fnic: fnic Control Path Trace Utility

Fnic Ctlr Path Trace utility is a tracing functionality built directly into fnic
driver to trace the control path frames like discovery, FLOGI request/reply,
PLOGI request/reply, link event etc.  It will be one trace file for all fnics.
It will help us to debug and resolve the discovery and initialization related
issues in more convenient way. This trace information includes time stamp,
Host Number, Frame type, Frame Length and Frame. By default,64 pages are
allocated but we can change the number of allocated pages by module parameter
fnic_fc_trace_max_page. Each entry is of 256 byte and available entries are
depends on allocated number of pages. We can turn on or off the fnic control
path trace functionality by module paramter fc_trace_enable and/or reset the
trace contain by module paramter fc_trace_clear.

Signed-off-by: Hiral Shah <hishah@cisco.com>
Signed-off-by: Sesidhar Baddela <sebaddel@cisco.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

1 files changed, 202 insertions, 36 deletions

diff --git a/drivers/scsi/fnic/fnic_debugfs.c b/drivers/scsi/fnic/fnic_debugfs.c
index b6073f8..2c613bd 100644
--- a/drivers/scsi/fnic/fnic_debugfs.c
+++ b/drivers/scsi/fnic/fnic_debugfs.c
@@ -25,6 +25,21 @@ static struct dentry *fnic_trace_debugfs_file;
 static struct dentry *fnic_trace_enable;
 static struct dentry *fnic_stats_debugfs_root;
 
+static struct dentry *fnic_fc_trace_debugfs_file;
+static struct dentry *fnic_fc_rdata_trace_debugfs_file;
+static struct dentry *fnic_fc_trace_enable;
+static struct dentry *fnic_fc_trace_clear;
+
+struct fc_trace_flag_type {
+	u8 fc_row_file;
+	u8 fc_normal_file;
+	u8 fnic_trace;
+	u8 fc_trace;
+	u8 fc_clear;
+};
+
+static struct fc_trace_flag_type *fc_trc_flag;
+
 /*
  * fnic_debugfs_init - Initialize debugfs for fnic debug logging
  *
@@ -56,6 +71,18 @@ int fnic_debugfs_init(void)
 		return rc;
 	}
 
+	/* Allocate memory to structure */
+	fc_trc_flag = (struct fc_trace_flag_type *)
+		vmalloc(sizeof(struct fc_trace_flag_type));
+
+	if (fc_trc_flag) {
+		fc_trc_flag->fc_row_file = 0;
+		fc_trc_flag->fc_normal_file = 1;
+		fc_trc_flag->fnic_trace = 2;
+		fc_trc_flag->fc_trace = 3;
+		fc_trc_flag->fc_clear = 4;
+	}
+
 	rc = 0;
 	return rc;
 }
@@ -74,15 +101,19 @@ void fnic_debugfs_terminate(void)
 
 	debugfs_remove(fnic_trace_debugfs_root);
 	fnic_trace_debugfs_root = NULL;
+
+	if (fc_trc_flag)
+		vfree(fc_trc_flag);
 }
 
 /*
- * fnic_trace_ctrl_open - Open the trace_enable file
+ * fnic_trace_ctrl_open - Open the trace_enable file for fnic_trace
+ *               Or Open fc_trace_enable file for fc_trace
  * @inode: The inode pointer.
  * @file: The file pointer to attach the trace enable/disable flag.
  *
  * Description:
- * This routine opens a debugsfs file trace_enable.
+ * This routine opens a debugsfs file trace_enable or fc_trace_enable.
  *
  * Returns:
  * This function returns zero if successful.
@@ -94,15 +125,19 @@ static int fnic_trace_ctrl_open(struct inode *inode, struct file *filp)
 }
 
