1 files changed, 907 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
new file mode 100644
index 000000000000..96843211cc5c
--- /dev/null
+++ b/arch/powerpc/kernel/process.c
@@ -0,0 +1,907 @@
+/*
+ *  arch/ppc/kernel/process.c
+ *
+ *  Derived from "arch/i386/kernel/process.c"
+ *    Copyright (C) 1995  Linus Torvalds
+ *
+ *  Updated and modified by Cort Dougan (cort@cs.nmt.edu) and
+ *  Paul Mackerras (paulus@cs.anu.edu.au)
+ *
+ *  PowerPC version
+ *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
+ *
+ *  This program is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU General Public License
+ *  as published by the Free Software Foundation; either version
+ *  2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/config.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/elf.h>
+#include <linux/init.h>
+#include <linux/prctl.h>
+#include <linux/init_task.h>
+#include <linux/module.h>
+#include <linux/kallsyms.h>
+#include <linux/mqueue.h>
+#include <linux/hardirq.h>
+#include <linux/utsname.h>
+#include <linux/kprobes.h>
+
+#include <asm/pgtable.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <asm/io.h>
+#include <asm/processor.h>
+#include <asm/mmu.h>
+#include <asm/prom.h>
+#ifdef CONFIG_PPC64
+#include <asm/firmware.h>
+#include <asm/time.h>
+#include <asm/machdep.h>
+#endif
+
+extern unsigned long _get_SP(void);
+
+#ifndef CONFIG_SMP
+struct task_struct *last_task_used_math = NULL;
+struct task_struct *last_task_used_altivec = NULL;
+struct task_struct *last_task_used_spe = NULL;
+#endif
+
+/*
+ * Make sure the floating-point register state in the
+ * the thread_struct is up to date for task tsk.
+ */
+void flush_fp_to_thread(struct task_struct *tsk)
+{
+	if (tsk->thread.regs) {
+		/*
+		 * We need to disable preemption here because if we didn't,
+		 * another process could get scheduled after the regs->msr
+		 * test but before we have finished saving the FP registers
+		 * to the thread_struct.  That process could take over the
+		 * FPU, and then when we get scheduled again we would store
+		 * bogus values for the remaining FP registers.
+		 */
+		preempt_disable();
+		if (tsk->thread.regs->msr & MSR_FP) {
+#ifdef CONFIG_SMP
+			/*
+			 * This should only ever be called for current or
+			 * for a stopped child process.  Since we save away
+			 * the FP register state on context switch on SMP,
+			 * there is something wrong if a stopped child appears
+			 * to still have its FP state in the CPU registers.
+			 */
+			BUG_ON(tsk != current);
+#endif
+			giveup_fpu(current);
+		}
+		preempt_enable();
+	}
+}
+
+void enable_kernel_fp(void)
+{
+	WARN_ON(preemptible());
+
+#ifdef CONFIG_SMP
+	if (current->thread.regs && (current->thread.regs->msr & MSR_FP))
+		giveup_fpu(current);
+	else
+		giveup_fpu(NULL);	/* just enables FP for kernel */
+#else
+	giveup_fpu(last_task_used_math);
+#endif /* CONFIG_SMP */
+}
+EXPORT_SYMBOL(enable_kernel_fp);
+
+int dump_task_fpu(struct task_struct *tsk, elf_fpregset_t *fpregs)
+{
+	if (!tsk->thread.regs)
+		return 0;
+	flush_fp_to_thread(current);
+
+	memcpy(fpregs, &tsk->thread.fpr[0], sizeof(*fpregs));
+
+	return 1;
+}
+
+#ifdef CONFIG_ALTIVEC
+void enable_kernel_altivec(void)
+{
+	WARN_ON(preemptible());
+
+#ifdef CONFIG_SMP
+	if (current->thread.regs && (current->thread.regs->msr & MSR_VEC))
+		giveup_altivec(current);
+	else
+		giveup_altivec(NULL);	/* just enable AltiVec for kernel - force */
+#else
+	giveup_altivec(last_task_used_altivec);
+#endif /* CONFIG_SMP */
+}
+EXPORT_SYMBOL(enable_kernel_altivec);
+
+/*
+ * Make sure the VMX/Altivec register state in the
+ * the thread_struct is up to date for task tsk.
