Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 869 insertions, 0 deletions

diff --git a/arch/sparc64/kernel/process.c b/arch/sparc64/kernel/process.c
new file mode 100644
index 00000000000..26d3ec41da1
--- /dev/null
+++ b/arch/sparc64/kernel/process.c
@@ -0,0 +1,869 @@
+/*  $Id: process.c,v 1.131 2002/02/09 19:49:30 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..
+ */
+
+#include <stdarg.h>
+
+#include <linux/config.h>
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/kallsyms.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/smp_lock.h>
+#include <linux/stddef.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 <linux/compat.h>
+#include <linux/init.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>
+#include <asm/cpudata.h>
+#include <asm/unistd.h>
+
+/* #define VERBOSE_SHOWREGS */
+
+/*
+ * Nothing special yet...
+ */
+void default_idle(void)
+{
+}
+
+#ifndef CONFIG_SMP
+
+/*
+ * the idle loop on a Sparc... ;)
+ */
+void cpu_idle(void)
+{
+	if (current->pid != 0)
+		return;
+
+	/* endless idle loop with no priority at all */
+	for (;;) {
+		/* If current->work.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 (!need_resched())
+			barrier();
+
+		schedule();
+		check_pgt_cache();
+	}
+	return;
+}
+
+#else
+
+/*
+ * the idle loop on a UltraMultiPenguin...
+ */
+#define idle_me_harder()	(cpu_data(smp_processor_id()).idle_volume += 1)
+#define unidle_me()		(cpu_data(smp_processor_id()).idle_volume = 0)
+void cpu_idle(void)
+{
+	set_thread_flag(TIF_POLLING_NRFLAG);
+	while(1) {
+		if (need_resched()) {
+			unidle_me();
+			clear_thread_flag(TIF_POLLING_NRFLAG);
+			schedule();
+			set_thread_flag(TIF_POLLING_NRFLAG);
+			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 [];
+
+extern void (*prom_palette)(int);
+extern void (*prom_keyboard)(void);
+
+void machine_halt(void)
+{
+	if (!serial_console && prom_palette)
+		prom_palette (1);
+	if (prom_keyboard)
+		prom_keyboard();
+	prom_halt();
+	panic("Halt failed!");
+}
+
+EXPORT_SYMBOL(machine_halt);
+
+void machine_alt_power_off(void)
+{
+	if (!serial_console && prom_palette)
+		prom_palette(1);
+	if (prom_keyboard)
+		prom_keyboard();
+	prom_halt_power_off();
+	panic("Power-off failed!");
+}
+
+void machine_restart(char * cmd)
+{
+	char *p;
+	
+	p = strchr (reboot_command, '\n');
+	if (p) *p = 0;
+	if (!serial_console && prom_palette)
+		prom_palette (1);
+	if (prom_keyboard)
+		prom_keyboard();
+	if (cmd)
+		prom_reboot(cmd);
+	if (*reboot_command)
+		prom_reboot(reboot_command);
+	prom_reboot("");
+	panic("Reboot failed!");
+}
+
+EXPORT_SYMBOL(machine_restart);
+
+static void show_regwindow32(struct pt_regs *regs)
+{
+	struct reg_window32 __user *rw;
+	struct reg_window32 r_w;
+	mm_segment_t old_fs;
+	
+	__asm__ __volatile__ ("flushw");
+	rw = compat_ptr((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;
+	}
+
+	set_fs (old_fs);			
+	printk("l0: %08x l1: %08x l2: %08x l3: %08x "
+	       "l4: %08x l5: %08x l6: %08x l7: %08x\n",
+	       r_w.locals[0], r_w.locals[1], r_w.locals[2], r_w.locals[3],
+	       r_w.locals[4], r_w.locals[5], r_w.locals[6], r_w.locals[7]);
+	printk("i0: %08x i1: %08x i2: %08x i3: %08x "
+	       "i4: %08x i5: %08x i6: %08x i7: %08x\n",
