[SCSI] qla2xxx: Add Fibre Channel Event (FCE) tracing support.

FCE support enables the firmware to record FC extended link
services and basic link services frames which have been
transmitted and received by the ISP.  This allows for a limited
view of the FC traffic through the ISP without using a FC
analyzer.  This can be useful in situations where a physical
connection to the FC bus is not possible.

The driver exports this information in two ways -- first, via a
debugfs node exported for all supported ISPs under:

	<debugfs_mount_point>/qla2xxx/qla2xxx_<host_no>/fce

where a read of the 'fce' file will provide a snapshot of the
firmware's FCE buffer; and finally, the FCE buffer will be
extracted during a firmware-dump scenario.

Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 175 insertions, 0 deletions

diff --git a/drivers/scsi/qla2xxx/qla_dfs.c b/drivers/scsi/qla2xxx/qla_dfs.c
new file mode 100644
index 0000000..1479c60
--- /dev/null
+++ b/drivers/scsi/qla2xxx/qla_dfs.c
@@ -0,0 +1,175 @@
+/*
+ * QLogic Fibre Channel HBA Driver
+ * Copyright (c)  2003-2005 QLogic Corporation
+ *
+ * See LICENSE.qla2xxx for copyright and licensing details.
+ */
+#include "qla_def.h"
+
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+
+static struct dentry *qla2x00_dfs_root;
+static atomic_t qla2x00_dfs_root_count;
+
+static int
+qla2x00_dfs_fce_show(struct seq_file *s, void *unused)
+{
+	scsi_qla_host_t *ha = s->private;
+	uint32_t cnt;
+	uint32_t *fce;
+	uint64_t fce_start;
+
+	mutex_lock(&ha->fce_mutex);
+
+	seq_printf(s, "FCE Trace Buffer\n");
+	seq_printf(s, "In Pointer = %llx\n\n", ha->fce_wr);
+	seq_printf(s, "Base = %llx\n\n", (unsigned long long) ha->fce_dma);
+	seq_printf(s, "FCE Enable Registers\n");
+	seq_printf(s, "%08x %08x %08x %08x %08x %08x\n",
+	    ha->fce_mb[0], ha->fce_mb[2], ha->fce_mb[3], ha->fce_mb[4],
+	    ha->fce_mb[5], ha->fce_mb[6]);
+
+	fce = (uint32_t *) ha->fce;
+	fce_start = (unsigned long long) ha->fce_dma;
+	for (cnt = 0; cnt < fce_calc_size(ha->fce_bufs) / 4; cnt++) {
+		if (cnt % 8 == 0)
+			seq_printf(s, "\n%llx: ",
+			    (unsigned long long)((cnt * 4) + fce_start));
+		else
+			seq_printf(s, " ");
+		seq_printf(s, "%08x", *fce++);
+	}
+
+	seq_printf(s, "\nEnd\n");
+
+	mutex_unlock(&ha->fce_mutex);
+
+	return 0;
+}
+
+static int
+qla2x00_dfs_fce_open(struct inode *inode, struct file *file)
+{
+	scsi_qla_host_t *ha = inode->i_private;
+	int rval;
+
+	if (!ha->flags.fce_enabled)
+		goto out;
+
+	mutex_lock(&ha->fce_mutex);
+
+	/* Pause tracing to flush FCE buffers. */
+	rval = qla2x00_disable_fce_trace(ha, &ha->fce_wr, &ha->fce_rd);
+	if (rval)
+		qla_printk(KERN_WARNING, ha,
+		    "DebugFS: Unable to disable FCE (%d).\n", rval);
+
+	ha->flags.fce_enabled = 0;
+
+	mutex_unlock(&ha->fce_mutex);
+out:
+	return single_open(file, qla2x00_dfs_fce_show, ha);
+}
+
+static int
+qla2x00_dfs_fce_release(struct inode *inode, struct file *file)
+{
+	scsi_qla_host_t *ha = inode->i_private;
+	int rval;
+
+	if (ha->flags.fce_enabled)
+		goto out;
+
+	mutex_lock(&ha->fce_mutex);
+
+	/* Re-enable FCE tracing. */
+	ha->flags.fce_enabled = 1;
+	memset(ha->fce, 0, fce_calc_size(ha->fce_bufs));
+	rval = qla2x00_enable_fce_trace(ha, ha->fce_dma, ha->fce_bufs,
+	    ha->fce_mb, &ha->fce_bufs);
+	if (rval) {
+		qla_printk(KERN_WARNING, ha,
+		    "DebugFS: Unable to reinitialize FCE (%d).\n", rval);
+		ha->flags.fce_enabled = 0;
+	}
+
+	mutex_unlock(&ha->fce_mutex);
+out:
+	return single_release(inode, file);
+}
+
+static const struct file_operations dfs_fce_ops = {
+	.open		= qla2x00_dfs_fce_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= qla2x00_dfs_fce_release,
+};
+
+int
+qla2x00_dfs_setup(scsi_qla_host_t *ha)
+{
+	if (!IS_QLA25XX(ha))
+		goto out;
+	if (!ha->fce)
+		goto out;
+
+	if (qla2x00_dfs_root)
+		goto create_dir;
+
+	atomic_set(&qla2x00_dfs_root_count, 0);
+	qla2x00_dfs_root = debugfs_create_dir(QLA2XXX_DRIVER_NAME, NULL);
+	if (!qla2x00_dfs_root) {
+		qla_printk(KERN_NOTICE, ha,
+		    "DebugFS: Unable to create root directory.\n");
+		goto out;
+	}
+
+create_dir:
+	if (ha->dfs_dir)
+		goto create_nodes;
+
+	mutex_init(&ha->fce_mutex);
+	ha->dfs_dir = debugfs_create_dir(ha->host_str, qla2x00_dfs_root);
+	if (!ha->dfs_dir) {
+		qla_printk(KERN_NOTICE, ha,
+		    "DebugFS: Unable to create ha directory.\n");
+		goto out;
+	}
+
+	atomic_inc(&qla2x00_dfs_root_count);
+
+create_nodes:
+	ha->dfs_fce = debugfs_create_file("fce", S_IRUSR, ha->dfs_dir, ha,
+	    &dfs_fce_ops);
+	if (!ha->dfs_fce) {
+		qla_printk(KERN_NOTICE, ha,
+		    "DebugFS: Unable to fce node.\n");
+		goto out;
+	}
+out:
+	return 0;
+}
+
+int
+qla2x00_dfs_remove(scsi_qla_host_t *ha)
+{
+	if (ha->dfs_fce) {
+		debugfs_remove(ha->dfs_fce);
+		ha->dfs_fce = NULL;
+	}
+
+	if (ha->dfs_dir) {
+		debugfs_remove(ha->dfs_dir);
+		ha->dfs_dir = NULL;
+		atomic_dec(&qla2x00_dfs_root_count);
+	}
+
+	if (atomic_read(&qla2x00_dfs_root_count) == 0 &&
+	    qla2x00_dfs_root) {
+		debugfs_remove(qla2x00_dfs_root);
+		qla2x00_dfs_root = NULL;
+	}
+
+	return 0;
+}