link_failure_count);
> +fc_host_fpin_statistic(li_loss_of_sync_count);
> +fc_host_fpin_statistic(li_loss_of_signals_count);
> +fc_host_fpin_statistic(li_prim_seq_err_count);
> +fc_host_fpin_statistic(li_invalid_tx_word_count);
> +fc_host_fpin_statistic(li_invalid_crc_count);
> +fc_host_fpin_statistic(li_device_specific);
> +
> static ssize_t
> fc_reset_statistics(struct device *dev, struct device_attribute *attr,
> 		    const char *buf, size_t count)
> @@ -1794,6 +1890,26 @@ static struct attribute *fc_statistics_attrs[] = {
> 	&device_attr_host_fc_seq_not_found.attr,
> 	&device_attr_host_fc_non_bls_resp.attr,
> 	&device_attr_host_reset_statistics.attr,
> +	&device_attr_host_fpin_dn.attr,
> +	&device_attr_host_fpin_dn_unknown.attr,
> +	&device_attr_host_fpin_dn_timeout.attr,
> +	&device_attr_host_fpin_dn_unable_to_route.attr,
> +	&device_attr_host_fpin_dn_device_specific.attr,
> +	&device_attr_host_fpin_li.attr,
> +	&device_attr_host_fpin_li_failure_unknown.attr,
> +	&device_attr_host_fpin_li_link_failure_count.attr,
> +	&device_attr_host_fpin_li_loss_of_sync_count.attr,
> +	&device_attr_host_fpin_li_loss_of_signals_count.attr,
> +	&device_attr_host_fpin_li_prim_seq_err_count.attr,
> +	&device_attr_host_fpin_li_invalid_tx_word_count.attr,
> +	&device_attr_host_fpin_li_invalid_crc_count.attr,
> +	&device_attr_host_fpin_li_device_specific.attr,
> +	&device_attr_host_fpin_cn.attr,
> +	&device_attr_host_fpin_cn_clear.attr,
> +	&device_attr_host_fpin_cn_lost_credit.attr,
> +	&device_attr_host_fpin_cn_credit_stall.attr,
> +	&device_attr_host_fpin_cn_oversubscription.attr,
> +	&device_attr_host_fpin_cn_device_specific.attr,
> 	NULL
> };
> 
> @@ -2177,6 +2293,7 @@ fc_attach_transport(struct fc_function_template *ft)
> 	i->rport_attr_cont.ac.attrs = &i->rport_attrs[0];
> 	i->rport_attr_cont.ac.class = &fc_rport_class.class;
> 	i->rport_attr_cont.ac.match = fc_rport_match;
> +	i->rport_attr_cont.statistics = &fc_rport_statistics_group;
> 	transport_container_register(&i->rport_attr_cont);
> 
> 	i->vport_attr_cont.ac.attrs = &i->vport_attrs[0];
> diff --git a/include/scsi/scsi_transport_fc.h b/include/scsi/scsi_transport_fc.h
> index 1c7dd35cb7a0..487a403ee51e 100644
> --- a/include/scsi/scsi_transport_fc.h
> +++ b/include/scsi/scsi_transport_fc.h
> @@ -285,6 +285,36 @@ struct fc_rport_identifiers {
> 	u32 roles;
> };
> 
> +/*
> + * Fabric Performance Impact Notification Statistics
> + */
> +struct fc_fpin_stats {
> +	/* Delivery */
> +	u64 dn;
> +	u64 dn_unknown;
> +	u64 dn_timeout;
> +	u64 dn_unable_to_route;
> +	u64 dn_device_specific;
> +
> +	/* Link Integrity */
> +	u64 li;
> +	u64 li_failure_unknown;
> +	u64 li_link_failure_count;
> +	u64 li_loss_of_sync_count;
> +	u64 li_loss_of_signals_count;
> +	u64 li_prim_seq_err_count;
> +	u64 li_invalid_tx_word_count;
> +	u64 li_invalid_crc_count;
> +	u64 li_device_specific;
> +
> +	/* Congestion/Peer Congestion */
> +	u64 cn;
> +	u64 cn_clear;
> +	u64 cn_lost_credit;
> +	u64 cn_credit_stall;
> +	u64 cn_oversubscription;
> +	u64 cn_device_specific;
> +};
> 
> /* Macro for use in defining Remote Port attributes */
> #define FC_RPORT_ATTR(_name,_mode,_show,_store)				\
> @@ -326,6 +356,7 @@ struct fc_rport {	/* aka fc_starget_attrs */
> 
> 	/* Dynamic Attributes */
> 	u32 dev_loss_tmo;	/* Remote Port loss timeout in seconds. */
> +	struct fc_fpin_stats fpin_stats;
> 
> 	/* Private (Transport-managed) Attributes */
> 	u64 node_name;
> @@ -516,6 +547,7 @@ struct fc_host_attrs {
> 	char symbolic_name[FC_SYMBOLIC_NAME_SIZE];
> 	char system_hostname[FC_SYMBOLIC_NAME_SIZE];
> 	u32 dev_loss_tmo;
> +	struct fc_fpin_stats fpin_stats;
> 
> 	/* Private (Transport-managed) Attributes */
> 	enum fc_tgtid_binding_type  tgtid_bind_type;
> -- 
> 2.19.0.rc0
> 

Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>

--
Himanshu Madhani	 Oracle Linux Engineering

Re: [PATCH v3 3/5] scsi: fc: Parse FPIN packets and update statistics

[Himanshu Madhani]

> On Oct 21, 2020, at 4:27 AM, Nilesh Javali <njavali@marvell.com> wrote:
> 
> From: Shyam Sundar <ssundar@marvell.com>
> 
> Parse the incoming FPIN packets and update the host and rport FPIN
> statistics based on the FPINs.
> 
> Signed-off-by: Shyam Sundar <ssundar@marvell.com>
> Signed-off-by: Nilesh Javali <njavali@marvell.com>
> ---
> drivers/scsi/scsi_transport_fc.c | 293 +++++++++++++++++++++++++++++++
> include/scsi/scsi_transport_fc.h |   1 +
> 2 files changed, 294 insertions(+)
> 
> diff --git a/drivers/scsi/scsi_transport_fc.c b/drivers/scsi/scsi_transport_fc.c
> index 501e165ae6f1..4dfa0e40d8e5 100644
> --- a/drivers/scsi/scsi_transport_fc.c
> +++ b/drivers/scsi/scsi_transport_fc.c
> @@ -34,6 +34,11 @@ static int fc_bsg_hostadd(struct Scsi_Host *, struct fc_host_attrs *);
> static int fc_bsg_rportadd(struct Scsi_Host *, struct fc_rport *);
> static void fc_bsg_remove(struct request_queue *);
> static void fc_bsg_goose_queue(struct fc_rport *);
> +static void fc_li_stats_update(struct fc_fn_li_desc *li_desc,
> +			       struct fc_fpin_stats *stats);
> +static void fc_delivery_stats_update(u32 reason_code,
> +				     struct fc_fpin_stats *stats);
> +static void fc_cn_stats_update(u16 event_type, struct fc_fpin_stats *stats);
> 
> /*
>  * Module Parameters
> @@ -630,6 +635,262 @@ fc_host_post_vendor_event(struct Scsi_Host *shost, u32 event_number,
> }
> EXPORT_SYMBOL(fc_host_post_vendor_event);
> 
> +/**
> + * fc_find_rport_by_wwpn - find the fc_rport pointer for a given wwpn
> + * @shost:		host the fc_rport is associated with
> + * @wwpn:		wwpn of the fc_rport device
> + *
> + * Notes:
> + *	This routine assumes no locks are held on entry.
> + */
> +struct fc_rport *
> +fc_find_rport_by_wwpn(struct Scsi_Host *shost, u64 wwpn)
> +{
> +	struct fc_rport *rport;
> +	unsigned long flags;
> +
> +	spin_lock_irqsave(shost->host_lock, flags);
> +
> +	list_for_each_entry(rport, &fc_host_rports(shost), peers) {
> +		if (rport->port_state != FC_PORTSTATE_ONLINE)
> +			continue;
> +
> +		if (rport->port_name == wwpn) {
> +			spin_unlock_irqrestore(shost->host_lock, flags);
> +			return rport;
> +		}
> +	}
> +
> +	spin_unlock_irqrestore(shost->host_lock, flags);
> +	return NULL;
> +}
> +EXPORT_SYMBOL(fc_find_rport_by_wwpn);
> +
> +static void
> +fc_li_stats_update(struct fc_fn_li_desc *li_desc,
> +		   struct fc_fpin_stats *stats)
> +{
> +	stats->li += be32_to_cpu(li_desc->event_count);
> +	switch (be16_to_cpu(li_desc->event_type)) {
> +	case FPIN_LI_UNKNOWN:
> +		stats->li_failure_unknown +=
> +		    be32_to_cpu(li_desc->event_count);
> +		break;
> +	case FPIN_LI_LINK_FAILURE:
