1 files changed, 314 insertions, 0 deletions
diff --git a/drivers/scsi/fnic/fnic_debugfs.c b/drivers/scsi/fnic/fnic_debugfs.c
new file mode 100644
index 000000000000..adc1f7f471f5
--- /dev/null
+++ b/drivers/scsi/fnic/fnic_debugfs.c
@@ -0,0 +1,314 @@
+/*
+ * Copyright 2012 Cisco Systems, Inc.  All rights reserved.
+ *
+ * This program is free software; you may redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/debugfs.h>
+#include "fnic.h"
+
+static struct dentry *fnic_trace_debugfs_root;
+static struct dentry *fnic_trace_debugfs_file;
+static struct dentry *fnic_trace_enable;
+
+/*
+ * fnic_trace_ctrl_open - Open the trace_enable file
+ * @inode: The inode pointer.
+ * @file: The file pointer to attach the trace enable/disable flag.
+ *
+ * Description:
+ * This routine opens a debugsfs file trace_enable.
+ *
+ * Returns:
+ * This function returns zero if successful.
+ */
+static int fnic_trace_ctrl_open(struct inode *inode, struct file *filp)
+{
+	filp->private_data = inode->i_private;
+	return 0;
+}
+
+/*
+ * fnic_trace_ctrl_read - Read a trace_enable 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
+ * copy up to @cnt of data to @ubuf from @buf.
+ *
+ * Returns:
+ * This function returns the amount of data that was read.
+ */
+static ssize_t fnic_trace_ctrl_read(struct file *filp,
+				  char __user *ubuf,
+				  size_t cnt, loff_t *ppos)
+{
+	char buf[64];
+	int len;
+	len = sprintf(buf, "%u\n", fnic_tracing_enabled);
+
+	return simple_read_from_buffer(ubuf, cnt, ppos, buf, len);
+}
+
+/*
+ * fnic_trace_ctrl_write - Write to trace_enable debugfs file
+ * @filp: The file pointer to write from.
+ * @ubuf: The buffer to copy the data from.
+ * @cnt: The number of bytes to write.
+ * @ppos: The position in the file to start writing to.
+ *
+ * Description:
+ * This routine writes data from user buffer @ubuf to buffer @buf and
+ * sets fnic_tracing_enabled value as per user input.
+ *
+ * Returns:
+ * This function returns the amount of data that was written.
+ */
+static ssize_t fnic_trace_ctrl_write(struct file *filp,
+				  const char __user *ubuf,
+				  size_t cnt, loff_t *ppos)
+{
+	char buf[64];
+	unsigned long val;
+	int ret;
+
+	if (cnt >= sizeof(buf))
+		return -EINVAL;
+
+	if (copy_from_user(&buf, ubuf, cnt))
+		return -EFAULT;
+
+	buf[cnt] = 0;
+
+	ret = kstrtoul(buf, 10, &val);
+	if (ret < 0)
+		return ret;
+
+	fnic_tracing_enabled = val;
+	(*ppos)++;
+
+	return cnt;
+}
+
+/*
+ * fnic_trace_debugfs_open - Open the fnic trace log
+ * @inode: The inode pointer
+ * @file: The file pointer to attach the log output
+ *
+ * Description:
+ * This routine is the entry point for the debugfs open file operation.
+ * It allocates the necessary buffer for the log, fills the buffer from
+ * the in-memory log and then returns a pointer to that log in
+ * the private_data field in @file.
+ *
+ * Returns:
+ * This function returns zero if successful. On error it will return
+ * a negative error value.
+ */
+static int fnic_trace_debugfs_open(struct inode *inode,
+				  struct file *file)
+{
+	fnic_dbgfs_t *fnic_dbg_prt;
+	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;
+	}
+	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;
+}
+
+/*
+ * fnic_trace_debugfs_lseek - Seek through a debugfs file
+ * @file: The file pointer to seek through.
+ * @offset: The offset to seek to or the amount to seek by.
+ * @howto: Indicates how to seek.
+ *
+ * Description:
+ * This routine is the entry point for the debugfs lseek file operation.
+ * The @howto parameter indicates whether @offset is the offset to directly
+ * seek to, or if it is a value to seek forward or reverse by. This function
+ * figures out what the new offset of the debugfs file will be and assigns
+ * that value to the f_pos field of @file.
+ *
+ * Returns:
+ * This function returns the new offset if successful and returns a negative
+ * error if unable to process the seek.
