/*  $Id: process.c,v 1.125.2.1 2001/12/18 19:40:17 davem Exp $
 *  arch/sparc64/kernel/process.c
 *
 *  Copyright (C) 1995, 1996 David S. Miller (davem@caip.rutgers.edu)
 *  Copyright (C) 1996       Eddie C. Dost   (ecd@skynet.be)
 *  Copyright (C) 1997, 1998 Jakub Jelinek   (jj@sunsite.mff.cuni.cz)
 */

/*
 * This file handles the architecture-dependent parts of process handling..
 */

#define __KERNEL_SYSCALLS__
#include <stdarg.h>

#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/ptrace.h>
#include <linux/slab.h>
#include <linux/user.h>
#include <linux/a.out.h>
#include <linux/config.h>
#include <linux/reboot.h>
#include <linux/delay.h>

#include <asm/oplib.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/processor.h>
#include <asm/pstate.h>
#include <asm/elf.h>
#include <asm/fpumacro.h>
#include <asm/head.h>

/* #define VERBOSE_SHOWREGS */

#ifndef CONFIG_SMP

/*
 * the idle loop on a Sparc... ;)
 */
int cpu_idle(void)
{
        if (current->pid != 0)
                return -EPERM;

        /* endless idle loop with no priority at all */
        current->nice = 20;
        current->counter = -100;
        init_idle();

        for (;;) {
                /* If current->need_resched is zero we should really
                 * setup for a system wakup event and execute a shutdown
                 * instruction.
                 *
                 * But this requires writing back the contents of the
                 * L2 cache etc. so implement this later. -DaveM
                 */
                while (!current->need_resched)
                        barrier();

                schedule();
                check_pgt_cache();
        }
        return 0;
}

#else

/*
 * the idle loop on a UltraMultiPenguin...
 */
#define idle_me_harder()        (cpu_data[current->processor].idle_volume += 1)
#define unidle_me()             (cpu_data[current->processor].idle_volume = 0)
int cpu_idle(void)
{
        current->nice = 20;
        current->counter = -100;
        init_idle();

        while(1) {
                if (current->need_resched != 0) {
                        unidle_me();
                        schedule();
                        check_pgt_cache();
                }
                idle_me_harder();

                /* The store ordering is so that IRQ handlers on
                 * other cpus see our increasing idleness for the buddy
                 * redistribution algorithm.  -DaveM
                 */
                membar("#StoreStore | #StoreLoad");
        }
}

#endif

extern char reboot_command [];

#ifdef CONFIG_SUN_CONSOLE
extern void (*prom_palette)(int);
extern int serial_console;
#endif
extern void (*prom_keyboard)(void);

void machine_halt(void)
{
        sti();
        mdelay(8);
        cli();
#ifdef CONFIG_SUN_CONSOLE
        if (!serial_console && prom_palette)
                prom_palette (1);
#endif
        if (prom_keyboard)
                prom_keyboard();
        prom_halt();
        panic("Halt failed!");
}

void machine_alt_power_off(void)
{
        sti();
        mdelay(8);
        cli();
#ifdef CONFIG_SUN_CONSOLE
        if (!serial_console && prom_palette)
                prom_palette(1);
#endif
        if (prom_keyboard)
                prom_keyboard();
        prom_halt_power_off();
        panic("Power-off failed!");
}

void machine_restart(char * cmd)
{
        char *p;
        
        sti();
        mdelay(8);
        cli();

        p = strchr (reboot_command, '\n');
        if (p) *p = 0;
#ifdef CONFIG_SUN_CONSOLE
        if (!serial_console && prom_palette)
                prom_palette (1);
#endif
        if (prom_keyboard)
                prom_keyboard();
        if (cmd)
                prom_reboot(cmd);
        if (*reboot_command)
                prom_reboot(reboot_command);
        prom_reboot("");
        panic("Reboot failed!");
}

static void show_regwindow32(struct pt_regs *regs)
{
        struct reg_window32 *rw;
        struct reg_window32 r_w;
        mm_segment_t old_fs;
        
