arch/powerpc/platforms/85xx/smp.c - kernel/quantenna - Git at Google

 /*
  * Author: Andy Fleming <afleming@freescale.com>
  * 	   Kumar Gala <galak@kernel.crashing.org>
  *
  * Copyright 2006-2008, 2011-2012, 2015 Freescale Semiconductor Inc.
  *
  * 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/stddef.h>
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/delay.h>
 #include <linux/of.h>
 #include <linux/kexec.h>
 #include <linux/highmem.h>
 #include <linux/cpu.h>
 #include <linux/fsl/guts.h>

 #include <asm/machdep.h>
 #include <asm/pgtable.h>
 #include <asm/page.h>
 #include <asm/mpic.h>
 #include <asm/cacheflush.h>
 #include <asm/dbell.h>
 #include <asm/code-patching.h>
 #include <asm/cputhreads.h>
 #include <asm/fsl_pm.h>

 #include <sysdev/fsl_soc.h>
 #include <sysdev/mpic.h>
 #include "smp.h"

 struct epapr_spin_table {
 	u32	addr_h;
 	u32	addr_l;
 	u32	r3_h;
 	u32	r3_l;
 	u32	reserved;
 	u32	pir;
 };

 #ifdef CONFIG_HOTPLUG_CPU
 static u64 timebase;
 static int tb_req;
 static int tb_valid;

 static void mpc85xx_give_timebase(void)
 {
 	unsigned long flags;

 	local_irq_save(flags);
 	hard_irq_disable();

 	while (!tb_req)
 		barrier();
 	tb_req = 0;

 	qoriq_pm_ops->freeze_time_base(true);
 #ifdef CONFIG_PPC64
 	/*
 	 * e5500/e6500 have a workaround for erratum A-006958 in place
 	 * that will reread the timebase until TBL is non-zero.
 	 * That would be a bad thing when the timebase is frozen.
 	 *
 	 * Thus, we read it manually, and instead of checking that
 	 * TBL is non-zero, we ensure that TB does not change.  We don't
 	 * do that for the main mftb implementation, because it requires
 	 * a scratch register
 	 */
 	{
 		u64 prev;

 		asm volatile("mfspr %0, %1" : "=r" (timebase) :
 			     "i" (SPRN_TBRL));

 		do {
 			prev = timebase;
 			asm volatile("mfspr %0, %1" : "=r" (timebase) :
 				     "i" (SPRN_TBRL));
 		} while (prev != timebase);
 	}
 #else
 	timebase = get_tb();
 #endif
 	mb();
 	tb_valid = 1;

 	while (tb_valid)
 		barrier();

 	qoriq_pm_ops->freeze_time_base(false);

 	local_irq_restore(flags);
 }

 static void mpc85xx_take_timebase(void)
 {
 	unsigned long flags;

 	local_irq_save(flags);
 	hard_irq_disable();

 	tb_req = 1;
 	while (!tb_valid)
 		barrier();

 	set_tb(timebase >> 32, timebase & 0xffffffff);
 	isync();
 	tb_valid = 0;

 	local_irq_restore(flags);
 }

 static void smp_85xx_mach_cpu_die(void)
 {
 	unsigned int cpu = smp_processor_id();

 	local_irq_disable();
 	hard_irq_disable();
 	/* mask all irqs to prevent cpu wakeup */
 	qoriq_pm_ops->irq_mask(cpu);

 	idle_task_exit();

 	mtspr(SPRN_TCR, 0);
 	mtspr(SPRN_TSR, mfspr(SPRN_TSR));

 	generic_set_cpu_dead(cpu);

 	cur_cpu_spec->cpu_down_flush();

 	qoriq_pm_ops->cpu_die(cpu);

 	while (1)
 		;
 }

 static void qoriq_cpu_kill(unsigned int cpu)
 {
 	int i;

 	for (i = 0; i < 500; i++) {
 		if (is_cpu_dead(cpu)) {
 #ifdef CONFIG_PPC64
 			paca[cpu].cpu_start = 0;
 #endif
 			return;
 		}
 		msleep(20);
 	}
 	pr_err("CPU%d didn't die...\n", cpu);
 }
 #endif

