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Commit 788dcfa6 authored by Joerg Roedel's avatar Joerg Roedel
Browse files

dma-debug: add debugfs interface 



Impact: add debugfs interface for configuring DMA-API debugging

Signed-off-by: default avatarJoerg Roedel <joerg.roedel@amd.com>
parent 59d3daaf

lib/dma-debug.c

+78 −0
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ 


#include <linux/dma-debug.h>

#include <linux/spinlock.h>

#include <linux/debugfs.h>

#include <linux/types.h>

#include <linux/list.h>

#include <linux/slab.h>
@@ -61,12 +62,29 @@ static DEFINE_SPINLOCK(free_entries_lock); 
/* Global disable flag - will be set in case of an error */

static bool global_disable __read_mostly;



/* Global error count */

static u32 error_count;



/* Global error show enable*/

static u32 show_all_errors __read_mostly;

/* Number of errors to show */

static u32 show_num_errors = 1;



static u32 num_free_entries;

static u32 min_free_entries;



/* number of preallocated entries requested by kernel cmdline */

static u32 req_entries;



/* debugfs dentry's for the stuff above */

static struct dentry *dma_debug_dent        __read_mostly;

static struct dentry *global_disable_dent   __read_mostly;

static struct dentry *error_count_dent      __read_mostly;

static struct dentry *show_all_errors_dent  __read_mostly;

static struct dentry *show_num_errors_dent  __read_mostly;

static struct dentry *num_free_entries_dent __read_mostly;

static struct dentry *min_free_entries_dent __read_mostly;



/*

 * Hash related functions

 *
@@ -241,6 +259,58 @@ out_err: 
	return -ENOMEM;

}



static int dma_debug_fs_init(void)

{

	dma_debug_dent = debugfs_create_dir("dma-api", NULL);

	if (!dma_debug_dent) {

		printk(KERN_ERR "DMA-API: can not create debugfs directory\n");

		return -ENOMEM;

	}



	global_disable_dent = debugfs_create_bool("disabled", 0444,

			dma_debug_dent,

			(u32 *)&global_disable);

	if (!global_disable_dent)

		goto out_err;



	error_count_dent = debugfs_create_u32("error_count", 0444,

			dma_debug_dent, &error_count);

	if (!error_count_dent)

		goto out_err;



	show_all_errors_dent = debugfs_create_u32("all_errors", 0644,

			dma_debug_dent,

			&show_all_errors);

	if (!show_all_errors_dent)

		goto out_err;



	show_num_errors_dent = debugfs_create_u32("num_errors", 0644,

			dma_debug_dent,

			&show_num_errors);

	if (!show_num_errors_dent)

		goto out_err;



	num_free_entries_dent = debugfs_create_u32("num_free_entries", 0444,

			dma_debug_dent,

			&num_free_entries);

	if (!num_free_entries_dent)

		goto out_err;



	min_free_entries_dent = debugfs_create_u32("min_free_entries", 0444,

			dma_debug_dent,

			&min_free_entries);

	if (!min_free_entries_dent)

		goto out_err;



	return 0;



out_err:

	debugfs_remove_recursive(dma_debug_dent);



	return -ENOMEM;

}





/*

 * Let the architectures decide how many entries should be preallocated.

 */
@@ -256,6 +326,14 @@ void dma_debug_init(u32 num_entries) 
		dma_entry_hash[i].lock = SPIN_LOCK_UNLOCKED;

	}



	if (dma_debug_fs_init() != 0) {

		printk(KERN_ERR "DMA-API: error creating debugfs entries "

				"- disabling\n");

		global_disable = true;



		return;

	}



	if (req_entries)

		num_entries = req_entries;