initial_commit

1 files changed, 1338 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
new file mode 100644
index 00000000..91e52df3
--- /dev/null
+++ b/arch/powerpc/kernel/process.c
@@ -0,0 +1,1338 @@
+/*
+ *  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/init.h>
+#include <linux/prctl.h>
+#include <linux/init_task.h>
+#include <linux/module.h>
+#include <linux/kallsyms.h>
+#include <linux/mqueue.h>
+#include <linux/hardirq.h>
+#include <linux/utsname.h>
+#include <linux/ftrace.h>
+#include <linux/kernel_stat.h>
+#include <linux/personality.h>
+#include <linux/random.h>
+#include <linux/hw_breakpoint.h>
+
+#include <asm/pgtable.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <asm/io.h>
+#include <asm/processor.h>
+#include <asm/mmu.h>
+#include <asm/prom.h>
+#include <asm/machdep.h>
+#include <asm/time.h>
+#include <asm/syscalls.h>
+#ifdef CONFIG_PPC64
+#include <asm/firmware.h>
+#endif
+#include <linux/kprobes.h>
+#include <linux/kdebug.h>
+
+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
+
+/*
+ * 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(tsk);
+		}
+		preempt_enable();
+	}
+}
+
+void enable_kernel_fp(void)
+{
+	WARN_ON(preemptible());
+
+#ifdef CONFIG_SMP
+	if (current->thread.regs && (current->thread.regs->msr & MSR_FP))
+		giveup_fpu(current);
+	else
+		giveup_fpu(NULL);	/* just enables FP for kernel */
+#else
+	giveup_fpu(last_task_used_math);
+#endif /* CONFIG_SMP */
+}
+EXPORT_SYMBOL(enable_kernel_fp);
+
+#ifdef CONFIG_ALTIVEC
+void enable_kernel_altivec(void)
+{
+	WARN_ON(preemptible());
+
+#ifdef CONFIG_SMP
+	if (current->thread.regs && (current->thread.regs->msr & MSR_VEC))
+		giveup_altivec(current);
+	else
+		giveup_altivec(NULL);	/* just enable AltiVec for kernel - force */
+#else
+	giveup_altivec(last_task_used_altivec);
+#endif /* CONFIG_SMP */
+}
+EXPORT_SYMBOL(enable_kernel_altivec);
+
+/*
+ * Make sure the VMX/Altivec register state in the
+ * the thread_struct is up to date for task tsk.
+ */
+void flush_altivec_to_thread(struct task_struct *tsk)
+{
+	if (tsk->thread.regs) {
+		preempt_disable();
+		if (tsk->thread.regs->msr & MSR_VEC) {
+#ifdef CONFIG_SMP
+			BUG_ON(tsk != current);
+#endif
+			giveup_altivec(tsk);
+		}
+		preempt_enable();
+	}
+}
+#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(tsk);
+	giveup_altivec(tsk);
+	__giveup_vsx(tsk);
+}
+
+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();
+	}
+}
+#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
+			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;
+
+	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_dabr(struct pt_regs *regs, unsigned long address,
+		    unsigned long error_code)
+{
+	siginfo_t info;
+
+	if (notify_die(DIE_DABR_MATCH, "dabr_match", regs, error_code,
+			11, SIGSEGV) == NOTIFY_STOP)
+		return;
+
+	if (debugger_dabr_match(regs))
+		return;
+
+	/* Clear the DABR */
+	set_dabr(0);
+
+	/* 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(unsigned long, current_dabr);
+
+#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->iac1 = thread->iac2 = 0;
+#if CONFIG_PPC_ADV_DEBUG_IACS > 2
+	thread->iac3 = thread->iac4 = 0;
+#endif
+	thread->dac1 = thread->dac2 = 0;
+#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
+	thread->dvc1 = thread->dvc2 = 0;
+#endif
+	thread->dbcr0 = 0;
+#ifdef CONFIG_BOOKE
+	/*
+	 * Force User/Supervisor bits to b11 (user-only MSR[PR]=1)
+	 */
+	thread->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->dbcr2 = DBCR2_DAC1US | DBCR2_DAC2US;
+#else
+	thread->dbcr1 = 0;
+#endif
+}
+
+static void prime_debug_regs(struct thread_struct *thread)
+{
+	mtspr(SPRN_IAC1, thread->iac1);
+	mtspr(SPRN_IAC2, thread->iac2);
+#if CONFIG_PPC_ADV_DEBUG_IACS > 2
+	mtspr(SPRN_IAC3, thread->iac3);
+	mtspr(SPRN_IAC4, thread->iac4);
+#endif
+	mtspr(SPRN_DAC1, thread->dac1);
+	mtspr(SPRN_DAC2, thread->dac2);
+#if CONFIG_PPC_ADV_DEBUG_DVCS > 0
+	mtspr(SPRN_DVC1, thread->dvc1);
+	mtspr(SPRN_DVC2, thread->dvc2);
+#endif
+	mtspr(SPRN_DBCR0, thread->dbcr0);
+	mtspr(SPRN_DBCR1, thread->dbcr1);
+#ifdef CONFIG_BOOKE
+	mtspr(SPRN_DBCR2, thread->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.