 /*
  * To keep it compatible with old boot program which uses
  * cache-inhibit spin table, we need to flush the cache
  * before accessing spin table to invalidate any staled data.
  * We also need to flush the cache after writing to spin
  * table to push data out.
  */
 static inline void flush_spin_table(void *spin_table)
 {
 	flush_dcache_range((ulong)spin_table,
 		(ulong)spin_table + sizeof(struct epapr_spin_table));
 }

 static inline u32 read_spin_table_addr_l(void *spin_table)
 {
 	flush_dcache_range((ulong)spin_table,
 		(ulong)spin_table + sizeof(struct epapr_spin_table));
 	return in_be32(&((struct epapr_spin_table *)spin_table)->addr_l);
 }

 #ifdef CONFIG_PPC64
 static void wake_hw_thread(void *info)
 {
 	void fsl_secondary_thread_init(void);
 	unsigned long inia;
 	int cpu = *(const int *)info;

 	inia = *(unsigned long *)fsl_secondary_thread_init;
 	book3e_start_thread(cpu_thread_in_core(cpu), inia);
 }
 #endif

 static int smp_85xx_start_cpu(int cpu)
 {
 	int ret = 0;
 	struct device_node *np;
 	const u64 *cpu_rel_addr;
 	unsigned long flags;
 	int ioremappable;
 	int hw_cpu = get_hard_smp_processor_id(cpu);
 	struct epapr_spin_table __iomem *spin_table;

 	np = of_get_cpu_node(cpu, NULL);
 	cpu_rel_addr = of_get_property(np, "cpu-release-addr", NULL);
 	if (!cpu_rel_addr) {
 		pr_err("No cpu-release-addr for cpu %d\n", cpu);
 		return -ENOENT;
 	}

 	/*
 	 * A secondary core could be in a spinloop in the bootpage
 	 * (0xfffff000), somewhere in highmem, or somewhere in lowmem.
 	 * The bootpage and highmem can be accessed via ioremap(), but
 	 * we need to directly access the spinloop if its in lowmem.
 	 */
 	ioremappable = *cpu_rel_addr > virt_to_phys(high_memory);

 	/* Map the spin table */
 	if (ioremappable)
 		spin_table = ioremap_prot(*cpu_rel_addr,
 			sizeof(struct epapr_spin_table), _PAGE_COHERENT);
 	else
 		spin_table = phys_to_virt(*cpu_rel_addr);

 	local_irq_save(flags);
 	hard_irq_disable();

 	if (qoriq_pm_ops)
 		qoriq_pm_ops->cpu_up_prepare(cpu);

 	/* if cpu is not spinning, reset it */
 	if (read_spin_table_addr_l(spin_table) != 1) {
 		/*
 		 * We don't set the BPTR register here since it already points
 		 * to the boot page properly.
 		 */
 		mpic_reset_core(cpu);

 		/*
 		 * wait until core is ready...
 		 * We need to invalidate the stale data, in case the boot
 		 * loader uses a cache-inhibited spin table.
 		 */
 		if (!spin_event_timeout(
 				read_spin_table_addr_l(spin_table) == 1,
 				10000, 100)) {
 			pr_err("timeout waiting for cpu %d to reset\n",
 				hw_cpu);
 			ret = -EAGAIN;
 			goto err;
 		}
 	}

 	flush_spin_table(spin_table);
 	out_be32(&spin_table->pir, hw_cpu);
 #ifdef CONFIG_PPC64
 	out_be64((u64 *)(&spin_table->addr_h),
 		__pa(ppc_function_entry(generic_secondary_smp_init)));
 #else
 	out_be32(&spin_table->addr_l, __pa(__early_start));
 #endif
 	flush_spin_table(spin_table);
 err:
 	local_irq_restore(flags);

 	if (ioremappable)
 		iounmap(spin_table);

 	return ret;
 }

 static int smp_85xx_kick_cpu(int nr)
 {
 	int ret = 0;
 #ifdef CONFIG_PPC64
 	int primary = nr;
 #endif

