Initial import

1 files changed, 1661 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
new file mode 100644
index 000000000..febb50dd5
--- /dev/null
+++ b/arch/powerpc/kernel/process.c
@@ -0,0 +1,1661 @@
+/*
+ *  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/errno.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/smp.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/prctl.h>
+#include <linux/init_task.h>
+#include <linux/export.h>
+#include <linux/kallsyms.h>
+#include <linux/mqueue.h>
+#include <linux/hardirq.h>
+#include <linux/utsname.h>
+#include <linux/ftrace.h>
+#include <linux/kernel_stat.h>
+#include <linux/personality.h>
+#include <linux/random.h>
+#include <linux/hw_breakpoint.h>
+#include <linux/uaccess.h>
+
+#include <asm/pgtable.h>
+#include <asm/io.h>
+#include <asm/processor.h>
+#include <asm/mmu.h>
+#include <asm/prom.h>
+#include <asm/machdep.h>
+#include <asm/time.h>
+#include <asm/runlatch.h>
+#include <asm/syscalls.h>
+#include <asm/switch_to.h>
+#include <asm/tm.h>
+#include <asm/debug.h>
+#ifdef CONFIG_PPC64
+#include <asm/firmware.h>
+#endif
+#include <asm/code-patching.h>
+#include <linux/kprobes.h>
+#include <linux/kdebug.h>
+
+/* Transactional Memory debug */
+#ifdef TM_DEBUG_SW
+#define TM_DEBUG(x...) printk(KERN_INFO x)
+#else
+#define TM_DEBUG(x...) do { } while(0)
+#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_vsx = NULL;
+struct task_struct *last_task_used_spe = NULL;
+#endif
+
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+void giveup_fpu_maybe_transactional(struct task_struct *tsk)
+{
+	/*
+	 * If we are saving the current thread's registers, and the
+	 * thread is in a transactional state, set the TIF_RESTORE_TM
+	 * bit so that we know to restore the registers before
+	 * returning to userspace.
+	 */
+	if (tsk == current && tsk->thread.regs &&
+	    MSR_TM_ACTIVE(tsk->thread.regs->msr) &&
+	    !test_thread_flag(TIF_RESTORE_TM)) {
+		tsk->thread.tm_orig_msr = tsk->thread.regs->msr;
+		set_thread_flag(TIF_RESTORE_TM);
+	}
+
+	giveup_fpu(tsk);
+}
+
+void giveup_altivec_maybe_transactional(struct task_struct *tsk)
+{
+	/*
+	 * If we are saving the current thread's registers, and the
+	 * thread is in a transactional state, set the TIF_RESTORE_TM
+	 * bit so that we know to restore the registers before
+	 * returning to userspace.
+	 */
+	if (tsk == current && tsk->thread.regs &&
+	    MSR_TM_ACTIVE(tsk->thread.regs->msr) &&
+	    !test_thread_flag(TIF_RESTORE_TM)) {
+		tsk->thread.tm_orig_msr = tsk->thread.regs->msr;
+		set_thread_flag(TIF_RESTORE_TM);
+	}
+
+	giveup_altivec(tsk);
+}
+
+#else
+#define giveup_fpu_maybe_transactional(tsk)	giveup_fpu(tsk)
+#define giveup_altivec_maybe_transactional(tsk)	giveup_altivec(tsk)
+#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
+
+#ifdef CONFIG_PPC_FPU
+/*
+ * 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_maybe_transactional(tsk);
+		}
+		preempt_enable();
+	}
+}
+EXPORT_SYMBOL_GPL(flush_fp_to_thread);
+#endif /* CONFIG_PPC_FPU */
+
+void enable_kernel_fp(void)
+{
+	WARN_ON(preemptible());
+
+#ifdef CONFIG_SMP
+	if (current->thread.regs && (current->thread.regs->msr & MSR_FP))
+		giveup_fpu_maybe_transactional(current);
+	else
+		giveup_fpu(NULL);	/* just enables FP for kernel */
+#else
+	giveup_fpu_maybe_transactional(last_task_used_math);
+#endif /* CONFIG_SMP */
+}
+EXPORT_SYMBOL(enable_kernel_fp);
+
+#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_maybe_transactional(current);
+	else
+		giveup_altivec_notask();
+#else
+	giveup_altivec_maybe_transactional(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_maybe_transactional(tsk);
+		}
+		preempt_enable();
+	}
+}
+EXPORT_SYMBOL_GPL(flush_altivec_to_thread);
+#endif /* CONFIG_ALTIVEC */
+
+#ifdef CONFIG_VSX
+#if 0
+/* not currently used, but some crazy RAID module might want to later */
+void enable_kernel_vsx(void)
+{
+	WARN_ON(preemptible());
+
+#ifdef CONFIG_SMP
+	if (current->thread.regs && (current->thread.regs->msr & MSR_VSX))
+		giveup_vsx(current);
+	else
+		giveup_vsx(NULL);	/* just enable vsx for kernel - force */
+#else
+	giveup_vsx(last_task_used_vsx);
+#endif /* CONFIG_SMP */
+}
+EXPORT_SYMBOL(enable_kernel_vsx);
+#endif
+
+void giveup_vsx(struct task_struct *tsk)
+{
+	giveup_fpu_maybe_transactional(tsk);
+	giveup_altivec_maybe_transactional(tsk);
+	__giveup_vsx(tsk);
+}
+EXPORT_SYMBOL(giveup_vsx);
+
+void flush_vsx_to_thread(struct task_struct *tsk)
+{
+	if (tsk->thread.regs) {
+		preempt_disable();
+		if (tsk->thread.regs->msr & MSR_VSX) {
+#ifdef CONFIG_SMP
+			BUG_ON(tsk != current);
+#endif
+			giveup_vsx(tsk);
+		}
+		preempt_enable();
+	}
+}
+EXPORT_SYMBOL_GPL(flush_vsx_to_thread);
+#endif /* CONFIG_VSX */
+
+#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
+			tsk->thread.spefscr = mfspr(SPRN_SPEFSCR);
+			giveup_spe(tsk);
+		}
+		preempt_enable();
+	}
+}
+#endif /* CONFIG_SPE */
+
+#ifndef CONFIG_SMP
+/*
+ * If we are doing lazy switching of CPU state (FP, altivec or SPE),
+ * and the current task has some state, discard it.
