/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _DYNAMIC_DEBUG_H
#define _DYNAMIC_DEBUG_H

#if defined(CONFIG_JUMP_LABEL)
#include <linux/jump_label.h>
#endif

#include <linux/build_bug.h>

/*
 * An instance of this structure is created in a special
 * ELF section at every dynamic debug callsite.  At runtime,
 * the special section is treated as an array of these.
 */
struct _ddebug {
        /*
         * These fields are used to drive the user interface
         * for selecting and displaying debug callsites.
         */
        const char *modname;
        const char *function;
        const char *filename;
        const char *format;
        unsigned int lineno:18;
#define CLS_BITS 6
        unsigned int class_id:CLS_BITS;
#define _DPRINTK_CLASS_DFLT             ((1 << CLS_BITS) - 1)
        /*
         * The flags field controls the behaviour at the callsite.
         * The bits here are changed dynamically when the user
         * writes commands to <debugfs>/dynamic_debug/control
         */
#define _DPRINTK_FLAGS_NONE     0
#define _DPRINTK_FLAGS_PRINT    (1<<0) /* printk() a message using the format */
#define _DPRINTK_FLAGS_INCL_MODNAME     (1<<1)
#define _DPRINTK_FLAGS_INCL_FUNCNAME    (1<<2)
#define _DPRINTK_FLAGS_INCL_LINENO      (1<<3)
#define _DPRINTK_FLAGS_INCL_TID         (1<<4)
#define _DPRINTK_FLAGS_INCL_SOURCENAME  (1<<5)
#define _DPRINTK_FLAGS_INCL_STACK       (1<<6)

#define _DPRINTK_FLAGS_INCL_ANY         \
        (_DPRINTK_FLAGS_INCL_MODNAME | _DPRINTK_FLAGS_INCL_FUNCNAME |\
         _DPRINTK_FLAGS_INCL_LINENO  | _DPRINTK_FLAGS_INCL_TID |\
         _DPRINTK_FLAGS_INCL_SOURCENAME | _DPRINTK_FLAGS_INCL_STACK)

#if defined DEBUG
#define _DPRINTK_FLAGS_DEFAULT _DPRINTK_FLAGS_PRINT
#else
#define _DPRINTK_FLAGS_DEFAULT 0
#endif
        unsigned int flags:8;
#ifdef CONFIG_JUMP_LABEL
        union {
                struct static_key_true dd_key_true;
                struct static_key_false dd_key_false;
        } key;
#endif
} __attribute__((aligned(8)));

enum class_map_type {
        DD_CLASS_TYPE_DISJOINT_BITS,
        /**
         * DD_CLASS_TYPE_DISJOINT_BITS: classes are independent, one per bit.
         * expecting hex input. Built for drm.debug, basis for other types.
         */
        DD_CLASS_TYPE_LEVEL_NUM,
        /**
         * DD_CLASS_TYPE_LEVEL_NUM: input is numeric level, 0-N.
         * N turns on just bits N-1 .. 0, so N=0 turns all bits off.
         */
        DD_CLASS_TYPE_DISJOINT_NAMES,
        /**
         * DD_CLASS_TYPE_DISJOINT_NAMES: input is a CSV of [+-]CLASS_NAMES,
         * classes are independent, like _DISJOINT_BITS.
         */
        DD_CLASS_TYPE_LEVEL_NAMES,
        /**
         * DD_CLASS_TYPE_LEVEL_NAMES: input is a CSV of [+-]CLASS_NAMES,
         * intended for names like: INFO,DEBUG,TRACE, with a module prefix
         * avoid EMERG,ALERT,CRIT,ERR,WARNING: they're not debug
         */
};

struct ddebug_class_map {
        struct list_head link;
        struct module *mod;
        const char *mod_name;   /* needed for builtins */
        const char **class_names;
        const int length;
        const int base;         /* index of 1st .class_id, allows split/shared space */
        enum class_map_type map_type;
};