+ */
+void flush_altivec_to_thread(struct task_struct *tsk)
+{
+	if (tsk->thread.regs) {
+		preempt_disable();
+		if (tsk->thread.regs->msr & MSR_VEC) {
+#ifdef CONFIG_SMP
+			BUG_ON(tsk != current);
+#endif
+			giveup_altivec(current);
+		}
+		preempt_enable();
+	}
+}
+
+int dump_task_altivec(struct pt_regs *regs, elf_vrregset_t *vrregs)
+{
+	flush_altivec_to_thread(current);
+	memcpy(vrregs, &current->thread.vr[0], sizeof(*vrregs));
+	return 1;
+}
+#endif /* CONFIG_ALTIVEC */
+
+#ifdef CONFIG_SPE
+
+void enable_kernel_spe(void)
+{
+	WARN_ON(preemptible());
+
+#ifdef CONFIG_SMP
+	if (current->thread.regs && (current->thread.regs->msr & MSR_SPE))
+		giveup_spe(current);
+	else
+		giveup_spe(NULL);	/* just enable SPE for kernel - force */
+#else
+	giveup_spe(last_task_used_spe);
+#endif /* __SMP __ */
+}
+EXPORT_SYMBOL(enable_kernel_spe);
+
+void flush_spe_to_thread(struct task_struct *tsk)
+{
+	if (tsk->thread.regs) {
+		preempt_disable();
+		if (tsk->thread.regs->msr & MSR_SPE) {
+#ifdef CONFIG_SMP
+			BUG_ON(tsk != current);
+#endif
+			giveup_spe(current);
+		}
+		preempt_enable();
+	}
+}
+
+int dump_spe(struct pt_regs *regs, elf_vrregset_t *evrregs)
+{
+	flush_spe_to_thread(current);
+	/* We copy u32 evr[32] + u64 acc + u32 spefscr -> 35 */
+	memcpy(evrregs, &current->thread.evr[0], sizeof(u32) * 35);
+	return 1;
+}
+#endif /* CONFIG_SPE */
+
+int set_dabr(unsigned long dabr)
+{
+#ifdef CONFIG_PPC64
+	if (ppc_md.set_dabr)
+		return ppc_md.set_dabr(dabr);
+#endif
+
+	mtspr(SPRN_DABR, dabr);
+	return 0;
+}
+
+#ifdef CONFIG_PPC64
+DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array);
+static DEFINE_PER_CPU(unsigned long, current_dabr);
+#endif
+
+struct task_struct *__switch_to(struct task_struct *prev,
+	struct task_struct *new)
+{
+	struct thread_struct *new_thread, *old_thread;
+	unsigned long flags;
+	struct task_struct *last;
+
+#ifdef CONFIG_SMP
+	/* avoid complexity of lazy save/restore of fpu
+	 * by just saving it every time we switch out if
+	 * this task used the fpu during the last quantum.
+	 *
+	 * If it tries to use the fpu again, it'll trap and
+	 * reload its fp regs.  So we don't have to do a restore
+	 * every switch, just a save.
+	 *  -- Cort
+	 */
+	if (prev->thread.regs && (prev->thread.regs->msr & MSR_FP))
+		giveup_fpu(prev);
+#ifdef CONFIG_ALTIVEC
+	/*
+	 * If the previous thread used altivec in the last quantum
+	 * (thus changing altivec regs) then save them.
+	 * We used to check the VRSAVE register but not all apps
+	 * set it, so we don't rely on it now (and in fact we need
+	 * to save & restore VSCR even if VRSAVE == 0).  -- paulus
+	 *
+	 * On SMP we always save/restore altivec regs just to avoid the
+	 * complexity of changing processors.