+ */
+static void switch_booke_debug_regs(struct thread_struct *new_thread)
+{
+	if ((current->thread.dbcr0 & DBCR0_IDM)
+		|| (new_thread->dbcr0 & DBCR0_IDM))
+			prime_debug_regs(new_thread);
+}
+#else	/* !CONFIG_PPC_ADV_DEBUG_REGS */
+#ifndef CONFIG_HAVE_HW_BREAKPOINT
+static void set_debug_reg_defaults(struct thread_struct *thread)
+{
+	if (thread->dabr) {
+		thread->dabr = 0;
+		set_dabr(0);
+	}
+}
+#endif /* !CONFIG_HAVE_HW_BREAKPOINT */
+#endif	/* CONFIG_PPC_ADV_DEBUG_REGS */
+
+int set_dabr(unsigned long dabr)
+{
+	__get_cpu_var(current_dabr) = dabr;
+
+	if (ppc_md.set_dabr)
+		return ppc_md.set_dabr(dabr);
+
+	/* XXX should we have a CPU_FTR_HAS_DABR ? */
+#ifdef CONFIG_PPC_ADV_DEBUG_REGS
+	mtspr(SPRN_DAC1, dabr);
+#ifdef CONFIG_PPC_47x
+	isync();
+#endif
+#elif defined(CONFIG_PPC_BOOK3S)
+	mtspr(SPRN_DABR, dabr);
+#endif
+
+
+	return 0;
+}
+
+#ifdef CONFIG_PPC64
+DEFINE_PER_CPU(struct cpu_usage, cpu_usage_array);
+#endif
+
+struct task_struct *__switch_to(struct task_struct *prev,
+	struct task_struct *new)
+{
+	struct thread_struct *new_thread, *old_thread;
+	unsigned long flags;
+	struct task_struct *last;
+#ifdef CONFIG_PPC_BOOK3S_64
+	struct ppc64_tlb_batch *batch;
+#endif
+
+#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);
+#else
+/*
+ * For PPC_BOOK3S_64, we use the hw-breakpoint interfaces that would
+ * schedule DABR
+ */
+#ifndef CONFIG_HAVE_HW_BREAKPOINT
+	if (unlikely(__get_cpu_var(current_dabr) != new->thread.dabr))
+		set_dabr(new->thread.dabr);
+#endif /* CONFIG_HAVE_HW_BREAKPOINT */
+#endif
+
+
+	new_thread = &new->thread;
+	old_thread = &current->thread;
+
+#if defined(CONFIG_PPC_BOOK3E_64)
+	/* XXX Current Book3E code doesn't deal with kernel side DBCR0,
+	 * we always hold the user values, so we set it now.
+	 *
+	 * However, we ensure the kernel MSR:DE is appropriately cleared too
+	 * to avoid spurrious single step exceptions in the kernel.
