arch/arm/mach-exynos/mcpm-exynos.c - kernel/bruno - Git at Google

 /*
  * Copyright (c) 2014 Samsung Electronics Co., Ltd.
  *		http://www.samsung.com
  *
  * arch/arm/mach-exynos/mcpm-exynos.c
  *
  * Based on arch/arm/mach-vexpress/dcscb.c
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  */

 #include <linux/arm-cci.h>
 #include <linux/delay.h>
 #include <linux/io.h>
 #include <linux/of_address.h>
 #include <linux/syscore_ops.h>

 #include <asm/cputype.h>
 #include <asm/cp15.h>
 #include <asm/mcpm.h>

 #include "regs-pmu.h"
 #include "common.h"

 #define EXYNOS5420_CPUS_PER_CLUSTER	4
 #define EXYNOS5420_NR_CLUSTERS		2

 #define EXYNOS5420_ENABLE_AUTOMATIC_CORE_DOWN	BIT(9)
 #define EXYNOS5420_USE_ARM_CORE_DOWN_STATE	BIT(29)
 #define EXYNOS5420_USE_L2_COMMON_UP_STATE	BIT(30)

 static void __iomem *ns_sram_base_addr;

 /*
  * The common v7_exit_coherency_flush API could not be used because of the
  * Erratum 799270 workaround. This macro is the same as the common one (in
  * arch/arm/include/asm/cacheflush.h) except for the erratum handling.
  */
 #define exynos_v7_exit_coherency_flush(level) \
 	asm volatile( \
 	"stmfd	sp!, {fp, ip}\n\t"\
 	"mrc	p15, 0, r0, c1, c0, 0	@ get SCTLR\n\t" \
 	"bic	r0, r0, #"__stringify(CR_C)"\n\t" \
 	"mcr	p15, 0, r0, c1, c0, 0	@ set SCTLR\n\t" \
 	"isb\n\t"\
 	"bl	v7_flush_dcache_"__stringify(level)"\n\t" \
 	"mrc	p15, 0, r0, c1, c0, 1	@ get ACTLR\n\t" \
 	"bic	r0, r0, #(1 << 6)	@ disable local coherency\n\t" \
 	/* Dummy Load of a device register to avoid Erratum 799270 */ \
 	"ldr	r4, [%0]\n\t" \
 	"and	r4, r4, #0\n\t" \
 	"orr	r0, r0, r4\n\t" \
 	"mcr	p15, 0, r0, c1, c0, 1	@ set ACTLR\n\t" \
 	"isb\n\t" \
 	"dsb\n\t" \
 	"ldmfd	sp!, {fp, ip}" \
 	: \
 	: "Ir" (pmu_base_addr + S5P_INFORM0) \
 	: "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", \
 	  "r9", "r10", "lr", "memory")

 /*
  * We can't use regular spinlocks. In the switcher case, it is possible
  * for an outbound CPU to call power_down() after its inbound counterpart
  * is already live using the same logical CPU number which trips lockdep
  * debugging.
  */
 static arch_spinlock_t exynos_mcpm_lock = __ARCH_SPIN_LOCK_UNLOCKED;
 static int
 cpu_use_count[EXYNOS5420_CPUS_PER_CLUSTER][EXYNOS5420_NR_CLUSTERS];

 #define exynos_cluster_usecnt(cluster) \
 	(cpu_use_count[0][cluster] +   \
 	 cpu_use_count[1][cluster] +   \
 	 cpu_use_count[2][cluster] +   \
 	 cpu_use_count[3][cluster])

 #define exynos_cluster_unused(cluster) !exynos_cluster_usecnt(cluster)

 static int exynos_power_up(unsigned int cpu, unsigned int cluster)
 {
 	unsigned int cpunr = cpu + (cluster * EXYNOS5420_CPUS_PER_CLUSTER);

 	pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
 	if (cpu >= EXYNOS5420_CPUS_PER_CLUSTER ||
 		cluster >= EXYNOS5420_NR_CLUSTERS)
 		return -EINVAL;

 	/*
 	 * Since this is called with IRQs enabled, and no arch_spin_lock_irq
 	 * variant exists, we need to disable IRQs manually here.
 	 */
 	local_irq_disable();
 	arch_spin_lock(&exynos_mcpm_lock);

 	cpu_use_count[cpu][cluster]++;
 	if (cpu_use_count[cpu][cluster] == 1) {
 		bool was_cluster_down =
 			(exynos_cluster_usecnt(cluster) == 1);