 /*
- * fnic_trace_ctrl_read - Read a trace_enable debugfs file
+ * fnic_trace_ctrl_read -
+ *          Read  trace_enable ,fc_trace_enable
+ *              or fc_trace_clear debugfs file
  * @filp: The file pointer to read from.
  * @ubuf: The buffer to copy the data to.
  * @cnt: The number of bytes to read.
  * @ppos: The position in the file to start reading from.
  *
  * Description:
- * This routine reads value of variable fnic_tracing_enabled
- * and stores into local @buf. It will start reading file at @ppos and
+ * This routine reads value of variable fnic_tracing_enabled or
+ * fnic_fc_tracing_enabled or fnic_fc_trace_cleared
+ * and stores into local @buf.
+ * It will start reading file at @ppos and
  * copy up to @cnt of data to @ubuf from @buf.
  *
  * Returns:
@@ -114,13 +149,25 @@ static ssize_t fnic_trace_ctrl_read(struct file *filp,
 {
 	char buf[64];
 	int len;
-	len = sprintf(buf, "%u\n", fnic_tracing_enabled);
+	u8 *trace_type;
+	len = 0;
+	trace_type = (u8 *)filp->private_data;
+	if (*trace_type == fc_trc_flag->fnic_trace)
+		len = sprintf(buf, "%u\n", fnic_tracing_enabled);
+	else if (*trace_type == fc_trc_flag->fc_trace)
+		len = sprintf(buf, "%u\n", fnic_fc_tracing_enabled);
+	else if (*trace_type == fc_trc_flag->fc_clear)
+		len = sprintf(buf, "%u\n", fnic_fc_trace_cleared);
+	else
+		pr_err("fnic: Cannot read to any debugfs file\n");
 
 	return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
 }
 
 /*
- * fnic_trace_ctrl_write - Write to trace_enable debugfs file
+ * fnic_trace_ctrl_write -
+ * Write to trace_enable, fc_trace_enable or
+ *         fc_trace_clear debugfs file
  * @filp: The file pointer to write from.
  * @ubuf: The buffer to copy the data from.
  * @cnt: The number of bytes to write.
@@ -128,7 +175,8 @@ static ssize_t fnic_trace_ctrl_read(struct file *filp,
  *
  * Description:
  * This routine writes data from user buffer @ubuf to buffer @buf and
- * sets fnic_tracing_enabled value as per user input.
+ * sets fc_trace_enable ,tracing_enable or fnic_fc_trace_cleared
+ * value as per user input.
  *
  * Returns:
  * This function returns the amount of data that was written.
@@ -140,6 +188,8 @@ static ssize_t fnic_trace_ctrl_write(struct file *filp,
 	char buf[64];
 	unsigned long val;
 	int ret;
+	u8 *trace_type;
+	trace_type = (u8 *)filp->private_data;
 
 	if (cnt >= sizeof(buf))
 		return -EINVAL;
@@ -153,12 +203,27 @@ static ssize_t fnic_trace_ctrl_write(struct file *filp,
 	if (ret < 0)
 		return ret;
 
-	fnic_tracing_enabled = val;
+	if (*trace_type == fc_trc_flag->fnic_trace)
+		fnic_tracing_enabled = val;
+	else if (*trace_type == fc_trc_flag->fc_trace)
+		fnic_fc_tracing_enabled = val;
+	else if (*trace_type == fc_trc_flag->fc_clear)
+		fnic_fc_trace_cleared = val;
+	else
+		pr_err("fnic: cannot write to any debufs file\n");
+
 	(*ppos)++;
 
 	return cnt;
 }
 
+static const struct file_operations fnic_trace_ctrl_fops = {
+	.owner = THIS_MODULE,
+	.open = fnic_trace_ctrl_open,
+	.read = fnic_trace_ctrl_read,
+	.write = fnic_trace_ctrl_write,
+};
+
 /*
  * fnic_trace_debugfs_open - Open the fnic trace log
  * @inode: The inode pointer
@@ -178,19 +243,36 @@ static int fnic_trace_debugfs_open(struct inode *inode,
 				  struct file *file)
 {
 	fnic_dbgfs_t *fnic_dbg_prt;
+	u8 *rdata_ptr;
+	rdata_ptr = (u8 *)inode->i_private;
 	fnic_dbg_prt = kzalloc(sizeof(fnic_dbgfs_t), GFP_KERNEL);
 	if (!fnic_dbg_prt)
 		return -ENOMEM;
 