+	 *  -- Cort
+	 */
+	if (prev->thread.regs && (prev->thread.regs->msr & MSR_VEC))
+		giveup_altivec(prev);
+#endif /* CONFIG_ALTIVEC */
+#ifdef CONFIG_SPE
+	/*
+	 * If the previous thread used spe in the last quantum
+	 * (thus changing spe regs) then save them.
+	 *
+	 * On SMP we always save/restore spe regs just to avoid the
+	 * complexity of changing processors.
+	 */
+	if ((prev->thread.regs && (prev->thread.regs->msr & MSR_SPE)))
+		giveup_spe(prev);
+#endif /* CONFIG_SPE */
+
+#else  /* CONFIG_SMP */
+#ifdef CONFIG_ALTIVEC
+	/* Avoid the trap.  On smp this this never happens since
+	 * we don't set last_task_used_altivec -- Cort
+	 */
+	if (new->thread.regs && last_task_used_altivec == new)
+		new->thread.regs->msr |= MSR_VEC;
+#endif /* CONFIG_ALTIVEC */
+#ifdef CONFIG_SPE
+	/* Avoid the trap.  On smp this this never happens since
+	 * we don't set last_task_used_spe
+	 */
+	if (new->thread.regs && last_task_used_spe == new)
+		new->thread.regs->msr |= MSR_SPE;
+#endif /* CONFIG_SPE */
+
+#endif /* CONFIG_SMP */
+
+#ifdef CONFIG_PPC64	/* for now */
+	if (unlikely(__get_cpu_var(current_dabr) != new->thread.dabr)) {
+		set_dabr(new->thread.dabr);
+		__get_cpu_var(current_dabr) = new->thread.dabr;
+	}
+
+	flush_tlb_pending();
+#endif
+
+	new_thread = &new->thread;
+	old_thread = &current->thread;
+
+#ifdef CONFIG_PPC64
+	/*
+	 * Collect processor utilization data per process
+	 */
+	if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
+		struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array);
+		long unsigned start_tb, current_tb;
+		start_tb = old_thread->start_tb;
+		cu->current_tb = current_tb = mfspr(SPRN_PURR);
+		old_thread->accum_tb += (current_tb - start_tb);
+		new_thread->start_tb = current_tb;
+	}
+#endif
+
+	local_irq_save(flags);
+	last = _switch(old_thread, new_thread);
+
+	local_irq_restore(flags);
+
+	return last;
+}
+
+static int instructions_to_print = 16;
+
+#ifdef CONFIG_PPC64
+#define BAD_PC(pc)	((REGION_ID(pc) != KERNEL_REGION_ID) && \
+		         (REGION_ID(pc) != VMALLOC_REGION_ID))
+#else
+#define BAD_PC(pc)	((pc) < KERNELBASE)
+#endif
+
+static void show_instructions(struct pt_regs *regs)
+{
+	int i;
+	unsigned long pc = regs->nip - (instructions_to_print * 3 / 4 *
+			sizeof(int));
+
+	printk("Instruction dump:");
+
+	for (i = 0; i < instructions_to_print; i++) {
+		int instr;
+
+		if (!(i % 8))
+			printk("\n");
+
+		if (BAD_PC(pc) || __get_user(instr, (unsigned int *)pc)) {
+			printk("XXXXXXXX ");
+		} else {
+			if (regs->nip == pc)
+				printk("<%08x> ", instr);
+			else
+				printk("%08x ", instr);
+		}
+
+		pc += sizeof(int);
+	}
+
+	printk("\n");
+}
+
+static struct regbit {
+	unsigned long bit;
+	const char *name;
+} msr_bits[] = {
+	{MSR_EE,	"EE"},
+	{MSR_PR,	"PR"},
+	{MSR_FP,	"FP"},
+	{MSR_ME,	"ME"},
+	{MSR_IR,	"IR"},
+	{MSR_DR,	"DR"},
+	{0,		NULL}
+};
+
+static void printbits(unsigned long val, struct regbit *bits)
+{