/**
 * DECLARE_DYNDBG_CLASSMAP - declare classnames known by a module
 * @_var:   a struct ddebug_class_map, passed to module_param_cb
 * @_type:  enum class_map_type, chooses bits/verbose, numeric/symbolic
 * @_base:  offset of 1st class-name. splits .class_id space
 * @classes: class-names used to control class'd prdbgs
 */
#define DECLARE_DYNDBG_CLASSMAP(_var, _maptype, _base, ...)             \
        static const char *_var##_classnames[] = { __VA_ARGS__ };       \
        static struct ddebug_class_map __aligned(8) __used              \
                __section("__dyndbg_classes") _var = {                  \
                .mod = THIS_MODULE,                                     \
                .mod_name = KBUILD_MODNAME,                             \
                .base = _base,                                          \
                .map_type = _maptype,                                   \
                .length = NUM_TYPE_ARGS(char*, __VA_ARGS__),            \
                .class_names = _var##_classnames,                       \
        }
#define NUM_TYPE_ARGS(eltype, ...)                              \
        (sizeof((eltype[]){__VA_ARGS__}) / sizeof(eltype))

/* encapsulate linker provided built-in (or module) dyndbg data */
struct _ddebug_info {
        struct _ddebug *descs;
        struct ddebug_class_map *classes;
        unsigned int num_descs;
        unsigned int num_classes;
};

struct ddebug_class_param {
        union {
                unsigned long *bits;
                unsigned int *lvl;
        };
        char flags[8];
        const struct ddebug_class_map *map;
};

/*
 * pr_debug() and friends are globally enabled or modules have selectively
 * enabled them.
 */
#if defined(CONFIG_DYNAMIC_DEBUG) || \
        (defined(CONFIG_DYNAMIC_DEBUG_CORE) && defined(DYNAMIC_DEBUG_MODULE))

extern __printf(2, 3)
void __dynamic_pr_debug(struct _ddebug *descriptor, const char *fmt, ...);

struct device;

extern __printf(3, 4)
void __dynamic_dev_dbg(struct _ddebug *descriptor, const struct device *dev,
                       const char *fmt, ...);

struct net_device;

extern __printf(3, 4)
void __dynamic_netdev_dbg(struct _ddebug *descriptor,
                          const struct net_device *dev,
                          const char *fmt, ...);

struct ib_device;

extern __printf(3, 4)
void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
                         const struct ib_device *ibdev,
                         const char *fmt, ...);

#define __dynamic_dump_stack(desc)                              \
{                                                               \
        if (desc.flags & _DPRINTK_FLAGS_INCL_STACK)             \
                dump_stack();                                   \
}

#define DEFINE_DYNAMIC_DEBUG_METADATA_CLS(name, cls, fmt)       \
        static struct _ddebug  __aligned(8)                     \
        __section("__dyndbg") name = {                          \
                .modname = KBUILD_MODNAME,                      \
                .function = __func__,                           \
                .filename = __FILE__,                           \
                .format = (fmt),                                \
                .lineno = __LINE__,                             \
                .flags = _DPRINTK_FLAGS_DEFAULT,                \
                .class_id = cls,                                \
                _DPRINTK_KEY_INIT                               \
        };                                                      \
        BUILD_BUG_ON_MSG(cls > _DPRINTK_CLASS_DFLT,             \
                         "classid value overflow")

#define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt)                \
        DEFINE_DYNAMIC_DEBUG_METADATA_CLS(name, _DPRINTK_CLASS_DFLT, fmt)

#ifdef CONFIG_JUMP_LABEL

#ifdef DEBUG

#define _DPRINTK_KEY_INIT .key.dd_key_true = (STATIC_KEY_TRUE_INIT)

#define DYNAMIC_DEBUG_BRANCH(descriptor) \
        static_branch_likely(&descriptor.key.dd_key_true)
#else
#define _DPRINTK_KEY_INIT .key.dd_key_false = (STATIC_KEY_FALSE_INIT)

