Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2308 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
new file mode 100644
index 000000000..f2cbad522
--- /dev/null
+++ b/arch/powerpc/kernel/process.c
@@ -0,0 +1,2308 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  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)
+ */
+
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/sched/debug.h>
+#include <linux/sched/task.h>
+#include <linux/sched/task_stack.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/hw_breakpoint.h>
+#include <linux/uaccess.h>
+#include <linux/pkeys.h>
+#include <linux/seq_buf.h>
+
+#include <asm/interrupt.h>
+#include <asm/io.h>
+#include <asm/processor.h>
+#include <asm/mmu.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>
+#include <asm/hw_irq.h>
+#endif
+#include <asm/code-patching.h>
+#include <asm/exec.h>
+#include <asm/livepatch.h>
+#include <asm/cpu_has_feature.h>
+#include <asm/asm-prototypes.h>
+#include <asm/stacktrace.h>
+#include <asm/hw_breakpoint.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);
+
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+/*
+ * Are we running in "Suspend disabled" mode? If so we have to block any
+ * sigreturn that would get us into suspended state, and we also warn in some
+ * other paths that we should never reach with suspend disabled.
+ */
+bool tm_suspend_disabled __ro_after_init = false;
+
+static void check_if_tm_restore_required(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)) {
+		regs_set_return_msr(&tsk->thread.ckpt_regs,
+						tsk->thread.regs->msr);
+		set_thread_flag(TIF_RESTORE_TM);
+	}
+}
+
+#else
+static inline void check_if_tm_restore_required(struct task_struct *tsk) { }
+#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
+
+bool strict_msr_control;
+EXPORT_SYMBOL(strict_msr_control);
+
+static int __init enable_strict_msr_control(char *str)
+{
+	strict_msr_control = true;
+	pr_info("Enabling strict facility control\n");
+
+	return 0;
+}
+early_param("ppc_strict_facility_enable", enable_strict_msr_control);
+
+/* notrace because it's called by restore_math */
+unsigned long notrace msr_check_and_set(unsigned long bits)
+{
+	unsigned long oldmsr = mfmsr();
+	unsigned long newmsr;
+
+	newmsr = oldmsr | bits;
+
+	if (cpu_has_feature(CPU_FTR_VSX) && (bits & MSR_FP))
+		newmsr |= MSR_VSX;
+
+	if (oldmsr != newmsr)
+		newmsr = mtmsr_isync_irqsafe(newmsr);
+
+	return newmsr;
+}
+EXPORT_SYMBOL_GPL(msr_check_and_set);
+
+/* notrace because it's called by restore_math */
+void notrace __msr_check_and_clear(unsigned long bits)
+{
+	unsigned long oldmsr = mfmsr();
+	unsigned long newmsr;
+
+	newmsr = oldmsr & ~bits;
+
+	if (cpu_has_feature(CPU_FTR_VSX) && (bits & MSR_FP))
+		newmsr &= ~MSR_VSX;
+
+	if (oldmsr != newmsr)
+		mtmsr_isync_irqsafe(newmsr);
+}
+EXPORT_SYMBOL(__msr_check_and_clear);
+
+#ifdef CONFIG_PPC_FPU
+static void __giveup_fpu(struct task_struct *tsk)
+{
+	unsigned long msr;
+
+	save_fpu(tsk);
+	msr = tsk->thread.regs->msr;
+	msr &= ~(MSR_FP|MSR_FE0|MSR_FE1);
+	if (cpu_has_feature(CPU_FTR_VSX))
+		msr &= ~MSR_VSX;
+	regs_set_return_msr(tsk->thread.regs, msr);
+}
+
+void giveup_fpu(struct task_struct *tsk)
+{
+	check_if_tm_restore_required(tsk);
+
+	msr_check_and_set(MSR_FP);
+	__giveup_fpu(tsk);
+	msr_check_and_clear(MSR_FP);
+}
+EXPORT_SYMBOL(giveup_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) {
+			/*
+			 * 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,
+			 * there is something wrong if a stopped child appears
+			 * to still have its FP state in the CPU registers.
+			 */
+			BUG_ON(tsk != current);
+			giveup_fpu(tsk);
+		}
+		preempt_enable();
+	}
+}
+EXPORT_SYMBOL_GPL(flush_fp_to_thread);
+
+void enable_kernel_fp(void)
+{
+	unsigned long cpumsr;
+
+	WARN_ON(preemptible());
+
+	cpumsr = msr_check_and_set(MSR_FP);
+
+	if (current->thread.regs && (current->thread.regs->msr & MSR_FP)) {
+		check_if_tm_restore_required(current);
+		/*
+		 * If a thread has already been reclaimed then the
+		 * checkpointed registers are on the CPU but have definitely
+		 * been saved by the reclaim code. Don't need to and *cannot*
+		 * giveup as this would save  to the 'live' structure not the
+		 * checkpointed structure.
+		 */
+		if (!MSR_TM_ACTIVE(cpumsr) &&
+		     MSR_TM_ACTIVE(current->thread.regs->msr))
+			return;
+		__giveup_fpu(current);
+	}
+}
+EXPORT_SYMBOL(enable_kernel_fp);
+#else
+static inline void __giveup_fpu(struct task_struct *tsk) { }
+#endif /* CONFIG_PPC_FPU */
+
+#ifdef CONFIG_ALTIVEC
+static void __giveup_altivec(struct task_struct *tsk)
+{
+	unsigned long msr;
+
+	save_altivec(tsk);
+	msr = tsk->thread.regs->msr;
+	msr &= ~MSR_VEC;
+	if (cpu_has_feature(CPU_FTR_VSX))
+		msr &= ~MSR_VSX;
+	regs_set_return_msr(tsk->thread.regs, msr);
+}
+
+void giveup_altivec(struct task_struct *tsk)
+{
+	check_if_tm_restore_required(tsk);
+
+	msr_check_and_set(MSR_VEC);
+	__giveup_altivec(tsk);
+	msr_check_and_clear(MSR_VEC);
+}
+EXPORT_SYMBOL(giveup_altivec);
+
+void enable_kernel_altivec(void)
+{
+	unsigned long cpumsr;
+
+	WARN_ON(preemptible());
+
+	cpumsr = msr_check_and_set(MSR_VEC);
+
+	if (current->thread.regs && (current->thread.regs->msr & MSR_VEC)) {
+		check_if_tm_restore_required(current);
+		/*
+		 * If a thread has already been reclaimed then the
+		 * checkpointed registers are on the CPU but have definitely
+		 * been saved by the reclaim code. Don't need to and *cannot*
+		 * giveup as this would save  to the 'live' structure not the
+		 * checkpointed structure.
