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devres: Enable trace events

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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: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20210517122946.53161-4-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Andy Shevchenko 2021-05-17 15:29:46 +03:00 committed by Greg Kroah-Hartman
parent a7f1d03b60
commit 09705dcb63
5 changed files with 100 additions and 47 deletions
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3
drivers/base/Makefile
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@ -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

69
drivers/base/devres.c
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@ -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.
@ -134,9 +139,23 @@ 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)
/**
* __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
* other devres_*() functions.
*
* 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,
const char *name)
{
struct devres *dr;
@ -147,32 +166,6 @@ void * __devres_alloc_node(dr_release_t release, size_t size, gfp_t gfp, int nid
return dr->data;
}
EXPORT_SYMBOL_GPL(__devres_alloc_node);
#else
/**
* devres_alloc_node - Allocate device resource data
* @release: Release function devres will be associated with
* @size: Allocation size
* @gfp: Allocation flags
* @nid: NUMA node
*
* Allocate devres of @size bytes. The allocated area is zeroed, then
* associated with @release. The returned pointer can be passed to
* other devres_*() functions.
*
* 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)
{
struct devres *dr;
dr = alloc_dr(release, size, gfp | __GFP_ZERO, nid);
if (unlikely(!dr))
return NULL;
return dr->data;
}
EXPORT_SYMBOL_GPL(devres_alloc_node);
#endif
/**
* devres_for_each_res - Resource iterator

10
drivers/base/trace.c Normal file
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@ -0,0 +1,10 @@
/* 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"

56
drivers/base/trace.h Normal file
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@ -0,0 +1,56 @@
/* 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>

9
include/linux/device.h
View File

@ -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,