SCSI: Add FC transport host statistics

From: 	James.Smart@Emulex.Com

This patch updates the fc_transport with statistics for local FC ports
(e.g. Hosts).  The statistics are defined per HBAAPI v2.0 definitions.

Caveats:
------------
- The information below is supplied by a simple test driver 
that does not
  talk to real hardware, but fully acts as a LLDD that supports the
  fc transport.


This patch results in the following in /sys/class:
-----------------------------------------------------

[jsmart@elxware class]$ cd /sys/class
[jsmart@elxware class]$ ls
fc_host       graphics  misc     pci_bus       scsi_host  usb_host
fc_transport  input     net      scsi_device   tty        vc
firmware      mem       netlink  scsi_generic  usb
[jsmart@elxware class]$ cd fc_host
[jsmart@elxware fc_host]$ ls
host4

[jsmart@elxware fc_host]$ cd host4
[jsmart@elxware host4]$ ls
device                 host_link_down_tmo           statistics
[jsmart@elxware host4]$ ls -ld *
lrwxrwxrwx  1 root root    0 Oct 13 17:16 device -> 
../../../devices/platform/host4
-rw-r--r--  1 root root 4096 Oct 13 17:16 host_link_down_tmo
drwxr-xr-x  2 root root    0 Oct 13 17:16 statistics

[jsmart@elxware host4]$ cd statistics
dumped_frames         invalid_crc_count      
prim_seq_protocol_err_count
error_frames          invalid_tx_word_count  reset_statistics
fcp_control_requests  link_failure_count     rx_frames
fcp_input_megabytes   lip_count              rx_words
fcp_input_requests    loss_of_signal_count   seconds_since_last_reset
fcp_output_megabytes  loss_of_sync_count     tx_frames
fcp_output_requests   nos_count              tx_words
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/scsi_transport_fc.c

@@ -279,6 +279,112 @@ static CLASS_DEVICE_ATTR(host_##field, S_IRUGO | S_IWUSR,		\
 fc_host_rw_attr(link_down_tmo, "%d\n");
 
 
+/*
+ * Host Statistics Management
+ */
+
+/* Show a given an attribute in the statistics group */
+static ssize_t
+fc_stat_show(const struct class_device *cdev, char *buf, unsigned long offset)
+{
+	struct Scsi_Host *shost = transport_class_to_shost(cdev);
+	struct fc_internal *i = to_fc_internal(shost->transportt);
+	struct fc_host_statistics *stats;
+	ssize_t ret = -ENOENT;
+
+	if (offset > sizeof(struct fc_host_statistics) ||
+	    offset % sizeof(uint64_t) != 0)
+		WARN_ON(1);
+
+	if (i->f->get_fc_host_stats) {
+		stats = (i->f->get_fc_host_stats)(shost);
+		if (stats)
+			ret = snprintf(buf, 20, "0x%llx\n",
+			      *(uint64_t *)(((u8 *) stats) + offset));
+	}
+	return ret;
+}
+
+
+/* generate a read-only statistics attribute */
+#define fc_host_statistic(name)						\
+static ssize_t show_fcstat_##name(struct class_device *cd, char *buf) 	\
+{									\
+	return fc_stat_show(cd, buf, 					\
+			    offsetof(struct fc_host_statistics, name));	\
+}									\
+static CLASS_DEVICE_ATTR(name, S_IRUGO, show_fcstat_##name, NULL)
+
+fc_host_statistic(seconds_since_last_reset);
+fc_host_statistic(tx_frames);
+fc_host_statistic(tx_words);
+fc_host_statistic(rx_frames);
+fc_host_statistic(rx_words);
+fc_host_statistic(lip_count);
+fc_host_statistic(nos_count);
+fc_host_statistic(error_frames);
+fc_host_statistic(dumped_frames);
+fc_host_statistic(link_failure_count);
+fc_host_statistic(loss_of_sync_count);
+fc_host_statistic(loss_of_signal_count);
+fc_host_statistic(prim_seq_protocol_err_count);
+fc_host_statistic(invalid_tx_word_count);
+fc_host_statistic(invalid_crc_count);
+fc_host_statistic(fcp_input_requests);
+fc_host_statistic(fcp_output_requests);
+fc_host_statistic(fcp_control_requests);
+fc_host_statistic(fcp_input_megabytes);
+fc_host_statistic(fcp_output_megabytes);
+
+static ssize_t
+fc_reset_statistics(struct class_device *cdev, const char *buf,
+			   size_t count)
+{
+	struct Scsi_Host *shost = transport_class_to_shost(cdev);
+	struct fc_internal *i = to_fc_internal(shost->transportt);
+
+	/* ignore any data value written to the attribute */
+	if (i->f->reset_fc_host_stats) {
+		i->f->reset_fc_host_stats(shost);
+		return count;
+	}
+
+	return -ENOENT;
+}
+static CLASS_DEVICE_ATTR(reset_statistics, S_IWUSR, NULL, fc_reset_statistics);
+
+
+static struct attribute *fc_statistics_attrs[] = {
+	&class_device_attr_seconds_since_last_reset.attr,
+	&class_device_attr_tx_frames.attr,
+	&class_device_attr_tx_words.attr,
+	&class_device_attr_rx_frames.attr,
+	&class_device_attr_rx_words.attr,
+	&class_device_attr_lip_count.attr,
+	&class_device_attr_nos_count.attr,
+	&class_device_attr_error_frames.attr,
+	&class_device_attr_dumped_frames.attr,
+	&class_device_attr_link_failure_count.attr,
+	&class_device_attr_loss_of_sync_count.attr,
+	&class_device_attr_loss_of_signal_count.attr,
+	&class_device_attr_prim_seq_protocol_err_count.attr,
+	&class_device_attr_invalid_tx_word_count.attr,
+	&class_device_attr_invalid_crc_count.attr,
+	&class_device_attr_fcp_input_requests.attr,
+	&class_device_attr_fcp_output_requests.attr,
+	&class_device_attr_fcp_control_requests.attr,
+	&class_device_attr_fcp_input_megabytes.attr,
+	&class_device_attr_fcp_output_megabytes.attr,
+	&class_device_attr_reset_statistics.attr,
+	NULL
+};
+
+static struct attribute_group fc_statistics_group = {
+	.name = "statistics",
+	.attrs = fc_statistics_attrs,
+};
+
+
 