+	const char *sep = "";
+
+	printk("<");
+	for (; bits->bit; ++bits)
+		if (val & bits->bit) {
+			printk("%s%s", sep, bits->name);
+			sep = ",";
+		}
+	printk(">");
+}
+
+#ifdef CONFIG_PPC64
+#define REG		"%016lX"
+#define REGS_PER_LINE	4
+#define LAST_VOLATILE	13
+#else
+#define REG		"%08lX"
+#define REGS_PER_LINE	8
+#define LAST_VOLATILE	12
+#endif
+
+void show_regs(struct pt_regs * regs)
+{
+	int i, trap;
+
+	printk("NIP: "REG" LR: "REG" CTR: "REG"\n",
+	       regs->nip, regs->link, regs->ctr);
+	printk("REGS: %p TRAP: %04lx   %s  (%s)\n",
+	       regs, regs->trap, print_tainted(), system_utsname.release);
+	printk("MSR: "REG" ", regs->msr);
+	printbits(regs->msr, msr_bits);
+	printk("  CR: %08lX  XER: %08lX\n", regs->ccr, regs->xer);
+	trap = TRAP(regs);
+	if (trap == 0x300 || trap == 0x600)
+		printk("DAR: "REG", DSISR: "REG"\n", regs->dar, regs->dsisr);
+	printk("TASK = %p[%d] '%s' THREAD: %p",
+	       current, current->pid, current->comm, current->thread_info);
+
+#ifdef CONFIG_SMP
+	printk(" CPU: %d", smp_processor_id());
+#endif /* CONFIG_SMP */
+
+	for (i = 0;  i < 32;  i++) {
+		if ((i % REGS_PER_LINE) == 0)
+			printk("\n" KERN_INFO "GPR%02d: ", i);
+		printk(REG " ", regs->gpr[i]);
+		if (i == LAST_VOLATILE && !FULL_REGS(regs))
+			break;
+	}
+	printk("\n");
+#ifdef CONFIG_KALLSYMS
+	/*
+	 * Lookup NIP late so we have the best change of getting the
+	 * above info out without failing
+	 */
+	printk("NIP ["REG"] ", regs->nip);
+	print_symbol("%s\n", regs->nip);
+	printk("LR ["REG"] ", regs->link);
+	print_symbol("%s\n", regs->link);
+#endif
+	show_stack(current, (unsigned long *) regs->gpr[1]);
+	if (!user_mode(regs))
+		show_instructions(regs);
+}
+
+void exit_thread(void)
+{
+	kprobe_flush_task(current);
+
+#ifndef CONFIG_SMP
+	if (last_task_used_math == current)
+		last_task_used_math = NULL;
+#ifdef CONFIG_ALTIVEC
+	if (last_task_used_altivec == current)
+		last_task_used_altivec = NULL;
+#endif /* CONFIG_ALTIVEC */
+#ifdef CONFIG_SPE
+	if (last_task_used_spe == current)
+		last_task_used_spe = NULL;
+#endif
+#endif /* CONFIG_SMP */
+}
+
+void flush_thread(void)
+{
+#ifdef CONFIG_PPC64
+	struct thread_info *t = current_thread_info();
+
+	if (t->flags & _TIF_ABI_PENDING)
+		t->flags ^= (_TIF_ABI_PENDING | _TIF_32BIT);
+#endif
+	kprobe_flush_task(current);
+
+#ifndef CONFIG_SMP
+	if (last_task_used_math == current)
+		last_task_used_math = NULL;
+#ifdef CONFIG_ALTIVEC
+	if (last_task_used_altivec == current)
+		last_task_used_altivec = NULL;
+#endif /* CONFIG_ALTIVEC */
+#ifdef CONFIG_SPE
+	if (last_task_used_spe == current)
+		last_task_used_spe = NULL;
+#endif
+#endif /* CONFIG_SMP */
+
+#ifdef CONFIG_PPC64	/* for now */
+	if (current->thread.dabr) {
+		current->thread.dabr = 0;
+		set_dabr(0);
+	}
+#endif
+}
+
+void
+release_thread(struct task_struct *t)
+{
+}
+
+/*
+ * This gets called before we allocate a new thread and copy
+ * the current task into it.
