/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Copyright (C) 2012 Regents of the University of California
 */

#ifndef _ASM_RISCV_PTRACE_H
#define _ASM_RISCV_PTRACE_H

#include <uapi/asm/ptrace.h>
#include <asm/csr.h>
#include <linux/compiler.h>

#ifndef __ASSEMBLER__

struct pt_regs {
        unsigned long epc;
        unsigned long ra;
        unsigned long sp;
        unsigned long gp;
        unsigned long tp;
        unsigned long t0;
        unsigned long t1;
        unsigned long t2;
        unsigned long s0;
        unsigned long s1;
        struct_group(a_regs,
                unsigned long a0;
                unsigned long a1;
                unsigned long a2;
                unsigned long a3;
                unsigned long a4;
                unsigned long a5;
                unsigned long a6;
                unsigned long a7;
        );
        unsigned long s2;
        unsigned long s3;
        unsigned long s4;
        unsigned long s5;
        unsigned long s6;
        unsigned long s7;
        unsigned long s8;
        unsigned long s9;
        unsigned long s10;
        unsigned long s11;
        unsigned long t3;
        unsigned long t4;
        unsigned long t5;
        unsigned long t6;
        /* Supervisor/Machine CSRs */
        unsigned long status;
        unsigned long badaddr;
        unsigned long cause;
        /* a0 value before the syscall */
        unsigned long orig_a0;
};

#define PTRACE_SYSEMU                   0x1f
#define PTRACE_SYSEMU_SINGLESTEP        0x20

#ifdef CONFIG_64BIT
#define REG_FMT "%016lx"
#else
#define REG_FMT "%08lx"
#endif

#define user_mode(regs) (((regs)->status & SR_PP) == 0)

#define MAX_REG_OFFSET offsetof(struct pt_regs, orig_a0)

/* Helpers for working with the instruction pointer */
static inline unsigned long instruction_pointer(struct pt_regs *regs)
{
        return regs->epc;
}
static inline void instruction_pointer_set(struct pt_regs *regs,
                                           unsigned long val)
{
        regs->epc = val;
}

#define profile_pc(regs) instruction_pointer(regs)

/* Helpers for working with the user stack pointer */
static inline unsigned long user_stack_pointer(struct pt_regs *regs)
{
        return regs->sp;
}
static inline void user_stack_pointer_set(struct pt_regs *regs,
                                          unsigned long val)
{
        regs->sp =  val;
}

/* Valid only for Kernel mode traps. */
static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
{
        return regs->sp;
}

/* Helpers for working with the frame pointer */
static inline unsigned long frame_pointer(struct pt_regs *regs)
{
        return regs->s0;
}
static inline void frame_pointer_set(struct pt_regs *regs,
                                     unsigned long val)
{
        regs->s0 = val;
}

static inline unsigned long regs_return_value(struct pt_regs *regs)
{
        return regs->a0;
}

static inline void regs_set_return_value(struct pt_regs *regs,
                                         unsigned long val)
{
        regs->a0 = val;
}

extern int regs_query_register_offset(const char *name);
extern unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
                                               unsigned int n);

void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr,
                           unsigned long frame_pointer);

/**
 * regs_get_register() - get register value from its offset
 * @regs:       pt_regs from which register value is gotten
 * @offset:     offset of the register.
 *
 * regs_get_register returns the value of a register whose offset from @regs.
 * The @offset is the offset of the register in struct pt_regs.
 * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
 */
static inline unsigned long regs_get_register(struct pt_regs *regs,
                                              unsigned int offset)
{
        if (unlikely(offset > MAX_REG_OFFSET))
                return 0;

        return *(unsigned long *)((unsigned long)regs + offset);
}

/**
 * regs_get_kernel_argument() - get Nth function argument in kernel
 * @regs:       pt_regs of that context
 * @n:          function argument number (start from 0)
 *
 * regs_get_argument() returns @n th argument of the function call.
 *
 * Note you can get the parameter correctly if the function has no
 * more than eight arguments.
 */
static inline unsigned long regs_get_kernel_argument(struct pt_regs *regs,
                                                unsigned int n)
{
        static const int nr_reg_arguments = 8;
        static const unsigned int argument_offs[] = {
                offsetof(struct pt_regs, a0),
                offsetof(struct pt_regs, a1),
                offsetof(struct pt_regs, a2),
                offsetof(struct pt_regs, a3),
                offsetof(struct pt_regs, a4),
                offsetof(struct pt_regs, a5),
                offsetof(struct pt_regs, a6),
                offsetof(struct pt_regs, a7),
        };

        if (n < nr_reg_arguments)
                return regs_get_register(regs, argument_offs[n]);
        return 0;
}

static __always_inline bool regs_irqs_disabled(struct pt_regs *regs)
{
        return !(regs->status & SR_PIE);
}

#endif /* __ASSEMBLER__ */

#endif /* _ASM_RISCV_PTRACE_H */