/* SPDX-License-Identifier: GPL-2.0 */
/*
* S/390 debug facility
*
* Copyright IBM Corp. 1999, 2020
*/
#ifndef _ASM_S390_DEBUG_H
#define _ASM_S390_DEBUG_H
#include <linux/string.h>
#include <linux/spinlock.h>
#include <linux/kernel.h>
#include <linux/time.h>
#include <linux/refcount.h>
#include <linux/fs.h>
#include <linux/init.h>
#define DEBUG_MAX_LEVEL 6 /* debug levels range from 0 to 6 */
#define DEBUG_OFF_LEVEL -1 /* level where debug is switched off */
#define DEBUG_FLUSH_ALL -1 /* parameter to flush all areas */
#define DEBUG_MAX_VIEWS 10 /* max number of views in proc fs */
#define DEBUG_MAX_NAME_LEN 64 /* max length for a debugfs file name */
#define DEBUG_DEFAULT_LEVEL 3 /* initial debug level */
#define DEBUG_DIR_ROOT "s390dbf" /* name of debug root directory in proc fs */
#define DEBUG_DATA(entry) (char *)(entry + 1) /* data is stored behind */
/* the entry information */
#define __DEBUG_FEATURE_VERSION 3 /* version of debug feature */
struct __debug_entry {
unsigned long clock : 60;
unsigned long exception : 1;
unsigned long level : 3;
void *caller;
unsigned short cpu;
} __packed;
typedef struct __debug_entry debug_entry_t;
struct debug_view;
typedef struct debug_info {
struct debug_info *next;
struct debug_info *prev;
refcount_t ref_count;
spinlock_t lock;
int level;
int nr_areas;
int pages_per_area;
int buf_size;
int entry_size;
debug_entry_t ***areas;
int active_area;
int *active_pages;
int *active_entries;
struct dentry *debugfs_root_entry;
struct dentry *debugfs_entries[DEBUG_MAX_VIEWS];
struct debug_view *views[DEBUG_MAX_VIEWS];
char name[DEBUG_MAX_NAME_LEN];
umode_t mode;
} debug_info_t;
typedef int (debug_header_proc_t) (debug_info_t *id,
struct debug_view *view,
int area,
debug_entry_t *entry,
char *out_buf);
typedef int (debug_format_proc_t) (debug_info_t *id,
struct debug_view *view, char *out_buf,
const char *in_buf);
typedef int (debug_prolog_proc_t) (debug_info_t *id,
struct debug_view *view,
char *out_buf);
typedef int (debug_input_proc_t) (debug_info_t *id,
struct debug_view *view,
struct file *file,
const char __user *user_buf,
size_t in_buf_size, loff_t *offset);
int debug_dflt_header_fn(debug_info_t *id, struct debug_view *view,
int area, debug_entry_t *entry, char *out_buf);
struct debug_view {
char name[DEBUG_MAX_NAME_LEN];
debug_prolog_proc_t *prolog_proc;
debug_header_proc_t *header_proc;
debug_format_proc_t *format_proc;
debug_input_proc_t *input_proc;
void *private_data;
};
extern struct debug_view debug_hex_ascii_view;
extern struct debug_view debug_sprintf_view;
/* do NOT use the _common functions */
debug_entry_t *debug_event_common(debug_info_t *id, int level,
const void *data, int length);
debug_entry_t *debug_exception_common(debug_info_t *id, int level,
const void *data, int length);
/* Debug Feature API: */
debug_info_t *debug_register(const char *name, int pages, int nr_areas,
int buf_size);
debug_info_t *debug_register_mode(const char *name, int pages, int nr_areas,
int buf_size, umode_t mode, uid_t uid,
gid_t gid);
void debug_unregister(debug_info_t *id);
void debug_set_level(debug_info_t *id, int new_level);
void debug_set_critical(void);
void debug_stop_all(void);
/**
* debug_level_enabled() - Returns true if debug events for the specified
* level would be logged. Otherwise returns false.
*
* @id: handle for debug log
* @level: debug level
*
* Return:
* - %true if level is less or equal to the current debug level.