+	       r_w.ins[0], r_w.ins[1], r_w.ins[2], r_w.ins[3],
+	       r_w.ins[4], r_w.ins[5], r_w.ins[6], r_w.ins[7]);
+}
+
+static void show_regwindow(struct pt_regs *regs)
+{
+	struct reg_window __user *rw;
+	struct reg_window *rwk;
+	struct reg_window r_w;
+	mm_segment_t old_fs;
+
+	if ((regs->tstate & TSTATE_PRIV) || !(test_thread_flag(TIF_32BIT))) {
+		__asm__ __volatile__ ("flushw");
+		rw = (struct reg_window __user *)
+			(regs->u_regs[14] + STACK_BIAS);
+		rwk = (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;
+			}
+			rwk = &r_w;
+			set_fs (old_fs);			
+		}
+	} else {
+		show_regwindow32(regs);
+		return;
+	}
+	printk("l0: %016lx l1: %016lx l2: %016lx l3: %016lx\n",
+	       rwk->locals[0], rwk->locals[1], rwk->locals[2], rwk->locals[3]);
+	printk("l4: %016lx l5: %016lx l6: %016lx l7: %016lx\n",
+	       rwk->locals[4], rwk->locals[5], rwk->locals[6], rwk->locals[7]);
+	printk("i0: %016lx i1: %016lx i2: %016lx i3: %016lx\n",
+	       rwk->ins[0], rwk->ins[1], rwk->ins[2], rwk->ins[3]);
+	printk("i4: %016lx i5: %016lx i6: %016lx i7: %016lx\n",
+	       rwk->ins[4], rwk->ins[5], rwk->ins[6], rwk->ins[7]);
+	if (regs->tstate & TSTATE_PRIV)
+		print_symbol("I7: <%s>\n", rwk->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 DEFINE_SPINLOCK(regdump_lock);
+#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);
+#endif
+	printk("TSTATE: %016lx TPC: %016lx TNPC: %016lx Y: %08x    %s\n", regs->tstate,
+	       regs->tpc, regs->tnpc, regs->y, print_tainted());
+	print_symbol("TPC: <%s>\n", regs->tpc);
+	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]);
+	print_symbol("RPC: <%s>\n", 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]);
+}
+
+unsigned long thread_saved_pc(struct task_struct *tsk)
+{
+	struct thread_info *ti = tsk->thread_info;
+	unsigned long ret = 0xdeadbeefUL;
+	
+	if (ti && ti->ksp) {
+		unsigned long *sp;
+		sp = (unsigned long *)(ti->ksp + STACK_BIAS);
+		if (((unsigned long)sp & (sizeof(long) - 1)) == 0UL &&
+		    sp[14]) {
+			unsigned long *fp;
+			fp = (unsigned long *)(sp[14] + STACK_BIAS);
+			if (((unsigned long)fp & (sizeof(long) - 1)) == 0UL)
+				ret = fp[15];
+		}
+	}
+	return ret;
+}
+
+/* Free current thread data structures etc.. */
+void exit_thread(void)
+{
+	struct thread_info *t = current_thread_info();
+
+	if (t->utraps) {
+		if (t->utraps[0] < 2)
+			kfree (t->utraps);
+		else
+			t->utraps[0]--;
+	}
+
+	if (test_and_clear_thread_flag(TIF_PERFCTR)) {
+		t->user_cntd0 = t->user_cntd1 = NULL;
+		t->pcr_reg = 0;
+		write_pcr(0);
+	}
+}
+
+void flush_thread(void)
+{
+	struct thread_info *t = current_thread_info();
+
+	if (t->flags & _TIF_ABI_PENDING)
+		t->flags ^= (_TIF_ABI_PENDING | _TIF_32BIT);
+
+	if (t->task->mm) {
+		unsigned long pgd_cache = 0UL;
+		if (test_thread_flag(TIF_32BIT)) {
+			struct mm_struct *mm = t->task->mm;
+			pgd_t *pgd0 = &mm->pgd[0];
+			pud_t *pud0 = pud_offset(pgd0, 0);
+
+			if (pud_none(*pud0)) {
+				pmd_t *page = pmd_alloc_one(mm, 0);
+				pud_set(pud0, page);
+			}
+			pgd_cache = get_pgd_cache(pgd0);
+		}
+		__asm__ __volatile__("stxa %0, [%1] %2\n\t"
+				     "membar #Sync"
+				     : /* no outputs */
+				     : "r" (pgd_cache),
+				     "r" (TSB_REG),
