/*
 * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
 * Copyright (C) 2008-2009 PetaLogix
 * Copyright (C) 2006 Atmark Techno, Inc.
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License. See the file "COPYING" in the main directory of this archive
 * for more details.
 */

#include <linux/export.h>
#include <linux/sched.h>
#include <linux/pm.h>
#include <linux/tick.h>
#include <linux/bitops.h>
#include <linux/ptrace.h>
#include <asm/pgalloc.h>
#include <linux/uaccess.h> /* for USER_DS macros */
#include <asm/cacheflush.h>

void show_regs(struct pt_regs *regs)
{
        show_regs_print_info(KERN_INFO);

        pr_info(" Registers dump: mode=%X\r\n", regs->pt_mode);
        pr_info(" r1=%08lX, r2=%08lX, r3=%08lX, r4=%08lX\n",
                                regs->r1, regs->r2, regs->r3, regs->r4);
        pr_info(" r5=%08lX, r6=%08lX, r7=%08lX, r8=%08lX\n",
                                regs->r5, regs->r6, regs->r7, regs->r8);
        pr_info(" r9=%08lX, r10=%08lX, r11=%08lX, r12=%08lX\n",
                                regs->r9, regs->r10, regs->r11, regs->r12);
        pr_info(" r13=%08lX, r14=%08lX, r15=%08lX, r16=%08lX\n",
                                regs->r13, regs->r14, regs->r15, regs->r16);
        pr_info(" r17=%08lX, r18=%08lX, r19=%08lX, r20=%08lX\n",
                                regs->r17, regs->r18, regs->r19, regs->r20);
        pr_info(" r21=%08lX, r22=%08lX, r23=%08lX, r24=%08lX\n",
                                regs->r21, regs->r22, regs->r23, regs->r24);
        pr_info(" r25=%08lX, r26=%08lX, r27=%08lX, r28=%08lX\n",
                                regs->r25, regs->r26, regs->r27, regs->r28);
        pr_info(" r29=%08lX, r30=%08lX, r31=%08lX, rPC=%08lX\n",
                                regs->r29, regs->r30, regs->r31, regs->pc);
        pr_info(" msr=%08lX, ear=%08lX, esr=%08lX, fsr=%08lX\n",
                                regs->msr, regs->ear, regs->esr, regs->fsr);
}

void (*pm_power_off)(void) = NULL;
EXPORT_SYMBOL(pm_power_off);

void flush_thread(void)
{
}

int copy_thread(unsigned long clone_flags, unsigned long usp,
                unsigned long arg, struct task_struct *p)
{
        struct pt_regs *childregs = task_pt_regs(p);
        struct thread_info *ti = task_thread_info(p);

        if (unlikely(p->flags & PF_KTHREAD)) {
                /* if we're creating a new kernel thread then just zeroing all
                 * the registers. That's OK for a brand new thread.*/
                memset(childregs, 0, sizeof(struct pt_regs));
                memset(&ti->cpu_context, 0, sizeof(struct cpu_context));
                ti->cpu_context.r1  = (unsigned long)childregs;
                ti->cpu_context.r20 = (unsigned long)usp; /* fn */
                ti->cpu_context.r19 = (unsigned long)arg;
                childregs->pt_mode = 1;
                local_save_flags(childregs->msr);
#ifdef CONFIG_MMU
                ti->cpu_context.msr = childregs->msr & ~MSR_IE;
#endif
                ti->cpu_context.r15 = (unsigned long)ret_from_kernel_thread - 8;
                return 0;
        }
        *childregs = *current_pt_regs();
        if (usp)
                childregs->r1 = usp;

        memset(&ti->cpu_context, 0, sizeof(struct cpu_context));
        ti->cpu_context.r1 = (unsigned long)childregs;
#ifndef CONFIG_MMU
        ti->cpu_context.msr = (unsigned long)childregs->msr;
#else
        childregs->msr |= MSR_UMS;

        /* we should consider the fact that childregs is a copy of the parent
         * regs which were saved immediately after entering the kernel state
         * before enabling VM. This MSR will be restored in switch_to and
         * RETURN() and we want to have the right machine state there
         * specifically this state must have INTs disabled before and enabled
         * after performing rtbd
         * compose the right MSR for RETURN(). It will work for switch_to also
         * excepting for VM and UMS
         * don't touch UMS , CARRY and cache bits
         * right now MSR is a copy of parent one */
        childregs->msr &= ~MSR_EIP;
        childregs->msr |= MSR_IE;
        childregs->msr &= ~MSR_VM;
        childregs->msr |= MSR_VMS;
        childregs->msr |= MSR_EE; /* exceptions will be enabled*/

        ti->cpu_context.msr = (childregs->msr|MSR_VM);
        ti->cpu_context.msr &= ~MSR_UMS; /* switch_to to kernel mode */
        ti->cpu_context.msr &= ~MSR_IE;
#endif
        ti->cpu_context.r15 = (unsigned long)ret_from_fork - 8;

        /*
         *  r21 is the thread reg, r10 is 6th arg to clone
         *  which contains TLS area
         */
        if (clone_flags & CLONE_SETTLS)
                childregs->r21 = childregs->r10;

        return 0;
}

#ifndef CONFIG_MMU
/*
 * Return saved PC of a blocked thread.
 */
unsigned long thread_saved_pc(struct task_struct *tsk)
{
        struct cpu_context *ctx =
                &(((struct thread_info *)(tsk->stack))->cpu_context);

        /* Check whether the thread is blocked in resume() */
        if (in_sched_functions(ctx->r15))
                return (unsigned long)ctx->r15;
        else
                return ctx->r14;
}
#endif

unsigned long get_wchan(struct task_struct *p)
{
/* TBD (used by procfs) */
        return 0;
}

/* Set up a thread for executing a new program */
void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long usp)
{
        regs->pc = pc;
        regs->r1 = usp;
        regs->pt_mode = 0;
#ifdef CONFIG_MMU
        regs->msr |= MSR_UMS;
        regs->msr &= ~MSR_VM;
#endif
}

#ifdef CONFIG_MMU
#include <linux/elfcore.h>
/*
 * Set up a thread for executing a new program
 */
int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpregs)
{
        return 0; /* MicroBlaze has no separate FPU registers */
}
#endif /* CONFIG_MMU */

void arch_cpu_idle(void)
{
       local_irq_enable();
}