*/
static inline bool debug_level_enabled(debug_info_t *id, int level)
{
return level <= id->level;
}
/**
* debug_event() - writes binary debug entry to active debug area
* (if level <= actual debug level)
*
* @id: handle for debug log
* @level: debug level
* @data: pointer to data for debug entry
* @length: length of data in bytes
*
* Return:
* - Address of written debug entry
* - %NULL if error
*/
static inline debug_entry_t *debug_event(debug_info_t *id, int level,
void *data, int length)
{
if ((!id) || (level > id->level) || (id->pages_per_area == 0))
return NULL;
return debug_event_common(id, level, data, length);
}
/**
* debug_int_event() - writes unsigned integer debug entry to active debug area
* (if level <= actual debug level)
*
* @id: handle for debug log
* @level: debug level
* @tag: integer value for debug entry
*
* Return:
* - Address of written debug entry
* - %NULL if error
*/
static inline debug_entry_t *debug_int_event(debug_info_t *id, int level,
unsigned int tag)
{
unsigned int t = tag;
if ((!id) || (level > id->level) || (id->pages_per_area == 0))
return NULL;
return debug_event_common(id, level, &t, sizeof(unsigned int));
}
/**
* debug_long_event() - writes unsigned long debug entry to active debug area
* (if level <= actual debug level)
*
* @id: handle for debug log
* @level: debug level
* @tag: long integer value for debug entry
*
* Return:
* - Address of written debug entry
* - %NULL if error
*/
static inline debug_entry_t *debug_long_event(debug_info_t *id, int level,
unsigned long tag)
{
unsigned long t = tag;
if ((!id) || (level > id->level) || (id->pages_per_area == 0))
return NULL;
return debug_event_common(id, level, &t, sizeof(unsigned long));
}
/**
* debug_text_event() - writes string debug entry in ascii format to active
* debug area (if level <= actual debug level)
*
* @id: handle for debug log
* @level: debug level
* @txt: string for debug entry
*
* Return:
* - Address of written debug entry
* - %NULL if error
*/
static inline debug_entry_t *debug_text_event(debug_info_t *id, int level,
const char *txt)
{
if ((!id) || (level > id->level) || (id->pages_per_area == 0))
return NULL;
return debug_event_common(id, level, txt, strlen(txt));
}
/*
* IMPORTANT: Use "%s" in sprintf format strings with care! Only pointers are
* stored in the s390dbf. See Documentation/arch/s390/s390dbf.rst for more details!
*/
extern debug_entry_t *
__debug_sprintf_event(debug_info_t *id, int level, char *string, ...)
__attribute__ ((format(printf, 3, 4)));
/**
* debug_sprintf_event() - writes debug entry with format string
* and varargs (longs) to active debug area
* (if level $<=$ actual debug level).
*
* @_id: handle for debug log
* @_level: debug level
* @_fmt: format string for debug entry
* @...: varargs used as in sprintf()
*
* Return:
* - Address of written debug entry
* - %NULL if error
*
* floats and long long datatypes cannot be used as varargs.
*/
#define debug_sprintf_event(_id, _level, _fmt, ...) \
({ \
debug_entry_t *__ret; \
debug_info_t *__id = _id; \
int __level = _level; \
\
if ((!__id) || (__level > __id->level)) \
__ret = NULL; \
else \
__ret = __debug_sprintf_event(__id, __level, \
_fmt, ## __VA_ARGS__); \
__ret; \
})
/**
* debug_exception() - writes binary debug entry to active debug area
* (if level <= actual debug level)
* and switches to next debug area
*
* @id: handle for debug log
* @level: debug level
* @data: pointer to data for debug entry
* @length: length of data in bytes
*
* Return:
* - Address of written debug entry
* - %NULL if error
*/
static inline debug_entry_t *debug_exception(debug_info_t *id, int level,
void *data, int length)
{
if ((!id) || (level > id->level) || (id->pages_per_area == 0))
return NULL;
return debug_exception_common(id, level, data, length);
}
/**
* debug_int_exception() - writes unsigned int debug entry to active debug area
* (if level <= actual debug level)
* and switches to next debug area
*
* @id: handle for debug log
* @level: debug level
* @tag: integer value for debug entry
*
* Return:
* - Address of written debug entry
* - %NULL if error
*/
static inline debug_entry_t *debug_int_exception(debug_info_t *id, int level,
unsigned int tag)
{
unsigned int t = tag;
if ((!id) || (level > id->level) || (id->pages_per_area == 0))
return NULL;
return debug_exception_common(id, level, &t, sizeof(unsigned int));
}
/**
* debug_long_exception() - writes long debug entry to active debug area
* (if level <= actual debug level)
* and switches to next debug area
*
* @id: handle for debug log
* @level: debug level
* @tag: long integer value for debug entry
*
* Return:
* - Address of written debug entry
* - %NULL if error
*/
static inline debug_entry_t *debug_long_exception (debug_info_t *id, int level,
unsigned long tag)
{
unsigned long t = tag;
if ((!id) || (level > id->level) || (id->pages_per_area == 0))
return NULL;
return debug_exception_common(id, level, &t, sizeof(unsigned long));
}
/**
* debug_text_exception() - writes string debug entry in ascii format to active
* debug area (if level <= actual debug level)
* and switches to next debug area
* area
*
* @id: handle for debug log
* @level: debug level
* @txt: string for debug entry
*
* Return:
* - Address of written debug entry
* - %NULL if error
*/
static inline debug_entry_t *debug_text_exception(debug_info_t *id, int level,
const char *txt)
{
if ((!id) || (level > id->level) || (id->pages_per_area == 0))
return NULL;
return debug_exception_common(id, level, txt, strlen(txt));
}
/*
* IMPORTANT: Use "%s" in sprintf format strings with care! Only pointers are
* stored in the s390dbf. See Documentation/arch/s390/s390dbf.rst for more details!