+ */
+void discard_lazy_cpu_state(void)
+{
+	preempt_disable();
+	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_VSX
+	if (last_task_used_vsx == current)
+		last_task_used_vsx = NULL;
+#endif /* CONFIG_VSX */
+#ifdef CONFIG_SPE
+	if (last_task_used_spe == current)
+		last_task_used_spe = NULL;
+#endif
+	preempt_enable();
+}
+#endif /* CONFIG_SMP */
+
+#ifdef CONFIG_PPC_ADV_DEBUG_REGS
+void do_send_trap(struct pt_regs *regs, unsigned long address,
+		  unsigned long error_code, int signal_code, int breakpt)
+{
+	siginfo_t info;
+
+	current->thread.trap_nr = signal_code;
+	if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code,
+			11, SIGSEGV) == NOTIFY_STOP)
+		return;
+
+	/* Deliver the signal to userspace */
+	info.si_signo = SIGTRAP;
+	info.si_errno = breakpt;	/* breakpoint or watchpoint id */
+	info.si_code = signal_code;
+	info.si_addr = (void __user *)address;
+	force_sig_info(SIGTRAP, &info, current);
+}
+#else	/* !CONFIG_PPC_ADV_DEBUG_REGS */
+void do_break (struct pt_regs *regs, unsigned long address,
+		    unsigned long error_code)
+{
+	siginfo_t info;
+
+	current->thread.trap_nr = TRAP_HWBKPT;
+	if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code,
+			11, SIGSEGV) == NOTIFY_STOP)
+		return;
+
+	if (debugger_break_match(regs))
+		return;
+
+	/* Clear the breakpoint */
+	hw_breakpoint_disable();
+
+	/* Deliver the signal to userspace */
+	info.si_signo = SIGTRAP;
+	info.si_errno = 0;
+	info.si_code = TRAP_HWBKPT;
+	info.si_addr = (void __user *)address;
+	force_sig_info(SIGTRAP, &info, current);
+}
+#endif	/* CONFIG_PPC_ADV_DEBUG_REGS */
+
+static DEFINE_PER_CPU(struct arch_hw_breakpoint, current_brk);
+
+#ifdef CONFIG_PPC_ADV_DEBUG_REGS
+/*
+ * Set the debug registers back to their default "safe" values.
+ */
+static void set_debug_reg_defaults(struct thread_struct *thread)
+{
+	thread->debug.iac1 = thread->debug.iac2 = 0;
+#if CONFIG_PPC_ADV_DEBUG_IACS > 2
+	thread->debug.iac3 = thread->debug.iac4 = 0;
+#endif
+	thread->debug.dac1 = thread->debug.dac2 = 0;
+#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
+	thread->debug.dvc1 = thread->debug.dvc2 = 0;
+#endif
+	thread->debug.dbcr0 = 0;
+#ifdef CONFIG_BOOKE
+	/*
+	 * Force User/Supervisor bits to b11 (user-only MSR[PR]=1)
+	 */
+	thread->debug.dbcr1 = DBCR1_IAC1US | DBCR1_IAC2US |
+			DBCR1_IAC3US | DBCR1_IAC4US;
+	/*
+	 * Force Data Address Compare User/Supervisor bits to be User-only
+	 * (0b11 MSR[PR]=1) and set all other bits in DBCR2 register to be 0.
+	 */
+	thread->debug.dbcr2 = DBCR2_DAC1US | DBCR2_DAC2US;
+#else
+	thread->debug.dbcr1 = 0;
+#endif
+}
+
+static void prime_debug_regs(struct debug_reg *debug)
+{
+	/*
+	 * We could have inherited MSR_DE from userspace, since
+	 * it doesn't get cleared on exception entry.  Make sure
+	 * MSR_DE is clear before we enable any debug events.
+	 */
+	mtmsr(mfmsr() & ~MSR_DE);
+
+	mtspr(SPRN_IAC1, debug->iac1);
+	mtspr(SPRN_IAC2, debug->iac2);
+#if CONFIG_PPC_ADV_DEBUG_IACS > 2
+	mtspr(SPRN_IAC3, debug->iac3);
+	mtspr(SPRN_IAC4, debug->iac4);
+#endif
+	mtspr(SPRN_DAC1, debug->dac1);
+	mtspr(SPRN_DAC2, debug->dac2);
+#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
+	mtspr(SPRN_DVC1, debug->dvc1);
+	mtspr(SPRN_DVC2, debug->dvc2);
+#endif
+	mtspr(SPRN_DBCR0, debug->dbcr0);
+	mtspr(SPRN_DBCR1, debug->dbcr1);
+#ifdef CONFIG_BOOKE
+	mtspr(SPRN_DBCR2, debug->dbcr2);
+#endif
+}
+/*
+ * Unless neither the old or new thread are making use of the
+ * debug registers, set the debug registers from the values
+ * stored in the new thread.