        __asm__ __volatile__ ("flushw");
        rw = (struct reg_window32 *)((long)(unsigned)regs->u_regs[14]);
        old_fs = get_fs();
        set_fs (USER_DS);
        if (copy_from_user (&r_w, rw, sizeof(r_w))) {
                set_fs (old_fs);
                return;
        }
        rw = &r_w;
        set_fs (old_fs);                        
        printk("l0: %08x l1: %08x l2: %08x l3: %08x "
               "l4: %08x l5: %08x l6: %08x l7: %08x\n",
               rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3],
               rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]);
        printk("i0: %08x i1: %08x i2: %08x i3: %08x "
               "i4: %08x i5: %08x i6: %08x i7: %08x\n",
               rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3],
               rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]);
}

static void show_regwindow(struct pt_regs *regs)
{
        struct reg_window *rw;
        struct reg_window r_w;
        mm_segment_t old_fs;

        if ((regs->tstate & TSTATE_PRIV) || !(current->thread.flags & SPARC_FLAG_32BIT)) {
                __asm__ __volatile__ ("flushw");
                rw = (struct reg_window *)(regs->u_regs[14] + STACK_BIAS);
                if (!(regs->tstate & TSTATE_PRIV)) {
                        old_fs = get_fs();
                        set_fs (USER_DS);
                        if (copy_from_user (&r_w, rw, sizeof(r_w))) {
                                set_fs (old_fs);
                                return;
                        }
                        rw = &r_w;
                        set_fs (old_fs);                        
                }
        } else {
                show_regwindow32(regs);
                return;
        }
        printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n",
               rw->locals[0], rw->locals[1], rw->locals[2], rw->locals[3]);
        printk("l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
               rw->locals[4], rw->locals[5], rw->locals[6], rw->locals[7]);
        printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n",
               rw->ins[0], rw->ins[1], rw->ins[2], rw->ins[3]);
        printk("i4: %016lx i5: %016lx i6: %016lx i7: %016lx\n",
               rw->ins[4], rw->ins[5], rw->ins[6], rw->ins[7]);
}

void show_stackframe(struct sparc_stackf *sf)
{
        unsigned long size;
        unsigned long *stk;
        int i;

        printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n"
               "l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
               sf->locals[0], sf->locals[1], sf->locals[2], sf->locals[3],
               sf->locals[4], sf->locals[5], sf->locals[6], sf->locals[7]);
        printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n"
               "i4: %016lx i5: %016lx fp: %016lx ret_pc: %016lx\n",
               sf->ins[0], sf->ins[1], sf->ins[2], sf->ins[3],
               sf->ins[4], sf->ins[5], (unsigned long)sf->fp, sf->callers_pc);
        printk("sp: %016lx x0: %016lx x1: %016lx x2: %016lx\n"
               "x3: %016lx x4: %016lx x5: %016lx xx: %016lx\n",
               (unsigned long)sf->structptr, sf->xargs[0], sf->xargs[1],
               sf->xargs[2], sf->xargs[3], sf->xargs[4], sf->xargs[5],
               sf->xxargs[0]);
        size = ((unsigned long)sf->fp) - ((unsigned long)sf);
        size -= STACKFRAME_SZ;
        stk = (unsigned long *)((unsigned long)sf + STACKFRAME_SZ);
        i = 0;
        do {
                printk("s%d: %016lx\n", i++, *stk++);
        } while ((size -= sizeof(unsigned long)));
}

void show_stackframe32(struct sparc_stackf32 *sf)
{
        unsigned long size;
        unsigned *stk;
        int i;

        printk("l0: %08x l1: %08x l2: %08x l3: %08x\n",
               sf->locals[0], sf->locals[1], sf->locals[2], sf->locals[3]);
        printk("l4: %08x l5: %08x l6: %08x l7: %08x\n",
               sf->locals[4], sf->locals[5], sf->locals[6], sf->locals[7]);
        printk("i0: %08x i1: %08x i2: %08x i3: %08x\n",
               sf->ins[0], sf->ins[1], sf->ins[2], sf->ins[3]);
        printk("i4: %08x i5: %08x fp: %08x ret_pc: %08x\n",
               sf->ins[4], sf->ins[5], sf->fp, sf->callers_pc);
        printk("sp: %08x x0: %08x x1: %08x x2: %08x\n"
               "x3: %08x x4: %08x x5: %08x xx: %08x\n",
               sf->structptr, sf->xargs[0], sf->xargs[1],
               sf->xargs[2], sf->xargs[3], sf->xargs[4], sf->xargs[5],
               sf->xxargs[0]);
        size = ((unsigned long)sf->fp) - ((unsigned long)sf);
        size -= STACKFRAME32_SZ;
        stk = (unsigned *)((unsigned long)sf + STACKFRAME32_SZ);
        i = 0;
        do {
                printk("s%d: %08x\n", i++, *stk++);
        } while ((size -= sizeof(unsigned)));
}