+ */
+void prepare_to_copy(struct task_struct *tsk)
+{
+	flush_fp_to_thread(current);
+	flush_altivec_to_thread(current);
+	flush_spe_to_thread(current);
+}
+
+/*
+ * Copy a thread..
+ */
+int copy_thread(int nr, unsigned long clone_flags, unsigned long usp,
+		unsigned long unused, struct task_struct *p,
+		struct pt_regs *regs)
+{
+	struct pt_regs *childregs, *kregs;
+	extern void ret_from_fork(void);
+	unsigned long sp = (unsigned long)p->thread_info + THREAD_SIZE;
+
+	CHECK_FULL_REGS(regs);
+	/* Copy registers */
+	sp -= sizeof(struct pt_regs);
+	childregs = (struct pt_regs *) sp;
+	*childregs = *regs;
+	if ((childregs->msr & MSR_PR) == 0) {
+		/* for kernel thread, set `current' and stackptr in new task */
+		childregs->gpr[1] = sp + sizeof(struct pt_regs);
+#ifdef CONFIG_PPC32
+		childregs->gpr[2] = (unsigned long) p;
+#else
+		clear_ti_thread_flag(p->thread_info, TIF_32BIT);
+#endif
+		p->thread.regs = NULL;	/* no user register state */
+	} else {
+		childregs->gpr[1] = usp;
+		p->thread.regs = childregs;
+		if (clone_flags & CLONE_SETTLS) {
+#ifdef CONFIG_PPC64
+			if (!test_thread_flag(TIF_32BIT))
+				childregs->gpr[13] = childregs->gpr[6];
+			else
+#endif
+				childregs->gpr[2] = childregs->gpr[6];
+		}
+	}
+	childregs->gpr[3] = 0;  /* Result from fork() */
+	sp -= STACK_FRAME_OVERHEAD;
+
+	/*
+	 * The way this works is that at some point in the future
+	 * some task will call _switch to switch to the new task.
+	 * That will pop off the stack frame created below and start
+	 * the new task running at ret_from_fork.  The new task will
+	 * do some house keeping and then return from the fork or clone
+	 * system call, using the stack frame created above.
+	 */
+	sp -= sizeof(struct pt_regs);
+	kregs = (struct pt_regs *) sp;
+	sp -= STACK_FRAME_OVERHEAD;
+	p->thread.ksp = sp;
+
+#ifdef CONFIG_PPC64
+	if (cpu_has_feature(CPU_FTR_SLB)) {
+		unsigned long sp_vsid = get_kernel_vsid(sp);
+
+		sp_vsid <<= SLB_VSID_SHIFT;
+		sp_vsid |= SLB_VSID_KERNEL;
+		if (cpu_has_feature(CPU_FTR_16M_PAGE))
+			sp_vsid |= SLB_VSID_L;
+
+		p->thread.ksp_vsid = sp_vsid;
+	}
+
+	/*
+	 * The PPC64 ABI makes use of a TOC to contain function 
+	 * pointers.  The function (ret_from_except) is actually a pointer
+	 * to the TOC entry.  The first entry is a pointer to the actual
+	 * function.
+ 	 */
+	kregs->nip = *((unsigned long *)ret_from_fork);
+#else
+	kregs->nip = (unsigned long)ret_from_fork;
+	p->thread.last_syscall = -1;
+#endif
+
+	return 0;
+}
+
+/*
+ * Set up a thread for executing a new program
+ */
+void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
+{
+#ifdef CONFIG_PPC64
+	unsigned long load_addr = regs->gpr[2];	/* saved by ELF_PLAT_INIT */
+#endif
+
+	set_fs(USER_DS);
+
+	/*
+	 * If we exec out of a kernel thread then thread.regs will not be
+	 * set.  Do it now.