+ */
+void switch_booke_debug_regs(struct debug_reg *new_debug)
+{
+	if ((current->thread.debug.dbcr0 & DBCR0_IDM)
+		|| (new_debug->dbcr0 & DBCR0_IDM))
+			prime_debug_regs(new_debug);
+}
+EXPORT_SYMBOL_GPL(switch_booke_debug_regs);
+#else	/* !CONFIG_PPC_ADV_DEBUG_REGS */
+#ifndef CONFIG_HAVE_HW_BREAKPOINT
+static void set_debug_reg_defaults(struct thread_struct *thread)
+{
+	thread->hw_brk.address = 0;
+	thread->hw_brk.type = 0;
+	set_breakpoint(&thread->hw_brk);
+}
+#endif /* !CONFIG_HAVE_HW_BREAKPOINT */
+#endif	/* CONFIG_PPC_ADV_DEBUG_REGS */
+
+#ifdef CONFIG_PPC_ADV_DEBUG_REGS
+static inline int __set_dabr(unsigned long dabr, unsigned long dabrx)
+{
+	mtspr(SPRN_DAC1, dabr);
+#ifdef CONFIG_PPC_47x
+	isync();
+#endif
+	return 0;
+}
+#elif defined(CONFIG_PPC_BOOK3S)
+static inline int __set_dabr(unsigned long dabr, unsigned long dabrx)
+{
+	mtspr(SPRN_DABR, dabr);
+	if (cpu_has_feature(CPU_FTR_DABRX))
+		mtspr(SPRN_DABRX, dabrx);
+	return 0;
+}
+#else
+static inline int __set_dabr(unsigned long dabr, unsigned long dabrx)
+{
+	return -EINVAL;
+}
+#endif
+
+static inline int set_dabr(struct arch_hw_breakpoint *brk)
+{
+	unsigned long dabr, dabrx;
+
+	dabr = brk->address | (brk->type & HW_BRK_TYPE_DABR);
+	dabrx = ((brk->type >> 3) & 0x7);
+
+	if (ppc_md.set_dabr)
+		return ppc_md.set_dabr(dabr, dabrx);
+
+	return __set_dabr(dabr, dabrx);
+}
+
+static inline int set_dawr(struct arch_hw_breakpoint *brk)
+{
+	unsigned long dawr, dawrx, mrd;
+
+	dawr = brk->address;
+
+	dawrx  = (brk->type & (HW_BRK_TYPE_READ | HW_BRK_TYPE_WRITE)) \
+		                   << (63 - 58); //* read/write bits */
+	dawrx |= ((brk->type & (HW_BRK_TYPE_TRANSLATE)) >> 2) \
+		                   << (63 - 59); //* translate */
+	dawrx |= (brk->type & (HW_BRK_TYPE_PRIV_ALL)) \
+		                   >> 3; //* PRIM bits */
+	/* dawr length is stored in field MDR bits 48:53.  Matches range in
+	   doublewords (64 bits) baised by -1 eg. 0b000000=1DW and
+	   0b111111=64DW.
+	   brk->len is in bytes.
+	   This aligns up to double word size, shifts and does the bias.
+	*/
+	mrd = ((brk->len + 7) >> 3) - 1;
+	dawrx |= (mrd & 0x3f) << (63 - 53);
+
+	if (ppc_md.set_dawr)
+		return ppc_md.set_dawr(dawr, dawrx);
+	mtspr(SPRN_DAWR, dawr);
+	mtspr(SPRN_DAWRX, dawrx);
+	return 0;
+}
+
+void __set_breakpoint(struct arch_hw_breakpoint *brk)
+{
+	memcpy(this_cpu_ptr(&current_brk), brk, sizeof(*brk));
+
+	if (cpu_has_feature(CPU_FTR_DAWR))
+		set_dawr(brk);
+	else
+		set_dabr(brk);
+}
+
+void set_breakpoint(struct arch_hw_breakpoint *brk)
+{
+	preempt_disable();
+	__set_breakpoint(brk);
+	preempt_enable();
+}
+
+#ifdef CONFIG_PPC64
+DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array);
+#endif
+
+static inline bool hw_brk_match(struct arch_hw_breakpoint *a,
+			      struct arch_hw_breakpoint *b)
+{
+	if (a->address != b->address)
+		return false;
+	if (a->type != b->type)
+		return false;
+	if (a->len != b->len)
+		return false;
+	return true;
+}
+
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+static void tm_reclaim_thread(struct thread_struct *thr,
+			      struct thread_info *ti, uint8_t cause)
+{
+	unsigned long msr_diff = 0;
+
+	/*
+	 * If FP/VSX registers have been already saved to the
+	 * thread_struct, move them to the transact_fp array.
+	 * We clear the TIF_RESTORE_TM bit since after the reclaim
+	 * the thread will no longer be transactional.
+	 */
+	if (test_ti_thread_flag(ti, TIF_RESTORE_TM)) {
+		msr_diff = thr->tm_orig_msr & ~thr->regs->msr;
+		if (msr_diff & MSR_FP)
+			memcpy(&thr->transact_fp, &thr->fp_state,
+			       sizeof(struct thread_fp_state));
+		if (msr_diff & MSR_VEC)
+			memcpy(&thr->transact_vr, &thr->vr_state,
+			       sizeof(struct thread_vr_state));
+		clear_ti_thread_flag(ti, TIF_RESTORE_TM);
+		msr_diff &= MSR_FP | MSR_VEC | MSR_VSX | MSR_FE0 | MSR_FE1;
+	}
+
+	tm_reclaim(thr, thr->regs->msr, cause);
+
+	/* Having done the reclaim, we now have the checkpointed
+	 * FP/VSX values in the registers.  These might be valid
+	 * even if we have previously called enable_kernel_fp() or
+	 * flush_fp_to_thread(), so update thr->regs->msr to
+	 * indicate their current validity.
+	 */
+	thr->regs->msr |= msr_diff;
+}
+
+void tm_reclaim_current(uint8_t cause)
+{
+	tm_enable();
+	tm_reclaim_thread(&current->thread, current_thread_info(), cause);
+}
+
+static inline void tm_reclaim_task(struct task_struct *tsk)
+{
+	/* We have to work out if we're switching from/to a task that's in the
+	 * middle of a transaction.
+	 *
+	 * In switching we need to maintain a 2nd register state as
+	 * oldtask->thread.ckpt_regs.  We tm_reclaim(oldproc); this saves the
+	 * checkpointed (tbegin) state in ckpt_regs and saves the transactional
+	 * (current) FPRs into oldtask->thread.transact_fpr[].
+	 *
+	 * We also context switch (save) TFHAR/TEXASR/TFIAR in here.
+	 */
+	struct thread_struct *thr = &tsk->thread;
+
+	if (!thr->regs)
+		return;
+
+	if (!MSR_TM_ACTIVE(thr->regs->msr))
+		goto out_and_saveregs;
+
+	/* Stash the original thread MSR, as giveup_fpu et al will
+	 * modify it.  We hold onto it to see whether the task used
+	 * FP & vector regs.  If the TIF_RESTORE_TM flag is set,
+	 * tm_orig_msr is already set.