+		 */
+		if (!MSR_TM_ACTIVE(cpumsr) &&
+		     MSR_TM_ACTIVE(current->thread.regs->msr))
+			return;
+		__giveup_altivec(current);
+	}
+}
+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) {
+			BUG_ON(tsk != current);
+			giveup_altivec(tsk);
+		}
+		preempt_enable();
+	}
+}
+EXPORT_SYMBOL_GPL(flush_altivec_to_thread);
+#endif /* CONFIG_ALTIVEC */
+
+#ifdef CONFIG_VSX
+static void __giveup_vsx(struct task_struct *tsk)
+{
+	unsigned long msr = tsk->thread.regs->msr;
+
+	/*
+	 * We should never be setting MSR_VSX without also setting
+	 * MSR_FP and MSR_VEC
+	 */
+	WARN_ON((msr & MSR_VSX) && !((msr & MSR_FP) && (msr & MSR_VEC)));
+
+	/* __giveup_fpu will clear MSR_VSX */
+	if (msr & MSR_FP)
+		__giveup_fpu(tsk);
+	if (msr & MSR_VEC)
+		__giveup_altivec(tsk);
+}
+
+static void giveup_vsx(struct task_struct *tsk)
+{
+	check_if_tm_restore_required(tsk);
+
+	msr_check_and_set(MSR_FP|MSR_VEC|MSR_VSX);
+	__giveup_vsx(tsk);
+	msr_check_and_clear(MSR_FP|MSR_VEC|MSR_VSX);
+}
+
+void enable_kernel_vsx(void)
+{
+	unsigned long cpumsr;
+
+	WARN_ON(preemptible());
+
+	cpumsr = msr_check_and_set(MSR_FP|MSR_VEC|MSR_VSX);
+
+	if (current->thread.regs &&
+	    (current->thread.regs->msr & (MSR_VSX|MSR_VEC|MSR_FP))) {
+		check_if_tm_restore_required(current);
+		/*
+		 * If a thread has already been reclaimed then the
+		 * checkpointed registers are on the CPU but have definitely
+		 * been saved by the reclaim code. Don't need to and *cannot*
+		 * giveup as this would save  to the 'live' structure not the
+		 * checkpointed structure.
+		 */
+		if (!MSR_TM_ACTIVE(cpumsr) &&
+		     MSR_TM_ACTIVE(current->thread.regs->msr))
+			return;
+		__giveup_vsx(current);
+	}
+}
+EXPORT_SYMBOL(enable_kernel_vsx);
+
+void flush_vsx_to_thread(struct task_struct *tsk)
+{
+	if (tsk->thread.regs) {
+		preempt_disable();
+		if (tsk->thread.regs->msr & (MSR_VSX|MSR_VEC|MSR_FP)) {
+			BUG_ON(tsk != current);
+			giveup_vsx(tsk);
+		}
+		preempt_enable();
+	}
+}
+EXPORT_SYMBOL_GPL(flush_vsx_to_thread);
+#endif /* CONFIG_VSX */
+
+#ifdef CONFIG_SPE
+void giveup_spe(struct task_struct *tsk)
+{
+	check_if_tm_restore_required(tsk);
+
+	msr_check_and_set(MSR_SPE);
+	__giveup_spe(tsk);
+	msr_check_and_clear(MSR_SPE);
+}
+EXPORT_SYMBOL(giveup_spe);
+
+void enable_kernel_spe(void)
+{
+	WARN_ON(preemptible());
+
+	msr_check_and_set(MSR_SPE);
+
+	if (current->thread.regs && (current->thread.regs->msr & MSR_SPE)) {
+		check_if_tm_restore_required(current);
+		__giveup_spe(current);
+	}
+}
+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) {
+			BUG_ON(tsk != current);
+			tsk->thread.spefscr = mfspr(SPRN_SPEFSCR);
+			giveup_spe(tsk);
+		}
+		preempt_enable();
+	}
+}
+#endif /* CONFIG_SPE */
+
+static unsigned long msr_all_available;
+
+static int __init init_msr_all_available(void)
+{
+	if (IS_ENABLED(CONFIG_PPC_FPU))
+		msr_all_available |= MSR_FP;
+	if (cpu_has_feature(CPU_FTR_ALTIVEC))
+		msr_all_available |= MSR_VEC;
+	if (cpu_has_feature(CPU_FTR_VSX))
+		msr_all_available |= MSR_VSX;
+	if (cpu_has_feature(CPU_FTR_SPE))
+		msr_all_available |= MSR_SPE;
+
+	return 0;
+}
+early_initcall(init_msr_all_available);
+
+void giveup_all(struct task_struct *tsk)
+{
+	unsigned long usermsr;
+
+	if (!tsk->thread.regs)
+		return;
+
+	check_if_tm_restore_required(tsk);
+
+	usermsr = tsk->thread.regs->msr;
+
+	if ((usermsr & msr_all_available) == 0)
+		return;
+
+	msr_check_and_set(msr_all_available);
+
+	WARN_ON((usermsr & MSR_VSX) && !((usermsr & MSR_FP) && (usermsr & MSR_VEC)));
+
+	if (usermsr & MSR_FP)
+		__giveup_fpu(tsk);
+	if (usermsr & MSR_VEC)
+		__giveup_altivec(tsk);
+	if (usermsr & MSR_SPE)
+		__giveup_spe(tsk);
+
+	msr_check_and_clear(msr_all_available);
+}
+EXPORT_SYMBOL(giveup_all);
+
+#ifdef CONFIG_PPC_BOOK3S_64
+#ifdef CONFIG_PPC_FPU
+static bool should_restore_fp(void)
+{
+	if (current->thread.load_fp) {
+		current->thread.load_fp++;
+		return true;
+	}
+	return false;
+}
+
+static void do_restore_fp(void)
+{
+	load_fp_state(&current->thread.fp_state);
+}
+#else
+static bool should_restore_fp(void) { return false; }
+static void do_restore_fp(void) { }
+#endif /* CONFIG_PPC_FPU */
+
+#ifdef CONFIG_ALTIVEC
+static bool should_restore_altivec(void)
+{
+	if (cpu_has_feature(CPU_FTR_ALTIVEC) && (current->thread.load_vec)) {
+		current->thread.load_vec++;
+		return true;
+	}
+	return false;
+}
+
+static void do_restore_altivec(void)
+{
+	load_vr_state(&current->thread.vr_state);
+	current->thread.used_vr = 1;
+}
+#else
+static bool should_restore_altivec(void) { return false; }
+static void do_restore_altivec(void) { }
+#endif /* CONFIG_ALTIVEC */
+
+static bool should_restore_vsx(void)
+{
+	if (cpu_has_feature(CPU_FTR_VSX))
+		return true;
+	return false;
+}
+#ifdef CONFIG_VSX
+static void do_restore_vsx(void)
+{
+	current->thread.used_vsr = 1;
+}
+#else
+static void do_restore_vsx(void) { }
+#endif /* CONFIG_VSX */
+
+/*
+ * The exception exit path calls restore_math() with interrupts hard disabled
+ * but the soft irq state not "reconciled". ftrace code that calls
+ * local_irq_save/restore causes warnings.
+ *
+ * Rather than complicate the exit path, just don't trace restore_math. This
+ * could be done by having ftrace entry code check for this un-reconciled
+ * condition where MSR[EE]=0 and PACA_IRQ_HARD_DIS is not set, and
+ * temporarily fix it up for the duration of the ftrace call.
+ */
+void notrace restore_math(struct pt_regs *regs)
+{
+	unsigned long msr;
+	unsigned long new_msr = 0;
+
+	msr = regs->msr;
+
+	/*
+	 * new_msr tracks the facilities that are to be restored. Only reload
+	 * if the bit is not set in the user MSR (if it is set, the registers
+	 * are live for the user thread).