 	WARN_ON(nr < 0 || nr >= num_possible_cpus());

 	pr_debug("kick CPU #%d\n", nr);

 #ifdef CONFIG_PPC64
 	if (threads_per_core == 2) {
 		if (WARN_ON_ONCE(!cpu_has_feature(CPU_FTR_SMT)))
 			return -ENOENT;

 		booting_thread_hwid = cpu_thread_in_core(nr);
 		primary = cpu_first_thread_sibling(nr);

 		if (qoriq_pm_ops)
 			qoriq_pm_ops->cpu_up_prepare(nr);

 		/*
 		 * If either thread in the core is online, use it to start
 		 * the other.
 		 */
 		if (cpu_online(primary)) {
 			smp_call_function_single(primary,
 					wake_hw_thread, &nr, 1);
 			goto done;
 		} else if (cpu_online(primary + 1)) {
 			smp_call_function_single(primary + 1,
 					wake_hw_thread, &nr, 1);
 			goto done;
 		}

 		/*
 		 * If getting here, it means both threads in the core are
 		 * offline. So start the primary thread, then it will start
 		 * the thread specified in booting_thread_hwid, the one
 		 * corresponding to nr.
 		 */

 	} else if (threads_per_core == 1) {
 		/*
 		 * If one core has only one thread, set booting_thread_hwid to
 		 * an invalid value.
 		 */
 		booting_thread_hwid = INVALID_THREAD_HWID;

 	} else if (threads_per_core > 2) {
 		pr_err("Do not support more than 2 threads per CPU.");
 		return -EINVAL;
 	}

 	ret = smp_85xx_start_cpu(primary);
 	if (ret)
 		return ret;

 done:
 	paca[nr].cpu_start = 1;
 	generic_set_cpu_up(nr);

 	return ret;
 #else
 	ret = smp_85xx_start_cpu(nr);
 	if (ret)
 		return ret;

 	generic_set_cpu_up(nr);

 	return ret;
 #endif
 }

 struct smp_ops_t smp_85xx_ops = {
 	.kick_cpu = smp_85xx_kick_cpu,
 	.cpu_bootable = smp_generic_cpu_bootable,
 #ifdef CONFIG_HOTPLUG_CPU
 	.cpu_disable	= generic_cpu_disable,
 	.cpu_die	= generic_cpu_die,
 #endif
 #if defined(CONFIG_KEXEC) && !defined(CONFIG_PPC64)
 	.give_timebase	= smp_generic_give_timebase,
 	.take_timebase	= smp_generic_take_timebase,
 #endif
 };

 #ifdef CONFIG_KEXEC
 #ifdef CONFIG_PPC32
 atomic_t kexec_down_cpus = ATOMIC_INIT(0);

 void mpc85xx_smp_kexec_cpu_down(int crash_shutdown, int secondary)
 {
 	local_irq_disable();

 	if (secondary) {
 		cur_cpu_spec->cpu_down_flush();
 		atomic_inc(&kexec_down_cpus);
 		/* loop forever */
 		while (1);
 	}
 }

 static void mpc85xx_smp_kexec_down(void *arg)
 {
 	if (ppc_md.kexec_cpu_down)
 		ppc_md.kexec_cpu_down(0,1);
 }
 #else
 void mpc85xx_smp_kexec_cpu_down(int crash_shutdown, int secondary)
 {
 	int cpu = smp_processor_id();
 	int sibling = cpu_last_thread_sibling(cpu);
 	bool notified = false;
 	int disable_cpu;
 	int disable_threadbit = 0;
 	long start = mftb();
 	long now;

 	local_irq_disable();
 	hard_irq_disable();
 	mpic_teardown_this_cpu(secondary);

