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

#ifndef _ASM_RISCV_PROCESSOR_H
#define _ASM_RISCV_PROCESSOR_H

#include <linux/const.h>
#include <linux/cache.h>

#include <vdso/processor.h>

#include <asm/ptrace.h>

/*
 * This decides where the kernel will search for a free chunk of vm
 * space during mmap's.
 */
#define TASK_UNMAPPED_BASE    PAGE_ALIGN(TASK_SIZE / 3)

#define STACK_TOP        TASK_SIZE
#ifdef CONFIG_64BIT
#define STACK_TOP_MAX        TASK_SIZE_64
#else
#define STACK_TOP_MAX        TASK_SIZE
#endif
#define STACK_ALIGN        16

#ifndef __ASSEMBLY__

struct task_struct;
struct pt_regs;

/* CPU-specific state of a task */
struct thread_struct {
    /* Callee-saved registers */
    unsigned long ra;
    unsigned long sp;    /* Kernel mode stack */
    unsigned long s[12];    /* s[0]: frame pointer */
    struct __riscv_d_ext_state fstate;
    unsigned long bad_cause;
    unsigned long vstate_ctrl;
    struct __riscv_v_ext_state vstate;
};

/* Whitelist the fstate from the task_struct for hardened usercopy */
static inline void arch_thread_struct_whitelist(unsigned long *offset,
                        unsigned long *size)
{
    *offset = offsetof(struct thread_struct, fstate);
    *size = sizeof_field(struct thread_struct, fstate);
}

#define INIT_THREAD {                    \
    .sp = sizeof(init_stack) + (long)&init_stack,    \
}

#define task_pt_regs(tsk)                        \
    ((struct pt_regs *)(task_stack_page(tsk) + THREAD_SIZE        \
                - ALIGN(sizeof(struct pt_regs), STACK_ALIGN)))

#define KSTK_EIP(tsk)        (task_pt_regs(tsk)->epc)
#define KSTK_ESP(tsk)        (task_pt_regs(tsk)->sp)


/* Do necessary setup to start up a newly executed thread. */
extern void start_thread(struct pt_regs *regs,
            unsigned long pc, unsigned long sp);

extern unsigned long __get_wchan(struct task_struct *p);


static inline void wait_for_interrupt(void)
{
    __asm__ __volatile__ ("wfi");
}

struct device_node;
int riscv_of_processor_hartid(struct device_node *node, unsigned long *hartid);
int riscv_early_of_processor_hartid(struct device_node *node, unsigned long *hartid);
int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid);

extern void riscv_fill_hwcap(void);
extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);

extern unsigned long signal_minsigstksz __ro_after_init;

#ifdef CONFIG_RISCV_ISA_V
/* Userspace interface for PR_RISCV_V_{SET,GET}_VS prctl()s: */
#define RISCV_V_SET_CONTROL(arg)    riscv_v_vstate_ctrl_set_current(arg)
#define RISCV_V_GET_CONTROL()        riscv_v_vstate_ctrl_get_current()
extern long riscv_v_vstate_ctrl_set_current(unsigned long arg);
extern long riscv_v_vstate_ctrl_get_current(void);
#endif /* CONFIG_RISCV_ISA_V */

#endif /* __ASSEMBLY__ */

#endif /* _ASM_RISCV_PROCESSOR_H */