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

 // SPDX-License-Identifier: GPL-2.0
 // Copyright (c) 2014 Samsung Electronics Co., Ltd.
 //		http://www.samsung.com
 //
 // Based on arch/arm/mach-vexpress/dcscb.c

 #include <linux/arm-cci.h>
 #include <linux/delay.h>
 #include <linux/io.h>
 #include <linux/of_address.h>
 #include <linux/syscore_ops.h>
 #include <linux/soc/samsung/exynos-regs-pmu.h>

 #include <asm/cputype.h>
 #include <asm/cp15.h>
 #include <asm/mcpm.h>
 #include <asm/smp_plat.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 __ro_after_init;

 /*
  * 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")

 static int exynos_cpu_powerup(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;

 	if (!exynos_cpu_power_state(cpunr)) {
 		exynos_cpu_power_up(cpunr);

 		/*
 		 * This assumes the cluster number of the big cores(Cortex A15)
 		 * is 0 and the Little cores(Cortex A7) is 1.
 		 * When the system was booted from the Little core,
 		 * they should be reset during power up cpu.
 		 */
 		if (cluster &&
 		    cluster == MPIDR_AFFINITY_LEVEL(cpu_logical_map(0), 1)) {
 			unsigned int timeout = 16;

 			/*
 			 * Before we reset the Little cores, we should wait
 			 * the SPARE2 register is set to 1 because the init
 			 * codes of the iROM will set the register after
 			 * initialization.
 			 */
 			while (timeout && !pmu_raw_readl(S5P_PMU_SPARE2)) {
 				timeout--;
 				udelay(10);
 			}

 			if (timeout == 0) {
 				pr_err("cpu %u cluster %u powerup failed\n",
 				       cpu, cluster);
 				exynos_cpu_power_down(cpunr);
 				return -ETIMEDOUT;
 			}

 			pmu_raw_writel(EXYNOS5420_KFC_CORE_RESET(cpu),
 					EXYNOS_SWRESET);
 		}
 	}

 	return 0;
 }

 static int exynos_cluster_powerup(unsigned int cluster)
 {
 	pr_debug("%s: cluster %u\n", __func__, cluster);
 	if (cluster >= EXYNOS5420_NR_CLUSTERS)
 		return -EINVAL;

 	exynos_cluster_power_up(cluster);
 	return 0;
 }

 static void exynos_cpu_powerdown_prepare(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);
 	BUG_ON(cpu >= EXYNOS5420_CPUS_PER_CLUSTER ||
 			cluster >= EXYNOS5420_NR_CLUSTERS);
 	exynos_cpu_power_down(cpunr);
 }

 static void exynos_cluster_powerdown_prepare(unsigned int cluster)
 {
 	pr_debug("%s: cluster %u\n", __func__, cluster);
 	BUG_ON(cluster >= EXYNOS5420_NR_CLUSTERS);
 	exynos_cluster_power_down(cluster);
 }

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

 static void exynos_cluster_cache_disable(void)
 {
 	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(read_cpuid_mpidr());
 }

 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 ((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_cpu_is_up(unsigned int cpu, unsigned int cluster)
 {
 	/* especially when resuming: make sure power control is set */
 	exynos_cpu_powerup(cpu, cluster);
 }

 static const struct mcpm_platform_ops exynos_power_ops = {
 	.cpu_powerup		= exynos_cpu_powerup,
 	.cluster_powerup	= exynos_cluster_powerup,
 	.cpu_powerdown_prepare	= exynos_cpu_powerdown_prepare,
 	.cluster_powerdown_prepare = exynos_cluster_powerdown_prepare,
 	.cpu_cache_disable	= exynos_cpu_cache_disable,
 	.cluster_cache_disable	= exynos_cluster_cache_disable,
 	.wait_for_powerdown	= exynos_wait_for_powerdown,
 	.cpu_is_up		= exynos_cpu_is_up,
 };