 	if (cpu == crashing_cpu && cpu_thread_in_core(cpu) != 0) {
 		/*
 		 * We enter the crash kernel on whatever cpu crashed,
 		 * even if it's a secondary thread.  If that's the case,
 		 * disable the corresponding primary thread.
 		 */
 		disable_threadbit = 1;
 		disable_cpu = cpu_first_thread_sibling(cpu);
 	} else if (sibling != crashing_cpu &&
 		   cpu_thread_in_core(cpu) == 0 &&
 		   cpu_thread_in_core(sibling) != 0) {
 		disable_threadbit = 2;
 		disable_cpu = sibling;
 	}

 	if (disable_threadbit) {
 		while (paca[disable_cpu].kexec_state < KEXEC_STATE_REAL_MODE) {
 			barrier();
 			now = mftb();
 			if (!notified && now - start > 1000000) {
 				pr_info("%s/%d: waiting for cpu %d to enter KEXEC_STATE_REAL_MODE (%d)\n",
 					__func__, smp_processor_id(),
 					disable_cpu,
 					paca[disable_cpu].kexec_state);
 				notified = true;
 			}
 		}

 		if (notified) {
 			pr_info("%s: cpu %d done waiting\n",
 				__func__, disable_cpu);
 		}

 		mtspr(SPRN_TENC, disable_threadbit);
 		while (mfspr(SPRN_TENSR) & disable_threadbit)
 			cpu_relax();
 	}
 }
 #endif

 static void mpc85xx_smp_machine_kexec(struct kimage *image)
 {
 #ifdef CONFIG_PPC32
 	int timeout = INT_MAX;
 	int i, num_cpus = num_present_cpus();

 	if (image->type == KEXEC_TYPE_DEFAULT)
 		smp_call_function(mpc85xx_smp_kexec_down, NULL, 0);

 	while ( (atomic_read(&kexec_down_cpus) != (num_cpus - 1)) &&
 		( timeout > 0 ) )
 	{
 		timeout--;
 	}

 	if ( !timeout )
 		printk(KERN_ERR "Unable to bring down secondary cpu(s)");

 	for_each_online_cpu(i)
 	{
 		if ( i == smp_processor_id() ) continue;
 		mpic_reset_core(i);
 	}
 #endif

 	default_machine_kexec(image);
 }
 #endif /* CONFIG_KEXEC */

 static void smp_85xx_basic_setup(int cpu_nr)
 {
 	if (cpu_has_feature(CPU_FTR_DBELL))
 		doorbell_setup_this_cpu();
 }

 static void smp_85xx_setup_cpu(int cpu_nr)
 {
 	mpic_setup_this_cpu();
 	smp_85xx_basic_setup(cpu_nr);
 }

 void __init mpc85xx_smp_init(void)
 {
 	struct device_node *np;


 	np = of_find_node_by_type(NULL, "open-pic");
 	if (np) {
 		smp_85xx_ops.probe = smp_mpic_probe;
 		smp_85xx_ops.setup_cpu = smp_85xx_setup_cpu;
 		smp_85xx_ops.message_pass = smp_mpic_message_pass;
 	} else
 		smp_85xx_ops.setup_cpu = smp_85xx_basic_setup;

 	if (cpu_has_feature(CPU_FTR_DBELL)) {
 		/*
 		 * If left NULL, .message_pass defaults to
 		 * smp_muxed_ipi_message_pass
 		 */
 		smp_85xx_ops.message_pass = NULL;
 		smp_85xx_ops.cause_ipi = doorbell_cause_ipi;
 		smp_85xx_ops.probe = NULL;
 	}

 #ifdef CONFIG_HOTPLUG_CPU
 #ifdef CONFIG_FSL_CORENET_RCPM
 	fsl_rcpm_init();
 #endif

 #ifdef CONFIG_FSL_PMC
 	mpc85xx_setup_pmc();
 #endif
 	if (qoriq_pm_ops) {
 		smp_85xx_ops.give_timebase = mpc85xx_give_timebase;
 		smp_85xx_ops.take_timebase = mpc85xx_take_timebase;
 		ppc_md.cpu_die = smp_85xx_mach_cpu_die;
 		smp_85xx_ops.cpu_die = qoriq_cpu_kill;
 	}
 #endif
 	smp_ops = &smp_85xx_ops;