#ifdef CONFIG_SMP
static spinlock_t regdump_lock = SPIN_LOCK_UNLOCKED;
#endif

void __show_regs(struct pt_regs * regs)
{
#ifdef CONFIG_SMP
        unsigned long flags;

        /* Protect against xcall ipis which might lead to livelock on the lock */
        __asm__ __volatile__("rdpr      %%pstate, %0\n\t"
                             "wrpr      %0, %1, %%pstate"
                             : "=r" (flags)
                             : "i" (PSTATE_IE));
        spin_lock(&regdump_lock);
        printk("CPU[%d]: local_irq_count[%u] irqs_running[%d]\n",
               smp_processor_id(),
               local_irq_count(smp_processor_id()),
               irqs_running());
#endif
        printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x    %s\n", regs->tstate,
               regs->tpc, regs->tnpc, regs->y, print_tainted());
        printk("g0: %016lx g1: %016lx g2: %016lx g3: %016lx\n",
               regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
               regs->u_regs[3]);
        printk("g4: %016lx g5: %016lx g6: %016lx g7: %016lx\n",
               regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
               regs->u_regs[7]);
        printk("o0: %016lx o1: %016lx o2: %016lx o3: %016lx\n",
               regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
               regs->u_regs[11]);
        printk("o4: %016lx o5: %016lx sp: %016lx ret_pc: %016lx\n",
               regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
               regs->u_regs[15]);
        show_regwindow(regs);
#ifdef CONFIG_SMP
        spin_unlock(&regdump_lock);
        __asm__ __volatile__("wrpr      %0, 0, %%pstate"
                             : : "r" (flags));
#endif
}

#ifdef VERBOSE_SHOWREGS
static void idump_from_user (unsigned int *pc)
{
        int i;
        int code;
        
        if((((unsigned long) pc) & 3))
                return;
        
        pc -= 3;
        for(i = -3; i < 6; i++) {
                get_user(code, pc);
                printk("%c%08x%c",i?' ':'<',code,i?' ':'>');
                pc++;
        }
        printk("\n");
}
#endif

void show_regs(struct pt_regs *regs)
{
#ifdef VERBOSE_SHOWREGS
        extern long etrap, etraptl1;
#endif
        __show_regs(regs);
#ifdef CONFIG_SMP
        {
                extern void smp_report_regs(void);

                smp_report_regs();
        }
#endif

#ifdef VERBOSE_SHOWREGS 
        if (regs->tpc >= &etrap && regs->tpc < &etraptl1 &&
            regs->u_regs[14] >= (long)current - PAGE_SIZE &&
            regs->u_regs[14] < (long)current + 6 * PAGE_SIZE) {
                printk ("*********parent**********\n");
                __show_regs((struct pt_regs *)(regs->u_regs[14] + PTREGS_OFF));
                idump_from_user(((struct pt_regs *)(regs->u_regs[14] + PTREGS_OFF))->tpc);
                printk ("*********endpar**********\n");
        }
#endif
}

void show_regs32(struct pt_regs32 *regs)
{
        printk("PSR: %08x PC: %08x NPC: %08x Y: %08x    %s\n", regs->psr,
               regs->pc, regs->npc, regs->y, print_tainted());
        printk("g0: %08x g1: %08x g2: %08x g3: %08x ",
               regs->u_regs[0], regs->u_regs[1], regs->u_regs[2],
               regs->u_regs[3]);
        printk("g4: %08x g5: %08x g6: %08x g7: %08x\n",
               regs->u_regs[4], regs->u_regs[5], regs->u_regs[6],
               regs->u_regs[7]);
        printk("o0: %08x o1: %08x o2: %08x o3: %08x ",
               regs->u_regs[8], regs->u_regs[9], regs->u_regs[10],
               regs->u_regs[11]);
        printk("o4: %08x o5: %08x sp: %08x ret_pc: %08x\n",
               regs->u_regs[12], regs->u_regs[13], regs->u_regs[14],
               regs->u_regs[15]);
}

void show_thread(struct thread_struct *thread)
{
        int i;