 struct scsi_transport_template *
 fc_attach_transport(struct fc_function_template *ft)
@@ -303,6 +409,10 @@ fc_attach_transport(struct fc_function_template *ft)
 	i->t.host_setup = &fc_setup_host_transport_attrs;
 	i->t.host_destroy = &fc_destroy_host;
 	i->t.host_size = sizeof(struct fc_host_attrs);
+
+	if (ft->get_fc_host_stats)
+		i->t.host_statistics = &fc_statistics_group;
+
 	i->f = ft;
 
 	

include/scsi/scsi_transport_fc.h

@@ -43,6 +43,39 @@ struct fc_starget_attrs {	/* aka fc_target_attrs */
 #define fc_starget_dev_loss_work(x) \
 	(((struct fc_starget_attrs *)&(x)->starget_data)->dev_loss_work)
 
+
+/*
+ * FC Local Port (Host) Statistics
+ */
+
+/* FC Statistics - Following FC HBAAPI v2.0 guidelines */
+struct fc_host_statistics {
+	/* port statistics */
+	uint64_t seconds_since_last_reset;
+	uint64_t tx_frames;
+	uint64_t tx_words;
+	uint64_t rx_frames;
+	uint64_t rx_words;
+	uint64_t lip_count;
+	uint64_t nos_count;
+	uint64_t error_frames;
+	uint64_t dumped_frames;
+	uint64_t link_failure_count;
+	uint64_t loss_of_sync_count;
+	uint64_t loss_of_signal_count;
+	uint64_t prim_seq_protocol_err_count;
+	uint64_t invalid_tx_word_count;
+	uint64_t invalid_crc_count;
+	
+	/* fc4 statistics  (only FCP supported currently) */
+	uint64_t fcp_input_requests;
+	uint64_t fcp_output_requests;
+	uint64_t fcp_control_requests;
+	uint64_t fcp_input_megabytes;
+	uint64_t fcp_output_megabytes;
+};
+
+
 struct fc_host_attrs {
 	uint32_t link_down_tmo;	/* Link Down timeout in seconds. */
 	struct work_struct link_down_work;
@@ -65,6 +98,9 @@ struct fc_function_template {
 	void    (*get_host_link_down_tmo)(struct Scsi_Host *);
 	void	(*set_host_link_down_tmo)(struct Scsi_Host *, uint32_t);
 
+	struct fc_host_statistics * (*get_fc_host_stats)(struct Scsi_Host *);
+	void	(*reset_fc_host_stats)(struct Scsi_Host *);
+
 	/* 
 	 * The driver sets these to tell the transport class it
 	 * wants the attributes displayed in sysfs.  If the show_ flag