 #ifdef CONFIG_KEXEC
 	ppc_md.kexec_cpu_down = mpc85xx_smp_kexec_cpu_down;
 	ppc_md.machine_kexec = mpc85xx_smp_machine_kexec;
 #endif
 }
	/*
	* Author: Andy Fleming <afleming@freescale.com>
	* Kumar Gala <galak@kernel.crashing.org>
	*
	* Copyright 2006-2008, 2011-2012, 2015 Freescale Semiconductor Inc.
	*
	* 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/stddef.h>
	#include <linux/kernel.h>
	#include <linux/init.h>
	#include <linux/delay.h>
	#include <linux/of.h>
	#include <linux/kexec.h>
	#include <linux/highmem.h>
	#include <linux/cpu.h>
	#include <linux/fsl/guts.h>

	#include <asm/machdep.h>
	#include <asm/pgtable.h>
	#include <asm/page.h>
	#include <asm/mpic.h>
	#include <asm/cacheflush.h>
	#include <asm/dbell.h>
	#include <asm/code-patching.h>
	#include <asm/cputhreads.h>
	#include <asm/fsl_pm.h>

	#include <sysdev/fsl_soc.h>
	#include <sysdev/mpic.h>
	#include "smp.h"

	struct epapr_spin_table {
	u32 addr_h;
	u32 addr_l;
	u32 r3_h;
	u32 r3_l;
	u32 reserved;
	u32 pir;
	};

	#ifdef CONFIG_HOTPLUG_CPU
	static u64 timebase;
	static int tb_req;
	static int tb_valid;

	static void mpc85xx_give_timebase(void)
	{
	unsigned long flags;

	local_irq_save(flags);
	hard_irq_disable();

	while (!tb_req)
	barrier();
	tb_req = 0;

	qoriq_pm_ops->freeze_time_base(true);
	#ifdef CONFIG_PPC64
	/*
	* e5500/e6500 have a workaround for erratum A-006958 in place
	* that will reread the timebase until TBL is non-zero.
	* That would be a bad thing when the timebase is frozen.
	*
	* Thus, we read it manually, and instead of checking that
	* TBL is non-zero, we ensure that TB does not change. We don't
	* do that for the main mftb implementation, because it requires
	* a scratch register
	*/
	{
	u64 prev;

	asm volatile("mfspr %0, %1" : "=r" (timebase) :
	"i" (SPRN_TBRL));

	do {
	prev = timebase;
	asm volatile("mfspr %0, %1" : "=r" (timebase) :
	"i" (SPRN_TBRL));
	} while (prev != timebase);
	}
	#else
	timebase = get_tb();
	#endif
	mb();
	tb_valid = 1;

	while (tb_valid)
	barrier();

	qoriq_pm_ops->freeze_time_base(false);

	local_irq_restore(flags);
	}

	static void mpc85xx_take_timebase(void)
	{
	unsigned long flags;

	local_irq_save(flags);
	hard_irq_disable();

	tb_req = 1;
	while (!tb_valid)
	barrier();

	set_tb(timebase >> 32, timebase & 0xffffffff);
	isync();
	tb_valid = 0;

	local_irq_restore(flags);
	}

	static void smp_85xx_mach_cpu_die(void)
	{
	unsigned int cpu = smp_processor_id();

	local_irq_disable();
	hard_irq_disable();
	/* mask all irqs to prevent cpu wakeup */
	qoriq_pm_ops->irq_mask(cpu);

	idle_task_exit();

	mtspr(SPRN_TCR, 0);
	mtspr(SPRN_TSR, mfspr(SPRN_TSR));

	generic_set_cpu_dead(cpu);

	cur_cpu_spec->cpu_down_flush();

	qoriq_pm_ops->cpu_die(cpu);

	while (1)
	;
	}

	static void qoriq_cpu_kill(unsigned int cpu)
	{
	int i;

	for (i = 0; i < 500; i++) {
	if (is_cpu_dead(cpu)) {
	#ifdef CONFIG_PPC64
	paca[cpu].cpu_start = 0;
	#endif
	return;
	}
	msleep(20);
	}
	pr_err("CPU%d didn't die...\n", cpu);
	}
	#endif