#define DYNAMIC_DEBUG_BRANCH(descriptor) \
        static_branch_unlikely(&descriptor.key.dd_key_false)
#endif

#else /* !CONFIG_JUMP_LABEL */

#define _DPRINTK_KEY_INIT

#ifdef DEBUG
#define DYNAMIC_DEBUG_BRANCH(descriptor) \
        likely(descriptor.flags & _DPRINTK_FLAGS_PRINT)
#else
#define DYNAMIC_DEBUG_BRANCH(descriptor) \
        unlikely(descriptor.flags & _DPRINTK_FLAGS_PRINT)
#endif

#endif /* CONFIG_JUMP_LABEL */

/*
 * Factory macros: ($prefix)dynamic_func_call($suffix)
 *
 * Lower layer (with __ prefix) gets the callsite metadata, and wraps
 * the func inside a debug-branch/static-key construct.  Upper layer
 * (with _ prefix) does the UNIQUE_ID once, so that lower can ref the
 * name/label multiple times, and tie the elements together.
 * Multiple flavors:
 * (|_cls):     adds in _DPRINT_CLASS_DFLT as needed
 * (|_no_desc): former gets callsite descriptor as 1st arg (for prdbgs)
 */
#define __dynamic_func_call_cls(id, cls, fmt, func, ...) do {   \
        DEFINE_DYNAMIC_DEBUG_METADATA_CLS(id, cls, fmt);        \
        if (DYNAMIC_DEBUG_BRANCH(id)) {                         \
                func(&id, ##__VA_ARGS__);                       \
                __dynamic_dump_stack(id);                       \
        }                                                       \
} while (0)
#define __dynamic_func_call(id, fmt, func, ...)                         \
        __dynamic_func_call_cls(id, _DPRINTK_CLASS_DFLT, fmt,           \
                                func, ##__VA_ARGS__)

#define __dynamic_func_call_cls_no_desc(id, cls, fmt, func, ...) do {   \
        DEFINE_DYNAMIC_DEBUG_METADATA_CLS(id, cls, fmt);                \
        if (DYNAMIC_DEBUG_BRANCH(id)) {                                 \
                func(__VA_ARGS__);                                      \
                __dynamic_dump_stack(id);                               \
        }                                                               \
} while (0)
#define __dynamic_func_call_no_desc(id, fmt, func, ...)                 \
        __dynamic_func_call_cls_no_desc(id, _DPRINTK_CLASS_DFLT,        \
                                        fmt, func, ##__VA_ARGS__)

/*
 * "Factory macro" for generating a call to func, guarded by a
 * DYNAMIC_DEBUG_BRANCH. The dynamic debug descriptor will be
 * initialized using the fmt argument. The function will be called with
 * the address of the descriptor as first argument, followed by all
 * the varargs. Note that fmt is repeated in invocations of this
 * macro.
 */
#define _dynamic_func_call_cls(cls, fmt, func, ...)                     \
        __dynamic_func_call_cls(__UNIQUE_ID(ddebug), cls, fmt, func, ##__VA_ARGS__)
#define _dynamic_func_call(fmt, func, ...)                              \
        _dynamic_func_call_cls(_DPRINTK_CLASS_DFLT, fmt, func, ##__VA_ARGS__)

/*
 * A variant that does the same, except that the descriptor is not
 * passed as the first argument to the function; it is only called
 * with precisely the macro's varargs.
 */
#define _dynamic_func_call_cls_no_desc(cls, fmt, func, ...)             \
        __dynamic_func_call_cls_no_desc(__UNIQUE_ID(ddebug), cls, fmt,  \
                                        func, ##__VA_ARGS__)
#define _dynamic_func_call_no_desc(fmt, func, ...)                      \
        _dynamic_func_call_cls_no_desc(_DPRINTK_CLASS_DFLT, fmt,        \
                                       func, ##__VA_ARGS__)

#define dynamic_pr_debug_cls(cls, fmt, ...)                             \
        _dynamic_func_call_cls(cls, fmt, __dynamic_pr_debug,            \
                           pr_fmt(fmt), ##__VA_ARGS__)