> +		stats->li_link_failure_count +=
> +		    be32_to_cpu(li_desc->event_count);
> +		break;
> +	case FPIN_LI_LOSS_OF_SYNC:
> +		stats->li_loss_of_sync_count +=
> +		    be32_to_cpu(li_desc->event_count);
> +		break;
> +	case FPIN_LI_LOSS_OF_SIG:
> +		stats->li_loss_of_signals_count +=
> +		    be32_to_cpu(li_desc->event_count);
> +		break;
> +	case FPIN_LI_PRIM_SEQ_ERR:
> +		stats->li_prim_seq_err_count +=
> +		    be32_to_cpu(li_desc->event_count);
> +		break;
> +	case FPIN_LI_INVALID_TX_WD:
> +		stats->li_invalid_tx_word_count +=
> +		    be32_to_cpu(li_desc->event_count);
> +		break;
> +	case FPIN_LI_INVALID_CRC:
> +		stats->li_invalid_crc_count +=
> +		    be32_to_cpu(li_desc->event_count);
> +		break;
> +	case FPIN_LI_DEVICE_SPEC:
> +		stats->li_device_specific +=
> +		    be32_to_cpu(li_desc->event_count);
> +		break;
> +	}
> +}
> +
> +static void
> +fc_delivery_stats_update(u32 reason_code, struct fc_fpin_stats *stats)
> +{
> +	stats->dn++;
> +	switch (reason_code) {
> +	case FPIN_DELI_UNKNOWN:
> +		stats->dn_unknown++;
> +		break;
> +	case FPIN_DELI_TIMEOUT:
> +		stats->dn_timeout++;
> +		break;
> +	case FPIN_DELI_UNABLE_TO_ROUTE:
> +		stats->dn_unable_to_route++;
> +		break;
> +	case FPIN_DELI_DEVICE_SPEC:
> +		stats->dn_device_specific++;
> +		break;
> +	}
> +}
> +
> +static void
> +fc_cn_stats_update(u16 event_type, struct fc_fpin_stats *stats)
> +{
> +	stats->cn++;
> +	switch (event_type) {
> +	case FPIN_CONGN_CLEAR:
> +		stats->cn_clear++;
> +		break;
> +	case FPIN_CONGN_LOST_CREDIT:
> +		stats->cn_lost_credit++;
> +		break;
> +	case FPIN_CONGN_CREDIT_STALL:
> +		stats->cn_credit_stall++;
> +		break;
> +	case FPIN_CONGN_OVERSUBSCRIPTION:
> +		stats->cn_oversubscription++;
> +		break;
> +	case FPIN_CONGN_DEVICE_SPEC:
> +		stats->cn_device_specific++;
> +	}
> +}
> +
> +/*
> + * fc_fpin_li_stats_update - routine to update Link Integrity
> + * event statistics.
> + * @shost:		host the FPIN was received on
> + * @tlv:		pointer to link integrity descriptor
> + *
> + */
> +static void
> +fc_fpin_li_stats_update(struct Scsi_Host *shost, struct fc_tlv_desc *tlv)
> +{
> +	u8 i;
> +	struct fc_rport *rport = NULL;
> +	struct fc_rport *attach_rport = NULL;
> +	struct fc_host_attrs *fc_host = shost_to_fc_host(shost);
> +	struct fc_fn_li_desc *li_desc = (struct fc_fn_li_desc *)tlv;
> +	u64 wwpn;
> +
> +	rport = fc_find_rport_by_wwpn(shost,
> +				      be64_to_cpu(li_desc->attached_wwpn));
> +	if (rport &&
> +	    (rport->roles & FC_PORT_ROLE_FCP_TARGET ||
> +	     rport->roles & FC_PORT_ROLE_NVME_TARGET)) {
> +		attach_rport = rport;
> +		fc_li_stats_update(li_desc, &attach_rport->fpin_stats);
> +	}
> +
> +	if (be32_to_cpu(li_desc->pname_count) > 0) {
> +		for (i = 0;
> +		    i < be32_to_cpu(li_desc->pname_count);
> +		    i++) {
