[PATCH 2/2] mtip32xx: Create debugfs entries for troubleshooting

From: Asai Thambi S P
Date: Mon Jun 04 2012 - 15:44:06 EST



On module load, creates a debugfs parent 'rssd' in debugfs root. Then for each
device, create a new node with corresponding disk name. Under the new node, two
entries 'registers' and 'flags' are created.

NOTE: These entries were removed from sysfs in the previous patch

Signed-off-by: Asai Thambi S P <asamymuthupa@xxxxxxxxxx>
---
drivers/block/mtip32xx/mtip32xx.c | 162 ++++++++++++++++++++++++++++++++++++-
drivers/block/mtip32xx/mtip32xx.h | 4 +
2 files changed, 165 insertions(+), 1 deletions(-)

diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c
index b6e95b9..a8fddeb 100644
--- a/drivers/block/mtip32xx/mtip32xx.c
+++ b/drivers/block/mtip32xx/mtip32xx.c
@@ -37,6 +37,7 @@
#include <linux/kthread.h>
#include <../drivers/ata/ahci.h>
#include <linux/export.h>
+#include <linux/debugfs.h>
#include "mtip32xx.h"

#define HW_CMD_SLOT_SZ (MTIP_MAX_COMMAND_SLOTS * 32)
@@ -85,6 +86,7 @@ static int instance;
* allocated in mtip_init().
*/
static int mtip_major;
+static struct dentry *dfs_parent;

static DEFINE_SPINLOCK(rssd_index_lock);
static DEFINE_IDA(rssd_index_ida);
@@ -2574,6 +2576,120 @@ static ssize_t mtip_hw_show_status(struct device *dev,

static DEVICE_ATTR(status, S_IRUGO, mtip_hw_show_status, NULL);

+static ssize_t mtip_hw_read_registers(struct file *f, char __user *ubuf,
+ size_t len, loff_t *offset)
+{
+ struct driver_data *dd = (struct driver_data *)f->private_data;
+ char buf[MTIP_DFS_MAX_BUF_SIZE];
+ u32 group_allocated;
+ int size = *offset;
+ int n;
+
+ if (!len || size)
+ return 0;
+
+ if (size < 0)
+ return -EINVAL;
+
+ size += sprintf(&buf[size], "H/ S ACTive : [ 0x");
+
+ for (n = dd->slot_groups-1; n >= 0; n--)
+ size += sprintf(&buf[size], "%08X ",
+ readl(dd->port->s_active[n]));
+
+ size += sprintf(&buf[size], "]\n");
+ size += sprintf(&buf[size], "H/ Command Issue : [ 0x");
+
+ for (n = dd->slot_groups-1; n >= 0; n--)
+ size += sprintf(&buf[size], "%08X ",
+ readl(dd->port->cmd_issue[n]));
+
+ size += sprintf(&buf[size], "]\n");
+ size += sprintf(&buf[size], "H/ Completed : [ 0x");
+
+ for (n = dd->slot_groups-1; n >= 0; n--)
+ size += sprintf(&buf[size], "%08X ",
+ readl(dd->port->completed[n]));
+
+ size += sprintf(&buf[size], "]\n");
+ size += sprintf(&buf[size], "H/ PORT IRQ STAT : [ 0x%08X ]\n",
+ readl(dd->port->mmio + PORT_IRQ_STAT));
+ size += sprintf(&buf[size], "H/ HOST IRQ STAT : [ 0x%08X ]\n",
+ readl(dd->mmio + HOST_IRQ_STAT));
+ size += sprintf(&buf[size], "\n");
+
+ size += sprintf(&buf[size], "L/ Allocated : [ 0x");
+
+ for (n = dd->slot_groups-1; n >= 0; n--) {
+ if (sizeof(long) > sizeof(u32))
+ group_allocated =
+ dd->port->allocated[n/2] >> (32*(n&1));
+ else
+ group_allocated = dd->port->allocated[n];
+ size += sprintf(&buf[size], "%08X ", group_allocated);
+ }
+ size += sprintf(&buf[size], "]\n");
+
+ size += sprintf(&buf[size], "L/ Commands in Q : [ 0x");
+
+ for (n = dd->slot_groups-1; n >= 0; n--) {
+ if (sizeof(long) > sizeof(u32))
+ group_allocated =
+ dd->port->cmds_to_issue[n/2] >> (32*(n&1));
+ else
+ group_allocated = dd->port->cmds_to_issue[n];
+ size += sprintf(&buf[size], "%08X ", group_allocated);
+ }
+ size += sprintf(&buf[size], "]\n");
+
+ *offset = size <= len ? size : len;
+ size = copy_to_user(ubuf, buf, *offset);
+ if (size)
+ return -EFAULT;
+
+ return *offset;
+}
+
+static ssize_t mtip_hw_read_flags(struct file *f, char __user *ubuf,
+ size_t len, loff_t *offset)
+{
+ struct driver_data *dd = (struct driver_data *)f->private_data;
+ char buf[MTIP_DFS_MAX_BUF_SIZE];
+ int size = *offset;
+
+ if (!len || size)
+ return 0;
+
+ if (size < 0)
+ return -EINVAL;
+
+ size += sprintf(&buf[size], "Flag-port : [ %08lX ]\n",
+ dd->port->flags);
+ size += sprintf(&buf[size], "Flag-dd : [ %08lX ]\n",
+ dd->dd_flag);
+
+ *offset = size <= len ? size : len;
+ size = copy_to_user(ubuf, buf, *offset);
+ if (size)
+ return -EFAULT;
+
+ return *offset;
+}
+
+static const struct file_operations mtip_regs_fops = {
+ .owner = THIS_MODULE,
+ .open = simple_open,
+ .read = mtip_hw_read_registers,
+ .llseek = no_llseek,
+};
+
+static const struct file_operations mtip_flags_fops = {
+ .owner = THIS_MODULE,
+ .open = simple_open,
+ .read = mtip_hw_read_flags,
+ .llseek = no_llseek,
+};
+
/*
* Create the sysfs related attributes.
*
@@ -2615,6 +2731,34 @@ static int mtip_hw_sysfs_exit(struct driver_data *dd, struct kobject *kobj)
return 0;
}

