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

#include <asm/ptrace.h>
#include <asm/asm.h>
#include <linux/stringify.h>

#ifdef CONFIG_KALLSYMS
extern int raw_show_trace;
extern unsigned long unwind_stack(struct task_struct *task, unsigned long *sp,
                                  unsigned long pc, unsigned long *ra);
extern unsigned long unwind_stack_by_address(unsigned long stack_page,
                                             unsigned long *sp,
                                             unsigned long pc,
                                             unsigned long *ra);
#else
#define raw_show_trace 1
static inline unsigned long unwind_stack(struct task_struct *task,
        unsigned long *sp, unsigned long pc, unsigned long *ra)
{
        return 0;
}
#endif

#define STR_PTR_LA    __stringify(PTR_LA)
#define STR_LONG_S    __stringify(LONG_S)
#define STR_LONG_L    __stringify(LONG_L)
#define STR_LONGSIZE  __stringify(LONGSIZE)

#define STORE_ONE_REG(r) \
    STR_LONG_S   " $" __stringify(r)",("STR_LONGSIZE"*"__stringify(r)")(%1)\n\t"

static __always_inline void prepare_frametrace(struct pt_regs *regs)
{
#ifndef CONFIG_KALLSYMS
        /*
         * Remove any garbage that may be in regs (specially func
         * addresses) to avoid show_raw_backtrace() to report them
         */
        memset(regs, 0, sizeof(*regs));
#endif
        __asm__ __volatile__(
                ".set push\n\t"
                ".set noat\n\t"
                /* Store $1 so we can use it */
                STR_LONG_S " $1,"STR_LONGSIZE"(%1)\n\t"
                /* Store the PC */
                "1: " STR_PTR_LA " $1, 1b\n\t"
                STR_LONG_S " $1,%0\n\t"
                STORE_ONE_REG(2)
                STORE_ONE_REG(3)
                STORE_ONE_REG(4)
                STORE_ONE_REG(5)
                STORE_ONE_REG(6)
                STORE_ONE_REG(7)
                STORE_ONE_REG(8)
                STORE_ONE_REG(9)
                STORE_ONE_REG(10)
                STORE_ONE_REG(11)
                STORE_ONE_REG(12)
                STORE_ONE_REG(13)
                STORE_ONE_REG(14)
                STORE_ONE_REG(15)
                STORE_ONE_REG(16)
                STORE_ONE_REG(17)
                STORE_ONE_REG(18)
                STORE_ONE_REG(19)
                STORE_ONE_REG(20)
                STORE_ONE_REG(21)
                STORE_ONE_REG(22)
                STORE_ONE_REG(23)
                STORE_ONE_REG(24)
                STORE_ONE_REG(25)
                STORE_ONE_REG(26)
                STORE_ONE_REG(27)
                STORE_ONE_REG(28)
                STORE_ONE_REG(29)
                STORE_ONE_REG(30)
                STORE_ONE_REG(31)
                /* Restore $1 */
                STR_LONG_L " $1,"STR_LONGSIZE"(%1)\n\t"
                ".set pop\n\t"
                : "=m" (regs->cp0_epc)
                : "r" (regs->regs)
                : "memory");
}

#endif /* _ASM_STACKTRACE_H */