+				     "i" (ASI_DMMU));
+	}
+	set_thread_wsaved(0);
+
+	/* Turn off performance counters if on. */
+	if (test_and_clear_thread_flag(TIF_PERFCTR)) {
+		t->user_cntd0 = t->user_cntd1 = NULL;
+		t->pcr_reg = 0;
+		write_pcr(0);
+	}
+
+	/* Clear FPU register state. */
+	t->fpsaved[0] = 0;
+	
+	if (get_thread_current_ds() != ASI_AIUS)
+		set_fs(USER_DS);
+
+	/* Init new signal delivery disposition. */
+	clear_thread_flag(TIF_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 (!(test_thread_flag(TIF_32BIT))) {
+		csp += STACK_BIAS;
+		psp += STACK_BIAS;
+		__get_user(fp, &(((struct reg_window __user *)psp)->ins[6]));
+		fp += STACK_BIAS;
+	} else
+		__get_user(fp, &(((struct reg_window32 __user *)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 __user *) rval, (void __user *) psp, distance))
+		rval = 0;
+	else if (test_thread_flag(TIF_32BIT)) {
+		if (put_user(((u32)csp),
+			     &(((struct reg_window32 __user *)rval)->ins[6])))
+			rval = 0;
+	} else {
+		if (put_user(((u64)csp - STACK_BIAS),
+			     &(((struct reg_window __user *)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_info *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_info *t = current_thread_info();
+	unsigned long window;
+
+	flush_user_windows();
+	if ((window = get_thread_wsaved()) != 0) {
+		int winsize = sizeof(struct reg_window);
+		int bias = 0;
+
+		if (test_thread_flag(TIF_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 __user *)sp, rwin, winsize)) {
+				shift_window_buffer(window, get_thread_wsaved() - 1, t);
+				set_thread_wsaved(get_thread_wsaved() - 1);
+			}
+		} while (window--);
+	}
+}
+
+void fault_in_user_windows(void)
+{
+	struct thread_info *t = current_thread_info();
+	unsigned long window;
+	int winsize = sizeof(struct reg_window);
+	int bias = 0;
+
+	if (test_thread_flag(TIF_32BIT))
+		winsize = sizeof(struct reg_window32);
+	else
+		bias = STACK_BIAS;
+
+	flush_user_windows();
+	window = get_thread_wsaved();
+
+	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 __user *)sp, rwin, winsize))
+				goto barf;
+		} while (window--);
+	}
+	set_thread_wsaved(0);
+	return;
+
+barf:
+	set_thread_wsaved(window + 1);
+	do_exit(SIGILL);
+}
+
+asmlinkage long sparc_do_fork(unsigned long clone_flags,
+			      unsigned long stack_start,
+			      struct pt_regs *regs,
+			      unsigned long stack_size)
+{
+	int __user *parent_tid_ptr, *child_tid_ptr;
+
+#ifdef CONFIG_COMPAT
+	if (test_thread_flag(TIF_32BIT)) {
+		parent_tid_ptr = compat_ptr(regs->u_regs[UREG_I2]);
+		child_tid_ptr = compat_ptr(regs->u_regs[UREG_I4]);
+	} else
+#endif
+	{
+		parent_tid_ptr = (int __user *) regs->u_regs[UREG_I2];
+		child_tid_ptr = (int __user *) regs->u_regs[UREG_I4];
+	}
+
+	return do_fork(clone_flags, stack_start,
+		       regs, stack_size,
+		       parent_tid_ptr, child_tid_ptr);
+}
+
+/* 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_info *t = p->thread_info;
+	char *child_trap_frame;
+
+#ifdef CONFIG_DEBUG_SPINLOCK
+	p->thread.smp_lock_count = 0;
+	p->thread.smp_lock_pc = 0;
+#endif
+
+	/* Calculate offset to stack_frame & pt_regs */
+	child_trap_frame = ((char *)t) + (THREAD_SIZE - (TRACEREG_SZ+STACKFRAME_SZ));
+	memcpy(child_trap_frame, (((struct sparc_stackf *)regs)-1), (TRACEREG_SZ+STACKFRAME_SZ));