	/*
	* To keep it compatible with old boot program which uses
	* cache-inhibit spin table, we need to flush the cache
	* before accessing spin table to invalidate any staled data.
	* We also need to flush the cache after writing to spin
	* table to push data out.
	*/
	static inline void flush_spin_table(void *spin_table)
	{
	flush_dcache_range((ulong)spin_table,
	(ulong)spin_table + sizeof(struct epapr_spin_table));
	}

	static inline u32 read_spin_table_addr_l(void *spin_table)
	{
	flush_dcache_range((ulong)spin_table,
	(ulong)spin_table + sizeof(struct epapr_spin_table));
	return in_be32(&((struct epapr_spin_table *)spin_table)->addr_l);
	}

	#ifdef CONFIG_PPC64
	static void wake_hw_thread(void *info)
	{
	void fsl_secondary_thread_init(void);
	unsigned long inia;
	int cpu = (const int )info;

	inia = (unsigned long )fsl_secondary_thread_init;
	book3e_start_thread(cpu_thread_in_core(cpu), inia);
	}
	#endif

	static int smp_85xx_start_cpu(int cpu)
	{
	int ret = 0;
	struct device_node *np;
	const u64 *cpu_rel_addr;
	unsigned long flags;
	int ioremappable;
	int hw_cpu = get_hard_smp_processor_id(cpu);
	struct epapr_spin_table __iomem *spin_table;

	np = of_get_cpu_node(cpu, NULL);
	cpu_rel_addr = of_get_property(np, "cpu-release-addr", NULL);
	if (!cpu_rel_addr) {
	pr_err("No cpu-release-addr for cpu %d\n", cpu);
	return -ENOENT;
	}

	/*
	* A secondary core could be in a spinloop in the bootpage
	* (0xfffff000), somewhere in highmem, or somewhere in lowmem.
	* The bootpage and highmem can be accessed via ioremap(), but
	* we need to directly access the spinloop if its in lowmem.
	*/
	ioremappable = *cpu_rel_addr > virt_to_phys(high_memory);

	/* Map the spin table */
	if (ioremappable)
	spin_table = ioremap_prot(*cpu_rel_addr,
	sizeof(struct epapr_spin_table), _PAGE_COHERENT);
	else
	spin_table = phys_to_virt(*cpu_rel_addr);

	local_irq_save(flags);
	hard_irq_disable();

	if (qoriq_pm_ops)
	qoriq_pm_ops->cpu_up_prepare(cpu);

	/* if cpu is not spinning, reset it */
	if (read_spin_table_addr_l(spin_table) != 1) {
	/*
	* We don't set the BPTR register here since it already points
	* to the boot page properly.
	*/
	mpic_reset_core(cpu);

	/*
	* wait until core is ready...
	* We need to invalidate the stale data, in case the boot
	* loader uses a cache-inhibited spin table.
	*/
	if (!spin_event_timeout(
	read_spin_table_addr_l(spin_table) == 1,
	10000, 100)) {
	pr_err("timeout waiting for cpu %d to reset\n",
	hw_cpu);
	ret = -EAGAIN;
	goto err;
	}
	}

	flush_spin_table(spin_table);
	out_be32(&spin_table->pir, hw_cpu);
	#ifdef CONFIG_PPC64
	out_be64((u64 *)(&spin_table->addr_h),
	__pa(ppc_function_entry(generic_secondary_smp_init)));
	#else
	out_be32(&spin_table->addr_l, __pa(__early_start));
	#endif
	flush_spin_table(spin_table);
	err:
	local_irq_restore(flags);

	if (ioremappable)
	iounmap(spin_table);

	return ret;
	}

	static int smp_85xx_kick_cpu(int nr)
	{
	int ret = 0;
	#ifdef CONFIG_PPC64
	int primary = nr;
	#endif