+	 */
+	if ((!(msr & MSR_FP)) && should_restore_fp())
+		new_msr |= MSR_FP;
+
+	if ((!(msr & MSR_VEC)) && should_restore_altivec())
+		new_msr |= MSR_VEC;
+
+	if ((!(msr & MSR_VSX)) && should_restore_vsx()) {
+		if (((msr | new_msr) & (MSR_FP | MSR_VEC)) == (MSR_FP | MSR_VEC))
+			new_msr |= MSR_VSX;
+	}
+
+	if (new_msr) {
+		unsigned long fpexc_mode = 0;
+
+		msr_check_and_set(new_msr);
+
+		if (new_msr & MSR_FP) {
+			do_restore_fp();
+
+			// This also covers VSX, because VSX implies FP
+			fpexc_mode = current->thread.fpexc_mode;
+		}
+
+		if (new_msr & MSR_VEC)
+			do_restore_altivec();
+
+		if (new_msr & MSR_VSX)
+			do_restore_vsx();
+
+		msr_check_and_clear(new_msr);
+
+		regs_set_return_msr(regs, regs->msr | new_msr | fpexc_mode);
+	}
+}
+#endif /* CONFIG_PPC_BOOK3S_64 */
+
+static void save_all(struct task_struct *tsk)
+{
+	unsigned long usermsr;
+
+	if (!tsk->thread.regs)
+		return;
+
+	usermsr = tsk->thread.regs->msr;
+
+	if ((usermsr & msr_all_available) == 0)
+		return;
+
+	msr_check_and_set(msr_all_available);
+
+	WARN_ON((usermsr & MSR_VSX) && !((usermsr & MSR_FP) && (usermsr & MSR_VEC)));
+
+	if (usermsr & MSR_FP)
+		save_fpu(tsk);
+
+	if (usermsr & MSR_VEC)
+		save_altivec(tsk);
+
+	if (usermsr & MSR_SPE)
+		__giveup_spe(tsk);
+
+	msr_check_and_clear(msr_all_available);
+}
+
+void flush_all_to_thread(struct task_struct *tsk)
+{
+	if (tsk->thread.regs) {
+		preempt_disable();
+		BUG_ON(tsk != current);
+#ifdef CONFIG_SPE
+		if (tsk->thread.regs->msr & MSR_SPE)
+			tsk->thread.spefscr = mfspr(SPRN_SPEFSCR);
+#endif
+		save_all(tsk);
+
+		preempt_enable();
+	}
+}
+EXPORT_SYMBOL(flush_all_to_thread);
+
+#ifdef CONFIG_PPC_ADV_DEBUG_REGS
+void do_send_trap(struct pt_regs *regs, unsigned long address,
+		  unsigned long error_code, int breakpt)
+{
+	current->thread.trap_nr = TRAP_HWBKPT;
+	if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code,
+			11, SIGSEGV) == NOTIFY_STOP)
+		return;
+
+	/* Deliver the signal to userspace */
+	force_sig_ptrace_errno_trap(breakpt, /* breakpoint or watchpoint id */
+				    (void __user *)address);
+}
+#else	/* !CONFIG_PPC_ADV_DEBUG_REGS */
+
+static void do_break_handler(struct pt_regs *regs)
+{
+	struct arch_hw_breakpoint null_brk = {0};
+	struct arch_hw_breakpoint *info;
+	ppc_inst_t instr = ppc_inst(0);
+	int type = 0;
+	int size = 0;
+	unsigned long ea;
+	int i;
+
+	/*
+	 * If underneath hw supports only one watchpoint, we know it
+	 * caused exception. 8xx also falls into this category.
+	 */
+	if (nr_wp_slots() == 1) {
+		__set_breakpoint(0, &null_brk);
+		current->thread.hw_brk[0] = null_brk;
+		current->thread.hw_brk[0].flags |= HW_BRK_FLAG_DISABLED;
+		return;
+	}
+
+	/* Otherwise find out which DAWR caused exception and disable it. */
+	wp_get_instr_detail(regs, &instr, &type, &size, &ea);
+
+	for (i = 0; i < nr_wp_slots(); i++) {
+		info = &current->thread.hw_brk[i];
+		if (!info->address)
+			continue;
+
+		if (wp_check_constraints(regs, instr, ea, type, size, info)) {
+			__set_breakpoint(i, &null_brk);
+			current->thread.hw_brk[i] = null_brk;
+			current->thread.hw_brk[i].flags |= HW_BRK_FLAG_DISABLED;
+		}
+	}
+}
+
+DEFINE_INTERRUPT_HANDLER(do_break)
+{
+	current->thread.trap_nr = TRAP_HWBKPT;
+	if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, regs->dsisr,
+			11, SIGSEGV) == NOTIFY_STOP)
+		return;
+
+	if (debugger_break_match(regs))
+		return;
+
+	/*
+	 * We reach here only when watchpoint exception is generated by ptrace
+	 * event (or hw is buggy!). Now if CONFIG_HAVE_HW_BREAKPOINT is set,
+	 * watchpoint is already handled by hw_breakpoint_handler() so we don't
+	 * have to do anything. But when CONFIG_HAVE_HW_BREAKPOINT is not set,
+	 * we need to manually handle the watchpoint here.
+	 */
+	if (!IS_ENABLED(CONFIG_HAVE_HW_BREAKPOINT))
+		do_break_handler(regs);
+
+	/* Deliver the signal to userspace */
+	force_sig_fault(SIGTRAP, TRAP_HWBKPT, (void __user *)regs->dar);
+}
+#endif	/* CONFIG_PPC_ADV_DEBUG_REGS */
+
+static DEFINE_PER_CPU(struct arch_hw_breakpoint, current_brk[HBP_NUM_MAX]);
+
+#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_breakpoint(int i, struct arch_hw_breakpoint *brk)
+{
+	preempt_disable();
+	__set_breakpoint(i, brk);
+	preempt_enable();
+}
+
+static void set_debug_reg_defaults(struct thread_struct *thread)
+{
+	int i;
+	struct arch_hw_breakpoint null_brk = {0};
+
+	for (i = 0; i < nr_wp_slots(); i++) {
+		thread->hw_brk[i] = null_brk;
+		if (ppc_breakpoint_available())
+			set_breakpoint(i, &thread->hw_brk[i]);
+	}
+}
+
+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;
+	/* no need to check hw_len. it's calculated from address and len */
+	return true;
+}
+
+static void switch_hw_breakpoint(struct task_struct *new)
+{
+	int i;
+
+	for (i = 0; i < nr_wp_slots(); i++) {
+		if (likely(hw_brk_match(this_cpu_ptr(&current_brk[i]),
+					&new->thread.hw_brk[i])))
+			continue;
+
+		__set_breakpoint(i, &new->thread.hw_brk[i]);
+	}
+}
+#endif /* !CONFIG_HAVE_HW_BREAKPOINT */
+#endif	/* CONFIG_PPC_ADV_DEBUG_REGS */
+
+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);
+
+	if (IS_ENABLED(CONFIG_PPC_ADV_DEBUG_REGS)) {
+		mtspr(SPRN_DAC1, dabr);
+		if (IS_ENABLED(CONFIG_PPC_47x))
+			isync();
+		return 0;
+	} else if (IS_ENABLED(CONFIG_PPC_BOOK3S)) {
+		mtspr(SPRN_DABR, dabr);
+		if (cpu_has_feature(CPU_FTR_DABRX))
+			mtspr(SPRN_DABRX, dabrx);
+		return 0;
+	} else {
+		return -EINVAL;
+	}
+}
+
+static inline int set_breakpoint_8xx(struct arch_hw_breakpoint *brk)
+{
+	unsigned long lctrl1 = LCTRL1_CTE_GT | LCTRL1_CTF_LT | LCTRL1_CRWE_RW |
+			       LCTRL1_CRWF_RW;
+	unsigned long lctrl2 = LCTRL2_LW0EN | LCTRL2_LW0LADC | LCTRL2_SLW0EN;
+	unsigned long start_addr = ALIGN_DOWN(brk->address, HW_BREAKPOINT_SIZE);