+	 */
+	if (!current->thread.regs) {
+		unsigned long childregs = (unsigned long)current->thread_info +
+						THREAD_SIZE;
+		childregs -= sizeof(struct pt_regs);
+		current->thread.regs = (struct pt_regs *)childregs;
+	}
+
+	memset(regs->gpr, 0, sizeof(regs->gpr));
+	regs->ctr = 0;
+	regs->link = 0;
+	regs->xer = 0;
+	regs->ccr = 0;
+	regs->gpr[1] = sp;
+
+#ifdef CONFIG_PPC32
+	regs->mq = 0;
+	regs->nip = start;
+	regs->msr = MSR_USER;
+#else
+	if (!test_thread_flag(TIF_32BIT)) {
+		unsigned long entry, toc;
+
+		/* start is a relocated pointer to the function descriptor for
+		 * the elf _start routine.  The first entry in the function
+		 * descriptor is the entry address of _start and the second
+		 * entry is the TOC value we need to use.
+		 */
+		__get_user(entry, (unsigned long __user *)start);
+		__get_user(toc, (unsigned long __user *)start+1);
+
+		/* Check whether the e_entry function descriptor entries
+		 * need to be relocated before we can use them.
+		 */
+		if (load_addr != 0) {
+			entry += load_addr;
+			toc   += load_addr;
+		}
+		regs->nip = entry;
+		regs->gpr[2] = toc;
+		regs->msr = MSR_USER64;
+	} else {
+		regs->nip = start;
+		regs->gpr[2] = 0;
+		regs->msr = MSR_USER32;
+	}
+#endif
+
+#ifndef CONFIG_SMP
+	if (last_task_used_math == current)
+		last_task_used_math = NULL;
+#ifdef CONFIG_ALTIVEC
+	if (last_task_used_altivec == current)
+		last_task_used_altivec = NULL;
+#endif
+#ifdef CONFIG_SPE
+	if (last_task_used_spe == current)
+		last_task_used_spe = NULL;
+#endif
+#endif /* CONFIG_SMP */
+	memset(current->thread.fpr, 0, sizeof(current->thread.fpr));
+	current->thread.fpscr.val = 0;
+#ifdef CONFIG_ALTIVEC
+	memset(current->thread.vr, 0, sizeof(current->thread.vr));
+	memset(&current->thread.vscr, 0, sizeof(current->thread.vscr));
+	current->thread.vscr.u[3] = 0x00010000; /* Java mode disabled */
+	current->thread.vrsave = 0;
+	current->thread.used_vr = 0;
+#endif /* CONFIG_ALTIVEC */
+#ifdef CONFIG_SPE
+	memset(current->thread.evr, 0, sizeof(current->thread.evr));
+	current->thread.acc = 0;
+	current->thread.spefscr = 0;
+	current->thread.used_spe = 0;
+#endif /* CONFIG_SPE */
+}
+
+#define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \
+		| PR_FP_EXC_RES | PR_FP_EXC_INV)
+
+int set_fpexc_mode(struct task_struct *tsk, unsigned int val)
+{
+	struct pt_regs *regs = tsk->thread.regs;
+
+	/* This is a bit hairy.  If we are an SPE enabled  processor
+	 * (have embedded fp) we store the IEEE exception enable flags in
+	 * fpexc_mode.  fpexc_mode is also used for setting FP exception
+	 * mode (asyn, precise, disabled) for 'Classic' FP. */
+	if (val & PR_FP_EXC_SW_ENABLE) {
+#ifdef CONFIG_SPE
+		tsk->thread.fpexc_mode = val &
+			(PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT);
+		return 0;
+#else
+		return -EINVAL;
+#endif
+	}
+