*/
extern debug_entry_t *
__debug_sprintf_exception(debug_info_t *id, int level, char *string, ...)
__attribute__ ((format(printf, 3, 4)));
/**
* debug_sprintf_exception() - writes debug entry with format string and
* varargs (longs) to active debug area
* (if level <= actual debug level)
* and switches to next debug area.
*
* @_id: handle for debug log
* @_level: debug level
* @_fmt: format string for debug entry
* @...: varargs used as in sprintf()
*
* Return:
* - Address of written debug entry
* - %NULL if error
*
* floats and long long datatypes cannot be used as varargs.
*/
#define debug_sprintf_exception(_id, _level, _fmt, ...) \
({ \
debug_entry_t *__ret; \
debug_info_t *__id = _id; \
int __level = _level; \
\
if ((!__id) || (__level > __id->level)) \
__ret = NULL; \
else \
__ret = __debug_sprintf_exception(__id, __level, \
_fmt, ## __VA_ARGS__);\
__ret; \
})
int debug_register_view(debug_info_t *id, struct debug_view *view);
int debug_unregister_view(debug_info_t *id, struct debug_view *view);
#ifndef MODULE
/*
* Note: Initial page and area numbers must be fixed to allow static
* initialization. This enables very early tracing. Changes to these values
* must be reflected in __DEFINE_STATIC_AREA.
*/
#define EARLY_PAGES 8
#define EARLY_AREAS 1
#define VNAME(var, suffix) __##var##_##suffix
/*
* Define static areas for early trace data. During boot debug_register_static()
* will replace these with dynamically allocated areas to allow custom page and
* area sizes, and dynamic resizing.
*/
#define __DEFINE_STATIC_AREA(var) \
static char VNAME(var, data)[EARLY_PAGES][PAGE_SIZE] __initdata; \
static debug_entry_t *VNAME(var, pages)[EARLY_PAGES] __initdata = { \
(debug_entry_t *)VNAME(var, data)[0], \
(debug_entry_t *)VNAME(var, data)[1], \
(debug_entry_t *)VNAME(var, data)[2], \
(debug_entry_t *)VNAME(var, data)[3], \
(debug_entry_t *)VNAME(var, data)[4], \
(debug_entry_t *)VNAME(var, data)[5], \
(debug_entry_t *)VNAME(var, data)[6], \
(debug_entry_t *)VNAME(var, data)[7], \
}; \
static debug_entry_t **VNAME(var, areas)[EARLY_AREAS] __initdata = { \
(debug_entry_t **)VNAME(var, pages), \
}; \
static int VNAME(var, active_pages)[EARLY_AREAS] __initdata; \
static int VNAME(var, active_entries)[EARLY_AREAS] __initdata
#define __DEBUG_INFO_INIT(var, _name, _buf_size) { \
.next = NULL, \
.prev = NULL, \
.ref_count = REFCOUNT_INIT(1), \
.lock = __SPIN_LOCK_UNLOCKED(var.lock), \
.level = DEBUG_DEFAULT_LEVEL, \
.nr_areas = EARLY_AREAS, \
.pages_per_area = EARLY_PAGES, \
.buf_size = (_buf_size), \
.entry_size = sizeof(debug_entry_t) + (_buf_size), \
.areas = VNAME(var, areas), \
.active_area = 0, \
.active_pages = VNAME(var, active_pages), \
.active_entries = VNAME(var, active_entries), \
.debugfs_root_entry = NULL, \
.debugfs_entries = { NULL }, \
.views = { NULL }, \
.name = (_name), \
.mode = 0600, \
}
#define __REGISTER_STATIC_DEBUG_INFO(var, name, pages, areas, view) \
static int __init VNAME(var, reg)(void) \
{ \
debug_register_static(&var, (pages), (areas)); \
debug_register_view(&var, (view)); \
return 0; \
} \
arch_initcall(VNAME(var, reg))
/**
* DEFINE_STATIC_DEBUG_INFO - Define static debug_info_t
*
* @var: Name of debug_info_t variable
* @name: Name of debug log (e.g. used for debugfs entry)
* @pages: Number of pages per area
* @nr_areas: Number of debug areas
* @buf_size: Size of data area in each debug entry
* @view: Pointer to debug view struct
*
* Define a static debug_info_t for early tracing. The associated debugfs log
* is automatically registered with the specified debug view.
*
* Important: Users of this macro must not call any of the
* debug_register/_unregister() functions for this debug_info_t!
*
* Note: Tracing will start with a fixed number of initial pages and areas.
* The debug area will be changed to use the specified numbers during
* arch_initcall.
*/
#define DEFINE_STATIC_DEBUG_INFO(var, name, pages, nr_areas, buf_size, view) \
__DEFINE_STATIC_AREA(var); \
static debug_info_t __refdata var = \
__DEBUG_INFO_INIT(var, (name), (buf_size)); \
__REGISTER_STATIC_DEBUG_INFO(var, name, pages, nr_areas, view)
void debug_register_static(debug_info_t *id, int pages_per_area, int nr_areas);
#endif /* MODULE */
#endif /* _ASM_S390_DEBUG_H */