+	unsigned long end_addr = ALIGN(brk->address + brk->len, HW_BREAKPOINT_SIZE);
+
+	if (start_addr == 0)
+		lctrl2 |= LCTRL2_LW0LA_F;
+	else if (end_addr == 0)
+		lctrl2 |= LCTRL2_LW0LA_E;
+	else
+		lctrl2 |= LCTRL2_LW0LA_EandF;
+
+	mtspr(SPRN_LCTRL2, 0);
+
+	if ((brk->type & HW_BRK_TYPE_RDWR) == 0)
+		return 0;
+
+	if ((brk->type & HW_BRK_TYPE_RDWR) == HW_BRK_TYPE_READ)
+		lctrl1 |= LCTRL1_CRWE_RO | LCTRL1_CRWF_RO;
+	if ((brk->type & HW_BRK_TYPE_RDWR) == HW_BRK_TYPE_WRITE)
+		lctrl1 |= LCTRL1_CRWE_WO | LCTRL1_CRWF_WO;
+
+	mtspr(SPRN_CMPE, start_addr - 1);
+	mtspr(SPRN_CMPF, end_addr);
+	mtspr(SPRN_LCTRL1, lctrl1);
+	mtspr(SPRN_LCTRL2, lctrl2);
+
+	return 0;
+}
+
+void __set_breakpoint(int nr, struct arch_hw_breakpoint *brk)
+{
+	memcpy(this_cpu_ptr(&current_brk[nr]), brk, sizeof(*brk));
+
+	if (dawr_enabled())
+		// Power8 or later
+		set_dawr(nr, brk);
+	else if (IS_ENABLED(CONFIG_PPC_8xx))
+		set_breakpoint_8xx(brk);
+	else if (!cpu_has_feature(CPU_FTR_ARCH_207S))
+		// Power7 or earlier
+		set_dabr(brk);
+	else
+		// Shouldn't happen due to higher level checks
+		WARN_ON_ONCE(1);
+}
+
+/* Check if we have DAWR or DABR hardware */
+bool ppc_breakpoint_available(void)
+{
+	if (dawr_enabled())
+		return true; /* POWER8 DAWR or POWER9 forced DAWR */
+	if (cpu_has_feature(CPU_FTR_ARCH_207S))
+		return false; /* POWER9 with DAWR disabled */
+	/* DABR: Everything but POWER8 and POWER9 */
+	return true;
+}
+EXPORT_SYMBOL_GPL(ppc_breakpoint_available);
+
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+
+static inline bool tm_enabled(struct task_struct *tsk)
+{
+	return tsk && tsk->thread.regs && (tsk->thread.regs->msr & MSR_TM);
+}
+
+static void tm_reclaim_thread(struct thread_struct *thr, uint8_t cause)
+{
+	/*
+	 * Use the current MSR TM suspended bit to track if we have
+	 * checkpointed state outstanding.
+	 * On signal delivery, we'd normally reclaim the checkpointed
+	 * state to obtain stack pointer (see:get_tm_stackpointer()).
+	 * This will then directly return to userspace without going
+	 * through __switch_to(). However, if the stack frame is bad,
+	 * we need to exit this thread which calls __switch_to() which
+	 * will again attempt to reclaim the already saved tm state.
+	 * Hence we need to check that we've not already reclaimed
+	 * this state.
+	 * We do this using the current MSR, rather tracking it in
+	 * some specific thread_struct bit, as it has the additional
+	 * benefit of checking for a potential TM bad thing exception.
+	 */
+	if (!MSR_TM_SUSPENDED(mfmsr()))
+		return;
+
+	giveup_all(container_of(thr, struct task_struct, thread));
+
+	tm_reclaim(thr, cause);
+
+	/*
+	 * If we are in a transaction and FP is off then we can't have
+	 * used FP inside that transaction. Hence the checkpointed
+	 * state is the same as the live state. We need to copy the
+	 * live state to the checkpointed state so that when the
+	 * transaction is restored, the checkpointed state is correct
+	 * and the aborted transaction sees the correct state. We use
+	 * ckpt_regs.msr here as that's what tm_reclaim will use to
+	 * determine if it's going to write the checkpointed state or
+	 * not. So either this will write the checkpointed registers,
+	 * or reclaim will. Similarly for VMX.
+	 */
+	if ((thr->ckpt_regs.msr & MSR_FP) == 0)
+		memcpy(&thr->ckfp_state, &thr->fp_state,
+		       sizeof(struct thread_fp_state));
+	if ((thr->ckpt_regs.msr & MSR_VEC) == 0)
+		memcpy(&thr->ckvr_state, &thr->vr_state,
+		       sizeof(struct thread_vr_state));
+}
+
+void tm_reclaim_current(uint8_t cause)
+{
+	tm_enable();
+	tm_reclaim_thread(&current->thread, 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, ckfp_state and
+	 * ckvr_state
+	 *
+	 * 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;
+
+	WARN_ON(tm_suspend_disabled);
+
+	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, 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);
+
+void tm_recheckpoint(struct thread_struct *thread)
+{
+	unsigned long flags;
+
+	if (!(thread->regs->msr & MSR_TM))
+		return;
+
+	/* 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);
+
+	local_irq_restore(flags);
+}
+
+static inline void tm_recheckpoint_new_task(struct task_struct *new)
+{
+	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
+	 * unavailable later, we are unable to determine which set of FP regs
+	 * need to be restored.
+	 */
+	if (!tm_enabled(new))
+		return;
+
+	if (!MSR_TM_ACTIVE(new->thread.regs->msr)){
+		tm_restore_sprs(&new->thread);
+		return;
+	}
+	/* Recheckpoint to restore original checkpointed register state. */
+	TM_DEBUG("*** tm_recheckpoint of pid %d (new->msr 0x%lx)\n",
+		 new->pid, new->thread.regs->msr);
+
+	tm_recheckpoint(&new->thread);
+
+	/*
+	 * The checkpointed state has been restored but the live state has
+	 * not, ensure all the math functionality is turned off to trigger
+	 * restore_math() to reload.
+	 */
+	new->thread.regs->msr &= ~(MSR_FP | MSR_VEC | 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,
+		struct task_struct *new)
+{
+	if (cpu_has_feature(CPU_FTR_TM)) {
+		if (tm_enabled(prev) || tm_enabled(new))
+			tm_enable();
+
+		if (tm_enabled(prev)) {
+			prev->thread.load_tm++;
+			tm_reclaim_task(prev);
+			if (!MSR_TM_ACTIVE(prev->thread.regs->msr) && prev->thread.load_tm == 0)
+				prev->thread.regs->msr &= ~MSR_TM;
+		}
+
+		tm_recheckpoint_new_task(new);
+	}
+}
+
+/*
+ * 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;
+
+	/*
+	 * This is the only moment we should clear TIF_RESTORE_TM as
+	 * it is here that ckpt_regs.msr and pt_regs.msr become the same
+	 * again, anything else could lead to an incorrect ckpt_msr being
+	 * saved and therefore incorrect signal contexts.