 		/*
 		 * Turn on the cluster (L2/COMMON) and then power on the
 		 * cores.
 		 */
 		if (was_cluster_down)
 			exynos_cluster_power_up(cluster);

 		exynos_cpu_power_up(cpunr);
 	} else if (cpu_use_count[cpu][cluster] != 2) {
 		/*
 		 * The only possible values are:
 		 * 0 = CPU down
 		 * 1 = CPU (still) up
 		 * 2 = CPU requested to be up before it had a chance
 		 *     to actually make itself down.
 		 * Any other value is a bug.
 		 */
 		BUG();
 	}

 	arch_spin_unlock(&exynos_mcpm_lock);
 	local_irq_enable();

 	return 0;
 }

 /*
  * NOTE: This function requires the stack data to be visible through power down
  * and can only be executed on processors like A15 and A7 that hit the cache
  * with the C bit clear in the SCTLR register.
  */
 static void exynos_power_down(void)
 {
 	unsigned int mpidr, cpu, cluster;
 	bool last_man = false, skip_wfi = false;
 	unsigned int cpunr;

 	mpidr = read_cpuid_mpidr();
 	cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
 	cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
 	cpunr =  cpu + (cluster * EXYNOS5420_CPUS_PER_CLUSTER);

 	pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
 	BUG_ON(cpu >= EXYNOS5420_CPUS_PER_CLUSTER ||
 			cluster >= EXYNOS5420_NR_CLUSTERS);

 	__mcpm_cpu_going_down(cpu, cluster);

 	arch_spin_lock(&exynos_mcpm_lock);
 	BUG_ON(__mcpm_cluster_state(cluster) != CLUSTER_UP);
 	cpu_use_count[cpu][cluster]--;
 	if (cpu_use_count[cpu][cluster] == 0) {
 		exynos_cpu_power_down(cpunr);

 		if (exynos_cluster_unused(cluster)) {
 			exynos_cluster_power_down(cluster);
 			last_man = true;
 		}
 	} else if (cpu_use_count[cpu][cluster] == 1) {
 		/*
 		 * A power_up request went ahead of us.
 		 * Even if we do not want to shut this CPU down,
 		 * the caller expects a certain state as if the WFI
 		 * was aborted.  So let's continue with cache cleaning.
 		 */
 		skip_wfi = true;
 	} else {
 		BUG();
 	}

 	if (last_man && __mcpm_outbound_enter_critical(cpu, cluster)) {
 		arch_spin_unlock(&exynos_mcpm_lock);

 		if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A15) {
 			/*
 			 * On the Cortex-A15 we need to disable
 			 * L2 prefetching before flushing the cache.
 			 */
 			asm volatile(
 			"mcr	p15, 1, %0, c15, c0, 3\n\t"
 			"isb\n\t"
 			"dsb"
 			: : "r" (0x400));
 		}

 		/* Flush all cache levels for this cluster. */
 		exynos_v7_exit_coherency_flush(all);

 		/*
 		 * Disable cluster-level coherency by masking
 		 * incoming snoops and DVM messages:
 		 */
 		cci_disable_port_by_cpu(mpidr);

 		__mcpm_outbound_leave_critical(cluster, CLUSTER_DOWN);
 	} else {
 		arch_spin_unlock(&exynos_mcpm_lock);

 		/* Disable and flush the local CPU cache. */
 		exynos_v7_exit_coherency_flush(louis);
 	}

 	__mcpm_cpu_down(cpu, cluster);

 	/* Now we are prepared for power-down, do it: */
 	if (!skip_wfi)
 		wfi();

 	/* Not dead at this point?  Let our caller cope. */
 }

 static int exynos_wait_for_powerdown(unsigned int cpu, unsigned int cluster)
 {
 	unsigned int tries = 100;
 	unsigned int cpunr = cpu + (cluster * EXYNOS5420_CPUS_PER_CLUSTER);

 	pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
 	BUG_ON(cpu >= EXYNOS5420_CPUS_PER_CLUSTER ||
 			cluster >= EXYNOS5420_NR_CLUSTERS);

