Commit 09705dcb authored by Andy Shevchenko's avatar Andy Shevchenko Committed by Greg Kroah-Hartman
Browse files

devres: Enable trace events 



In some cases the printf() mechanism is too heavy and can't be used.
For example, when debugging a race condition involving devres API.
When CONFIG_DEBUG_DEVRES is enabled I can't reproduce an issue, and
otherwise it's quite visible with a useful information being collected.

Enable trace events for devres part of the driver core.

Signed-off-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210517122946.53161-4-andriy.shevchenko@linux.intel.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent a7f1d03b

drivers/base/Makefile

+3 −0
Original line number Diff line number Diff line
@@ -30,3 +30,6 @@ obj-y += test/ 


ccflags-$(CONFIG_DEBUG_DRIVER) := -DDEBUG



# define_trace.h needs to know how to find our header

CFLAGS_trace.o		:= -I$(src)

obj-$(CONFIG_TRACING)	+= trace.o

drivers/base/devres.c

+20 −27
Original line number Diff line number Diff line
@@ -14,14 +14,13 @@ 
#include <asm/sections.h>



#include "base.h"

#include "trace.h"



struct devres_node {

	struct list_head		entry;

	dr_release_t			release;

#ifdef CONFIG_DEBUG_DEVRES

	const char			*name;

	size_t				size;

#endif

};



struct devres {
@@ -43,10 +42,6 @@ struct devres_group { 
	/* -- 8 pointers */

};



#ifdef CONFIG_DEBUG_DEVRES

static int log_devres = 0;

module_param_named(log, log_devres, int, S_IRUGO | S_IWUSR);



static void set_node_dbginfo(struct devres_node *node, const char *name,

			     size_t size)

{
@@ -54,7 +49,11 @@ static void set_node_dbginfo(struct devres_node *node, const char *name, 
	node->size = size;

}



static void devres_log(struct device *dev, struct devres_node *node,

#ifdef CONFIG_DEBUG_DEVRES

static int log_devres = 0;

module_param_named(log, log_devres, int, S_IRUGO | S_IWUSR);



static void devres_dbg(struct device *dev, struct devres_node *node,

		       const char *op)

{

	if (unlikely(log_devres))
@@ -62,10 +61,16 @@ static void devres_log(struct device *dev, struct devres_node *node, 
			op, node, node->name, node->size);

}

#else /* CONFIG_DEBUG_DEVRES */

#define set_node_dbginfo(node, n, s)	do {} while (0)

#define devres_log(dev, node, op)	do {} while (0)

#define devres_dbg(dev, node, op)	do {} while (0)

#endif /* CONFIG_DEBUG_DEVRES */



static void devres_log(struct device *dev, struct devres_node *node,

		       const char *op)

{

	trace_devres_log(dev, op, node, node->name, node->size);

	devres_dbg(dev, node, op);

}



/*

 * Release functions for devres group.  These callbacks are used only

 * for identification.
@@ -134,26 +139,13 @@ static void replace_dr(struct device *dev, 
	list_replace(&old->entry, &new->entry);

}



#ifdef CONFIG_DEBUG_DEVRES

void * __devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp, int nid,

		      const char *name)

{

	struct devres *dr;



	dr = alloc_dr(release, size, gfp | __GFP_ZERO, nid);

	if (unlikely(!dr))

		return NULL;

	set_node_dbginfo(&dr->node, name, size);

	return dr->data;

}

EXPORT_SYMBOL_GPL(__devres_alloc_node);

#else

/**

 * devres_alloc_node - Allocate device resource data

 * __devres_alloc_node - Allocate device resource data

 * @release: Release function devres will be associated with

 * @size: Allocation size

 * @gfp: Allocation flags

 * @nid: NUMA node

 * @name: Name of the resource

 *

 * Allocate devres of @size bytes.  The allocated area is zeroed, then

 * associated with @release.  The returned pointer can be passed to
@@ -162,17 +154,18 @@ EXPORT_SYMBOL_GPL(__devres_alloc_node); 
 * RETURNS:

 * Pointer to allocated devres on success, NULL on failure.

 */

void * devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp, int nid)

void *__devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp, int nid,

			  const char *name)

{

	struct devres *dr;



	dr = alloc_dr(release, size, gfp | __GFP_ZERO, nid);

	if (unlikely(!dr))

		return NULL;

	set_node_dbginfo(&dr->node, name, size);

	return dr->data;

}

EXPORT_SYMBOL_GPL(devres_alloc_node);

#endif

EXPORT_SYMBOL_GPL(__devres_alloc_node);



/**

 * devres_for_each_res - Resource iterator

drivers/base/trace.c

0 → 100644
+10 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 */

/*

 * Device core Trace Support

 * Copyright (C) 2021, Intel Corporation

 *

 * Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

 */



#define CREATE_TRACE_POINTS

#include "trace.h"

drivers/base/trace.h

0 → 100644
+56 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 */

/*

 * Device core Trace Support

 * Copyright (C) 2021, Intel Corporation

 *

 * Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

 */



#undef TRACE_SYSTEM

#define TRACE_SYSTEM dev



#if !defined(__DEV_TRACE_H) || defined(TRACE_HEADER_MULTI_READ)

#define __DEV_TRACE_H



#include <linux/device.h>

#include <linux/tracepoint.h>

#include <linux/types.h>



DECLARE_EVENT_CLASS(devres,

	TP_PROTO(struct device *dev, const char *op, void *node, const char *name, size_t size),

	TP_ARGS(dev, op, node, name, size),

	TP_STRUCT__entry(

		__string(devname, dev_name(dev))

		__field(struct device *, dev)

		__field(const char *, op)

		__field(void *, node)

		__field(const char *, name)

		__field(size_t, size)

	),

	TP_fast_assign(

		__assign_str(devname, dev_name(dev));

		__entry->op = op;

		__entry->node = node;

		__entry->name = name;

		__entry->size = size;

	),

	TP_printk("%s %3s %p %s (%zu bytes)", __get_str(devname),

		  __entry->op, __entry->node, __entry->name, __entry->size)

);



DEFINE_EVENT(devres, devres_log,

	TP_PROTO(struct device *dev, const char *op, void *node, const char *name, size_t size),

	TP_ARGS(dev, op, node, name, size)

);



#endif /* __DEV_TRACE_H */



/* this part has to be here */



#undef TRACE_INCLUDE_PATH

#define TRACE_INCLUDE_PATH .



#undef TRACE_INCLUDE_FILE

#define TRACE_INCLUDE_FILE trace



#include <trace/define_trace.h>

include/linux/device.h

+0 −9
Original line number Diff line number Diff line
@@ -165,21 +165,12 @@ void device_remove_bin_file(struct device *dev, 
typedef void (*dr_release_t)(struct device *dev, void *res);

typedef int (*dr_match_t)(struct device *dev, void *res, void *match_data);



#ifdef CONFIG_DEBUG_DEVRES

void *__devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp,

			  int nid, const char *name) __malloc;

#define devres_alloc(release, size, gfp) \

	__devres_alloc_node(release, size, gfp, NUMA_NO_NODE, #release)

#define devres_alloc_node(release, size, gfp, nid) \

	__devres_alloc_node(release, size, gfp, nid, #release)

#else

void *devres_alloc_node(dr_release_t release, size_t size,

			gfp_t gfp, int nid) __malloc;

static inline void *devres_alloc(dr_release_t release, size_t size, gfp_t gfp)

{

	return devres_alloc_node(release, size, gfp, NUMA_NO_NODE);

}

#endif



void devres_for_each_res(struct device *dev, dr_release_t release,

			 dr_match_t match, void *match_data,