+static int mtip_hw_debugfs_init(struct driver_data *dd)
+{
+ if (!dfs_parent)
+ return -1;
+
+ dd->dfs_node = debugfs_create_dir(dd->disk->disk_name, dfs_parent);
+ if (IS_ERR_OR_NULL(dd->dfs_node)) {
+ dev_warn(&dd->pdev->dev,
+ "Error creating node %s under debugfs\n",
+ dd->disk->disk_name);
+ dd->dfs_node = NULL;
+ return -1;
+ }
+
+ debugfs_create_file("flags", S_IRUGO, dd->dfs_node, dd,
+ &mtip_flags_fops);
+ debugfs_create_file("registers", S_IRUGO, dd->dfs_node, dd,
+ &mtip_regs_fops);
+
+ return 0;
+}
+
+static void mtip_hw_debugfs_exit(struct driver_data *dd)
+{
+ debugfs_remove_recursive(dd->dfs_node);
+}
+
+
/*
* Perform any init/resume time hardware setup
*
@@ -3640,6 +3784,7 @@ skip_create_disk:
mtip_hw_sysfs_init(dd, kobj);
kobject_put(kobj);
}
+ mtip_hw_debugfs_init(dd);

if (dd->mtip_svc_handler) {
set_bit(MTIP_DDF_INIT_DONE_BIT, &dd->dd_flag);
@@ -3665,6 +3810,8 @@ start_service_thread:
return rv;

kthread_run_error:
+ mtip_hw_debugfs_exit(dd);
+
/* Delete our gendisk. This also removes the device from /dev */
del_gendisk(dd->disk);

@@ -3715,6 +3862,7 @@ static int mtip_block_remove(struct driver_data *dd)
kobject_put(kobj);
}
}
+ mtip_hw_debugfs_exit(dd);

/*
* Delete our gendisk structure. This also removes the device
@@ -4062,10 +4210,20 @@ static int __init mtip_init(void)
}
mtip_major = error;

+ if (!dfs_parent) {
+ dfs_parent = debugfs_create_dir("rssd", NULL);
+ if (IS_ERR_OR_NULL(dfs_parent)) {
+ printk(KERN_WARNING "Error creating debugfs parent\n");
+ dfs_parent = NULL;
+ }
+ }
+
/* Register our PCI operations. */
error = pci_register_driver(&mtip_pci_driver);
- if (error)
+ if (error) {
+ debugfs_remove(dfs_parent);
unregister_blkdev(mtip_major, MTIP_DRV_NAME);
+ }

return error;
}
@@ -4082,6 +4240,8 @@ static int __init mtip_init(void)
*/
static void __exit mtip_exit(void)
{
+ debugfs_remove_recursive(dfs_parent);
+
/* Release the allocated major block device number. */
unregister_blkdev(mtip_major, MTIP_DRV_NAME);

diff --git a/drivers/block/mtip32xx/mtip32xx.h b/drivers/block/mtip32xx/mtip32xx.h
index b2c88da..0c15d70 100644
--- a/drivers/block/mtip32xx/mtip32xx.h
+++ b/drivers/block/mtip32xx/mtip32xx.h
@@ -111,6 +111,8 @@
#define dbg_printk(format, arg...)
#endif

+#define MTIP_DFS_MAX_BUF_SIZE 1024
+
#define __force_bit2int (unsigned int __force)

enum {
@@ -447,6 +449,8 @@ struct driver_data {
unsigned long dd_flag; /* NOTE: use atomic bit operations on this */

struct task_struct *mtip_svc_handler; /* task_struct of svc thd */
+
+ struct dentry *dfs_node;
};

#endif
--
1.7.1

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