	WARN_ON(nr < 0 \|\| nr >= num_possible_cpus());

	pr_debug("kick CPU #%d\n", nr);

	#ifdef CONFIG_PPC64
	if (threads_per_core == 2) {
	if (WARN_ON_ONCE(!cpu_has_feature(CPU_FTR_SMT)))
	return -ENOENT;

	booting_thread_hwid = cpu_thread_in_core(nr);
	primary = cpu_first_thread_sibling(nr);

	if (qoriq_pm_ops)
	qoriq_pm_ops->cpu_up_prepare(nr);

	/*
	* If either thread in the core is online, use it to start
	* the other.
	*/
	if (cpu_online(primary)) {
	smp_call_function_single(primary,
	wake_hw_thread, &nr, 1);
	goto done;
	} else if (cpu_online(primary + 1)) {
	smp_call_function_single(primary + 1,
	wake_hw_thread, &nr, 1);
	goto done;
	}

	/*
	* If getting here, it means both threads in the core are
	* offline. So start the primary thread, then it will start
	* the thread specified in booting_thread_hwid, the one
	* corresponding to nr.
	*/

	} else if (threads_per_core == 1) {
	/*
	* If one core has only one thread, set booting_thread_hwid to
	* an invalid value.
	*/
	booting_thread_hwid = INVALID_THREAD_HWID;

	} else if (threads_per_core > 2) {
	pr_err("Do not support more than 2 threads per CPU.");
	return -EINVAL;
	}

	ret = smp_85xx_start_cpu(primary);
	if (ret)
	return ret;

	done:
	paca[nr].cpu_start = 1;
	generic_set_cpu_up(nr);

	return ret;
	#else
	ret = smp_85xx_start_cpu(nr);
	if (ret)
	return ret;

	generic_set_cpu_up(nr);

	return ret;
	#endif
	}

	struct smp_ops_t smp_85xx_ops = {
	.kick_cpu = smp_85xx_kick_cpu,
	.cpu_bootable = smp_generic_cpu_bootable,
	#ifdef CONFIG_HOTPLUG_CPU
	.cpu_disable = generic_cpu_disable,
	.cpu_die = generic_cpu_die,
	#endif
	#if defined(CONFIG_KEXEC) && !defined(CONFIG_PPC64)
	.give_timebase = smp_generic_give_timebase,
	.take_timebase = smp_generic_take_timebase,
	#endif
	};

	#ifdef CONFIG_KEXEC
	#ifdef CONFIG_PPC32
	atomic_t kexec_down_cpus = ATOMIC_INIT(0);

	void mpc85xx_smp_kexec_cpu_down(int crash_shutdown, int secondary)
	{
	local_irq_disable();

	if (secondary) {
	cur_cpu_spec->cpu_down_flush();
	atomic_inc(&kexec_down_cpus);
	/* loop forever */
	while (1);
	}
	}

	static void mpc85xx_smp_kexec_down(void *arg)
	{
	if (ppc_md.kexec_cpu_down)
	ppc_md.kexec_cpu_down(0,1);
	}
	#else
	void mpc85xx_smp_kexec_cpu_down(int crash_shutdown, int secondary)
	{
	int cpu = smp_processor_id();
	int sibling = cpu_last_thread_sibling(cpu);
	bool notified = false;
	int disable_cpu;
	int disable_threadbit = 0;
	long start = mftb();
	long now;

	local_irq_disable();
	hard_irq_disable();
	mpic_teardown_this_cpu(secondary);

	if (cpu == crashing_cpu && cpu_thread_in_core(cpu) != 0) {
	/*
	* We enter the crash kernel on whatever cpu crashed,
	* even if it's a secondary thread. If that's the case,
	* disable the corresponding primary thread.
	*/
	disable_threadbit = 1;
	disable_cpu = cpu_first_thread_sibling(cpu);
	} else if (sibling != crashing_cpu &&
	cpu_thread_in_core(cpu) == 0 &&
	cpu_thread_in_core(sibling) != 0) {
	disable_threadbit = 2;
	disable_cpu = sibling;
	}