+	 *
+	 * This will have to change to merge with the ppc32 code at some point,
+	 * but I don't like much what ppc32 is doing today so there's some
+	 * thinking needed there
+	 */
+	if ((new_thread->dbcr0 | old_thread->dbcr0) & DBCR0_IDM) {
+		u32 dbcr0;
+
+		mtmsr(mfmsr() & ~MSR_DE);
+		isync();
+		dbcr0 = mfspr(SPRN_DBCR0);
+		dbcr0 = (dbcr0 & DBCR0_EDM) | new_thread->dbcr0;
+		mtspr(SPRN_DBCR0, dbcr0);
+	}
+#endif /* CONFIG_PPC64_BOOK3E */
+
+#ifdef CONFIG_PPC64
+	/*
+	 * Collect processor utilization data per process
+	 */
+	if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
+		struct cpu_usage *cu = &__get_cpu_var(cpu_usage_array);
+		long unsigned start_tb, current_tb;
+		start_tb = old_thread->start_tb;
+		cu->current_tb = current_tb = mfspr(SPRN_PURR);
+		old_thread->accum_tb += (current_tb - start_tb);
+		new_thread->start_tb = current_tb;
+	}
+#endif /* CONFIG_PPC64 */
+
+#ifdef CONFIG_PPC_BOOK3S_64
+	batch = &__get_cpu_var(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 */
+
+	local_irq_save(flags);
+
+	account_system_vtime(current);
+	account_process_vtime(current);
+
+	/*
+	 * 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();
+	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 = &__get_cpu_var(ppc64_tlb_batch);
+		batch->active = 1;
+	}
+#endif /* CONFIG_PPC_BOOK3S_64 */
+
+	local_irq_restore(flags);
+
+	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
+
+		/* We use __get_user here *only* to avoid an OOPS on a
+		 * bad address because the pc *should* only be a
+		 * kernel address.
+		 */
+		if (!__kernel_text_address(pc) ||
+		     __get_user(instr, (unsigned int __user *)pc)) {
+			printk("XXXXXXXX ");
+		} else {
+			if (regs->nip == pc)
+				printk("<%08x> ", instr);
+			else
+				printk("%08x ", instr);
+		}
+
+		pc += sizeof(int);
+	}
+
+	printk("\n");
+}
+
+static struct regbit {
+	unsigned long bit;
+	const char *name;
+} msr_bits[] = {
+	{MSR_EE,	"EE"},
+	{MSR_PR,	"PR"},
+	{MSR_FP,	"FP"},
+	{MSR_VEC,	"VEC"},
+	{MSR_VSX,	"VSX"},
+	{MSR_ME,	"ME"},
+	{MSR_CE,	"CE"},
+	{MSR_DE,	"DE"},
+	{MSR_IR,	"IR"},
+	{MSR_DR,	"DR"},
+	{0,		NULL}
+};
+
+static void printbits(unsigned long val, struct regbit *bits)
+{
+	const char *sep = "";
+
+	printk("<");
+	for (; bits->bit; ++bits)
+		if (val & bits->bit) {
+			printk("%s%s", sep, bits->name);
+			sep = ",";
+		}
+	printk(">");
+}
+
+#ifdef CONFIG_PPC64
+#define REG		"%016lx"
+#define REGS_PER_LINE	4
+#define LAST_VOLATILE	13
+#else
+#define REG		"%08lx"
+#define REGS_PER_LINE	8
+#define LAST_VOLATILE	12
+#endif
+
+void show_regs(struct pt_regs * regs)
+{
+	int i, trap;
+
+	printk("NIP: "REG" LR: "REG" CTR: "REG"\n",
+	       regs->nip, regs->link, regs->ctr);
+	printk("REGS: %p TRAP: %04lx   %s  (%s)\n",
+	       regs, regs->trap, print_tainted(), 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 (trap == 0x300 || trap == 0x600)
+#ifdef CONFIG_PPC_ADV_DEBUG_REGS
+		printk("DEAR: "REG", ESR: "REG"\n", regs->dar, regs->dsisr);
+#else
+		printk("DAR: "REG", DSISR: %08lx\n", regs->dar, regs->dsisr);
+#endif
+	printk("TASK = %p[%d] '%s' THREAD: %p",
+	       current, task_pid_nr(current), current->comm, task_thread_info(current));
+
+#ifdef CONFIG_SMP
+	printk(" CPU: %d", raw_smp_processor_id());
+#endif /* CONFIG_SMP */
+
+	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 before we allocate a new thread and copy
+ * the current task into it.