+	 */
+	if (!test_ti_thread_flag(task_thread_info(tsk), TIF_RESTORE_TM))
+		thr->tm_orig_msr = thr->regs->msr;
+
+	TM_DEBUG("--- tm_reclaim on pid %d (NIP=%lx, "
+		 "ccr=%lx, msr=%lx, trap=%lx)\n",
+		 tsk->pid, thr->regs->nip,
+		 thr->regs->ccr, thr->regs->msr,
+		 thr->regs->trap);
+
+	tm_reclaim_thread(thr, task_thread_info(tsk), TM_CAUSE_RESCHED);
+
+	TM_DEBUG("--- tm_reclaim on pid %d complete\n",
+		 tsk->pid);
+
+out_and_saveregs:
+	/* Always save the regs here, even if a transaction's not active.
+	 * This context-switches a thread's TM info SPRs.  We do it here to
+	 * be consistent with the restore path (in recheckpoint) which
+	 * cannot happen later in _switch().
+	 */
+	tm_save_sprs(thr);
+}
+
+extern void __tm_recheckpoint(struct thread_struct *thread,
+			      unsigned long orig_msr);
+
+void tm_recheckpoint(struct thread_struct *thread,
+		     unsigned long orig_msr)
+{
+	unsigned long flags;
+
+	/* We really can't be interrupted here as the TEXASR registers can't
+	 * change and later in the trecheckpoint code, we have a userspace R1.
+	 * So let's hard disable over this region.
+	 */
+	local_irq_save(flags);
+	hard_irq_disable();
+
+	/* The TM SPRs are restored here, so that TEXASR.FS can be set
+	 * before the trecheckpoint and no explosion occurs.
+	 */
+	tm_restore_sprs(thread);
+
+	__tm_recheckpoint(thread, orig_msr);
+
+	local_irq_restore(flags);
+}
+
+static inline void tm_recheckpoint_new_task(struct task_struct *new)
+{
+	unsigned long msr;
+
+	if (!cpu_has_feature(CPU_FTR_TM))
+		return;
+
+	/* Recheckpoint the registers of the thread we're about to switch to.
+	 *
+	 * If the task was using FP, we non-lazily reload both the original and
+	 * the speculative FP register states.  This is because the kernel
+	 * doesn't see if/when a TM rollback occurs, so if we take an FP
+	 * unavoidable later, we are unable to determine which set of FP regs
+	 * need to be restored.
+	 */
+	if (!new->thread.regs)
+		return;
+
+	if (!MSR_TM_ACTIVE(new->thread.regs->msr)){
+		tm_restore_sprs(&new->thread);
+		return;
+	}
+	msr = new->thread.tm_orig_msr;
+	/* Recheckpoint to restore original checkpointed register state. */
+	TM_DEBUG("*** tm_recheckpoint of pid %d "
+		 "(new->msr 0x%lx, new->origmsr 0x%lx)\n",
+		 new->pid, new->thread.regs->msr, msr);
+
+	/* This loads the checkpointed FP/VEC state, if used */
+	tm_recheckpoint(&new->thread, msr);
+
+	/* This loads the speculative FP/VEC state, if used */
+	if (msr & MSR_FP) {
+		do_load_up_transact_fpu(&new->thread);
+		new->thread.regs->msr |=
+			(MSR_FP | new->thread.fpexc_mode);
+	}
+#ifdef CONFIG_ALTIVEC
+	if (msr & MSR_VEC) {
+		do_load_up_transact_altivec(&new->thread);
+		new->thread.regs->msr |= MSR_VEC;
+	}
+#endif
+	/* We may as well turn on VSX too since all the state is restored now */
+	if (msr & MSR_VSX)
+		new->thread.regs->msr |= MSR_VSX;
+
+	TM_DEBUG("*** tm_recheckpoint of pid %d complete "
+		 "(kernel msr 0x%lx)\n",
+		 new->pid, mfmsr());
+}
+
+static inline void __switch_to_tm(struct task_struct *prev)
+{
+	if (cpu_has_feature(CPU_FTR_TM)) {
+		tm_enable();
+		tm_reclaim_task(prev);
+	}
+}
+
+/*
+ * This is called if we are on the way out to userspace and the
+ * TIF_RESTORE_TM flag is set.  It checks if we need to reload
+ * FP and/or vector state and does so if necessary.
+ * If userspace is inside a transaction (whether active or
+ * suspended) and FP/VMX/VSX instructions have ever been enabled
+ * inside that transaction, then we have to keep them enabled
+ * and keep the FP/VMX/VSX state loaded while ever the transaction
+ * continues.  The reason is that if we didn't, and subsequently
+ * got a FP/VMX/VSX unavailable interrupt inside a transaction,
+ * we don't know whether it's the same transaction, and thus we
+ * don't know which of the checkpointed state and the transactional
+ * state to use.
+ */
+void restore_tm_state(struct pt_regs *regs)
+{
+	unsigned long msr_diff;
+
+	clear_thread_flag(TIF_RESTORE_TM);
+	if (!MSR_TM_ACTIVE(regs->msr))
+		return;
+
+	msr_diff = current->thread.tm_orig_msr & ~regs->msr;
+	msr_diff &= MSR_FP | MSR_VEC | MSR_VSX;
+	if (msr_diff & MSR_FP) {
+		fp_enable();
+		load_fp_state(&current->thread.fp_state);
+		regs->msr |= current->thread.fpexc_mode;
+	}
+	if (msr_diff & MSR_VEC) {
+		vec_enable();
+		load_vr_state(&current->thread.vr_state);
+	}
+	regs->msr |= msr_diff;
+}
+
+#else
+#define tm_recheckpoint_new_task(new)
+#define __switch_to_tm(prev)
+#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
+
+struct task_struct *__switch_to(struct task_struct *prev,
+	struct task_struct *new)
+{
+	struct thread_struct *new_thread, *old_thread;
+	struct task_struct *last;
+#ifdef CONFIG_PPC_BOOK3S_64
+	struct ppc64_tlb_batch *batch;
+#endif
+
+	WARN_ON(!irqs_disabled());
+
+	/* Back up the TAR and DSCR across context switches.