> +			wwpn = be64_to_cpu(li_desc->pname_list[i]);
> +			rport = fc_find_rport_by_wwpn(shost, wwpn);
> +			if (rport &&
> +			    (rport->roles & FC_PORT_ROLE_FCP_TARGET ||
> +			    rport->roles & FC_PORT_ROLE_NVME_TARGET)) {
> +				if (rport == attach_rport)
> +					continue;
> +				fc_li_stats_update(li_desc,
> +						   &rport->fpin_stats);
> +			}
> +		}
> +	}
> +
> +	if (fc_host->port_name == be64_to_cpu(li_desc->attached_wwpn))
> +		fc_li_stats_update(li_desc, &fc_host->fpin_stats);
> +}
> +
> +/*
> + * fc_fpin_delivery_stats_update - routine to update Delivery Notification
> + * event statistics.
> + * @shost:		host the FPIN was received on
> + * @tlv:		pointer to delivery descriptor
> + *
> + */
> +static void
> +fc_fpin_delivery_stats_update(struct Scsi_Host *shost,
> +			      struct fc_tlv_desc *tlv)
> +{
> +	struct fc_rport *rport = NULL;
> +	struct fc_rport *attach_rport = NULL;
> +	struct fc_host_attrs *fc_host = shost_to_fc_host(shost);
> +	struct fc_fn_deli_desc *dn_desc = (struct fc_fn_deli_desc *)tlv;
> +	u32 reason_code = be32_to_cpu(dn_desc->deli_reason_code);
> +
> +	rport = fc_find_rport_by_wwpn(shost,
> +				      be64_to_cpu(dn_desc->attached_wwpn));
> +	if (rport &&
> +	    (rport->roles & FC_PORT_ROLE_FCP_TARGET ||
> +	     rport->roles & FC_PORT_ROLE_NVME_TARGET)) {
> +		attach_rport = rport;
> +		fc_delivery_stats_update(reason_code,
> +					 &attach_rport->fpin_stats);
> +	}
> +
> +	if (fc_host->port_name == be64_to_cpu(dn_desc->attached_wwpn))
> +		fc_delivery_stats_update(reason_code, &fc_host->fpin_stats);
> +}
> +
> +/*
> + * fc_fpin_peer_congn_stats_update - routine to update Peer Congestion
> + * event statistics.
> + * @shost:		host the FPIN was received on
> + * @tlv:		pointer to peer congestion descriptor
> + *
> + */
> +static void
> +fc_fpin_peer_congn_stats_update(struct Scsi_Host *shost,
> +				struct fc_tlv_desc *tlv)
> +{
> +	u8 i;
> +	struct fc_rport *rport = NULL;
> +	struct fc_rport *attach_rport = NULL;
> +	struct fc_fn_peer_congn_desc *pc_desc =
> +	    (struct fc_fn_peer_congn_desc *)tlv;
> +	u16 event_type = be16_to_cpu(pc_desc->event_type);
> +	u64 wwpn;
> +
> +	rport = fc_find_rport_by_wwpn(shost,
> +				      be64_to_cpu(pc_desc->attached_wwpn));
> +	if (rport &&
> +	    (rport->roles & FC_PORT_ROLE_FCP_TARGET ||
> +	     rport->roles & FC_PORT_ROLE_NVME_TARGET)) {
> +		attach_rport = rport;
> +		fc_cn_stats_update(event_type, &attach_rport->fpin_stats);
> +	}
> +
> +	if (be32_to_cpu(pc_desc->pname_count) > 0) {
> +		for (i = 0;
> +		    i < be32_to_cpu(pc_desc->pname_count);
> +		    i++) {
> +			wwpn = be64_to_cpu(pc_desc->pname_list[i]);
> +			rport = fc_find_rport_by_wwpn(shost, wwpn);
> +			if (rport &&
> +			    (rport->roles & FC_PORT_ROLE_FCP_TARGET ||
> +			     rport->roles & FC_PORT_ROLE_NVME_TARGET)) {
> +				if (rport == attach_rport)