+
+	t->flags = (t->flags & ~((0xffUL << TI_FLAG_CWP_SHIFT) | (0xffUL << TI_FLAG_CURRENT_DS_SHIFT))) |
+		_TIF_NEWCHILD |
+		(((regs->tstate + 1) & TSTATE_CWP) << TI_FLAG_CWP_SHIFT);
+	t->ksp = ((unsigned long) child_trap_frame) - STACK_BIAS;
+	t->kregs = (struct pt_regs *)(child_trap_frame+sizeof(struct sparc_stackf));
+	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 & _TIF_PERFCTR) {
+			t->user_cntd0 = t->user_cntd1 = NULL;
+			t->pcr_reg = 0;
+			t->flags &= ~_TIF_PERFCTR;
+		}
+		t->kregs->u_regs[UREG_FP] = t->ksp;
+		t->flags |= ((long)ASI_P << TI_FLAG_CURRENT_DS_SHIFT);
+		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) t;
+		t->kregs->u_regs[UREG_G4] = (unsigned long) t->task;
+	} else {
+		if (t->flags & _TIF_32BIT) {
+			sp &= 0x00000000ffffffffUL;
+			regs->u_regs[UREG_FP] &= 0x00000000ffffffffUL;
+		}
+		t->kregs->u_regs[UREG_FP] = sp;
+		t->flags |= ((long)ASI_AIUS << TI_FLAG_CURRENT_DS_SHIFT);
+		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;
+
+	if (clone_flags & CLONE_SETTLS)
+		t->kregs->u_regs[UREG_G7] = regs->u_regs[UREG_I3];
+
+	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 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 | CLONE_UNTRACED),
+			     "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)
+{
+	/* Only should be used for SunOS and ancient a.out
+	 * SparcLinux binaries...  Not worth implementing.
+	 */
+	memset(dump, 0, sizeof(struct user));
+}
+
+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 = current_thread_info()->fpregs;
+	unsigned long fprs = current_thread_info()->fpsaved[0];
+
+	if (test_thread_flag(TIF_32BIT)) {
+		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_info()->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_info()->xfsr[0];
+			fpregs->pr_gsr = current_thread_info()->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 __user *)regs->u_regs[base + UREG_I0]);
+	error = PTR_ERR(filename);
+	if (IS_ERR(filename))
+		goto out;
+	error = do_execve(filename,
+			  (char __user * __user *)
+			  regs->u_regs[base + UREG_I1],
+			  (char __user * __user *)
+			  regs->u_regs[base + UREG_I2], regs);
+	putname(filename);
+	if (!error) {
+		fprs_write(0);
+		current_thread_info()->xfsr[0] = 0;
+		current_thread_info()->fpsaved[0] = 0;
+		regs->tstate &= ~TSTATE_PEF;
+		task_lock(current);
+		current->ptrace &= ~PT_DTRACE;
+		task_unlock(current);
+	}
+out:
+	return error;
+}
+
+unsigned long get_wchan(struct task_struct *task)
+{
+	unsigned long pc, fp, bias = 0;
+	unsigned long thread_info_base;
+	struct reg_window *rw;
+        unsigned long ret = 0;
+	int count = 0; 
+
+	if (!task || task == current ||
+            task->state == TASK_RUNNING)
+		goto out;
+
+	thread_info_base = (unsigned long) task->thread_info;
+	bias = STACK_BIAS;
+	fp = task->thread_info->ksp + bias;
+
+	do {
+		/* Bogus frame pointer? */
+		if (fp < (thread_info_base + sizeof(struct thread_info)) ||
+		    fp >= (thread_info_base + THREAD_SIZE))
+			break;
+		rw = (struct reg_window *) fp;
+		pc = rw->ins[7];
+		if (!in_sched_functions(pc)) {
+			ret = pc;
+			goto out;
+		}
+		fp = rw->ins[6] + bias;
+	} while (++count < 16);
+
+out:
+	return ret;
+}