+	 * Note that the TAR is not available for use in the kernel.  (To
+	 * provide this, the TAR should be backed up/restored on exception
+	 * entry/exit instead, and be in pt_regs.  FIXME, this should be in
+	 * pt_regs anyway (for debug).)
+	 * Save the TAR and DSCR here before we do treclaim/trecheckpoint as
+	 * these will change them.
+	 */
+	save_early_sprs(&prev->thread);
+
+	__switch_to_tm(prev);
+
+#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_VSX
+	if (prev->thread.regs && (prev->thread.regs->msr & MSR_VSX))
+		/* VMX and FPU registers are already save here */
+		__giveup_vsx(prev);
+#endif /* CONFIG_VSX */
+#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_VSX
+	if (new->thread.regs && last_task_used_vsx == new)
+		new->thread.regs->msr |= MSR_VSX;
+#endif /* CONFIG_VSX */
+#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_PPC_ADV_DEBUG_REGS
+	switch_booke_debug_regs(&new->thread.debug);
+#else
+/*
+ * For PPC_BOOK3S_64, we use the hw-breakpoint interfaces that would
+ * schedule DABR
+ */
+#ifndef CONFIG_HAVE_HW_BREAKPOINT
+	if (unlikely(!hw_brk_match(this_cpu_ptr(&current_brk), &new->thread.hw_brk)))
+		__set_breakpoint(&new->thread.hw_brk);
+#endif /* CONFIG_HAVE_HW_BREAKPOINT */
+#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 = this_cpu_ptr(&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 /* CONFIG_PPC64 */
+
+#ifdef CONFIG_PPC_BOOK3S_64
+	batch = this_cpu_ptr(&ppc64_tlb_batch);
+	if (batch->active) {
+		current_thread_info()->local_flags |= _TLF_LAZY_MMU;
+		if (batch->index)
+			__flush_tlb_pending(batch);
+		batch->active = 0;
+	}
+#endif /* CONFIG_PPC_BOOK3S_64 */
+
+	/*
+	 * We can't take a PMU exception inside _switch() since there is a
+	 * window where the kernel stack SLB and the kernel stack are out
+	 * of sync. Hard disable here.
+	 */
+	hard_irq_disable();
+
+	tm_recheckpoint_new_task(new);
+
+	last = _switch(old_thread, new_thread);
+
+#ifdef CONFIG_PPC_BOOK3S_64
+	if (current_thread_info()->local_flags & _TLF_LAZY_MMU) {
+		current_thread_info()->local_flags &= ~_TLF_LAZY_MMU;
+		batch = this_cpu_ptr(&ppc64_tlb_batch);
+		batch->active = 1;
+	}
+#endif /* CONFIG_PPC_BOOK3S_64 */
+
+	return last;
+}
+
+static int instructions_to_print = 16;
+
+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 !defined(CONFIG_BOOKE)
+		/* If executing with the IMMU off, adjust pc rather
+		 * than print XXXXXXXX.
+		 */
+		if (!(regs->msr & MSR_IR))
+			pc = (unsigned long)phys_to_virt(pc);
+#endif
+
+		if (!__kernel_text_address(pc) ||
+		     probe_kernel_address((unsigned int __user *)pc, instr)) {
+			printk(KERN_CONT "XXXXXXXX ");
+		} else {
+			if (regs->nip == pc)
+				printk(KERN_CONT "<%08x> ", instr);
+			else
+				printk(KERN_CONT "%08x ", instr);
+		}
+
+		pc += sizeof(int);
+	}
+
+	printk("\n");
+}
+
+static struct regbit {
+	unsigned long bit;
+	const char *name;
+} msr_bits[] = {
+#if defined(CONFIG_PPC64) && !defined(CONFIG_BOOKE)
+	{MSR_SF,	"SF"},
+	{MSR_HV,	"HV"},
+#endif
+	{MSR_VEC,	"VEC"},
+	{MSR_VSX,	"VSX"},
+#ifdef CONFIG_BOOKE
+	{MSR_CE,	"CE"},
+#endif
+	{MSR_EE,	"EE"},
+	{MSR_PR,	"PR"},
+	{MSR_FP,	"FP"},
+	{MSR_ME,	"ME"},
+#ifdef CONFIG_BOOKE
+	{MSR_DE,	"DE"},
+#else
+	{MSR_SE,	"SE"},
+	{MSR_BE,	"BE"},
+#endif
+	{MSR_IR,	"IR"},
+	{MSR_DR,	"DR"},
+	{MSR_PMM,	"PMM"},
+#ifndef CONFIG_BOOKE
+	{MSR_RI,	"RI"},
+	{MSR_LE,	"LE"},
+#endif
+	{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;
+
+	show_regs_print_info(KERN_DEFAULT);
+
+	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(), init_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 ((regs->trap != 0xc00) && cpu_has_feature(CPU_FTR_CFAR))
+		printk("CFAR: "REG" ", regs->orig_gpr3);
+	if (trap == 0x200 || trap == 0x300 || trap == 0x600)
+#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
+		printk("DEAR: "REG" ESR: "REG" ", regs->dar, regs->dsisr);
+#else
+		printk("DAR: "REG" DSISR: %08lx ", regs->dar, regs->dsisr);
+#endif
+#ifdef CONFIG_PPC64
+	printk("SOFTE: %ld ", regs->softe);
+#endif
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+	if (MSR_TM_ACTIVE(regs->msr))
+		printk("\nPACATMSCRATCH: %016llx ", get_paca()->tm_scratch);
+#endif
+
+	for (i = 0;  i < 32;  i++) {
+		if ((i % REGS_PER_LINE) == 0)
+			printk("\nGPR%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"] %pS\n", regs->nip, (void *)regs->nip);
+	printk("LR ["REG"] %pS\n", regs->link, (void *)regs->link);
+#endif
+	show_stack(current, (unsigned long *) regs->gpr[1]);
+	if (!user_mode(regs))
+		show_instructions(regs);
+}
+
+void exit_thread(void)
+{
+	discard_lazy_cpu_state();
+}
+
+void flush_thread(void)
+{
+	discard_lazy_cpu_state();
+
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+	flush_ptrace_hw_breakpoint(current);
+#else /* CONFIG_HAVE_HW_BREAKPOINT */
+	set_debug_reg_defaults(&current->thread);
+#endif /* CONFIG_HAVE_HW_BREAKPOINT */
+}
+
+void
+release_thread(struct task_struct *t)
+{
+}
+
+/*
+ * this gets called so that we can store coprocessor state into memory and
+ * copy the current task into the new thread.