+ */
+void prepare_to_copy(struct task_struct *tsk)
+{
+	flush_fp_to_thread(current);
+	flush_altivec_to_thread(current);
+	flush_vsx_to_thread(current);
+	flush_spe_to_thread(current);
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+	flush_ptrace_hw_breakpoint(tsk);
+#endif /* CONFIG_HAVE_HW_BREAKPOINT */
+}
+
+/*
+ * Copy a thread..
+ */
+extern unsigned long dscr_default; /* defined in arch/powerpc/kernel/sysfs.c */
+
+int copy_thread(unsigned long clone_flags, unsigned long usp,
+		unsigned long unused, struct task_struct *p,
+		struct pt_regs *regs)
+{
+	struct pt_regs *childregs, *kregs;
+	extern void ret_from_fork(void);
+	unsigned long sp = (unsigned long)task_stack_page(p) + THREAD_SIZE;
+
+	CHECK_FULL_REGS(regs);
+	/* Copy registers */
+	sp -= sizeof(struct pt_regs);
+	childregs = (struct pt_regs *) sp;
+	*childregs = *regs;
+	if ((childregs->msr & MSR_PR) == 0) {
+		/* for kernel thread, set `current' and stackptr in new task */
+		childregs->gpr[1] = sp + sizeof(struct pt_regs);
+#ifdef CONFIG_PPC32
+		childregs->gpr[2] = (unsigned long) p;
+#else
+		clear_tsk_thread_flag(p, TIF_32BIT);
+#endif
+		p->thread.regs = NULL;	/* no user register state */
+	} else {
+		childregs->gpr[1] = usp;
+		p->thread.regs = childregs;
+		if (clone_flags & CLONE_SETTLS) {
+#ifdef CONFIG_PPC64
+			if (!is_32bit_task())
+				childregs->gpr[13] = childregs->gpr[6];
+			else
+#endif
+				childregs->gpr[2] = childregs->gpr[6];
+		}
+	}
+	childregs->gpr[3] = 0;  /* Result from fork() */
+	sp -= STACK_FRAME_OVERHEAD;
+
+	/*
+	 * The way this works is that at some point in the future
+	 * some task will call _switch to switch to the new task.
+	 * That will pop off the stack frame created below and start
+	 * the new task running at ret_from_fork.  The new task will
+	 * do some house keeping and then return from the fork or clone
+	 * system call, using the stack frame created above.
+	 */
+	sp -= sizeof(struct pt_regs);
+	kregs = (struct pt_regs *) sp;
+	sp -= STACK_FRAME_OVERHEAD;
+	p->thread.ksp = sp;
+	p->thread.ksp_limit = (unsigned long)task_stack_page(p) +
+				_ALIGN_UP(sizeof(struct thread_info), 16);
+
+#ifdef CONFIG_PPC_STD_MMU_64
+	if (mmu_has_feature(MMU_FTR_SLB)) {
+		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 /* CONFIG_PPC_STD_MMU_64 */
+#ifdef CONFIG_PPC64 
+	if (cpu_has_feature(CPU_FTR_DSCR)) {
+		if (current->thread.dscr_inherit) {
+			p->thread.dscr_inherit = 1;
+			p->thread.dscr = current->thread.dscr;
+		} else if (0 != dscr_default) {
+			p->thread.dscr_inherit = 1;
+			p->thread.dscr = dscr_default;
+		} else {
+			p->thread.dscr_inherit = 0;
+			p->thread.dscr = 0;
+		}
+	}
+#endif
+
+	/*
+	 * The PPC64 ABI makes use of a TOC to contain function 
+	 * pointers.  The function (ret_from_except) is actually a pointer
+	 * to the TOC entry.  The first entry is a pointer to the actual
+	 * function.
+ 	 */
+#ifdef CONFIG_PPC64
+	kregs->nip = *((unsigned long *)ret_from_fork);
+#else
+	kregs->nip = (unsigned long)ret_from_fork;
+#endif
+
+	return 0;
+}
+
+/*
+ * Set up a thread for executing a new program
+ */
+void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
+{
+#ifdef CONFIG_PPC64
+	unsigned long load_addr = regs->gpr[2];	/* saved by ELF_PLAT_INIT */
+#endif
+
+	set_fs(USER_DS);
+
+	/*
+	 * If we exec out of a kernel thread then thread.regs will not be
+	 * set.  Do it now.