 	/* Wait for the core state to be OFF */
 	while (tries--) {
 		if (ACCESS_ONCE(cpu_use_count[cpu][cluster]) == 0) {
 			if ((exynos_cpu_power_state(cpunr) == 0))
 				return 0; /* success: the CPU is halted */
 		}

 		/* Otherwise, wait and retry: */
 		msleep(1);
 	}

 	return -ETIMEDOUT; /* timeout */
 }

 static void exynos_powered_up(void)
 {
 	unsigned int mpidr, cpu, cluster;

 	mpidr = read_cpuid_mpidr();
 	cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
 	cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);

 	arch_spin_lock(&exynos_mcpm_lock);
 	if (cpu_use_count[cpu][cluster] == 0)
 		cpu_use_count[cpu][cluster] = 1;
 	arch_spin_unlock(&exynos_mcpm_lock);
 }

 static void exynos_suspend(u64 residency)
 {
 	unsigned int mpidr, cpunr;

 	exynos_power_down();

 	/*
 	 * Execution reaches here only if cpu did not power down.
 	 * Hence roll back the changes done in exynos_power_down function.
 	 *
 	 * CAUTION: "This function requires the stack data to be visible through
 	 * power down and can only be executed on processors like A15 and A7
 	 * that hit the cache with the C bit clear in the SCTLR register."
 	*/
 	mpidr = read_cpuid_mpidr();
 	cpunr = exynos_pmu_cpunr(mpidr);

 	exynos_cpu_power_up(cpunr);
 }

 static const struct mcpm_platform_ops exynos_power_ops = {
 	.power_up		= exynos_power_up,
 	.power_down		= exynos_power_down,
 	.wait_for_powerdown	= exynos_wait_for_powerdown,
 	.suspend		= exynos_suspend,
 	.powered_up		= exynos_powered_up,
 };

 static void __init exynos_mcpm_usage_count_init(void)
 {
 	unsigned int mpidr, cpu, cluster;

 	mpidr = read_cpuid_mpidr();
 	cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
 	cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);

 	pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
 	BUG_ON(cpu >= EXYNOS5420_CPUS_PER_CLUSTER  ||
 			cluster >= EXYNOS5420_NR_CLUSTERS);

 	cpu_use_count[cpu][cluster] = 1;
 }

 /*
  * Enable cluster-level coherency, in preparation for turning on the MMU.
  */
 static void __naked exynos_pm_power_up_setup(unsigned int affinity_level)
 {
 	asm volatile ("\n"
 	"cmp	r0, #1\n"
 	"bxne	lr\n"
 	"b	cci_enable_port_for_self");
 }

 static void __init exynos_cache_off(void)
 {
 	if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A15) {
 		/* disable L2 prefetching on the Cortex-A15 */
 		asm volatile(
 		"mcr	p15, 1, %0, c15, c0, 3\n\t"
 		"isb\n\t"
 		"dsb"
 		: : "r" (0x400));
 	}
 	exynos_v7_exit_coherency_flush(all);
 }

 static const struct of_device_id exynos_dt_mcpm_match[] = {
 	{ .compatible = "samsung,exynos5420" },
 	{ .compatible = "samsung,exynos5800" },
 	{},
 };

 static void exynos_mcpm_setup_entry_point(void)
 {
 	/*
 	 * U-Boot SPL is hardcoded to jump to the start of ns_sram_base_addr
 	 * as part of secondary_cpu_start().  Let's redirect it to the
 	 * mcpm_entry_point(). This is done during both secondary boot-up as
 	 * well as system resume.
 	 */
 	__raw_writel(0xe59f0000, ns_sram_base_addr);     /* ldr r0, [pc, #0] */
 	__raw_writel(0xe12fff10, ns_sram_base_addr + 4); /* bx  r0 */
 	__raw_writel(virt_to_phys(mcpm_entry_point), ns_sram_base_addr + 8);
 }

 static struct syscore_ops exynos_mcpm_syscore_ops = {
 	.resume	= exynos_mcpm_setup_entry_point,
 };

 static int __init exynos_mcpm_init(void)
 {
 	struct device_node *node;
 	unsigned int value, i;
 	int ret;

 	node = of_find_matching_node(NULL, exynos_dt_mcpm_match);
 	if (!node)
 		return -ENODEV;
 	of_node_put(node);

 	if (!cci_probed())
 		return -ENODEV;

 	node = of_find_compatible_node(NULL, NULL,
 			"samsung,exynos4210-sysram-ns");
 	if (!node)
 		return -ENODEV;

 	ns_sram_base_addr = of_iomap(node, 0);
 	of_node_put(node);
 	if (!ns_sram_base_addr) {
 		pr_err("failed to map non-secure iRAM base address\n");
 		return -ENOMEM;
 	}