> +					continue;
> +				fc_cn_stats_update(event_type,
> +						   &rport->fpin_stats);
> +			}
> +		}
> +	}
> +}
> +
> +/*
> + * fc_fpin_congn_stats_update - routine to update Congestion
> + * event statistics.
> + * @shost:		host the FPIN was received on
> + * @tlv:		pointer to congestion descriptor
> + *
> + */
> +static void
> +fc_fpin_congn_stats_update(struct Scsi_Host *shost,
> +			   struct fc_tlv_desc *tlv)
> +{
> +	struct fc_host_attrs *fc_host = shost_to_fc_host(shost);
> +	struct fc_fn_congn_desc *congn = (struct fc_fn_congn_desc *)tlv;
> +
> +	fc_cn_stats_update(be16_to_cpu(congn->event_type),
> +			   &fc_host->fpin_stats);
> +}
> +
> /**
>  * fc_host_rcv_fpin - routine to process a received FPIN.
>  * @shost:		host the FPIN was received on
> @@ -642,6 +903,38 @@ EXPORT_SYMBOL(fc_host_post_vendor_event);
> void
> fc_host_fpin_rcv(struct Scsi_Host *shost, u32 fpin_len, char *fpin_buf)
> {
> +	struct fc_els_fpin *fpin = (struct fc_els_fpin *)fpin_buf;
> +	struct fc_tlv_desc *tlv;
> +	u32 desc_cnt = 0, bytes_remain;
> +	u32 dtag;
> +
> +	/* Update Statistics */
> +	tlv = (struct fc_tlv_desc *)&fpin->fpin_desc[0];
> +	bytes_remain = fpin_len - offsetof(struct fc_els_fpin, fpin_desc);
> +	bytes_remain = min_t(u32, bytes_remain, be32_to_cpu(fpin->desc_len));
> +
> +	while (bytes_remain >= FC_TLV_DESC_HDR_SZ &&
> +	       bytes_remain >= FC_TLV_DESC_SZ_FROM_LENGTH(tlv)) {
> +		dtag = be32_to_cpu(tlv->desc_tag);
> +		switch (dtag) {
> +		case ELS_DTAG_LNK_INTEGRITY:
> +			fc_fpin_li_stats_update(shost, tlv);
> +			break;
> +		case ELS_DTAG_DELIVERY:
> +			fc_fpin_delivery_stats_update(shost, tlv);
> +			break;
> +		case ELS_DTAG_PEER_CONGEST:
> +			fc_fpin_peer_congn_stats_update(shost, tlv);
> +			break;
> +		case ELS_DTAG_CONGESTION:
> +			fc_fpin_congn_stats_update(shost, tlv);
> +		}
> +
> +		desc_cnt++;
> +		bytes_remain -= FC_TLV_DESC_SZ_FROM_LENGTH(tlv);
> +		tlv = fc_tlv_next_desc(tlv);
> +	}
> +
> 	fc_host_post_fc_event(shost, fc_get_event_number(),
> 				FCH_EVT_LINK_FPIN, fpin_len, fpin_buf, 0);
> }
> diff --git a/include/scsi/scsi_transport_fc.h b/include/scsi/scsi_transport_fc.h
> index 487a403ee51e..a636c1986e22 100644
> --- a/include/scsi/scsi_transport_fc.h
> +++ b/include/scsi/scsi_transport_fc.h
> @@ -819,6 +819,7 @@ void fc_host_post_event(struct Scsi_Host *shost, u32 event_number,
> 		enum fc_host_event_code event_code, u32 event_data);
> void fc_host_post_vendor_event(struct Scsi_Host *shost, u32 event_number,
> 		u32 data_len, char *data_buf, u64 vendor_id);
> +struct fc_rport *fc_find_rport_by_wwpn(struct Scsi_Host *shost, u64 wwpn);
> void fc_host_post_fc_event(struct Scsi_Host *shost, u32 event_number,
> 		enum fc_host_event_code event_code,
> 		u32 data_len, char *data_buf, u64 vendor_id);
> -- 
> 2.19.0.rc0
> 

Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>

--
Himanshu Madhani	 Oracle Linux Engineering

Re: [PATCH v3 4/5] scsi: fc: Add mechanism to update FPIN signal statistics

[Himanshu Madhani]

> On Oct 21, 2020, at 4:27 AM, Nilesh Javali <njavali@marvell.com> wrote:
> 
> From: Shyam Sundar <ssundar@marvell.com>
> 
> Add statistics for Congestion Signals that are delivered to the host as
> interrupt signals, under fc_host_statistics.
> 
> Signed-off-by: Shyam Sundar <ssundar@marvell.com>
> Signed-off-by: Nilesh Javali <njavali@marvell.com>
> Reviewed-by: James Smart <james.smart@broadcom.com>
> ---
> drivers/scsi/scsi_transport_fc.c | 5 +++++
> include/scsi/scsi_transport_fc.h | 3 +++
> 2 files changed, 8 insertions(+)
> 
> diff --git a/drivers/scsi/scsi_transport_fc.c b/drivers/scsi/scsi_transport_fc.c
> index 4dfa0e40d8e5..3f816ab1d845 100644
> --- a/drivers/scsi/scsi_transport_fc.c
> +++ b/drivers/scsi/scsi_transport_fc.c
> @@ -2100,6 +2100,9 @@ fc_host_statistic(fc_xid_not_found);
> fc_host_statistic(fc_xid_busy);
> fc_host_statistic(fc_seq_not_found);
> fc_host_statistic(fc_non_bls_resp);
> +fc_host_statistic(cn_sig_warn);
> +fc_host_statistic(cn_sig_alarm);
> +
> 
> #define fc_host_fpin_statistic(name)					\
> static ssize_t fc_host_fpinstat_##name(struct device *cd,		\
> @@ -2182,6 +2185,8 @@ static struct attribute *fc_statistics_attrs[] = {
> 	&device_attr_host_fc_xid_busy.attr,
> 	&device_attr_host_fc_seq_not_found.attr,
> 	&device_attr_host_fc_non_bls_resp.attr,
> +	&device_attr_host_cn_sig_warn.attr,
> +	&device_attr_host_cn_sig_alarm.attr,
> 	&device_attr_host_reset_statistics.attr,
> 	&device_attr_host_fpin_dn.attr,
> 	&device_attr_host_fpin_dn_unknown.attr,
> diff --git a/include/scsi/scsi_transport_fc.h b/include/scsi/scsi_transport_fc.h
> index a636c1986e22..c759b29e46c7 100644
> --- a/include/scsi/scsi_transport_fc.h
> +++ b/include/scsi/scsi_transport_fc.h
> @@ -468,6 +468,9 @@ struct fc_host_statistics {
> 	u64 fc_seq_not_found;		/* seq is not found for exchange */
> 	u64 fc_non_bls_resp;		/* a non BLS response frame with
> 					   a sequence responder in new exch */
> +	/* Host Congestion Signals */
> +	u64 cn_sig_warn;
> +	u64 cn_sig_alarm;
> };
> 
> 
> -- 
> 2.19.0.rc0
> 

Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>

--
Himanshu Madhani	 Oracle Linux Engineering

Re: [PATCH v3 5/5] scsi: fc: Update documentation of sysfs nodes for FPIN stats

[Himanshu Madhani]