+	/* on a CONFIG_SPE this does not hurt us.  The bits that
+	 * __pack_fe01 use do not overlap with bits used for
+	 * PR_FP_EXC_SW_ENABLE.  Additionally, the MSR[FE0,FE1] bits
+	 * on CONFIG_SPE implementations are reserved so writing to
+	 * them does not change anything */
+	if (val > PR_FP_EXC_PRECISE)
+		return -EINVAL;
+	tsk->thread.fpexc_mode = __pack_fe01(val);
+	if (regs != NULL && (regs->msr & MSR_FP) != 0)
+		regs->msr = (regs->msr & ~(MSR_FE0|MSR_FE1))
+			| tsk->thread.fpexc_mode;
+	return 0;
+}
+
+int get_fpexc_mode(struct task_struct *tsk, unsigned long adr)
+{
+	unsigned int val;
+
+	if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE)
+#ifdef CONFIG_SPE
+		val = tsk->thread.fpexc_mode;
+#else
+		return -EINVAL;
+#endif
+	else
+		val = __unpack_fe01(tsk->thread.fpexc_mode);
+	return put_user(val, (unsigned int __user *) adr);
+}
+
+#define TRUNC_PTR(x)	((typeof(x))(((unsigned long)(x)) & 0xffffffff))
+
+int sys_clone(unsigned long clone_flags, unsigned long usp,
+	      int __user *parent_tidp, void __user *child_threadptr,
+	      int __user *child_tidp, int p6,
+	      struct pt_regs *regs)
+{
+	CHECK_FULL_REGS(regs);
+	if (usp == 0)
+		usp = regs->gpr[1];	/* stack pointer for child */
+#ifdef CONFIG_PPC64
+	if (test_thread_flag(TIF_32BIT)) {
+		parent_tidp = TRUNC_PTR(parent_tidp);
+		child_tidp = TRUNC_PTR(child_tidp);
+	}
+#endif
+ 	return do_fork(clone_flags, usp, regs, 0, parent_tidp, child_tidp);
+}
+
+int sys_fork(unsigned long p1, unsigned long p2, unsigned long p3,
+	     unsigned long p4, unsigned long p5, unsigned long p6,
+	     struct pt_regs *regs)
+{
+	CHECK_FULL_REGS(regs);
+	return do_fork(SIGCHLD, regs->gpr[1], regs, 0, NULL, NULL);
+}
+
+int sys_vfork(unsigned long p1, unsigned long p2, unsigned long p3,
+	      unsigned long p4, unsigned long p5, unsigned long p6,
+	      struct pt_regs *regs)
+{
+	CHECK_FULL_REGS(regs);
+	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gpr[1],
+			regs, 0, NULL, NULL);
+}
+
+int sys_execve(unsigned long a0, unsigned long a1, unsigned long a2,
+	       unsigned long a3, unsigned long a4, unsigned long a5,
+	       struct pt_regs *regs)
+{
+	int error;
+	char *filename;
+
+	filename = getname((char __user *) a0);
+	error = PTR_ERR(filename);
+	if (IS_ERR(filename))
+		goto out;
+	flush_fp_to_thread(current);
+	flush_altivec_to_thread(current);
+	flush_spe_to_thread(current);
+	error = do_execve(filename, (char __user * __user *) a1,
+			  (char __user * __user *) a2, regs);
+	if (error == 0) {
+		task_lock(current);
+		current->ptrace &= ~PT_DTRACE;
+		task_unlock(current);
+	}
+	putname(filename);
+out:
+	return error;
+}
+
+static int validate_sp(unsigned long sp, struct task_struct *p,
+		       unsigned long nbytes)
+{
+	unsigned long stack_page = (unsigned long)p->thread_info;
+
+	if (sp >= stack_page + sizeof(struct thread_struct)