#if 0
        printk("kregs:             0x%016lx\n", (unsigned long)thread->kregs);
        show_regs(thread->kregs);
#endif  
        printk("ksp:               0x%016lx\n", thread->ksp);

        if (thread->w_saved) {
                for (i = 0; i < NSWINS; i++) {
                        if (!thread->rwbuf_stkptrs[i])
                                continue;
                        printk("reg_window[%d]:\n", i);
                        printk("stack ptr:         0x%016lx\n", thread->rwbuf_stkptrs[i]);
                }
                printk("w_saved:           0x%04x\n", thread->w_saved);
        }

        printk("flags:             0x%08x\n", thread->flags);
        printk("current_ds:        0x%x\n", thread->current_ds.seg);
}

/* Free current thread data structures etc.. */
void exit_thread(void)
{
        struct thread_struct *t = &current->thread;

        if (t->utraps) {
                if (t->utraps[0] < 2)
                        kfree (t->utraps);
                else
                        t->utraps[0]--;
        }

        /* Turn off performance counters if on. */
        if (t->flags & SPARC_FLAG_PERFCTR) {
                t->user_cntd0 = t->user_cntd1 = NULL;
                t->pcr_reg = 0;
                t->flags &= ~(SPARC_FLAG_PERFCTR);
                write_pcr(0);
        }
}

void flush_thread(void)
{
        struct thread_struct *t = &current->thread;

        if (t->flags & SPARC_FLAG_ABI_PENDING)
                t->flags ^= (SPARC_FLAG_ABI_PENDING |
                             SPARC_FLAG_32BIT);
        if (current->mm) {
                unsigned long pgd_cache = 0UL;

                if (t->flags & SPARC_FLAG_32BIT) {
                        struct mm_struct *mm = current->mm;
                        pgd_t *pgd0 = &mm->pgd[0];

                        if (pgd_none(*pgd0)) {
                                pmd_t *page = pmd_alloc_one_fast(NULL, 0);
                                if (!page)
                                        page = pmd_alloc_one(NULL, 0);
                                pgd_set(pgd0, page);
                        }
                        pgd_cache = ((unsigned long) pgd_val(*pgd0)) << 11UL;
                }
                __asm__ __volatile__("stxa %0, [%1] %2\n\t"
                                     "membar #Sync"
                                     : /* no outputs */
                                     : "r" (pgd_cache),
                                     "r" (TSB_REG),
                                     "i" (ASI_DMMU));
        }
        t->w_saved = 0;

        /* Turn off performance counters if on. */
        if (t->flags & SPARC_FLAG_PERFCTR) {
                t->user_cntd0 = t->user_cntd1 = NULL;
                t->pcr_reg = 0;
                t->flags &= ~(SPARC_FLAG_PERFCTR);
                write_pcr(0);
        }

        /* Clear FPU register state. */
        t->fpsaved[0] = 0;
        
        if (t->current_ds.seg != ASI_AIUS)
                set_fs(USER_DS);

        /* Init new signal delivery disposition. */
        t->flags &= ~SPARC_FLAG_NEWSIGNALS;
}

/* It's a bit more tricky when 64-bit tasks are involved... */
static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)
{
        unsigned long fp, distance, rval;

        if (!(current->thread.flags & SPARC_FLAG_32BIT)) {
                csp += STACK_BIAS;
                psp += STACK_BIAS;
                __get_user(fp, &(((struct reg_window *)psp)->ins[6]));
                fp += STACK_BIAS;
        } else
                __get_user(fp, &(((struct reg_window32 *)psp)->ins[6]));