+	 */
+	clear_thread_flag(TIF_RESTORE_TM);
+	if (!MSR_TM_ACTIVE(regs->msr))
+		return;
+
+	msr_diff = current->thread.ckpt_regs.msr & ~regs->msr;
+	msr_diff &= MSR_FP | MSR_VEC | MSR_VSX;
+
+	/* Ensure that restore_math() will restore */
+	if (msr_diff & MSR_FP)
+		current->thread.load_fp = 1;
+#ifdef CONFIG_ALTIVEC
+	if (cpu_has_feature(CPU_FTR_ALTIVEC) && msr_diff & MSR_VEC)
+		current->thread.load_vec = 1;
+#endif
+	restore_math(regs);
+
+	regs_set_return_msr(regs, regs->msr | msr_diff);
+}
+
+#else /* !CONFIG_PPC_TRANSACTIONAL_MEM */
+#define tm_recheckpoint_new_task(new)
+#define __switch_to_tm(prev, new)
+void tm_reclaim_current(uint8_t cause) {}
+#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
+
+static inline void save_sprs(struct thread_struct *t)
+{
+#ifdef CONFIG_ALTIVEC
+	if (cpu_has_feature(CPU_FTR_ALTIVEC))
+		t->vrsave = mfspr(SPRN_VRSAVE);
+#endif
+#ifdef CONFIG_SPE
+	if (cpu_has_feature(CPU_FTR_SPE))
+		t->spefscr = mfspr(SPRN_SPEFSCR);
+#endif
+#ifdef CONFIG_PPC_BOOK3S_64
+	if (cpu_has_feature(CPU_FTR_DSCR))
+		t->dscr = mfspr(SPRN_DSCR);
+
+	if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
+		t->bescr = mfspr(SPRN_BESCR);
+		t->ebbhr = mfspr(SPRN_EBBHR);
+		t->ebbrr = mfspr(SPRN_EBBRR);
+
+		t->fscr = mfspr(SPRN_FSCR);
+
+		/*
+		 * 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).)
+		 */
+		t->tar = mfspr(SPRN_TAR);
+	}
+#endif
+}
+
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+void kvmppc_save_user_regs(void)
+{
+	unsigned long usermsr;
+
+	if (!current->thread.regs)
+		return;
+
+	usermsr = current->thread.regs->msr;
+
+	/* Caller has enabled FP/VEC/VSX/TM in MSR */
+	if (usermsr & MSR_FP)
+		__giveup_fpu(current);
+	if (usermsr & MSR_VEC)
+		__giveup_altivec(current);
+
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+	if (usermsr & MSR_TM) {
+		current->thread.tm_tfhar = mfspr(SPRN_TFHAR);
+		current->thread.tm_tfiar = mfspr(SPRN_TFIAR);
+		current->thread.tm_texasr = mfspr(SPRN_TEXASR);
+		current->thread.regs->msr &= ~MSR_TM;
+	}
+#endif
+}
+EXPORT_SYMBOL_GPL(kvmppc_save_user_regs);
+
+void kvmppc_save_current_sprs(void)
+{
+	save_sprs(&current->thread);
+}
+EXPORT_SYMBOL_GPL(kvmppc_save_current_sprs);
+#endif /* CONFIG_KVM_BOOK3S_HV_POSSIBLE */
+
+static inline void restore_sprs(struct thread_struct *old_thread,
+				struct thread_struct *new_thread)
+{
+#ifdef CONFIG_ALTIVEC
+	if (cpu_has_feature(CPU_FTR_ALTIVEC) &&
+	    old_thread->vrsave != new_thread->vrsave)
+		mtspr(SPRN_VRSAVE, new_thread->vrsave);
+#endif
+#ifdef CONFIG_SPE
+	if (cpu_has_feature(CPU_FTR_SPE) &&
+	    old_thread->spefscr != new_thread->spefscr)
+		mtspr(SPRN_SPEFSCR, new_thread->spefscr);
+#endif
+#ifdef CONFIG_PPC_BOOK3S_64
+	if (cpu_has_feature(CPU_FTR_DSCR)) {
+		u64 dscr = get_paca()->dscr_default;
+		if (new_thread->dscr_inherit)
+			dscr = new_thread->dscr;
+
+		if (old_thread->dscr != dscr)
+			mtspr(SPRN_DSCR, dscr);
+	}
+
+	if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
+		if (old_thread->bescr != new_thread->bescr)
+			mtspr(SPRN_BESCR, new_thread->bescr);
+		if (old_thread->ebbhr != new_thread->ebbhr)
+			mtspr(SPRN_EBBHR, new_thread->ebbhr);
+		if (old_thread->ebbrr != new_thread->ebbrr)
+			mtspr(SPRN_EBBRR, new_thread->ebbrr);
+
+		if (old_thread->fscr != new_thread->fscr)
+			mtspr(SPRN_FSCR, new_thread->fscr);
+
+		if (old_thread->tar != new_thread->tar)
+			mtspr(SPRN_TAR, new_thread->tar);
+	}
+
+	if (cpu_has_feature(CPU_FTR_P9_TIDR) &&
+	    old_thread->tidr != new_thread->tidr)
+		mtspr(SPRN_TIDR, new_thread->tidr);
+#endif
+
+}
+
+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_64S_HASH_MMU
+	struct ppc64_tlb_batch *batch;
+#endif
+
+	new_thread = &new->thread;
+	old_thread = &current->thread;
+
+	WARN_ON(!irqs_disabled());
+
+#ifdef CONFIG_PPC_64S_HASH_MMU
+	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;
+	}
+
+	/*
+	 * On POWER9 the copy-paste buffer can only paste into
+	 * foreign real addresses, so unprivileged processes can not
+	 * see the data or use it in any way unless they have
+	 * foreign real mappings. If the new process has the foreign
+	 * real address mappings, we must issue a cp_abort to clear
+	 * any state and prevent snooping, corruption or a covert
+	 * channel. ISA v3.1 supports paste into local memory.
+	 */
+	if (new->mm && (cpu_has_feature(CPU_FTR_ARCH_31) ||
+			atomic_read(&new->mm->context.vas_windows)))
+		asm volatile(PPC_CP_ABORT);
+#endif /* CONFIG_PPC_BOOK3S_64 */
+
+#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
+	switch_hw_breakpoint(new);
+#endif /* CONFIG_HAVE_HW_BREAKPOINT */
+#endif
+
+	/*
+	 * We need to save SPRs before treclaim/trecheckpoint as these will
+	 * change a number of them.
+	 */
+	save_sprs(&prev->thread);
+
+	/* Save FPU, Altivec, VSX and SPE state */
+	giveup_all(prev);
+
+	__switch_to_tm(prev, new);
+
+	if (!radix_enabled()) {
+		/*
+		 * 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();
+	}
+
+	/*
+	 * Call restore_sprs() and set_return_regs_changed() before calling
+	 * _switch(). If we move it after _switch() then we miss out on calling
+	 * it for new tasks. The reason for this is we manually create a stack
+	 * frame for new tasks that directly returns through ret_from_fork() or
+	 * ret_from_kernel_thread(). See copy_thread() for details.
+	 */
+	restore_sprs(old_thread, new_thread);
+
+	set_return_regs_changed(); /* _switch changes stack (and regs) */
+
+	if (!IS_ENABLED(CONFIG_PPC_BOOK3S_64))
+		kuap_assert_locked();
+
+	last = _switch(old_thread, new_thread);
+
+	/*
+	 * Nothing after _switch will be run for newly created tasks,
+	 * because they switch directly to ret_from_fork/ret_from_kernel_thread
+	 * etc. Code added here should have a comment explaining why that is
+	 * okay.