+	 */
+	if (!current->thread.regs) {
+		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, toc;
+
+		/* start is a relocated pointer to the function descriptor for
+		 * the elf _start routine.  The first entry in the function
+		 * descriptor is the entry address of _start and the second
+		 * entry is the TOC value we need to use.
+		 */
+		__get_user(entry, (unsigned long __user *)start);
+		__get_user(toc, (unsigned long __user *)start+1);
+
+		/* Check whether the e_entry function descriptor entries
+		 * need to be relocated before we can use them.
+		 */
+		if (load_addr != 0) {
+			entry += load_addr;
+			toc   += load_addr;
+		}
+		regs->nip = entry;
+		regs->gpr[2] = toc;
+		regs->msr = MSR_USER64;
+	} else {
+		regs->nip = start;
+		regs->gpr[2] = 0;
+		regs->msr = MSR_USER32;
+	}
+#endif
+
+	discard_lazy_cpu_state();
+#ifdef CONFIG_VSX
+	current->thread.used_vsr = 0;
+#endif
+	memset(current->thread.fpr, 0, sizeof(current->thread.fpr));
+	current->thread.fpscr.val = 0;
+#ifdef CONFIG_ALTIVEC
+	memset(current->thread.vr, 0, sizeof(current->thread.vr));
+	memset(&current->thread.vscr, 0, sizeof(current->thread.vscr));
+	current->thread.vscr.u[3] = 0x00010000; /* Java mode disabled */
+	current->thread.vrsave = 0;
+	current->thread.used_vr = 0;
+#endif /* CONFIG_ALTIVEC */
+#ifdef CONFIG_SPE
+	memset(current->thread.evr, 0, sizeof(current->thread.evr));
+	current->thread.acc = 0;
+	current->thread.spefscr = 0;
+	current->thread.used_spe = 0;
+#endif /* CONFIG_SPE */
+}
+
+#define PR_FP_ALL_EXCEPT (PR_FP_EXC_DIV | PR_FP_EXC_OVF | PR_FP_EXC_UND \
+		| PR_FP_EXC_RES | PR_FP_EXC_INV)
+
+int set_fpexc_mode(struct task_struct *tsk, unsigned int val)
+{
+	struct pt_regs *regs = tsk->thread.regs;
+
+	/* This is a bit hairy.  If we are an SPE enabled  processor
+	 * (have embedded fp) we store the IEEE exception enable flags in
+	 * fpexc_mode.  fpexc_mode is also used for setting FP exception
+	 * mode (asyn, precise, disabled) for 'Classic' FP. */
+	if (val & PR_FP_EXC_SW_ENABLE) {
+#ifdef CONFIG_SPE
+		if (cpu_has_feature(CPU_FTR_SPE)) {
+			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))
+			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);
+}
+
+#define TRUNC_PTR(x)	((typeof(x))(((unsigned long)(x)) & 0xffffffff))
+
+int sys_clone(unsigned long clone_flags, unsigned long usp,
+	      int __user *parent_tidp, void __user *child_threadptr,
+	      int __user *child_tidp, int p6,
+	      struct pt_regs *regs)
+{
+	CHECK_FULL_REGS(regs);
+	if (usp == 0)
+		usp = regs->gpr[1];	/* stack pointer for child */
+#ifdef CONFIG_PPC64
+	if (is_32bit_task()) {
+		parent_tidp = TRUNC_PTR(parent_tidp);
+		child_tidp = TRUNC_PTR(child_tidp);
+	}
+#endif
+ 	return do_fork(clone_flags, usp, regs, 0, parent_tidp, child_tidp);
+}
+
+int sys_fork(unsigned long p1, unsigned long p2, unsigned long p3,
+	     unsigned long p4, unsigned long p5, unsigned long p6,
+	     struct pt_regs *regs)
+{
+	CHECK_FULL_REGS(regs);
+	return do_fork(SIGCHLD, regs->gpr[1], regs, 0, NULL, NULL);
+}
+
+int sys_vfork(unsigned long p1, unsigned long p2, unsigned long p3,
+	      unsigned long p4, unsigned long p5, unsigned long p6,