        /* Now 8-byte align the stack as this is mandatory in the
         * Sparc ABI due to how register windows work.  This hides
         * the restriction from thread libraries etc.  -DaveM
         */
        csp &= ~7UL;

        distance = fp - psp;
        rval = (csp - distance);
        if (copy_in_user((void *)rval, (void *)psp, distance))
                rval = 0;
        else if (current->thread.flags & SPARC_FLAG_32BIT) {
                if (put_user(((u32)csp), &(((struct reg_window32 *)rval)->ins[6])))
                        rval = 0;
        } else {
                if (put_user(((u64)csp - STACK_BIAS),
                             &(((struct reg_window *)rval)->ins[6])))
                        rval = 0;
                else
                        rval = rval - STACK_BIAS;
        }

        return rval;
}

/* Standard stuff. */
static inline void shift_window_buffer(int first_win, int last_win,
                                       struct thread_struct *t)
{
        int i;

        for (i = first_win; i < last_win; i++) {
                t->rwbuf_stkptrs[i] = t->rwbuf_stkptrs[i+1];
                memcpy(&t->reg_window[i], &t->reg_window[i+1],
                       sizeof(struct reg_window));
        }
}

void synchronize_user_stack(void)
{
        struct thread_struct *t = &current->thread;
        unsigned long window;

        flush_user_windows();
        if ((window = t->w_saved) != 0) {
                int winsize = sizeof(struct reg_window);
                int bias = 0;

                if (t->flags & SPARC_FLAG_32BIT)
                        winsize = sizeof(struct reg_window32);
                else
                        bias = STACK_BIAS;

                window -= 1;
                do {
                        unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
                        struct reg_window *rwin = &t->reg_window[window];

                        if (!copy_to_user((char *)sp, rwin, winsize)) {
                                shift_window_buffer(window, t->w_saved - 1, t);
                                t->w_saved--;
                        }
                } while (window--);
        }
}

void fault_in_user_windows(void)
{
        struct thread_struct *t = &current->thread;
        unsigned long window;
        int winsize = sizeof(struct reg_window);
        int bias = 0;

        if (t->flags & SPARC_FLAG_32BIT)
                winsize = sizeof(struct reg_window32);
        else
                bias = STACK_BIAS;

        flush_user_windows();
        window = t->w_saved;

        if (window != 0) {
                window -= 1;
                do {
                        unsigned long sp = (t->rwbuf_stkptrs[window] + bias);
                        struct reg_window *rwin = &t->reg_window[window];

                        if (copy_to_user((char *)sp, rwin, winsize))
                                goto barf;
                } while (window--);
        }
        t->w_saved = 0;
        return;

barf:
        t->w_saved = window + 1;
        do_exit(SIGILL);
}

/* Copy a Sparc thread.  The fork() return value conventions
 * under SunOS are nothing short of bletcherous:
 * Parent -->  %o0 == childs  pid, %o1 == 0
 * Child  -->  %o0 == parents pid, %o1 == 1
 */
int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
                unsigned long unused,
                struct task_struct *p, struct pt_regs *regs)
{
        struct thread_struct *t = &p->thread;
        char *child_trap_frame;

#ifdef CONFIG_DEBUG_SPINLOCK
        t->smp_lock_count = 0;
        t->smp_lock_pc = 0;
#endif

        /* Calculate offset to stack_frame & pt_regs */
        child_trap_frame = ((char *)p) + (THREAD_SIZE - (TRACEREG_SZ+STACKFRAME_SZ));
        memcpy(child_trap_frame, (((struct sparc_stackf *)regs)-1), (TRACEREG_SZ+STACKFRAME_SZ));
        t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
        t->flags |= SPARC_FLAG_NEWCHILD;
        t->kregs = (struct pt_regs *)(child_trap_frame+sizeof(struct sparc_stackf));
        t->cwp = (regs->tstate + 1) & TSTATE_CWP;
        t->fpsaved[0] = 0;