> On Oct 21, 2020, at 4:27 AM, Nilesh Javali <njavali@marvell.com> wrote:
> 
> From: Shyam Sundar <ssundar@marvell.com>
> 
> Update documentation for sysfs nodes within,
>       /sys/class/fc_host
>       /sys/class/fc_remote_ports
> 
> Signed-off-by: Shyam Sundar <ssundar@marvell.com>
> Signed-off-by: Nilesh Javali <njavali@marvell.com>
> Reviewed-by: James Smart <james.smart@broadcom.com>
> ---
> Documentation/ABI/testing/sysfs-class-fc_host | 23 +++++++++++++++++++
> .../ABI/testing/sysfs-class-fc_remote_ports   | 23 +++++++++++++++++++
> 2 files changed, 46 insertions(+)
> create mode 100644 Documentation/ABI/testing/sysfs-class-fc_host
> create mode 100644 Documentation/ABI/testing/sysfs-class-fc_remote_ports
> 
> diff --git a/Documentation/ABI/testing/sysfs-class-fc_host b/Documentation/ABI/testing/sysfs-class-fc_host
> new file mode 100644
> index 000000000000..0a696cbd8232
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-class-fc_host
> @@ -0,0 +1,23 @@
> +What:		/sys/class/fc_host/hostX/statistics/fpin_cn_yyy
> +Date:		July 2020
> +Contact:	Shyam Sundar <ssundar@marvell.com>
> +Description:
> +		These files contain the number of congestion notification
> +		events recorded by the F_Port, reported using fabric
> +		performance impact notification (FPIN) event.
> +
> +What:		/sys/class/fc_host/hostX/statistics/fpin_li_yyy
> +Date:		July 2020
> +Contact:	Shyam Sundar <ssundar@marvell.com>
> +Description:
> +		These files contain the number of link integrity error
> +		events recorded by the F_Port/Nx_Port, reported using fabric
> +		performance impact notification (FPIN) event.
> +
> +What:		/sys/class/fc_host/hostX/statistics/fpin_dn_yyy
> +Date:		July 2020
> +Contact:	Shyam Sundar <ssundar@marvell.com>
> +Description:
> +		These files contain the number of delivery related errors
> +		recorded by the F_Port/Nx_Port, reported using fabric
> +		performance impact notification (FPIN) event.
> diff --git a/Documentation/ABI/testing/sysfs-class-fc_remote_ports b/Documentation/ABI/testing/sysfs-class-fc_remote_ports
> new file mode 100644
> index 000000000000..55a951529e03
> --- /dev/null
> +++ b/Documentation/ABI/testing/sysfs-class-fc_remote_ports
> @@ -0,0 +1,23 @@
> +What:		/sys/class/fc_remote_ports/rport-X:Y-Z/statistics/fpin_cn_yyy
> +Date:		July 2020
> +Contact:	Shyam Sundar <ssundar@marvell.com>
> +Description:
> +		These files contain the number of congestion notification
> +		events recorded by the F_Port/Nx_Port, reported using fabric
> +		performance impact notification (FPIN) event.
> +
> +What:		/sys/class/fc_remote_ports/rport-X:Y-Z/statistics/fpin_li_yyy
> +Date:		July 2020
> +Contact:	Shyam Sundar <ssundar@marvell.com>
> +Description:
> +		These files contain the number of link integrity error
> +		events recorded by the F_Port/Nx_Port, reported using fabric
> +		performance impact notification (FPIN) event.
> +
> +What:		/sys/class/fc_remote_ports/rport-X:Y-Z/statistics/fpin_dn_yyy
> +Date:		July 2020
> +Contact:	Shyam Sundar <ssundar@marvell.com>
> +Description:
> +		These files contain the number of delivery related errors
> +		recorded by the F_Port/Nx_Port, reported using fabric
> +		performance impact notification (FPIN) event.
> -- 
> 2.19.0.rc0
> 

Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>

--
Himanshu Madhani	 Oracle Linux Engineering

Re: [PATCH v3 3/5] scsi: fc: Parse FPIN packets and update statistics

[James Smart]

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On 10/21/2020 2:27 AM, Nilesh Javali wrote:
> From: Shyam Sundar <ssundar@marvell.com>
>
> Parse the incoming FPIN packets and update the host and rport FPIN
> statistics based on the FPINs.
>
> Signed-off-by: Shyam Sundar <ssundar@marvell.com>
> Signed-off-by: Nilesh Javali <njavali@marvell.com>
> ---
>

Reviewed-by: James Smart <james.smart@broadcom.com>

Thanks!

