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

/*
 * Kernel Debugger Architecture Independent Global Headers
 *
 * Copyright (c) 2000-2007 Silicon Graphics, Inc.  All Rights Reserved.
 * Copyright (C) 2000 Stephane Eranian <eranian@hpl.hp.com>
 * Copyright (C) 2009 Jason Wessel <jason.wessel@windriver.com>
 */

#include <linux/list.h>
#include <linux/smp.h>

/* Shifted versions of the command enable bits are be used if the command
 * has no arguments (see kdb_check_flags). This allows commands, such as
 * go, to have different permissions depending upon whether it is called
 * with an argument.
 */
#define KDB_ENABLE_NO_ARGS_SHIFT 10

typedef enum {
        KDB_ENABLE_ALL = (1 << 0), /* Enable everything */
        KDB_ENABLE_MEM_READ = (1 << 1),
        KDB_ENABLE_MEM_WRITE = (1 << 2),
        KDB_ENABLE_REG_READ = (1 << 3),
        KDB_ENABLE_REG_WRITE = (1 << 4),
        KDB_ENABLE_INSPECT = (1 << 5),
        KDB_ENABLE_FLOW_CTRL = (1 << 6),
        KDB_ENABLE_SIGNAL = (1 << 7),
        KDB_ENABLE_REBOOT = (1 << 8),
        /* User exposed values stop here, all remaining flags are
         * exclusively used to describe a commands behaviour.
         */

        KDB_ENABLE_ALWAYS_SAFE = (1 << 9),
        KDB_ENABLE_MASK = (1 << KDB_ENABLE_NO_ARGS_SHIFT) - 1,

        KDB_ENABLE_ALL_NO_ARGS = KDB_ENABLE_ALL << KDB_ENABLE_NO_ARGS_SHIFT,
        KDB_ENABLE_MEM_READ_NO_ARGS = KDB_ENABLE_MEM_READ
                                      << KDB_ENABLE_NO_ARGS_SHIFT,
        KDB_ENABLE_MEM_WRITE_NO_ARGS = KDB_ENABLE_MEM_WRITE
                                       << KDB_ENABLE_NO_ARGS_SHIFT,
        KDB_ENABLE_REG_READ_NO_ARGS = KDB_ENABLE_REG_READ
                                      << KDB_ENABLE_NO_ARGS_SHIFT,
        KDB_ENABLE_REG_WRITE_NO_ARGS = KDB_ENABLE_REG_WRITE
                                       << KDB_ENABLE_NO_ARGS_SHIFT,
        KDB_ENABLE_INSPECT_NO_ARGS = KDB_ENABLE_INSPECT
                                     << KDB_ENABLE_NO_ARGS_SHIFT,
        KDB_ENABLE_FLOW_CTRL_NO_ARGS = KDB_ENABLE_FLOW_CTRL
                                       << KDB_ENABLE_NO_ARGS_SHIFT,
        KDB_ENABLE_SIGNAL_NO_ARGS = KDB_ENABLE_SIGNAL
                                    << KDB_ENABLE_NO_ARGS_SHIFT,
        KDB_ENABLE_REBOOT_NO_ARGS = KDB_ENABLE_REBOOT
                                    << KDB_ENABLE_NO_ARGS_SHIFT,
        KDB_ENABLE_ALWAYS_SAFE_NO_ARGS = KDB_ENABLE_ALWAYS_SAFE
                                         << KDB_ENABLE_NO_ARGS_SHIFT,
        KDB_ENABLE_MASK_NO_ARGS = KDB_ENABLE_MASK << KDB_ENABLE_NO_ARGS_SHIFT,

        KDB_REPEAT_NO_ARGS = 0x40000000, /* Repeat the command w/o arguments */
        KDB_REPEAT_WITH_ARGS = 0x80000000, /* Repeat the command with args */
} kdb_cmdflags_t;

typedef int (*kdb_func_t)(int, const char **);

/* The KDB shell command table */
typedef struct _kdbtab {
        char    *name;                  /* Command name */
        kdb_func_t func;                /* Function to execute command */
        char    *usage;                 /* Usage String for this command */
        char    *help;                  /* Help message for this command */
        short    minlen;                /* Minimum legal # cmd chars required */
        kdb_cmdflags_t flags;           /* Command behaviour flags */
        struct list_head list_node;     /* Command list */
} kdbtab_t;

#ifdef  CONFIG_KGDB_KDB
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/atomic.h>

#define KDB_POLL_FUNC_MAX       5
extern int kdb_poll_idx;

/*
 * kdb_initial_cpu is initialized to -1, and is set to the cpu
 * number whenever the kernel debugger is entered.
 */
extern int kdb_initial_cpu;

/* Types and messages used for dynamically added kdb shell commands */

#define KDB_MAXARGS    16 /* Maximum number of arguments to a function  */

/* KDB return codes from a command or internal kdb function */
#define KDB_NOTFOUND    (-1)
#define KDB_ARGCOUNT    (-2)
#define KDB_BADWIDTH    (-3)
#define KDB_BADRADIX    (-4)
#define KDB_NOTENV      (-5)
#define KDB_NOENVVALUE  (-6)
#define KDB_NOTIMP      (-7)
#define KDB_ENVFULL     (-8)
#define KDB_KMALLOCFAILED       (-9)
#define KDB_TOOMANYBPT  (-10)
#define KDB_TOOMANYDBREGS (-11)
#define KDB_DUPBPT      (-12)
#define KDB_BPTNOTFOUND (-13)
#define KDB_BADMODE     (-14)
#define KDB_BADINT      (-15)
#define KDB_INVADDRFMT  (-16)
#define KDB_BADREG      (-17)
#define KDB_BADCPUNUM   (-18)
#define KDB_BADLENGTH   (-19)
#define KDB_NOBP        (-20)
#define KDB_BADADDR     (-21)
#define KDB_NOPERM      (-22)