 	/*
 	 * To increase the stability of KFC reset we need to program
 	 * the PMU SPARE3 register
 	 */
 	pmu_raw_writel(EXYNOS5420_SWRESET_KFC_SEL, S5P_PMU_SPARE3);

 	exynos_mcpm_usage_count_init();

 	ret = mcpm_platform_register(&exynos_power_ops);
 	if (!ret)
 		ret = mcpm_sync_init(exynos_pm_power_up_setup);
 	if (!ret)
 		ret = mcpm_loopback(exynos_cache_off); /* turn on the CCI */
 	if (ret) {
 		iounmap(ns_sram_base_addr);
 		return ret;
 	}

 	mcpm_smp_set_ops();

 	pr_info("Exynos MCPM support installed\n");

 	/*
 	 * On Exynos5420/5800 for the A15 and A7 clusters:
 	 *
 	 * EXYNOS5420_ENABLE_AUTOMATIC_CORE_DOWN ensures that all the cores
 	 * in a cluster are turned off before turning off the cluster L2.
 	 *
 	 * EXYNOS5420_USE_ARM_CORE_DOWN_STATE ensures that a cores is powered
 	 * off before waking it up.
 	 *
 	 * EXYNOS5420_USE_L2_COMMON_UP_STATE ensures that cluster L2 will be
 	 * turned on before the first man is powered up.
 	 */
 	for (i = 0; i < EXYNOS5420_NR_CLUSTERS; i++) {
 		value = pmu_raw_readl(EXYNOS_COMMON_OPTION(i));
 		value |= EXYNOS5420_ENABLE_AUTOMATIC_CORE_DOWN |
 			 EXYNOS5420_USE_ARM_CORE_DOWN_STATE    |
 			 EXYNOS5420_USE_L2_COMMON_UP_STATE;
 		pmu_raw_writel(value, EXYNOS_COMMON_OPTION(i));
 	}

 	exynos_mcpm_setup_entry_point();

 	register_syscore_ops(&exynos_mcpm_syscore_ops);

 	return ret;
 }

 early_initcall(exynos_mcpm_init);
	/*
	* Copyright (c) 2014 Samsung Electronics Co., Ltd.
	* http://www.samsung.com
	*
	* arch/arm/mach-exynos/mcpm-exynos.c
	*
	* Based on arch/arm/mach-vexpress/dcscb.c
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*/

	#include <linux/arm-cci.h>
	#include <linux/delay.h>
	#include <linux/io.h>
	#include <linux/of_address.h>
	#include <linux/syscore_ops.h>

	#include <asm/cputype.h>
	#include <asm/cp15.h>
	#include <asm/mcpm.h>

	#include "regs-pmu.h"
	#include "common.h"

	#define EXYNOS5420_CPUS_PER_CLUSTER 4
	#define EXYNOS5420_NR_CLUSTERS 2

	#define EXYNOS5420_ENABLE_AUTOMATIC_CORE_DOWN BIT(9)
	#define EXYNOS5420_USE_ARM_CORE_DOWN_STATE BIT(29)
	#define EXYNOS5420_USE_L2_COMMON_UP_STATE BIT(30)

	static void __iomem *ns_sram_base_addr;