-- james


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Re: [PATCH v3 0/5] SAN Congestion Management (SCM) statistics

[Martin K. Petersen]

Nilesh,

> Please apply the attached patchset implementing the SAN Congestion
> Management (SCM) statistics to the scsi tree at your earliest
> convenience.

Applied to 5.11/scsi-staging, thanks!

-- 
Martin K. Petersen	Oracle Linux Engineering

Re: [PATCH v3 0/5] SAN Congestion Management (SCM) statistics

[Martin K. Petersen]

On Wed, 21 Oct 2020 02:27:10 -0700, Nilesh Javali wrote:

> Martin,
> 
> Please apply the attached patchset implementing the SAN Congestion
> Management (SCM) statistics to the scsi tree at your earliest
> convenience.
> 
> v2->v3:
> Incorporate review comments for patch v2 3/5.
> Added Reviewed-by tag for other patches.
> 
> [...]

Applied to 5.11/scsi-queue, thanks!

[1/5] scsi: fc: Update formal FPIN descriptor definitions
      https://git.kernel.org/mkp/scsi/c/874163aab75a
[2/5] scsi: fc: Add FPIN statistics to fc_host and fc_rport objects
      https://git.kernel.org/mkp/scsi/c/547aab51a914
[3/5] scsi: fc: Parse FPIN packets and update statistics
      https://git.kernel.org/mkp/scsi/c/3dcfe0de5a97
[4/5] scsi: fc: Add mechanism to update FPIN signal statistics
      https://git.kernel.org/mkp/scsi/c/846101960fdb
[5/5] scsi: fc: Update documentation of sysfs nodes for FPIN stats
      https://git.kernel.org/mkp/scsi/c/434ee4251950

-- 
Martin K. Petersen	Oracle Linux Engineering

scsi_transport_fc: FPIN LI statistics

[James Smart]

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Nilesh, Shyam,

I'm looking at commit 3dcfe0de5a97.  When we increment stats, we are 
incrementing by the event_count:
> +static void
> +fc_li_stats_update(struct fc_fn_li_desc *li_desc,
> +		   struct fc_fpin_stats *stats)
> +{
> +	stats->li += be32_to_cpu(li_desc->event_count);
> +	switch (be16_to_cpu(li_desc->event_type)) {
> +	case FPIN_LI_UNKNOWN:
> +		stats->li_failure_unknown +=
> +		    be32_to_cpu(li_desc->event_count);
> +		break;
> +	case FPIN_LI_LINK_FAILURE:
> +		stats->li_link_failure_count +=
> +		    be32_to_cpu(li_desc->event_count);
> +		break;
> +	case FPIN_LI_LOSS_OF_SYNC:
> +		stats->li_loss_of_sync_count +=
> +		    be32_to_cpu(li_desc->event_count);
> +		break;
> +	case FPIN_LI_LOSS_OF_SIG:
> +		stats->li_loss_of_signals_count +=
> +		    be32_to_cpu(li_desc->event_count);
> +		break;
> +	case FPIN_LI_PRIM_SEQ_ERR:
> +		stats->li_prim_seq_err_count +=
> +		    be32_to_cpu(li_desc->event_count);
> +		break;
> +	case FPIN_LI_INVALID_TX_WD:
> +		stats->li_invalid_tx_word_count +=
> +		    be32_to_cpu(li_desc->event_count);
> +		break;
> +	case FPIN_LI_INVALID_CRC:
> +		stats->li_invalid_crc_count +=
> +		    be32_to_cpu(li_desc->event_count);
> +		break;
> +	case FPIN_LI_DEVICE_SPEC:
> +		stats->li_device_specific +=
> +		    be32_to_cpu(li_desc->event_count);
> +		break;
> +	}
> +}

I'm wondering if this is really what we want.   Event_count is the 
minimum # of events that must occur before an FPIN is sent.  Thus, its 
not the actual number of events, and could be significantly off (low).   
Are we ok with that ?  Do we set the wrong impression with the user 
(here's a count, but its not necessary accurate) ?    Would it be better 
to simply count the # of FPINs (increment by 1 each time) ?

-- james


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