-	fnic_dbg_prt->buffer = vmalloc((3*(trace_max_pages * PAGE_SIZE)));
-	if (!fnic_dbg_prt->buffer) {
-		kfree(fnic_dbg_prt);
-		return -ENOMEM;
+	if (*rdata_ptr == fc_trc_flag->fnic_trace) {
+		fnic_dbg_prt->buffer = vmalloc(3 *
+					(trace_max_pages * PAGE_SIZE));
+		if (!fnic_dbg_prt->buffer) {
+			kfree(fnic_dbg_prt);
+			return -ENOMEM;
+		}
+		memset((void *)fnic_dbg_prt->buffer, 0,
+		3 * (trace_max_pages * PAGE_SIZE));
+		fnic_dbg_prt->buffer_len = fnic_get_trace_data(fnic_dbg_prt);
+	} else {
+		fnic_dbg_prt->buffer =
+			vmalloc(3 * (fnic_fc_trace_max_pages * PAGE_SIZE));
+		if (!fnic_dbg_prt->buffer) {
+			kfree(fnic_dbg_prt);
+			return -ENOMEM;
+		}
+		memset((void *)fnic_dbg_prt->buffer, 0,
+			3 * (fnic_fc_trace_max_pages * PAGE_SIZE));
+		fnic_dbg_prt->buffer_len =
+			fnic_fc_trace_get_data(fnic_dbg_prt, *rdata_ptr);
 	}
-	memset((void *)fnic_dbg_prt->buffer, 0,
-			  (3*(trace_max_pages * PAGE_SIZE)));
-	fnic_dbg_prt->buffer_len = fnic_get_trace_data(fnic_dbg_prt);
 	file->private_data = fnic_dbg_prt;
+
 	return 0;
 }
 
@@ -272,13 +354,6 @@ static int fnic_trace_debugfs_release(struct inode *inode,
 	return 0;
 }
 
-static const struct file_operations fnic_trace_ctrl_fops = {
-	.owner = THIS_MODULE,
-	.open = fnic_trace_ctrl_open,
-	.read = fnic_trace_ctrl_read,
-	.write = fnic_trace_ctrl_write,
-};
-
 static const struct file_operations fnic_trace_debugfs_fops = {
 	.owner = THIS_MODULE,
 	.open = fnic_trace_debugfs_open,
@@ -306,9 +381,10 @@ int fnic_trace_debugfs_init(void)
 		return rc;
 	}
 	fnic_trace_enable = debugfs_create_file("tracing_enable",
-					  S_IFREG|S_IRUGO|S_IWUSR,
-					  fnic_trace_debugfs_root,
-					  NULL, &fnic_trace_ctrl_fops);
+					S_IFREG|S_IRUGO|S_IWUSR,
+					fnic_trace_debugfs_root,
+					&(fc_trc_flag->fnic_trace),
+					&fnic_trace_ctrl_fops);
 
 	if (!fnic_trace_enable) {
 		printk(KERN_DEBUG
@@ -317,10 +393,10 @@ int fnic_trace_debugfs_init(void)
 	}
 
 	fnic_trace_debugfs_file = debugfs_create_file("trace",
-						  S_IFREG|S_IRUGO|S_IWUSR,
-						  fnic_trace_debugfs_root,
-						  NULL,
-						  &fnic_trace_debugfs_fops);
+					S_IFREG|S_IRUGO|S_IWUSR,
+					fnic_trace_debugfs_root,
+					&(fc_trc_flag->fnic_trace),
+					&fnic_trace_debugfs_fops);
 