	/*
	* The common v7_exit_coherency_flush API could not be used because of the
	* Erratum 799270 workaround. This macro is the same as the common one (in
	* arch/arm/include/asm/cacheflush.h) except for the erratum handling.
	*/
	#define exynos_v7_exit_coherency_flush(level) \
	asm volatile( \
	"stmfd sp!, {fp, ip}\n\t"\
	"mrc p15, 0, r0, c1, c0, 0 @ get SCTLR\n\t" \
	"bic r0, r0, #"__stringify(CR_C)"\n\t" \
	"mcr p15, 0, r0, c1, c0, 0 @ set SCTLR\n\t" \
	"isb\n\t"\
	"bl v7_flush_dcache_"__stringify(level)"\n\t" \
	"mrc p15, 0, r0, c1, c0, 1 @ get ACTLR\n\t" \
	"bic r0, r0, #(1 << 6) @ disable local coherency\n\t" \
	/* Dummy Load of a device register to avoid Erratum 799270 */ \
	"ldr r4, [%0]\n\t" \
	"and r4, r4, #0\n\t" \
	"orr r0, r0, r4\n\t" \
	"mcr p15, 0, r0, c1, c0, 1 @ set ACTLR\n\t" \
	"isb\n\t" \
	"dsb\n\t" \
	"ldmfd sp!, {fp, ip}" \
	: \
	: "Ir" (pmu_base_addr + S5P_INFORM0) \
	: "r0", "r1", "r2", "r3", "r4", "r5", "r6", "r7", \
	"r9", "r10", "lr", "memory")

	/*
	* We can't use regular spinlocks. In the switcher case, it is possible
	* for an outbound CPU to call power_down() after its inbound counterpart
	* is already live using the same logical CPU number which trips lockdep
	* debugging.
	*/
	static arch_spinlock_t exynos_mcpm_lock = __ARCH_SPIN_LOCK_UNLOCKED;
	static int
	cpu_use_count[EXYNOS5420_CPUS_PER_CLUSTER][EXYNOS5420_NR_CLUSTERS];

	#define exynos_cluster_usecnt(cluster) \
	(cpu_use_count[0][cluster] + \
	cpu_use_count[1][cluster] + \
	cpu_use_count[2][cluster] + \
	cpu_use_count[3][cluster])

	#define exynos_cluster_unused(cluster) !exynos_cluster_usecnt(cluster)

	static int exynos_power_up(unsigned int cpu, unsigned int cluster)
	{
	unsigned int cpunr = cpu + (cluster * EXYNOS5420_CPUS_PER_CLUSTER);

	pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
	if (cpu >= EXYNOS5420_CPUS_PER_CLUSTER \|\|
	cluster >= EXYNOS5420_NR_CLUSTERS)
	return -EINVAL;

	/*
	* Since this is called with IRQs enabled, and no arch_spin_lock_irq
	* variant exists, we need to disable IRQs manually here.
	*/
	local_irq_disable();
	arch_spin_lock(&exynos_mcpm_lock);

	cpu_use_count[cpu][cluster]++;
	if (cpu_use_count[cpu][cluster] == 1) {
	bool was_cluster_down =
	(exynos_cluster_usecnt(cluster) == 1);

	/*
	* Turn on the cluster (L2/COMMON) and then power on the
	* cores.
	*/
	if (was_cluster_down)
	exynos_cluster_power_up(cluster);

	exynos_cpu_power_up(cpunr);
	} else if (cpu_use_count[cpu][cluster] != 2) {
	/*
	* The only possible values are:
	* 0 = CPU down
	* 1 = CPU (still) up
	* 2 = CPU requested to be up before it had a chance
	* to actually make itself down.
	* Any other value is a bug.
	*/
	BUG();
	}

	arch_spin_unlock(&exynos_mcpm_lock);
	local_irq_enable();

	return 0;
	}

	/*
	* NOTE: This function requires the stack data to be visible through power down
	* and can only be executed on processors like A15 and A7 that hit the cache
	* with the C bit clear in the SCTLR register.
	*/
	static void exynos_power_down(void)
	{
	unsigned int mpidr, cpu, cluster;
	bool last_man = false, skip_wfi = false;
	unsigned int cpunr;

	mpidr = read_cpuid_mpidr();
	cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
	cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
	cpunr = cpu + (cluster * EXYNOS5420_CPUS_PER_CLUSTER);

	pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
	BUG_ON(cpu >= EXYNOS5420_CPUS_PER_CLUSTER \|\|
	cluster >= EXYNOS5420_NR_CLUSTERS);