	if (disable_threadbit) {
	while (paca[disable_cpu].kexec_state < KEXEC_STATE_REAL_MODE) {
	barrier();
	now = mftb();
	if (!notified && now - start > 1000000) {
	pr_info("%s/%d: waiting for cpu %d to enter KEXEC_STATE_REAL_MODE (%d)\n",
	__func__, smp_processor_id(),
	disable_cpu,
	paca[disable_cpu].kexec_state);
	notified = true;
	}
	}

	if (notified) {
	pr_info("%s: cpu %d done waiting\n",
	__func__, disable_cpu);
	}

	mtspr(SPRN_TENC, disable_threadbit);
	while (mfspr(SPRN_TENSR) & disable_threadbit)
	cpu_relax();
	}
	}
	#endif

	static void mpc85xx_smp_machine_kexec(struct kimage *image)
	{
	#ifdef CONFIG_PPC32
	int timeout = INT_MAX;
	int i, num_cpus = num_present_cpus();

	if (image->type == KEXEC_TYPE_DEFAULT)
	smp_call_function(mpc85xx_smp_kexec_down, NULL, 0);

	while ( (atomic_read(&kexec_down_cpus) != (num_cpus - 1)) &&
	( timeout > 0 ) )
	{
	timeout--;
	}

	if ( !timeout )
	printk(KERN_ERR "Unable to bring down secondary cpu(s)");

	for_each_online_cpu(i)
	{
	if ( i == smp_processor_id() ) continue;
	mpic_reset_core(i);
	}
	#endif

	default_machine_kexec(image);
	}
	#endif /* CONFIG_KEXEC */

	static void smp_85xx_basic_setup(int cpu_nr)
	{
	if (cpu_has_feature(CPU_FTR_DBELL))
	doorbell_setup_this_cpu();
	}

	static void smp_85xx_setup_cpu(int cpu_nr)
	{
	mpic_setup_this_cpu();
	smp_85xx_basic_setup(cpu_nr);
	}

	void __init mpc85xx_smp_init(void)
	{
	struct device_node *np;


	np = of_find_node_by_type(NULL, "open-pic");
	if (np) {
	smp_85xx_ops.probe = smp_mpic_probe;
	smp_85xx_ops.setup_cpu = smp_85xx_setup_cpu;
	smp_85xx_ops.message_pass = smp_mpic_message_pass;
	} else
	smp_85xx_ops.setup_cpu = smp_85xx_basic_setup;

	if (cpu_has_feature(CPU_FTR_DBELL)) {
	/*
	* If left NULL, .message_pass defaults to
	* smp_muxed_ipi_message_pass
	*/
	smp_85xx_ops.message_pass = NULL;
	smp_85xx_ops.cause_ipi = doorbell_cause_ipi;
	smp_85xx_ops.probe = NULL;
	}

	#ifdef CONFIG_HOTPLUG_CPU
	#ifdef CONFIG_FSL_CORENET_RCPM
	fsl_rcpm_init();
	#endif

	#ifdef CONFIG_FSL_PMC
	mpc85xx_setup_pmc();
	#endif
	if (qoriq_pm_ops) {
	smp_85xx_ops.give_timebase = mpc85xx_give_timebase;
	smp_85xx_ops.take_timebase = mpc85xx_take_timebase;
	ppc_md.cpu_die = smp_85xx_mach_cpu_die;
	smp_85xx_ops.cpu_die = qoriq_cpu_kill;
	}
	#endif
	smp_ops = &smp_85xx_ops;

	#ifdef CONFIG_KEXEC
	ppc_md.kexec_cpu_down = mpc85xx_smp_kexec_cpu_down;
	ppc_md.machine_kexec = mpc85xx_smp_machine_kexec;
	#endif
	}