+	    && sp <= stack_page + THREAD_SIZE - nbytes)
+		return 1;
+
+#ifdef CONFIG_IRQSTACKS
+	stack_page = (unsigned long) hardirq_ctx[task_cpu(p)];
+	if (sp >= stack_page + sizeof(struct thread_struct)
+	    && sp <= stack_page + THREAD_SIZE - nbytes)
+		return 1;
+
+	stack_page = (unsigned long) softirq_ctx[task_cpu(p)];
+	if (sp >= stack_page + sizeof(struct thread_struct)
+	    && sp <= stack_page + THREAD_SIZE - nbytes)
+		return 1;
+#endif
+
+	return 0;
+}
+
+#ifdef CONFIG_PPC64
+#define MIN_STACK_FRAME	112	/* same as STACK_FRAME_OVERHEAD, in fact */
+#define FRAME_LR_SAVE	2
+#define INT_FRAME_SIZE	(sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD + 288)
+#define REGS_MARKER	0x7265677368657265ul
+#define FRAME_MARKER	12
+#else
+#define MIN_STACK_FRAME	16
+#define FRAME_LR_SAVE	1
+#define INT_FRAME_SIZE	(sizeof(struct pt_regs) + STACK_FRAME_OVERHEAD)
+#define REGS_MARKER	0x72656773ul
+#define FRAME_MARKER	2
+#endif
+
+unsigned long get_wchan(struct task_struct *p)
+{
+	unsigned long ip, sp;
+	int count = 0;
+
+	if (!p || p == current || p->state == TASK_RUNNING)
+		return 0;
+
+	sp = p->thread.ksp;
+	if (!validate_sp(sp, p, MIN_STACK_FRAME))
+		return 0;
+
+	do {
+		sp = *(unsigned long *)sp;
+		if (!validate_sp(sp, p, MIN_STACK_FRAME))
+			return 0;
+		if (count > 0) {
+			ip = ((unsigned long *)sp)[FRAME_LR_SAVE];
+			if (!in_sched_functions(ip))
+				return ip;
+		}
+	} while (count++ < 16);
+	return 0;
+}
+EXPORT_SYMBOL(get_wchan);
+
+static int kstack_depth_to_print = 64;
+
+void show_stack(struct task_struct *tsk, unsigned long *stack)
+{
+	unsigned long sp, ip, lr, newsp;
+	int count = 0;
+	int firstframe = 1;
+
+	sp = (unsigned long) stack;
+	if (tsk == NULL)
+		tsk = current;
+	if (sp == 0) {
+		if (tsk == current)
+			asm("mr %0,1" : "=r" (sp));
+		else
+			sp = tsk->thread.ksp;
+	}
+
+	lr = 0;
+	printk("Call Trace:\n");
+	do {
+		if (!validate_sp(sp, tsk, MIN_STACK_FRAME))
+			return;
+
+		stack = (unsigned long *) sp;
+		newsp = stack[0];
+		ip = stack[FRAME_LR_SAVE];
+		if (!firstframe || ip != lr) {
+			printk("["REG"] ["REG"] ", sp, ip);
+			print_symbol("%s", ip);
+			if (firstframe)
+				printk(" (unreliable)");
+			printk("\n");
+		}
+		firstframe = 0;
+
+		/*
+		 * See if this is an exception frame.
+		 * We look for the "regshere" marker in the current frame.
+		 */
+		if (validate_sp(sp, tsk, INT_FRAME_SIZE)
+		    && stack[FRAME_MARKER] == REGS_MARKER) {
+			struct pt_regs *regs = (struct pt_regs *)
+				(sp + STACK_FRAME_OVERHEAD);
+			printk("--- Exception: %lx", regs->trap);
+			print_symbol(" at %s\n", regs->nip);
+			lr = regs->link;
+			print_symbol("    LR = %s\n", lr);
+			firstframe = 1;
+		}
+
+		sp = newsp;
+	} while (count++ < kstack_depth_to_print);
+}
+
+void dump_stack(void)
+{
+	show_stack(current, NULL);
+}
+EXPORT_SYMBOL(dump_stack);