+	 */
+
+#ifdef CONFIG_PPC_BOOK3S_64
+#ifdef CONFIG_PPC_64S_HASH_MMU
+	/*
+	 * This applies to a process that was context switched while inside
+	 * arch_enter_lazy_mmu_mode(), to re-activate the batch that was
+	 * deactivated above, before _switch(). This will never be the case
+	 * for new tasks.
+	 */
+	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
+
+	/*
+	 * Math facilities are masked out of the child MSR in copy_thread.
+	 * A new task does not need to restore_math because it will
+	 * demand fault them.
+	 */
+	if (current->thread.regs)
+		restore_math(current->thread.regs);
+#endif /* CONFIG_PPC_BOOK3S_64 */
+
+	return last;
+}
+
+#define NR_INSN_TO_PRINT	16
+
+static void show_instructions(struct pt_regs *regs)
+{
+	int i;
+	unsigned long nip = regs->nip;
+	unsigned long pc = regs->nip - (NR_INSN_TO_PRINT * 3 / 4 * sizeof(int));
+
+	printk("Instruction dump:");
+
+	/*
+	 * If we were executing with the MMU off for instructions, adjust pc
+	 * rather than printing XXXXXXXX.
+	 */
+	if (!IS_ENABLED(CONFIG_BOOKE) && !(regs->msr & MSR_IR)) {
+		pc = (unsigned long)phys_to_virt(pc);
+		nip = (unsigned long)phys_to_virt(regs->nip);
+	}
+
+	for (i = 0; i < NR_INSN_TO_PRINT; i++) {
+		int instr;
+
+		if (!(i % 8))
+			pr_cont("\n");
+
+		if (!__kernel_text_address(pc) ||
+		    get_kernel_nofault(instr, (const void *)pc)) {
+			pr_cont("XXXXXXXX ");
+		} else {
+			if (nip == pc)
+				pr_cont("<%08x> ", instr);
+			else
+				pr_cont("%08x ", instr);
+		}
+
+		pc += sizeof(int);
+	}
+
+	pr_cont("\n");
+}
+
+void show_user_instructions(struct pt_regs *regs)
+{
+	unsigned long pc;
+	int n = NR_INSN_TO_PRINT;
+	struct seq_buf s;
+	char buf[96]; /* enough for 8 times 9 + 2 chars */
+
+	pc = regs->nip - (NR_INSN_TO_PRINT * 3 / 4 * sizeof(int));
+
+	seq_buf_init(&s, buf, sizeof(buf));
+
+	while (n) {
+		int i;
+
+		seq_buf_clear(&s);
+
+		for (i = 0; i < 8 && n; i++, n--, pc += sizeof(int)) {
+			int instr;
+
+			if (copy_from_user_nofault(&instr, (void __user *)pc,
+					sizeof(instr))) {
+				seq_buf_printf(&s, "XXXXXXXX ");
+				continue;
+			}
+			seq_buf_printf(&s, regs->nip == pc ? "<%08x> " : "%08x ", instr);
+		}
+
+		if (!seq_buf_has_overflowed(&s))
+			pr_info("%s[%d]: code: %s\n", current->comm,
+				current->pid, s.buffer);
+	}
+}
+
+struct regbit {
+	unsigned long bit;
+	const char *name;
+};
+
+static struct regbit 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 print_bits(unsigned long val, struct regbit *bits, const char *sep)
+{
+	const char *s = "";
+
+	for (; bits->bit; ++bits)
+		if (val & bits->bit) {
+			pr_cont("%s%s", s, bits->name);
+			s = sep;
+		}
+}
+
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+static struct regbit msr_tm_bits[] = {
+	{MSR_TS_T,	"T"},
+	{MSR_TS_S,	"S"},
+	{MSR_TM,	"E"},
+	{0,		NULL}
+};
+
+static void print_tm_bits(unsigned long val)
+{
+/*
+ * This only prints something if at least one of the TM bit is set.
+ * Inside the TM[], the output means:
+ *   E: Enabled		(bit 32)
+ *   S: Suspended	(bit 33)
+ *   T: Transactional	(bit 34)
+ */
+	if (val & (MSR_TM | MSR_TS_S | MSR_TS_T)) {
+		pr_cont(",TM[");
+		print_bits(val, msr_tm_bits, "");
+		pr_cont("]");
+	}
+}
+#else
+static void print_tm_bits(unsigned long val) {}
+#endif
+
+static void print_msr_bits(unsigned long val)
+{
+	pr_cont("<");
+	print_bits(val, msr_bits, ",");
+	print_tm_bits(val);
+	pr_cont(">");
+}
+
+#ifdef CONFIG_PPC64
+#define REG		"%016lx"
+#define REGS_PER_LINE	4
+#else
+#define REG		"%08lx"
+#define REGS_PER_LINE	8
+#endif
+
+static 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: %px TRAP: %04lx   %s  (%s)\n",
+	       regs, regs->trap, print_tainted(), init_utsname()->release);
+	printk("MSR:  "REG" ", regs->msr);
+	print_msr_bits(regs->msr);
+	pr_cont("  CR: %08lx  XER: %08lx\n", regs->ccr, regs->xer);
+	trap = TRAP(regs);
+	if (!trap_is_syscall(regs) && cpu_has_feature(CPU_FTR_CFAR))
+		pr_cont("CFAR: "REG" ", regs->orig_gpr3);
+	if (trap == INTERRUPT_MACHINE_CHECK ||
+	    trap == INTERRUPT_DATA_STORAGE ||
+	    trap == INTERRUPT_ALIGNMENT) {
+		if (IS_ENABLED(CONFIG_4xx) || IS_ENABLED(CONFIG_BOOKE))
+			pr_cont("DEAR: "REG" ESR: "REG" ", regs->dear, regs->esr);
+		else
+			pr_cont("DAR: "REG" DSISR: %08lx ", regs->dar, regs->dsisr);
+	}
+
+#ifdef CONFIG_PPC64
+	pr_cont("IRQMASK: %lx ", regs->softe);
+#endif
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+	if (MSR_TM_ACTIVE(regs->msr))
+		pr_cont("\nPACATMSCRATCH: %016llx ", get_paca()->tm_scratch);
+#endif
+
+	for (i = 0;  i < 32;  i++) {
+		if ((i % REGS_PER_LINE) == 0)
+			pr_cont("\nGPR%02d: ", i);
+		pr_cont(REG " ", regs->gpr[i]);
+	}
+	pr_cont("\n");
+	/*
+	 * Lookup NIP late so we have the best change of getting the
+	 * above info out without failing
+	 */
+	if (IS_ENABLED(CONFIG_KALLSYMS)) {
+		printk("NIP ["REG"] %pS\n", regs->nip, (void *)regs->nip);
+		printk("LR ["REG"] %pS\n", regs->link, (void *)regs->link);
+	}
+}
+
+void show_regs(struct pt_regs *regs)
+{
+	show_regs_print_info(KERN_DEFAULT);
+	__show_regs(regs);
+	show_stack(current, (unsigned long *) regs->gpr[1], KERN_DEFAULT);
+	if (!user_mode(regs))
+		show_instructions(regs);
+}
+
+void flush_thread(void)
+{
+#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 arch_setup_new_exec(void)
+{
+
+#ifdef CONFIG_PPC_BOOK3S_64
+	if (!radix_enabled())
+		hash__setup_new_exec();
+#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;
+	}
+
+#ifdef CONFIG_PPC_MEM_KEYS
+	current->thread.regs->amr  = default_amr;
+	current->thread.regs->iamr  = default_iamr;
+#endif
+}
+
+#ifdef CONFIG_PPC64
+/**
+ * Assign a TIDR (thread ID) for task @t and set it in the thread
+ * structure. For now, we only support setting TIDR for 'current' task.