+ */
+int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
+{
+	flush_fp_to_thread(src);
+	flush_altivec_to_thread(src);
+	flush_vsx_to_thread(src);
+	flush_spe_to_thread(src);
+	/*
+	 * Flush TM state out so we can copy it.  __switch_to_tm() does this
+	 * flush but it removes the checkpointed state from the current CPU and
+	 * transitions the CPU out of TM mode.  Hence we need to call
+	 * tm_recheckpoint_new_task() (on the same task) to restore the
+	 * checkpointed state back and the TM mode.
+	 */
+	__switch_to_tm(src);
+	tm_recheckpoint_new_task(src);
+
+	*dst = *src;
+
+	clear_task_ebb(dst);
+
+	return 0;
+}
+
+static void setup_ksp_vsid(struct task_struct *p, unsigned long sp)
+{
+#ifdef CONFIG_PPC_STD_MMU_64
+	unsigned long sp_vsid;
+	unsigned long llp = mmu_psize_defs[mmu_linear_psize].sllp;
+
+	if (mmu_has_feature(MMU_FTR_1T_SEGMENT))
+		sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_1T)
+			<< SLB_VSID_SHIFT_1T;
+	else
+		sp_vsid = get_kernel_vsid(sp, MMU_SEGSIZE_256M)
+			<< SLB_VSID_SHIFT;
+	sp_vsid |= SLB_VSID_KERNEL | llp;
+	p->thread.ksp_vsid = sp_vsid;
+#endif
+}
+
+/*
+ * Copy a thread..
+ */
+extern unsigned long dscr_default; /* defined in arch/powerpc/kernel/sysfs.c */
+
+/*
+ * Copy architecture-specific thread state
+ */
+int copy_thread(unsigned long clone_flags, unsigned long usp,
+		unsigned long kthread_arg, struct task_struct *p)
+{
+	struct pt_regs *childregs, *kregs;
+	extern void ret_from_fork(void);
+	extern void ret_from_kernel_thread(void);
+	void (*f)(void);
+	unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
+
+	/* Copy registers */
+	sp -= sizeof(struct pt_regs);
+	childregs = (struct pt_regs *) sp;
+	if (unlikely(p->flags & PF_KTHREAD)) {
+		/* kernel thread */
+		struct thread_info *ti = (void *)task_stack_page(p);
+		memset(childregs, 0, sizeof(struct pt_regs));
+		childregs->gpr[1] = sp + sizeof(struct pt_regs);
+		/* function */
+		if (usp)
+			childregs->gpr[14] = ppc_function_entry((void *)usp);
+#ifdef CONFIG_PPC64
+		clear_tsk_thread_flag(p, TIF_32BIT);
+		childregs->softe = 1;
+#endif
+		childregs->gpr[15] = kthread_arg;
+		p->thread.regs = NULL;	/* no user register state */
+		ti->flags |= _TIF_RESTOREALL;
+		f = ret_from_kernel_thread;
+	} else {
+		/* user thread */
+		struct pt_regs *regs = current_pt_regs();
+		CHECK_FULL_REGS(regs);
+		*childregs = *regs;
+		if (usp)
+			childregs->gpr[1] = usp;
+		p->thread.regs = childregs;
+		childregs->gpr[3] = 0;  /* Result from fork() */
+		if (clone_flags & CLONE_SETTLS) {
+#ifdef CONFIG_PPC64
+			if (!is_32bit_task())
+				childregs->gpr[13] = childregs->gpr[6];
+			else
+#endif
+				childregs->gpr[2] = childregs->gpr[6];
+		}
+
+		f = ret_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.
+	 */
+	((unsigned long *)sp)[0] = 0;
+	sp -= sizeof(struct pt_regs);
+	kregs = (struct pt_regs *) sp;
+	sp -= STACK_FRAME_OVERHEAD;
+	p->thread.ksp = sp;
+#ifdef CONFIG_PPC32
+	p->thread.ksp_limit = (unsigned long)task_stack_page(p) +
+				_ALIGN_UP(sizeof(struct thread_info), 16);
+#endif
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+	p->thread.ptrace_bps[0] = NULL;
+#endif
+
+	p->thread.fp_save_area = NULL;
+#ifdef CONFIG_ALTIVEC
+	p->thread.vr_save_area = NULL;
+#endif
+
+	setup_ksp_vsid(p, sp);
+
+#ifdef CONFIG_PPC64 
+	if (cpu_has_feature(CPU_FTR_DSCR)) {
+		p->thread.dscr_inherit = current->thread.dscr_inherit;
+		p->thread.dscr = current->thread.dscr;
+	}
+	if (cpu_has_feature(CPU_FTR_HAS_PPR))
+		p->thread.ppr = INIT_PPR;
+#endif
+	kregs->nip = ppc_function_entry(f);
+	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
+
+	/*
+	 * If we exec out of a kernel thread then thread.regs will not be
+	 * set.  Do it now.
+	 */
+	if (!current->thread.regs) {
+		struct pt_regs *regs = task_stack_page(current) + THREAD_SIZE;
+		current->thread.regs = regs - 1;
+	}
+
+	memset(regs->gpr, 0, sizeof(regs->gpr));
+	regs->ctr = 0;
+	regs->link = 0;
+	regs->xer = 0;
+	regs->ccr = 0;
+	regs->gpr[1] = sp;
+
+	/*
+	 * We have just cleared all the nonvolatile GPRs, so make
+	 * FULL_REGS(regs) return true.  This is necessary to allow
+	 * ptrace to examine the thread immediately after exec.