	__mcpm_cpu_going_down(cpu, cluster);

	arch_spin_lock(&exynos_mcpm_lock);
	BUG_ON(__mcpm_cluster_state(cluster) != CLUSTER_UP);
	cpu_use_count[cpu][cluster]--;
	if (cpu_use_count[cpu][cluster] == 0) {
	exynos_cpu_power_down(cpunr);

	if (exynos_cluster_unused(cluster)) {
	exynos_cluster_power_down(cluster);
	last_man = true;
	}
	} else if (cpu_use_count[cpu][cluster] == 1) {
	/*
	* A power_up request went ahead of us.
	* Even if we do not want to shut this CPU down,
	* the caller expects a certain state as if the WFI
	* was aborted. So let's continue with cache cleaning.
	*/
	skip_wfi = true;
	} else {
	BUG();
	}

	if (last_man && __mcpm_outbound_enter_critical(cpu, cluster)) {
	arch_spin_unlock(&exynos_mcpm_lock);

	if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A15) {
	/*
	* On the Cortex-A15 we need to disable
	* L2 prefetching before flushing the cache.
	*/
	asm volatile(
	"mcr p15, 1, %0, c15, c0, 3\n\t"
	"isb\n\t"
	"dsb"
	: : "r" (0x400));
	}

	/* Flush all cache levels for this cluster. */
	exynos_v7_exit_coherency_flush(all);

	/*
	* Disable cluster-level coherency by masking
	* incoming snoops and DVM messages:
	*/
	cci_disable_port_by_cpu(mpidr);

	__mcpm_outbound_leave_critical(cluster, CLUSTER_DOWN);
	} else {
	arch_spin_unlock(&exynos_mcpm_lock);

	/* Disable and flush the local CPU cache. */
	exynos_v7_exit_coherency_flush(louis);
	}

	__mcpm_cpu_down(cpu, cluster);

	/* Now we are prepared for power-down, do it: */
	if (!skip_wfi)
	wfi();

	/* Not dead at this point? Let our caller cope. */
	}

	static int exynos_wait_for_powerdown(unsigned int cpu, unsigned int cluster)
	{
	unsigned int tries = 100;
	unsigned int cpunr = cpu + (cluster * EXYNOS5420_CPUS_PER_CLUSTER);

	pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
	BUG_ON(cpu >= EXYNOS5420_CPUS_PER_CLUSTER \|\|
	cluster >= EXYNOS5420_NR_CLUSTERS);

	/* Wait for the core state to be OFF */
	while (tries--) {
	if (ACCESS_ONCE(cpu_use_count[cpu][cluster]) == 0) {
	if ((exynos_cpu_power_state(cpunr) == 0))
	return 0; /* success: the CPU is halted */
	}

	/* Otherwise, wait and retry: */
	msleep(1);
	}

	return -ETIMEDOUT; /* timeout */
	}

	static void exynos_powered_up(void)
	{
	unsigned int mpidr, cpu, cluster;

	mpidr = read_cpuid_mpidr();
	cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
	cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);

	arch_spin_lock(&exynos_mcpm_lock);
	if (cpu_use_count[cpu][cluster] == 0)
	cpu_use_count[cpu][cluster] = 1;
	arch_spin_unlock(&exynos_mcpm_lock);
	}

	static void exynos_suspend(u64 residency)
	{
	unsigned int mpidr, cpunr;

	exynos_power_down();

	/*
	* Execution reaches here only if cpu did not power down.
	* Hence roll back the changes done in exynos_power_down function.
	*
	* CAUTION: "This function requires the stack data to be visible through
	* power down and can only be executed on processors like A15 and A7
	* that hit the cache with the C bit clear in the SCTLR register."
	*/
	mpidr = read_cpuid_mpidr();
	cpunr = exynos_pmu_cpunr(mpidr);

	exynos_cpu_power_up(cpunr);
	}

	static const struct mcpm_platform_ops exynos_power_ops = {
	.power_up = exynos_power_up,
	.power_down = exynos_power_down,
	.wait_for_powerdown = exynos_wait_for_powerdown,
	.suspend = exynos_suspend,
	.powered_up = exynos_powered_up,
	};

	static void __init exynos_mcpm_usage_count_init(void)
	{
	unsigned int mpidr, cpu, cluster;

	mpidr = read_cpuid_mpidr();
	cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
	cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);

	pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
	BUG_ON(cpu >= EXYNOS5420_CPUS_PER_CLUSTER \|\|
	cluster >= EXYNOS5420_NR_CLUSTERS);