 /*
  * 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 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(__pa_symbol(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);

 	ret = mcpm_platform_register(&exynos_power_ops);
 	if (!ret)
 		ret = mcpm_sync_init(exynos_pm_power_up_setup);
 	if (!ret)
 		ret = mcpm_loopback(exynos_cluster_cache_disable); /* 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);
	// SPDX-License-Identifier: GPL-2.0
	// Copyright (c) 2014 Samsung Electronics Co., Ltd.
	// http://www.samsung.com
	//
	// Based on arch/arm/mach-vexpress/dcscb.c

	#include <linux/arm-cci.h>
	#include <linux/delay.h>
	#include <linux/io.h>
	#include <linux/of_address.h>
	#include <linux/syscore_ops.h>
	#include <linux/soc/samsung/exynos-regs-pmu.h>

	#include <asm/cputype.h>
	#include <asm/cp15.h>
	#include <asm/mcpm.h>
	#include <asm/smp_plat.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 __ro_after_init;

	/*
	* 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")

	static int exynos_cpu_powerup(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;

	if (!exynos_cpu_power_state(cpunr)) {
	exynos_cpu_power_up(cpunr);

	/*
	* This assumes the cluster number of the big cores(Cortex A15)
	* is 0 and the Little cores(Cortex A7) is 1.
	* When the system was booted from the Little core,
	* they should be reset during power up cpu.
	*/
	if (cluster &&
	cluster == MPIDR_AFFINITY_LEVEL(cpu_logical_map(0), 1)) {
	unsigned int timeout = 16;

	/*
	* Before we reset the Little cores, we should wait
	* the SPARE2 register is set to 1 because the init
	* codes of the iROM will set the register after
	* initialization.
	*/
	while (timeout && !pmu_raw_readl(S5P_PMU_SPARE2)) {
	timeout--;
	udelay(10);
	}

	if (timeout == 0) {
	pr_err("cpu %u cluster %u powerup failed\n",
	cpu, cluster);
	exynos_cpu_power_down(cpunr);
	return -ETIMEDOUT;
	}

	pmu_raw_writel(EXYNOS5420_KFC_CORE_RESET(cpu),
	EXYNOS_SWRESET);
	}
	}

	return 0;
	}

	static int exynos_cluster_powerup(unsigned int cluster)
	{
	pr_debug("%s: cluster %u\n", __func__, cluster);
	if (cluster >= EXYNOS5420_NR_CLUSTERS)
	return -EINVAL;

	exynos_cluster_power_up(cluster);
	return 0;
	}

	static void exynos_cpu_powerdown_prepare(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);
	BUG_ON(cpu >= EXYNOS5420_CPUS_PER_CLUSTER \|\|
	cluster >= EXYNOS5420_NR_CLUSTERS);
	exynos_cpu_power_down(cpunr);
	}

	static void exynos_cluster_powerdown_prepare(unsigned int cluster)
	{
	pr_debug("%s: cluster %u\n", __func__, cluster);
	BUG_ON(cluster >= EXYNOS5420_NR_CLUSTERS);
	exynos_cluster_power_down(cluster);
	}

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

	static void exynos_cluster_cache_disable(void)
	{
	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(read_cpuid_mpidr());
	}

	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 ((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_cpu_is_up(unsigned int cpu, unsigned int cluster)
	{
	/* especially when resuming: make sure power control is set */
	exynos_cpu_powerup(cpu, cluster);
	}

	static const struct mcpm_platform_ops exynos_power_ops = {
	.cpu_powerup = exynos_cpu_powerup,
	.cluster_powerup = exynos_cluster_powerup,
	.cpu_powerdown_prepare = exynos_cpu_powerdown_prepare,
	.cluster_powerdown_prepare = exynos_cluster_powerdown_prepare,
	.cpu_cache_disable = exynos_cpu_cache_disable,
	.cluster_cache_disable = exynos_cluster_cache_disable,
	.wait_for_powerdown = exynos_wait_for_powerdown,
	.cpu_is_up = exynos_cpu_is_up,
	};

	/*
	* 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 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(__pa_symbol(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);

	ret = mcpm_platform_register(&exynos_power_ops);
	if (!ret)
	ret = mcpm_sync_init(exynos_pm_power_up_setup);
	if (!ret)
	ret = mcpm_loopback(exynos_cluster_cache_disable); /* 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);