 	if (!fnic_trace_debugfs_file) {
 		printk(KERN_DEBUG
@@ -340,14 +416,104 @@ int fnic_trace_debugfs_init(void)
  */
 void fnic_trace_debugfs_terminate(void)
 {
-	if (fnic_trace_debugfs_file) {
-		debugfs_remove(fnic_trace_debugfs_file);
-		fnic_trace_debugfs_file = NULL;
+	debugfs_remove(fnic_trace_debugfs_file);
+	fnic_trace_debugfs_file = NULL;
+
+	debugfs_remove(fnic_trace_enable);
+	fnic_trace_enable = NULL;
+}
+
+/*
+ * fnic_fc_trace_debugfs_init -
+ * Initialize debugfs for fnic control frame trace logging
+ *
+ * Description:
+ * When Debugfs is configured this routine sets up the fnic_fc debugfs
+ * file system. If not already created, this routine will create the
+ * create file trace to log fnic fc trace buffer output into debugfs and
+ * it will also create file fc_trace_enable to control enable/disable of
+ * trace logging into trace buffer.
+ */
+
+int fnic_fc_trace_debugfs_init(void)
+{
+	int rc = -1;
+
+	if (!fnic_trace_debugfs_root) {
+		pr_err("fnic:Debugfs root directory doesn't exist\n");
+		return rc;
+	}
+
+	fnic_fc_trace_enable = debugfs_create_file("fc_trace_enable",
+					S_IFREG|S_IRUGO|S_IWUSR,
+					fnic_trace_debugfs_root,
+					&(fc_trc_flag->fc_trace),
+					&fnic_trace_ctrl_fops);
+
+	if (!fnic_fc_trace_enable) {
+		pr_err("fnic: Failed create fc_trace_enable file\n");
+		return rc;
+	}
+
+	fnic_fc_trace_clear = debugfs_create_file("fc_trace_clear",
+					S_IFREG|S_IRUGO|S_IWUSR,
+					fnic_trace_debugfs_root,
+					&(fc_trc_flag->fc_clear),
+					&fnic_trace_ctrl_fops);
+
+	if (!fnic_fc_trace_clear) {
+		pr_err("fnic: Failed to create fc_trace_enable file\n");
+		return rc;
+	}
+
+	fnic_fc_rdata_trace_debugfs_file =
+		debugfs_create_file("fc_trace_rdata",
+				    S_IFREG|S_IRUGO|S_IWUSR,
+				    fnic_trace_debugfs_root,
+				    &(fc_trc_flag->fc_normal_file),
+				    &fnic_trace_debugfs_fops);
+
+	if (!fnic_fc_rdata_trace_debugfs_file) {
+		pr_err("fnic: Failed create fc_rdata_trace file\n");
+		return rc;
 	}
-	if (fnic_trace_enable) {
-		debugfs_remove(fnic_trace_enable);
-		fnic_trace_enable = NULL;
+
+	fnic_fc_trace_debugfs_file =
+		debugfs_create_file("fc_trace",
+				    S_IFREG|S_IRUGO|S_IWUSR,
+				    fnic_trace_debugfs_root,
+				    &(fc_trc_flag->fc_row_file),
+				    &fnic_trace_debugfs_fops);
+
+	if (!fnic_fc_trace_debugfs_file) {
+		pr_err("fnic: Failed to create fc_trace file\n");
+		return rc;
 	}
+	rc = 0;
+	return rc;
+}
+
+/*
+ * fnic_fc_trace_debugfs_terminate - Tear down debugfs infrastructure
+ *
+ * Description:
+ * When Debugfs is configured this routine removes debugfs file system
+ * elements that are specific to fnic_fc trace logging.
+ */
+
+void fnic_fc_trace_debugfs_terminate(void)
+{
+	debugfs_remove(fnic_fc_trace_debugfs_file);
+	fnic_fc_trace_debugfs_file = NULL;
+
+	debugfs_remove(fnic_fc_rdata_trace_debugfs_file);
+	fnic_fc_rdata_trace_debugfs_file = NULL;
+
+	debugfs_remove(fnic_fc_trace_enable);
+	fnic_fc_trace_enable = NULL;
+
+	debugfs_remove(fnic_fc_trace_clear);
+	fnic_fc_trace_clear = NULL;
 }
 
 /*