+	 */
+	regs->trap &= ~1UL;
+
+#ifdef CONFIG_PPC32
+	regs->mq = 0;
+	regs->nip = start;
+	regs->msr = MSR_USER;
+#else
+	if (!is_32bit_task()) {
+		unsigned long entry;
+
+		if (is_elf2_task()) {
+			/* Look ma, no function descriptors! */
+			entry = start;
+
+			/*
+			 * Ulrich says:
+			 *   The latest iteration of the ABI requires that when
+			 *   calling a function (at its global entry point),
+			 *   the caller must ensure r12 holds the entry point
+			 *   address (so that the function can quickly
+			 *   establish addressability).
+			 */
+			regs->gpr[12] = start;
+			/* Make sure that's restored on entry to userspace. */
+			set_thread_flag(TIF_RESTOREALL);
+		} else {
+			unsigned long 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->gpr[2] = toc;
+		}
+		regs->nip = entry;
+		regs->msr = MSR_USER64;
+	} else {
+		regs->nip = start;
+		regs->gpr[2] = 0;
+		regs->msr = MSR_USER32;
+	}
+#endif
+	discard_lazy_cpu_state();
+#ifdef CONFIG_VSX
+	current->thread.used_vsr = 0;
+#endif
+	memset(&current->thread.fp_state, 0, sizeof(current->thread.fp_state));
+	current->thread.fp_save_area = NULL;
+#ifdef CONFIG_ALTIVEC
+	memset(&current->thread.vr_state, 0, sizeof(current->thread.vr_state));
+	current->thread.vr_state.vscr.u[3] = 0x00010000; /* Java mode disabled */
+	current->thread.vr_save_area = NULL;
+	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 */
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+	if (cpu_has_feature(CPU_FTR_TM))
+		regs->msr |= MSR_TM;
+	current->thread.tm_tfhar = 0;
+	current->thread.tm_texasr = 0;
+	current->thread.tm_tfiar = 0;
+#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
+}
+EXPORT_SYMBOL(start_thread);
+
+#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
+		if (cpu_has_feature(CPU_FTR_SPE)) {
+			/*
+			 * When the sticky exception bits are set
+			 * directly by userspace, it must call prctl
+			 * with PR_GET_FPEXC (with PR_FP_EXC_SW_ENABLE
+			 * in the existing prctl settings) or
+			 * PR_SET_FPEXC (with PR_FP_EXC_SW_ENABLE in
+			 * the bits being set).  <fenv.h> functions
+			 * saving and restoring the whole
+			 * floating-point environment need to do so
+			 * anyway to restore the prctl settings from
+			 * the saved environment.
+			 */
+			tsk->thread.spefscr_last = mfspr(SPRN_SPEFSCR);
+			tsk->thread.fpexc_mode = val &
+				(PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT);
+			return 0;
+		} else {
+			return -EINVAL;
+		}
+#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
+		if (cpu_has_feature(CPU_FTR_SPE)) {
+			/*
+			 * When the sticky exception bits are set
+			 * directly by userspace, it must call prctl
+			 * with PR_GET_FPEXC (with PR_FP_EXC_SW_ENABLE
+			 * in the existing prctl settings) or
+			 * PR_SET_FPEXC (with PR_FP_EXC_SW_ENABLE in
+			 * the bits being set).  <fenv.h> functions
+			 * saving and restoring the whole
+			 * floating-point environment need to do so
+			 * anyway to restore the prctl settings from
+			 * the saved environment.
+			 */
+			tsk->thread.spefscr_last = mfspr(SPRN_SPEFSCR);
+			val = tsk->thread.fpexc_mode;
+		} else
+			return -EINVAL;
+#else
+		return -EINVAL;
+#endif
+	else
+		val = __unpack_fe01(tsk->thread.fpexc_mode);
+	return put_user(val, (unsigned int __user *) adr);
+}
+
+int set_endian(struct task_struct *tsk, unsigned int val)
+{
+	struct pt_regs *regs = tsk->thread.regs;
+
+	if ((val == PR_ENDIAN_LITTLE && !cpu_has_feature(CPU_FTR_REAL_LE)) ||
+	    (val == PR_ENDIAN_PPC_LITTLE && !cpu_has_feature(CPU_FTR_PPC_LE)))
+		return -EINVAL;
+
+	if (regs == NULL)
+		return -EINVAL;
+
+	if (val == PR_ENDIAN_BIG)
+		regs->msr &= ~MSR_LE;
+	else if (val == PR_ENDIAN_LITTLE || val == PR_ENDIAN_PPC_LITTLE)
+		regs->msr |= MSR_LE;
+	else
+		return -EINVAL;
+
+	return 0;
+}
+
+int get_endian(struct task_struct *tsk, unsigned long adr)
+{
+	struct pt_regs *regs = tsk->thread.regs;
+	unsigned int val;
+
+	if (!cpu_has_feature(CPU_FTR_PPC_LE) &&
+	    !cpu_has_feature(CPU_FTR_REAL_LE))
+		return -EINVAL;
+
+	if (regs == NULL)
+		return -EINVAL;
+
+	if (regs->msr & MSR_LE) {
+		if (cpu_has_feature(CPU_FTR_REAL_LE))
+			val = PR_ENDIAN_LITTLE;
+		else
+			val = PR_ENDIAN_PPC_LITTLE;
+	} else
+		val = PR_ENDIAN_BIG;
+
+	return put_user(val, (unsigned int __user *)adr);
+}
+
+int set_unalign_ctl(struct task_struct *tsk, unsigned int val)
+{
+	tsk->thread.align_ctl = val;
+	return 0;
+}
+
+int get_unalign_ctl(struct task_struct *tsk, unsigned long adr)
+{
+	return put_user(tsk->thread.align_ctl, (unsigned int __user *)adr);
+}
+
+static inline int valid_irq_stack(unsigned long sp, struct task_struct *p,
+				  unsigned long nbytes)
+{
+	unsigned long stack_page;
+	unsigned long cpu = task_cpu(p);
+
+	/*
+	 * Avoid crashing if the stack has overflowed and corrupted
+	 * task_cpu(p), which is in the thread_info struct.