/*
 * kdb_diemsg
 *
 *      Contains a pointer to the last string supplied to the
 *      kernel 'die' panic function.
 */
extern const char *kdb_diemsg;

#define KDB_FLAG_EARLYKDB       (1 << 0) /* set from boot parameter kdb=early */
#define KDB_FLAG_CATASTROPHIC   (1 << 1) /* A catastrophic event has occurred */
#define KDB_FLAG_CMD_INTERRUPT  (1 << 2) /* Previous command was interrupted */
#define KDB_FLAG_NOIPI          (1 << 3) /* Do not send IPIs */
#define KDB_FLAG_NO_CONSOLE     (1 << 5) /* No console is available,
                                          * kdb is disabled */
#define KDB_FLAG_NO_VT_CONSOLE  (1 << 6) /* No VT console is available, do
                                          * not use keyboard */
#define KDB_FLAG_NO_I8042       (1 << 7) /* No i8042 chip is available, do
                                          * not use keyboard */

extern unsigned int kdb_flags;  /* Global flags, see kdb_state for per cpu state */

#define KDB_FLAG(flag)          (kdb_flags & KDB_FLAG_##flag)
#define KDB_FLAG_SET(flag)      ((void)(kdb_flags |= KDB_FLAG_##flag))
#define KDB_FLAG_CLEAR(flag)    ((void)(kdb_flags &= ~KDB_FLAG_##flag))

/*
 * External entry point for the kernel debugger.  The pt_regs
 * at the time of entry are supplied along with the reason for
 * entry to the kernel debugger.
 */

typedef enum {
        KDB_REASON_ENTER = 1,   /* KDB_ENTER() trap/fault - regs valid */
        KDB_REASON_ENTER_SLAVE, /* KDB_ENTER_SLAVE() trap/fault - regs valid */
        KDB_REASON_BREAK,       /* Breakpoint inst. - regs valid */
        KDB_REASON_DEBUG,       /* Debug Fault - regs valid */
        KDB_REASON_OOPS,        /* Kernel Oops - regs valid */
        KDB_REASON_SWITCH,      /* CPU switch - regs valid*/
        KDB_REASON_KEYBOARD,    /* Keyboard entry - regs valid */
        KDB_REASON_NMI,         /* Non-maskable interrupt; regs valid */
        KDB_REASON_RECURSE,     /* Recursive entry to kdb;
                                 * regs probably valid */
        KDB_REASON_SSTEP,       /* Single Step trap. - regs valid */
        KDB_REASON_SYSTEM_NMI,  /* In NMI due to SYSTEM cmd; regs valid */
} kdb_reason_t;

enum kdb_msgsrc {
        KDB_MSGSRC_INTERNAL, /* direct call to kdb_printf() */
        KDB_MSGSRC_PRINTK, /* trapped from printk() */
};

extern int kdb_trap_printk;
extern int kdb_printf_cpu;
extern __printf(2, 0) int vkdb_printf(enum kdb_msgsrc src, const char *fmt,
                                      va_list args);
extern __printf(1, 2) int kdb_printf(const char *, ...);
typedef __printf(1, 2) int (*kdb_printf_t)(const char *, ...);

extern void kdb_init(int level);

/* Access to kdb specific polling devices */
typedef int (*get_char_func)(void);
extern get_char_func kdb_poll_funcs[];
extern int kdb_get_kbd_char(void);

static inline
int kdb_process_cpu(const struct task_struct *p)
{
        unsigned int cpu = task_cpu(p);
        if (cpu > num_possible_cpus())
                cpu = 0;
        return cpu;
}

extern void kdb_send_sig(struct task_struct *p, int sig);

#ifdef CONFIG_KALLSYMS
extern const char *kdb_walk_kallsyms(loff_t *pos);
#else /* ! CONFIG_KALLSYMS */
static inline const char *kdb_walk_kallsyms(loff_t *pos)
{
        return NULL;
}
#endif /* ! CONFIG_KALLSYMS */

/* Dynamic kdb shell command registration */
extern int kdb_register(kdbtab_t *cmd);
extern void kdb_unregister(kdbtab_t *cmd);

/* Return true when KDB as locked for printing a message on this CPU. */
static inline
bool kdb_printf_on_this_cpu(void)
{
        /*
         * We can use raw_smp_processor_id() here because the task could
         * not get migrated when KDB has locked for printing on this CPU.
         */
        return unlikely(READ_ONCE(kdb_printf_cpu) == raw_smp_processor_id());
}

#else /* ! CONFIG_KGDB_KDB */
static inline __printf(1, 2) int kdb_printf(const char *fmt, ...) { return 0; }
static inline void kdb_init(int level) {}
static inline int kdb_register(kdbtab_t *cmd) { return 0; }
static inline void kdb_unregister(kdbtab_t *cmd) {}

static inline bool kdb_printf_on_this_cpu(void) { return false; }

#endif  /* CONFIG_KGDB_KDB */
enum {
        KDB_NOT_INITIALIZED,
        KDB_INIT_EARLY,
        KDB_INIT_FULL,
};

extern int kdbgetintenv(const char *, int *);
extern int kdb_set(int, const char **);
int kdb_lsmod(int argc, const char **argv);

#endif  /* !_KDB_H */