        if (regs->tstate & TSTATE_PRIV) {
                /* Special case, if we are spawning a kernel thread from
                 * a userspace task (via KMOD, NFS, or similar) we must
                 * disable performance counters in the child because the
                 * address space and protection realm are changing.
                 */
                if (t->flags & SPARC_FLAG_PERFCTR) {
                        t->user_cntd0 = t->user_cntd1 = NULL;
                        t->pcr_reg = 0;
                        t->flags &= ~(SPARC_FLAG_PERFCTR);
                }
                t->kregs->u_regs[UREG_FP] = p->thread.ksp;
                t->current_ds = KERNEL_DS;
                flush_register_windows();
                memcpy((void *)(t->ksp + STACK_BIAS),
                       (void *)(regs->u_regs[UREG_FP] + STACK_BIAS),
                       sizeof(struct sparc_stackf));
                t->kregs->u_regs[UREG_G6] = (unsigned long) p;
        } else {
                if (t->flags & SPARC_FLAG_32BIT) {
                        sp &= 0x00000000ffffffffUL;
                        regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
                }
                t->kregs->u_regs[UREG_FP] = sp;
                t->current_ds = USER_DS;
                if (sp != regs->u_regs[UREG_FP]) {
                        unsigned long csp;

                        csp = clone_stackframe(sp, regs->u_regs[UREG_FP]);
                        if (!csp)
                                return -EFAULT;
                        t->kregs->u_regs[UREG_FP] = csp;
                }
                if (t->utraps)
                        t->utraps[0]++;
        }

        /* Set the return value for the child. */
        t->kregs->u_regs[UREG_I0] = current->pid;
        t->kregs->u_regs[UREG_I1] = 1;

        /* Set the second return value for the parent. */
        regs->u_regs[UREG_I1] = 0;

        return 0;
}

/*
 * This is the mechanism for creating a new kernel thread.
 *
 * NOTE! Only a kernel-only process(ie the swapper or direct descendants
 * who haven't done an "execve()") should use this: it will work within
 * a system call from a "real" process, but the process memory space will
 * not be free'd until both the parent and the child have exited.
 */
pid_t arch_kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
{
        long retval;

        /* If the parent runs before fn(arg) is called by the child,
         * the input registers of this function can be clobbered.
         * So we stash 'fn' and 'arg' into global registers which
         * will not be modified by the parent.
         */
        __asm__ __volatile("mov %4, %%g2\n\t"      /* Save FN into global */
                           "mov %5, %%g3\n\t"      /* Save ARG into global */
                           "mov %1, %%g1\n\t"      /* Clone syscall nr. */
                           "mov %2, %%o0\n\t"      /* Clone flags. */
                           "mov 0, %%o1\n\t"       /* usp arg == 0 */
                           "t 0x6d\n\t"            /* Linux/Sparc clone(). */
                           "brz,a,pn %%o1, 1f\n\t" /* Parent, just return. */
                           " mov %%o0, %0\n\t"
                           "jmpl %%g2, %%o7\n\t"   /* Call the function. */
                           " mov %%g3, %%o0\n\t"   /* Set arg in delay. */
                           "mov %3, %%g1\n\t"
                           "t 0x6d\n\t"            /* Linux/Sparc exit(). */
                           /* Notreached by child. */
                           "1:" :
                           "=r" (retval) :
                           "i" (__NR_clone), "r" (flags | CLONE_VM),
                           "i" (__NR_exit),  "r" (fn), "r" (arg) :
                           "g1", "g2", "g3", "o0", "o1", "memory", "cc");
        return retval;
}

/*
 * fill in the user structure for a core dump..
 */
void dump_thread(struct pt_regs * regs, struct user * dump)
{
#if 1
        /* Only should be used for SunOS and ancient a.out
         * SparcLinux binaries...  Fixme some day when bored.
         * But for now at least plug the security hole :-)
         */
        memset(dump, 0, sizeof(struct user));
#else
        unsigned long first_stack_page;
        dump->magic = SUNOS_CORE_MAGIC;
        dump->len = sizeof(struct user);
        dump->regs.psr = regs->psr;
        dump->regs.pc = regs->pc;
        dump->regs.npc = regs->npc;
        dump->regs.y = regs->y;
        /* fuck me plenty */
        memcpy(&dump->regs.regs[0], &regs->u_regs[1], (sizeof(unsigned long) * 15));
        dump->u_tsize = (((unsigned long) current->mm->end_code) -
                ((unsigned long) current->mm->start_code)) & ~(PAGE_SIZE - 1);
        dump->u_dsize = ((unsigned long) (current->mm->brk + (PAGE_SIZE-1)));
        dump->u_dsize -= dump->u_tsize;
        dump->u_dsize &= ~(PAGE_SIZE - 1);
        first_stack_page = (regs->u_regs[UREG_FP] & ~(PAGE_SIZE - 1));
        dump->u_ssize = (TASK_SIZE - first_stack_page) & ~(PAGE_SIZE - 1);
        memcpy(&dump->fpu.fpstatus.fregs.regs[0], &current->thread.float_regs[0], (sizeof(unsigned long) * 32));
        dump->fpu.fpstatus.fsr = current->thread.fsr;
        dump->fpu.fpstatus.flags = dump->fpu.fpstatus.extra = 0;
#endif  
}