+	 */
+	if (cpu < NR_CPUS && cpu_possible(cpu)) {
+		stack_page = (unsigned long) hardirq_ctx[cpu];
+		if (sp >= stack_page + sizeof(struct thread_struct)
+		    && sp <= stack_page + THREAD_SIZE - nbytes)
+			return 1;
+
+		stack_page = (unsigned long) softirq_ctx[cpu];
+		if (sp >= stack_page + sizeof(struct thread_struct)
+		    && sp <= stack_page + THREAD_SIZE - nbytes)
+			return 1;
+	}
+	return 0;
+}
+
+int validate_sp(unsigned long sp, struct task_struct *p,
+		       unsigned long nbytes)
+{
+	unsigned long stack_page = (unsigned long)task_stack_page(p);
+
+	if (sp >= stack_page + sizeof(struct thread_struct)
+	    && sp <= stack_page + THREAD_SIZE - nbytes)
+		return 1;
+
+	return valid_irq_stack(sp, p, nbytes);
+}
+
+EXPORT_SYMBOL(validate_sp);
+
+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, STACK_FRAME_OVERHEAD))
+		return 0;
+
+	do {
+		sp = *(unsigned long *)sp;
+		if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD))
+			return 0;
+		if (count > 0) {
+			ip = ((unsigned long *)sp)[STACK_FRAME_LR_SAVE];
+			if (!in_sched_functions(ip))
+				return ip;
+		}
+	} while (count++ < 16);
+	return 0;
+}
+
+static int kstack_depth_to_print = CONFIG_PRINT_STACK_DEPTH;
+
+void show_stack(struct task_struct *tsk, unsigned long *stack)
+{
+	unsigned long sp, ip, lr, newsp;
+	int count = 0;
+	int firstframe = 1;
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+	int curr_frame = current->curr_ret_stack;
+	extern void return_to_handler(void);
+	unsigned long rth = (unsigned long)return_to_handler;
+#endif
+
+	sp = (unsigned long) stack;
+	if (tsk == NULL)
+		tsk = current;
+	if (sp == 0) {
+		if (tsk == current)
+			sp = current_stack_pointer();
+		else
+			sp = tsk->thread.ksp;
+	}
+
+	lr = 0;
+	printk("Call Trace:\n");
+	do {
+		if (!validate_sp(sp, tsk, STACK_FRAME_OVERHEAD))
+			return;
+
+		stack = (unsigned long *) sp;
+		newsp = stack[0];
+		ip = stack[STACK_FRAME_LR_SAVE];
+		if (!firstframe || ip != lr) {
+			printk("["REG"] ["REG"] %pS", sp, ip, (void *)ip);
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+			if ((ip == rth) && curr_frame >= 0) {
+				printk(" (%pS)",
+				       (void *)current->ret_stack[curr_frame].ret);
+				curr_frame--;
+			}
+#endif
+			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, STACK_INT_FRAME_SIZE)
+		    && stack[STACK_FRAME_MARKER] == STACK_FRAME_REGS_MARKER) {
+			struct pt_regs *regs = (struct pt_regs *)
+				(sp + STACK_FRAME_OVERHEAD);
+			lr = regs->link;
+			printk("--- interrupt: %lx at %pS\n    LR = %pS\n",
+			       regs->trap, (void *)regs->nip, (void *)lr);
+			firstframe = 1;
+		}
+
+		sp = newsp;
+	} while (count++ < kstack_depth_to_print);
+}
+
+#ifdef CONFIG_PPC64
+/* Called with hard IRQs off */
+void notrace __ppc64_runlatch_on(void)
+{
+	struct thread_info *ti = current_thread_info();
+	unsigned long ctrl;
+
+	ctrl = mfspr(SPRN_CTRLF);
+	ctrl |= CTRL_RUNLATCH;
+	mtspr(SPRN_CTRLT, ctrl);
+
+	ti->local_flags |= _TLF_RUNLATCH;
+}
+
+/* Called with hard IRQs off */
+void notrace __ppc64_runlatch_off(void)
+{
+	struct thread_info *ti = current_thread_info();
+	unsigned long ctrl;
+
+	ti->local_flags &= ~_TLF_RUNLATCH;
+
+	ctrl = mfspr(SPRN_CTRLF);
+	ctrl &= ~CTRL_RUNLATCH;
+	mtspr(SPRN_CTRLT, ctrl);
+}
+#endif /* CONFIG_PPC64 */
+
+unsigned long arch_align_stack(unsigned long sp)
+{
+	if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
+		sp -= get_random_int() & ~PAGE_MASK;
+	return sp & ~0xf;
+}
+
+static inline unsigned long brk_rnd(void)
+{
+        unsigned long rnd = 0;
+
+	/* 8MB for 32bit, 1GB for 64bit */
+	if (is_32bit_task())
+		rnd = (long)(get_random_int() % (1<<(23-PAGE_SHIFT)));
+	else
+		rnd = (long)(get_random_int() % (1<<(30-PAGE_SHIFT)));
+
+	return rnd << PAGE_SHIFT;
+}
+
+unsigned long arch_randomize_brk(struct mm_struct *mm)
+{
+	unsigned long base = mm->brk;
+	unsigned long ret;
+
+#ifdef CONFIG_PPC_STD_MMU_64
+	/*
+	 * If we are using 1TB segments and we are allowed to randomise
+	 * the heap, we can put it above 1TB so it is backed by a 1TB
+	 * segment. Otherwise the heap will be in the bottom 1TB
+	 * which always uses 256MB segments and this may result in a
+	 * performance penalty.
+	 */
+	if (!is_32bit_task() && (mmu_highuser_ssize == MMU_SEGSIZE_1T))
+		base = max_t(unsigned long, mm->brk, 1UL << SID_SHIFT_1T);
+#endif
+
+	ret = PAGE_ALIGN(base + brk_rnd());
+
+	if (ret < mm->brk)
+		return mm->brk;
+
+	return ret;
+}
+