// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2005-2017 Andes Technology Corporation

#include <linux/sched.h>
#include <linux/sched/debug.h>
#include <linux/sched/task_stack.h>
#include <linux/delay.h>
#include <linux/kallsyms.h>
#include <linux/uaccess.h>
#include <asm/elf.h>
#include <asm/proc-fns.h>
#include <linux/ptrace.h>
#include <linux/reboot.h>

extern void setup_mm_for_reboot(char mode);
#ifdef CONFIG_PROC_FS
struct proc_dir_entry *proc_dir_cpu;
EXPORT_SYMBOL(proc_dir_cpu);
#endif

extern inline void arch_reset(char mode)
{
        if (mode == 's') {
                /* Use cpu handler, jump to 0 */
                cpu_reset(0);
        }
}

void (*pm_power_off) (void);
EXPORT_SYMBOL(pm_power_off);

static char reboot_mode_nds32 = 'h';

int __init reboot_setup(char *str)
{
        reboot_mode_nds32 = str[0];
        return 1;
}

static int cpub_pwroff(void)
{
        return 0;
}

__setup("reboot=", reboot_setup);

void machine_halt(void)
{
        cpub_pwroff();
}

EXPORT_SYMBOL(machine_halt);

void machine_power_off(void)
{
        if (pm_power_off)
                pm_power_off();
}

EXPORT_SYMBOL(machine_power_off);

void machine_restart(char *cmd)
{
        /*
         * Clean and disable cache, and turn off interrupts
         */
        cpu_proc_fin();

        /*
         * Tell the mm system that we are going to reboot -
         * we may need it to insert some 1:1 mappings so that
         * soft boot works.
         */
        setup_mm_for_reboot(reboot_mode_nds32);

        /* Execute kernel restart handler call chain */
        do_kernel_restart(cmd);

        /*
         * Now call the architecture specific reboot code.
         */
        arch_reset(reboot_mode_nds32);

        /*
         * Whoops - the architecture was unable to reboot.
         * Tell the user!
         */
        mdelay(1000);
        pr_info("Reboot failed -- System halted\n");
        while (1) ;
}

EXPORT_SYMBOL(machine_restart);

void show_regs(struct pt_regs *regs)
{
        printk("PC is at %pS\n", (void *)instruction_pointer(regs));
        printk("LP is at %pS\n", (void *)regs->lp);
        pr_info("pc : [<%08lx>]    lp : [<%08lx>]    %s\n"
                "sp : %08lx  fp : %08lx  gp : %08lx\n",
                instruction_pointer(regs),
                regs->lp, print_tainted(), regs->sp, regs->fp, regs->gp);
        pr_info("r25: %08lx  r24: %08lx\n", regs->uregs[25], regs->uregs[24]);

        pr_info("r23: %08lx  r22: %08lx  r21: %08lx  r20: %08lx\n",
                regs->uregs[23], regs->uregs[22],
                regs->uregs[21], regs->uregs[20]);
        pr_info("r19: %08lx  r18: %08lx  r17: %08lx  r16: %08lx\n",
                regs->uregs[19], regs->uregs[18],
                regs->uregs[17], regs->uregs[16]);
        pr_info("r15: %08lx  r14: %08lx  r13: %08lx  r12: %08lx\n",
                regs->uregs[15], regs->uregs[14],
                regs->uregs[13], regs->uregs[12]);
        pr_info("r11: %08lx  r10: %08lx  r9 : %08lx  r8 : %08lx\n",
                regs->uregs[11], regs->uregs[10],
                regs->uregs[9], regs->uregs[8]);
        pr_info("r7 : %08lx  r6 : %08lx  r5 : %08lx  r4 : %08lx\n",
                regs->uregs[7], regs->uregs[6], regs->uregs[5], regs->uregs[4]);
        pr_info("r3 : %08lx  r2 : %08lx  r1 : %08lx  r0 : %08lx\n",
                regs->uregs[3], regs->uregs[2], regs->uregs[1], regs->uregs[0]);
        pr_info("  IRQs o%s  Segment %s\n",
                interrupts_enabled(regs) ? "n" : "ff",
                segment_eq(get_fs(), get_ds())? "kernel" : "user");
}

EXPORT_SYMBOL(show_regs);

void flush_thread(void)
{
}

DEFINE_PER_CPU(struct task_struct *, __entry_task);

asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
int copy_thread(unsigned long clone_flags, unsigned long stack_start,
            unsigned long stk_sz, struct task_struct *p)
{
        struct pt_regs *childregs = task_pt_regs(p);

        memset(&p->thread.cpu_context, 0, sizeof(struct cpu_context));

        if (unlikely(p->flags & PF_KTHREAD)) {
                memset(childregs, 0, sizeof(struct pt_regs));
                /* kernel thread fn */
                p->thread.cpu_context.r6 = stack_start;
                /* kernel thread argument */
                p->thread.cpu_context.r7 = stk_sz;
        } else {
                *childregs = *current_pt_regs();
                if (stack_start)
                        childregs->sp = stack_start;
                /* child get zero as ret. */
                childregs->uregs[0] = 0;
                childregs->osp = 0;
                if (clone_flags & CLONE_SETTLS)
                        childregs->uregs[25] = childregs->uregs[3];
        }
        /* cpu context switching  */
        p->thread.cpu_context.pc = (unsigned long)ret_from_fork;
        p->thread.cpu_context.sp = (unsigned long)childregs;

#ifdef CONFIG_HWZOL
        childregs->lb = 0;
        childregs->le = 0;
        childregs->lc = 0;
#endif

        return 0;
}

/*
 * fill in the fpe structure for a core dump...
 */
int dump_fpu(struct pt_regs *regs, elf_fpregset_t * fpu)
{
        int fpvalid = 0;
        return fpvalid;
}

EXPORT_SYMBOL(dump_fpu);

unsigned long get_wchan(struct task_struct *p)
{
        unsigned long fp, lr;
        unsigned long stack_start, stack_end;
        int count = 0;

        if (!p || p == current || p->state == TASK_RUNNING)
                return 0;

        if (IS_ENABLED(CONFIG_FRAME_POINTER)) {
                stack_start = (unsigned long)end_of_stack(p);
                stack_end = (unsigned long)task_stack_page(p) + THREAD_SIZE;

                fp = thread_saved_fp(p);
                do {
                        if (fp < stack_start || fp > stack_end)
                                return 0;
                        lr = ((unsigned long *)fp)[0];
                        if (!in_sched_functions(lr))
                                return lr;
                        fp = *(unsigned long *)(fp + 4);
                } while (count++ < 16);
        }
        return 0;
}

EXPORT_SYMBOL(get_wchan);