+ *
+ * Since the TID value is a truncated form of it PID, it is possible
+ * (but unlikely) for 2 threads to have the same TID. In the unlikely event
+ * that 2 threads share the same TID and are waiting, one of the following
+ * cases will happen:
+ *
+ * 1. The correct thread is running, the wrong thread is not
+ * In this situation, the correct thread is woken and proceeds to pass it's
+ * condition check.
+ *
+ * 2. Neither threads are running
+ * In this situation, neither thread will be woken. When scheduled, the waiting
+ * threads will execute either a wait, which will return immediately, followed
+ * by a condition check, which will pass for the correct thread and fail
+ * for the wrong thread, or they will execute the condition check immediately.
+ *
+ * 3. The wrong thread is running, the correct thread is not
+ * The wrong thread will be woken, but will fail it's condition check and
+ * re-execute wait. The correct thread, when scheduled, will execute either
+ * it's condition check (which will pass), or wait, which returns immediately
+ * when called the first time after the thread is scheduled, followed by it's
+ * condition check (which will pass).
+ *
+ * 4. Both threads are running
+ * Both threads will be woken. The wrong thread will fail it's condition check
+ * and execute another wait, while the correct thread will pass it's condition
+ * check.
+ *
+ * @t: the task to set the thread ID for
+ */
+int set_thread_tidr(struct task_struct *t)
+{
+	if (!cpu_has_feature(CPU_FTR_P9_TIDR))
+		return -EINVAL;
+
+	if (t != current)
+		return -EINVAL;
+
+	if (t->thread.tidr)
+		return 0;
+
+	t->thread.tidr = (u16)task_pid_nr(t);
+	mtspr(SPRN_TIDR, t->thread.tidr);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(set_thread_tidr);
+
+#endif /* CONFIG_PPC64 */
+
+/*
+ * 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_all_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.
+	 *
+	 * Can't pass dst because it isn't ready. Doesn't matter, passing
+	 * dst is only important for __switch_to()
+	 */
+	__switch_to_tm(src, src);
+
+	*dst = *src;
+
+	clear_task_ebb(dst);
+
+	return 0;
+}
+
+static void setup_ksp_vsid(struct task_struct *p, unsigned long sp)
+{
+#ifdef CONFIG_PPC_64S_HASH_MMU
+	unsigned long sp_vsid;
+	unsigned long llp = mmu_psize_defs[mmu_linear_psize].sllp;
+
+	if (radix_enabled())
+		return;
+
+	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..
+ */
+
+/*
+ * Copy architecture-specific thread state
+ */
+int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
+{
+	unsigned long clone_flags = args->flags;
+	unsigned long usp = args->stack;
+	unsigned long tls = args->tls;
+	struct pt_regs *childregs, *kregs;
+	extern void ret_from_fork(void);
+	extern void ret_from_fork_scv(void);
+	extern void ret_from_kernel_thread(void);
+	void (*f)(void);
+	unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
+	struct thread_info *ti = task_thread_info(p);
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+	int i;
+#endif
+
+	klp_init_thread_info(p);
+
+	/* Copy registers */
+	sp -= sizeof(struct pt_regs);
+	childregs = (struct pt_regs *) sp;
+	if (unlikely(args->fn)) {
+		/* kernel thread */
+		memset(childregs, 0, sizeof(struct pt_regs));
+		childregs->gpr[1] = sp + sizeof(struct pt_regs);
+		/* function */
+		if (args->fn)
+			childregs->gpr[14] = ppc_function_entry((void *)args->fn);
+#ifdef CONFIG_PPC64
+		clear_tsk_thread_flag(p, TIF_32BIT);
+		childregs->softe = IRQS_ENABLED;
+#endif
+		childregs->gpr[15] = (unsigned long)args->fn_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();
+		*childregs = *regs;
+		if (usp)
+			childregs->gpr[1] = usp;
+		p->thread.regs = childregs;
+		/* 64s sets this in ret_from_fork */
+		if (!IS_ENABLED(CONFIG_PPC_BOOK3S_64))
+			childregs->gpr[3] = 0;  /* Result from fork() */
+		if (clone_flags & CLONE_SETTLS) {
+			if (!is_32bit_task())
+				childregs->gpr[13] = tls;
+			else
+				childregs->gpr[2] = tls;
+		}
+
+		if (trap_is_scv(regs))
+			f = ret_from_fork_scv;
+		else
+			f = ret_from_fork;
+	}
+	childregs->msr &= ~(MSR_FP|MSR_VEC|MSR_VSX);
+	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_HAVE_HW_BREAKPOINT
+	for (i = 0; i < nr_wp_slots(); i++)
+		p->thread.ptrace_bps[i] = NULL;
+#endif
+
+#ifdef CONFIG_PPC_FPU_REGS
+	p->thread.fp_save_area = NULL;
+#endif
+#ifdef CONFIG_ALTIVEC
+	p->thread.vr_save_area = NULL;
+#endif
+#if defined(CONFIG_PPC_BOOK3S_32) && defined(CONFIG_PPC_KUAP)
+	p->thread.kuap = KUAP_NONE;
+#endif
+#if defined(CONFIG_BOOKE_OR_40x) && defined(CONFIG_PPC_KUAP)
+	p->thread.pid = MMU_NO_CONTEXT;
+#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 = mfspr(SPRN_DSCR);
+	}
+	if (cpu_has_feature(CPU_FTR_HAS_PPR))
+		childregs->ppr = DEFAULT_PPR;
+
+	p->thread.tidr = 0;
+#endif
+	/*
+	 * Run with the current AMR value of the kernel
+	 */
+#ifdef CONFIG_PPC_PKEY
+	if (mmu_has_feature(MMU_FTR_BOOK3S_KUAP))
+		kregs->amr = AMR_KUAP_BLOCKED;
+
+	if (mmu_has_feature(MMU_FTR_BOOK3S_KUEP))
+		kregs->iamr = AMR_KUEP_BLOCKED;
+#endif
+	kregs->nip = ppc_function_entry(f);
+	return 0;
+}
+
+void preload_new_slb_context(unsigned long start, unsigned long sp);
+
+/*
+ * 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 */
+
+	if (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && !radix_enabled())
+		preload_new_slb_context(start, sp);
+#endif
+
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+	/*
+	 * Clear any transactional state, we're exec()ing. The cause is
+	 * not important as there will never be a recheckpoint so it's not
+	 * user visible.
+	 */
+	if (MSR_TM_SUSPENDED(mfmsr()))
+		tm_reclaim_current(0);
+#endif
+
+	memset(&regs->gpr[1], 0, sizeof(regs->gpr) - sizeof(regs->gpr[0]));
+	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 (!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_set_return_ip(regs, entry);
+		regs_set_return_msr(regs, MSR_USER64);
+	} else {
+		regs->gpr[2] = 0;
+		regs_set_return_ip(regs, start);
+		regs_set_return_msr(regs, MSR_USER32);
+	}
+
+#endif
+#ifdef CONFIG_VSX
+	current->thread.used_vsr = 0;
+#endif
+	current->thread.load_slb = 0;
+	current->thread.load_fp = 0;
+#ifdef CONFIG_PPC_FPU_REGS
+	memset(&current->thread.fp_state, 0, sizeof(current->thread.fp_state));
+	current->thread.fp_save_area = NULL;
+#endif
+#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;
+	current->thread.load_vec = 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
+	current->thread.tm_tfhar = 0;
+	current->thread.tm_texasr = 0;
+	current->thread.tm_tfiar = 0;
+	current->thread.load_tm = 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) {
+		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.