+	      struct pt_regs *regs)
+{
+	CHECK_FULL_REGS(regs);
+	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gpr[1],
+			regs, 0, NULL, NULL);
+}
+
+int sys_execve(unsigned long a0, unsigned long a1, unsigned long a2,
+	       unsigned long a3, unsigned long a4, unsigned long a5,
+	       struct pt_regs *regs)
+{
+	int error;
+	char *filename;
+
+	filename = getname((const char __user *) a0);
+	error = PTR_ERR(filename);
+	if (IS_ERR(filename))
+		goto out;
+	flush_fp_to_thread(current);
+	flush_altivec_to_thread(current);
+	flush_spe_to_thread(current);
+	error = do_execve(filename,
+			  (const char __user *const __user *) a1,
+			  (const char __user *const __user *) a2, regs);
+	putname(filename);
+out:
+	return error;
+}
+
+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;
+	unsigned long mrth = -1;
+#ifdef CONFIG_PPC64
+	extern void mod_return_to_handler(void);
+	rth = *(unsigned long *)rth;
+	mrth = (unsigned long)mod_return_to_handler;
+	mrth = *(unsigned long *)mrth;
+#endif
+#endif
+
+	sp = (unsigned long) stack;
+	if (tsk == NULL)
+		tsk = current;
+	if (sp == 0) {
+		if (tsk == current)
+			asm("mr %0,1" : "=r" (sp));
+		else
+			sp = tsk->thread.ksp;
+	}
+
+	lr = 0;
+	printk("Call Trace:\n");
+	do {
+		if (!validate_sp(sp, tsk, 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 || ip == mrth) && 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("--- Exception: %lx at %pS\n    LR = %pS\n",
+			       regs->trap, (void *)regs->nip, (void *)lr);
+			firstframe = 1;
+		}
+
+		sp = newsp;
+	} while (count++ < kstack_depth_to_print);
+}
+
+void dump_stack(void)
+{
+	show_stack(current, NULL);
+}
+EXPORT_SYMBOL(dump_stack);
+
+#ifdef CONFIG_PPC64
+void ppc64_runlatch_on(void)
+{
+	unsigned long ctrl;
+
+	if (cpu_has_feature(CPU_FTR_CTRL) && !test_thread_flag(TIF_RUNLATCH)) {
+		HMT_medium();
+
+		ctrl = mfspr(SPRN_CTRLF);
+		ctrl |= CTRL_RUNLATCH;
+		mtspr(SPRN_CTRLT, ctrl);
+
+		set_thread_flag(TIF_RUNLATCH);
+	}
+}
+
+void __ppc64_runlatch_off(void)
+{
+	unsigned long ctrl;
+
+	HMT_medium();
+
+	clear_thread_flag(TIF_RUNLATCH);
+
+	ctrl = mfspr(SPRN_CTRLF);
+	ctrl &= ~CTRL_RUNLATCH;
+	mtspr(SPRN_CTRLT, ctrl);
+}
+#endif
+
+#if THREAD_SHIFT < PAGE_SHIFT
+
+static struct kmem_cache *thread_info_cache;
+
+struct thread_info *alloc_thread_info_node(struct task_struct *tsk, int node)
+{
+	struct thread_info *ti;
+
+	ti = kmem_cache_alloc_node(thread_info_cache, GFP_KERNEL, node);
+	if (unlikely(ti == NULL))
+		return NULL;
+#ifdef CONFIG_DEBUG_STACK_USAGE
+	memset(ti, 0, THREAD_SIZE);
+#endif
+	return ti;
+}
+
+void free_thread_info(struct thread_info *ti)
+{
+	kmem_cache_free(thread_info_cache, ti);
+}
+
+void thread_info_cache_init(void)
+{
+	thread_info_cache = kmem_cache_create("thread_info", THREAD_SIZE,
+					      THREAD_SIZE, 0, NULL);
+	BUG_ON(thread_info_cache == NULL);
+}
+
+#endif /* THREAD_SHIFT < PAGE_SHIFT */
+
+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;
+}
+
+unsigned long randomize_et_dyn(unsigned long base)
+{
+	unsigned long ret = PAGE_ALIGN(base + brk_rnd());
+
+	if (ret < base)
+		return base;
+
+	return ret;
+}