#define dynamic_pr_debug(fmt, ...)                              \
        _dynamic_func_call(fmt, __dynamic_pr_debug,             \
                           pr_fmt(fmt), ##__VA_ARGS__)

#define dynamic_dev_dbg(dev, fmt, ...)                          \
        _dynamic_func_call(fmt, __dynamic_dev_dbg,              \
                           dev, fmt, ##__VA_ARGS__)

#define dynamic_netdev_dbg(dev, fmt, ...)                       \
        _dynamic_func_call(fmt, __dynamic_netdev_dbg,           \
                           dev, fmt, ##__VA_ARGS__)

#define dynamic_ibdev_dbg(dev, fmt, ...)                        \
        _dynamic_func_call(fmt, __dynamic_ibdev_dbg,            \
                           dev, fmt, ##__VA_ARGS__)

#define dynamic_hex_dump(prefix_str, prefix_type, rowsize,              \
                         groupsize, buf, len, ascii)                    \
        _dynamic_func_call_no_desc(__builtin_constant_p(prefix_str) ? prefix_str : "hexdump", \
                                   print_hex_dump,                      \
                                   KERN_DEBUG, prefix_str, prefix_type, \
                                   rowsize, groupsize, buf, len, ascii)

/* for test only, generally expect drm.debug style macro wrappers */
#define __pr_debug_cls(cls, fmt, ...) do {                      \
        BUILD_BUG_ON_MSG(!__builtin_constant_p(cls),            \
                         "expecting constant class int/enum");  \
        dynamic_pr_debug_cls(cls, fmt, ##__VA_ARGS__);          \
        } while (0)

#else /* !(CONFIG_DYNAMIC_DEBUG || (CONFIG_DYNAMIC_DEBUG_CORE && DYNAMIC_DEBUG_MODULE)) */

#include <linux/string.h>
#include <linux/errno.h>
#include <linux/printk.h>

#define DEFINE_DYNAMIC_DEBUG_METADATA(name, fmt)
#define DYNAMIC_DEBUG_BRANCH(descriptor) false

#define dynamic_pr_debug(fmt, ...)                                      \
        no_printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
#define dynamic_dev_dbg(dev, fmt, ...)                                  \
        dev_no_printk(KERN_DEBUG, dev, fmt, ##__VA_ARGS__)
#define dynamic_hex_dump(prefix_str, prefix_type, rowsize,              \
                         groupsize, buf, len, ascii)                    \
        do { if (0)                                                     \
                print_hex_dump(KERN_DEBUG, prefix_str, prefix_type,     \
                                rowsize, groupsize, buf, len, ascii);   \
        } while (0)

#endif /* CONFIG_DYNAMIC_DEBUG || (CONFIG_DYNAMIC_DEBUG_CORE && DYNAMIC_DEBUG_MODULE) */


#ifdef CONFIG_DYNAMIC_DEBUG_CORE

extern int ddebug_dyndbg_module_param_cb(char *param, char *val,
                                        const char *modname);
struct kernel_param;
int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp);
int param_get_dyndbg_classes(char *buffer, const struct kernel_param *kp);

#else

static inline int ddebug_dyndbg_module_param_cb(char *param, char *val,
                                                const char *modname)
{
        if (!strcmp(param, "dyndbg")) {
                /* avoid pr_warn(), which wants pr_fmt() fully defined */
                printk(KERN_WARNING "dyndbg param is supported only in "
                        "CONFIG_DYNAMIC_DEBUG builds\n");
                return 0; /* allow and ignore */
        }
        return -EINVAL;
}

struct kernel_param;
static inline int param_set_dyndbg_classes(const char *instr, const struct kernel_param *kp)
{ return 0; }
static inline int param_get_dyndbg_classes(char *buffer, const struct kernel_param *kp)
{ return 0; }

#endif


extern const struct kernel_param_ops param_ops_dyndbg_classes;

#endif /* _DYNAMIC_DEBUG_H */