typedef struct {
        union {
                unsigned int    pr_regs[32];
                unsigned long   pr_dregs[16];
        } pr_fr;
        unsigned int __unused;
        unsigned int    pr_fsr;
        unsigned char   pr_qcnt;
        unsigned char   pr_q_entrysize;
        unsigned char   pr_en;
        unsigned int    pr_q[64];
} elf_fpregset_t32;

/*
 * fill in the fpu structure for a core dump.
 */
int dump_fpu (struct pt_regs * regs, elf_fpregset_t * fpregs)
{
        unsigned long *kfpregs = (unsigned long *)(((char *)current) + AOFF_task_fpregs);
        unsigned long fprs = current->thread.fpsaved[0];

        if ((current->thread.flags & SPARC_FLAG_32BIT) != 0) {
                elf_fpregset_t32 *fpregs32 = (elf_fpregset_t32 *)fpregs;

                if (fprs & FPRS_DL)
                        memcpy(&fpregs32->pr_fr.pr_regs[0], kfpregs,
                               sizeof(unsigned int) * 32);
                else
                        memset(&fpregs32->pr_fr.pr_regs[0], 0,
                               sizeof(unsigned int) * 32);
                fpregs32->pr_qcnt = 0;
                fpregs32->pr_q_entrysize = 8;
                memset(&fpregs32->pr_q[0], 0,
                       (sizeof(unsigned int) * 64));
                if (fprs & FPRS_FEF) {
                        fpregs32->pr_fsr = (unsigned int) current->thread.xfsr[0];
                        fpregs32->pr_en = 1;
                } else {
                        fpregs32->pr_fsr = 0;
                        fpregs32->pr_en = 0;
                }
        } else {
                if(fprs & FPRS_DL)
                        memcpy(&fpregs->pr_regs[0], kfpregs,
                               sizeof(unsigned int) * 32);
                else
                        memset(&fpregs->pr_regs[0], 0,
                               sizeof(unsigned int) * 32);
                if(fprs & FPRS_DU)
                        memcpy(&fpregs->pr_regs[16], kfpregs+16,
                               sizeof(unsigned int) * 32);
                else
                        memset(&fpregs->pr_regs[16], 0,
                               sizeof(unsigned int) * 32);
                if(fprs & FPRS_FEF) {
                        fpregs->pr_fsr = current->thread.xfsr[0];
                        fpregs->pr_gsr = current->thread.gsr[0];
                } else {
                        fpregs->pr_fsr = fpregs->pr_gsr = 0;
                }
                fpregs->pr_fprs = fprs;
        }
        return 1;
}

/*
 * sparc_execve() executes a new program after the asm stub has set
 * things up for us.  This should basically do what I want it to.
 */
asmlinkage int sparc_execve(struct pt_regs *regs)
{
        int error, base = 0;
        char *filename;

        /* User register window flush is done by entry.S */

        /* Check for indirect call. */
        if (regs->u_regs[UREG_G1] == 0)
                base = 1;

        filename = getname((char *)regs->u_regs[base + UREG_I0]);
        error = PTR_ERR(filename);
        if (IS_ERR(filename))
                goto out;
        error = do_execve(filename, (char **) regs->u_regs[base + UREG_I1],
                          (char **) regs->u_regs[base + UREG_I2], regs);
        putname(filename);
        if (!error) {
                fprs_write(0);
                current->thread.xfsr[0] = 0;
                current->thread.fpsaved[0] = 0;
                regs->tstate &= ~TSTATE_PEF;
        }
out:
        return error;
}