+ */
+static loff_t fnic_trace_debugfs_lseek(struct file *file,
+					loff_t offset,
+					int howto)
+{
+	fnic_dbgfs_t *fnic_dbg_prt = file->private_data;
+	loff_t pos = -1;
+
+	switch (howto) {
+	case 0:
+		pos = offset;
+		break;
+	case 1:
+		pos = file->f_pos + offset;
+		break;
+	case 2:
+		pos = fnic_dbg_prt->buffer_len - offset;
+	}
+	return (pos < 0 || pos > fnic_dbg_prt->buffer_len) ?
+			  -EINVAL : (file->f_pos = pos);
+}
+
+/*
+ * fnic_trace_debugfs_read - Read a debugfs file
+ * @file: The file pointer to read from.
+ * @ubuf: The buffer to copy the data to.
+ * @nbytes: The number of bytes to read.
+ * @pos: The position in the file to start reading from.
+ *
+ * Description:
+ * This routine reads data from the buffer indicated in the private_data
+ * field of @file. It will start reading at @pos and copy up to @nbytes of
+ * data to @ubuf.
+ *
+ * Returns:
+ * This function returns the amount of data that was read (this could be
+ * less than @nbytes if the end of the file was reached).
+ */
+static ssize_t fnic_trace_debugfs_read(struct file *file,
+					char __user *ubuf,
+					size_t nbytes,
+					loff_t *pos)
+{
+	fnic_dbgfs_t *fnic_dbg_prt = file->private_data;
+	int rc = 0;
+	rc = simple_read_from_buffer(ubuf, nbytes, pos,
+				  fnic_dbg_prt->buffer,
+				  fnic_dbg_prt->buffer_len);
+	return rc;
+}
+
+/*
+ * fnic_trace_debugfs_release - Release the buffer used to store
+ * debugfs file data
+ * @inode: The inode pointer
+ * @file: The file pointer that contains the buffer to release
+ *
+ * Description:
+ * This routine frees the buffer that was allocated when the debugfs
+ * file was opened.
+ *
+ * Returns:
+ * This function returns zero.
+ */
+static int fnic_trace_debugfs_release(struct inode *inode,
+					  struct file *file)
+{
+	fnic_dbgfs_t *fnic_dbg_prt = file->private_data;
+
+	vfree(fnic_dbg_prt->buffer);
+	kfree(fnic_dbg_prt);
+	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,
+	.llseek = fnic_trace_debugfs_lseek,
+	.read = fnic_trace_debugfs_read,
+	.release = fnic_trace_debugfs_release,
+};
+
+/*
+ * fnic_trace_debugfs_init - Initialize debugfs for fnic trace logging
+ *
+ * Description:
+ * When Debugfs is configured this routine sets up the fnic debugfs
+ * file system. If not already created, this routine will create the
+ * fnic directory. It will create file trace to log fnic trace buffer
+ * output into debugfs and it will also create file trace_enable to
+ * control enable/disable of trace logging into trace buffer.
+ */
+int fnic_trace_debugfs_init(void)
+{
+	int rc = -1;
+	fnic_trace_debugfs_root = debugfs_create_dir("fnic", NULL);
+	if (!fnic_trace_debugfs_root) {
+		printk(KERN_DEBUG "Cannot create debugfs root\n");
+		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);
+
+	if (!fnic_trace_enable) {
+		printk(KERN_DEBUG "Cannot create trace_enable file"
+				  " under debugfs");
+		return rc;
+	}
+
+	fnic_trace_debugfs_file = debugfs_create_file("trace",
+						  S_IFREG|S_IRUGO|S_IWUSR,
+						  fnic_trace_debugfs_root,
+						  NULL,
+						  &fnic_trace_debugfs_fops);
+
+	if (!fnic_trace_debugfs_file) {
+		printk(KERN_DEBUG "Cannot create trace file under debugfs");
+		return rc;
+	}
+	rc = 0;
+	return rc;
+}
+
+/*
+ * fnic_trace_debugfs_terminate - Tear down debugfs infrastructure
+ *
+ * Description:
+ * When Debugfs is configured this routine removes debugfs file system
+ * elements that are specific to fnic trace logging.
+ */
+void fnic_trace_debugfs_terminate(void)
+{
+	if (fnic_trace_debugfs_file) {
+		debugfs_remove(fnic_trace_debugfs_file);
+		fnic_trace_debugfs_file = NULL;
+	}
+	if (fnic_trace_enable) {
+		debugfs_remove(fnic_trace_enable);
+		fnic_trace_enable = NULL;
+	}
+	if (fnic_trace_debugfs_root) {
+		debugfs_remove(fnic_trace_debugfs_root);
+		fnic_trace_debugfs_root = NULL;
+	}
+}