	cpu_use_count[cpu][cluster] = 1;
	}

	/*
	* Enable cluster-level coherency, in preparation for turning on the MMU.
	*/
	static void __naked exynos_pm_power_up_setup(unsigned int affinity_level)
	{
	asm volatile ("\n"
	"cmp r0, #1\n"
	"bxne lr\n"
	"b cci_enable_port_for_self");
	}

	static void __init exynos_cache_off(void)
	{
	if (read_cpuid_part() == ARM_CPU_PART_CORTEX_A15) {
	/* disable L2 prefetching on the Cortex-A15 */
	asm volatile(
	"mcr p15, 1, %0, c15, c0, 3\n\t"
	"isb\n\t"
	"dsb"
	: : "r" (0x400));
	}
	exynos_v7_exit_coherency_flush(all);
	}

	static const struct of_device_id exynos_dt_mcpm_match[] = {
	{ .compatible = "samsung,exynos5420" },
	{ .compatible = "samsung,exynos5800" },
	{},
	};

	static void exynos_mcpm_setup_entry_point(void)
	{
	/*
	* U-Boot SPL is hardcoded to jump to the start of ns_sram_base_addr
	* as part of secondary_cpu_start(). Let's redirect it to the
	* mcpm_entry_point(). This is done during both secondary boot-up as
	* well as system resume.
	*/
	__raw_writel(0xe59f0000, ns_sram_base_addr); /* ldr r0, [pc, #0] */
	__raw_writel(0xe12fff10, ns_sram_base_addr + 4); /* bx r0 */
	__raw_writel(virt_to_phys(mcpm_entry_point), ns_sram_base_addr + 8);
	}

	static struct syscore_ops exynos_mcpm_syscore_ops = {
	.resume = exynos_mcpm_setup_entry_point,
	};

	static int __init exynos_mcpm_init(void)
	{
	struct device_node *node;
	unsigned int value, i;
	int ret;

	node = of_find_matching_node(NULL, exynos_dt_mcpm_match);
	if (!node)
	return -ENODEV;
	of_node_put(node);

	if (!cci_probed())
	return -ENODEV;

	node = of_find_compatible_node(NULL, NULL,
	"samsung,exynos4210-sysram-ns");
	if (!node)
	return -ENODEV;

	ns_sram_base_addr = of_iomap(node, 0);
	of_node_put(node);
	if (!ns_sram_base_addr) {
	pr_err("failed to map non-secure iRAM base address\n");
	return -ENOMEM;
	}

	/*
	* To increase the stability of KFC reset we need to program
	* the PMU SPARE3 register
	*/
	pmu_raw_writel(EXYNOS5420_SWRESET_KFC_SEL, S5P_PMU_SPARE3);

	exynos_mcpm_usage_count_init();

	ret = mcpm_platform_register(&exynos_power_ops);
	if (!ret)
	ret = mcpm_sync_init(exynos_pm_power_up_setup);
	if (!ret)
	ret = mcpm_loopback(exynos_cache_off); /* turn on the CCI */
	if (ret) {
	iounmap(ns_sram_base_addr);
	return ret;
	}

	mcpm_smp_set_ops();

	pr_info("Exynos MCPM support installed\n");

	/*
	* On Exynos5420/5800 for the A15 and A7 clusters:
	*
	* EXYNOS5420_ENABLE_AUTOMATIC_CORE_DOWN ensures that all the cores
	* in a cluster are turned off before turning off the cluster L2.
	*
	* EXYNOS5420_USE_ARM_CORE_DOWN_STATE ensures that a cores is powered
	* off before waking it up.
	*
	* EXYNOS5420_USE_L2_COMMON_UP_STATE ensures that cluster L2 will be
	* turned on before the first man is powered up.
	*/
	for (i = 0; i < EXYNOS5420_NR_CLUSTERS; i++) {
	value = pmu_raw_readl(EXYNOS_COMMON_OPTION(i));
	value \|= EXYNOS5420_ENABLE_AUTOMATIC_CORE_DOWN \|
	EXYNOS5420_USE_ARM_CORE_DOWN_STATE \|
	EXYNOS5420_USE_L2_COMMON_UP_STATE;
	pmu_raw_writel(value, EXYNOS_COMMON_OPTION(i));
	}

	exynos_mcpm_setup_entry_point();

	register_syscore_ops(&exynos_mcpm_syscore_ops);

	return ret;
	}

	early_initcall(exynos_mcpm_init);