+			 */
+#ifdef CONFIG_SPE
+			tsk->thread.spefscr_last = mfspr(SPRN_SPEFSCR);
+			tsk->thread.fpexc_mode = val &
+				(PR_FP_EXC_SW_ENABLE | PR_FP_ALL_EXCEPT);
+#endif
+			return 0;
+		} else {
+			return -EINVAL;
+		}
+	}
+
+	/* 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_set_return_msr(regs, (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 = 0;
+
+	if (tsk->thread.fpexc_mode & PR_FP_EXC_SW_ENABLE) {
+		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.
+			 */
+#ifdef CONFIG_SPE
+			tsk->thread.spefscr_last = mfspr(SPRN_SPEFSCR);
+			val = tsk->thread.fpexc_mode;
+#endif
+		} else
+			return -EINVAL;
+	} 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_set_return_msr(regs, regs->msr & ~MSR_LE);
+	else if (val == PR_ENDIAN_LITTLE || val == PR_ENDIAN_PPC_LITTLE)
+		regs_set_return_msr(regs, 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);
+
+	stack_page = (unsigned long)hardirq_ctx[cpu];
+	if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes)
+		return 1;
+
+	stack_page = (unsigned long)softirq_ctx[cpu];
+	if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes)
+		return 1;
+
+	return 0;
+}
+
+static inline int valid_emergency_stack(unsigned long sp, struct task_struct *p,
+					unsigned long nbytes)
+{
+#ifdef CONFIG_PPC64
+	unsigned long stack_page;
+	unsigned long cpu = task_cpu(p);
+
+	if (!paca_ptrs)
+		return 0;
+
+	stack_page = (unsigned long)paca_ptrs[cpu]->emergency_sp - THREAD_SIZE;
+	if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes)
+		return 1;
+
+# ifdef CONFIG_PPC_BOOK3S_64
+	stack_page = (unsigned long)paca_ptrs[cpu]->nmi_emergency_sp - THREAD_SIZE;
+	if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes)
+		return 1;
+
+	stack_page = (unsigned long)paca_ptrs[cpu]->mc_emergency_sp - THREAD_SIZE;
+	if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes)
+		return 1;
+# endif
+#endif
+
+	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 < THREAD_SIZE)
+		return 0;
+
+	if (sp >= stack_page && sp <= stack_page + THREAD_SIZE - nbytes)
+		return 1;
+
+	if (valid_irq_stack(sp, p, nbytes))
+		return 1;
+
+	return valid_emergency_stack(sp, p, nbytes);
+}
+
+EXPORT_SYMBOL(validate_sp);
+
+static unsigned long ___get_wchan(struct task_struct *p)
+{
+	unsigned long ip, sp;
+	int count = 0;
+
+	sp = p->thread.ksp;
+	if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD))
+		return 0;
+
+	do {
+		sp = READ_ONCE_NOCHECK(*(unsigned long *)sp);
+		if (!validate_sp(sp, p, STACK_FRAME_OVERHEAD) ||
+		    task_is_running(p))
+			return 0;
+		if (count > 0) {
+			ip = READ_ONCE_NOCHECK(((unsigned long *)sp)[STACK_FRAME_LR_SAVE]);
+			if (!in_sched_functions(ip))
+				return ip;
+		}
+	} while (count++ < 16);
+	return 0;
+}
+
+unsigned long __get_wchan(struct task_struct *p)
+{
+	unsigned long ret;
+
+	if (!try_get_task_stack(p))
+		return 0;
+
+	ret = ___get_wchan(p);
+
+	put_task_stack(p);
+
+	return ret;
+}
+
+static int kstack_depth_to_print = CONFIG_PRINT_STACK_DEPTH;
+
+void __no_sanitize_address show_stack(struct task_struct *tsk,
+				      unsigned long *stack,
+				      const char *loglvl)
+{
+	unsigned long sp, ip, lr, newsp;
+	int count = 0;
+	int firstframe = 1;
+	unsigned long ret_addr;
+	int ftrace_idx = 0;
+
+	if (tsk == NULL)
+		tsk = current;
+
+	if (!try_get_task_stack(tsk))
+		return;
+
+	sp = (unsigned long) stack;
+	if (sp == 0) {
+		if (tsk == current)
+			sp = current_stack_frame();
+		else
+			sp = tsk->thread.ksp;
+	}
+
+	lr = 0;
+	printk("%sCall Trace:\n", loglvl);
+	do {
+		if (!validate_sp(sp, tsk, STACK_FRAME_OVERHEAD))
+			break;
+
+		stack = (unsigned long *) sp;
+		newsp = stack[0];
+		ip = stack[STACK_FRAME_LR_SAVE];
+		if (!firstframe || ip != lr) {
+			printk("%s["REG"] ["REG"] %pS",
+				loglvl, sp, ip, (void *)ip);
+			ret_addr = ftrace_graph_ret_addr(current,
+						&ftrace_idx, ip, stack);
+			if (ret_addr != ip)
+				pr_cont(" (%pS)", (void *)ret_addr);
+			if (firstframe)
+				pr_cont(" (unreliable)");
+			pr_cont("\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_FRAME_WITH_PT_REGS)
+		    && stack[STACK_FRAME_MARKER] == STACK_FRAME_REGS_MARKER) {
+			struct pt_regs *regs = (struct pt_regs *)
+				(sp + STACK_FRAME_OVERHEAD);
+
+			lr = regs->link;
+			printk("%s--- interrupt: %lx at %pS\n",
+			       loglvl, regs->trap, (void *)regs->nip);
+			__show_regs(regs);
+			printk("%s--- interrupt: %lx\n",
+			       loglvl, regs->trap);
+
+			firstframe = 1;
+		}
+
+		sp = newsp;
+	} while (count++ < kstack_depth_to_print);
+
+	put_task_stack(tsk);
+}
+
+#ifdef CONFIG_PPC64
+/* Called with hard IRQs off */
+void notrace __ppc64_runlatch_on(void)
+{
+	struct thread_info *ti = current_thread_info();
+
+	if (cpu_has_feature(CPU_FTR_ARCH_206)) {
+		/*
+		 * Least significant bit (RUN) is the only writable bit of
+		 * the CTRL register, so we can avoid mfspr. 2.06 is not the
+		 * earliest ISA where this is the case, but it's convenient.
+		 */
+		mtspr(SPRN_CTRLT, CTRL_RUNLATCH);
+	} else {
+		unsigned long ctrl;
+
+		/*
+		 * Some architectures (e.g., Cell) have writable fields other
+		 * than RUN, so do the read-modify-write.
+		 */
+		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();
+
+	ti->local_flags &= ~_TLF_RUNLATCH;
+
+	if (cpu_has_feature(CPU_FTR_ARCH_206)) {
+		mtspr(SPRN_CTRLT, 0);
+	} else {
+		unsigned long ctrl;
+
+		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 -= prandom_u32_max(PAGE_SIZE);
+	return sp & ~0xf;
+}