Merge branch 'tracking-armlt-tc2-psci' into lsk-3.10-vexpress

arch/arm/boot/dts/vexpress-v2p-ca15_a7.dts

@@ -286,6 +286,15 @@
 		clock-output-names = "oscclk6a";
 	};
 
+	psci {
+		compatible      = "arm,psci";
+		method          = "smc";
+		cpu_suspend     = <0x80100001>;
+		cpu_off         = <0x80100002>;
+		cpu_on          = <0x80100003>;
+		migrate         = <0x80100004>;
+	};
+
 	dcc {
 		compatible = "arm,vexpress,config-bus";
 		arm,vexpress,config-bridge = <&v2m_sysreg>;

arch/arm/mach-vexpress/Makefile

@@ -10,5 +10,9 @@ obj-$(CONFIG_ARCH_VEXPRESS_DCSCB)	+= dcscb.o	dcscb_setup.o
 CFLAGS_REMOVE_dcscb.o			= -pg
 obj-$(CONFIG_ARCH_VEXPRESS_TC2)		+= tc2_pm.o tc2_pm_setup.o
 CFLAGS_REMOVE_tc2_pm.o			= -pg
+ifeq ($(CONFIG_ARCH_VEXPRESS_TC2),y)
+obj-$(CONFIG_ARM_PSCI)			+= tc2_pm_psci.o
+CFLAGS_REMOVE_tc2_pm_psci.o		= -pg
+endif
 obj-$(CONFIG_SMP)			+= platsmp.o
 obj-$(CONFIG_HOTPLUG_CPU)		+= hotplug.o

arch/arm/mach-vexpress/include/mach/tc2.h

@@ -0,0 +1,10 @@
+#ifndef __MACH_TC2_H
+#define __MACH_TC2_H
+
+/*
+ * cpu and cluster limits
+ */
+#define TC2_MAX_CPUS		3
+#define TC2_MAX_CLUSTERS	2
+
+#endif

arch/arm/mach-vexpress/tc2_pm.c

@@ -23,8 +23,10 @@
 #include <asm/cacheflush.h>
 #include <asm/cputype.h>
 #include <asm/cp15.h>
+#include <asm/psci.h>
 
 #include <mach/motherboard.h>
+#include <mach/tc2.h>
 
 #include <linux/vexpress.h>
 #include <linux/arm-cci.h>
@@ -37,12 +39,13 @@
  */
 static arch_spinlock_t tc2_pm_lock = __ARCH_SPIN_LOCK_UNLOCKED;
 
-static int tc2_pm_use_count[3][2];
+static int tc2_pm_use_count[TC2_MAX_CPUS][TC2_MAX_CLUSTERS];
 
 static int tc2_pm_power_up(unsigned int cpu, unsigned int cluster)
 {
 	pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
-	if (cluster >= 2 || cpu >= vexpress_spc_get_nb_cpus(cluster))
+	if (cluster >= TC2_MAX_CLUSTERS ||
+	    cpu >= vexpress_spc_get_nb_cpus(cluster))
 		return -EINVAL;
 
 	/*
@@ -90,7 +93,8 @@ static void tc2_pm_down(u64 residency)
 	cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
 
 	pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
-	BUG_ON(cluster >= 2 || cpu >= vexpress_spc_get_nb_cpus(cluster));
+	BUG_ON(cluster >= TC2_MAX_CLUSTERS ||
+	       cpu >= vexpress_spc_get_nb_cpus(cluster));
 
 	__mcpm_cpu_going_down(cpu, cluster);
 
@@ -194,7 +198,8 @@ static void tc2_pm_powered_up(void)
 	cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
 
 	pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
-	BUG_ON(cluster >= 2 || cpu >= vexpress_spc_get_nb_cpus(cluster));
+	BUG_ON(cluster >= TC2_MAX_CLUSTERS ||
+	       cpu >= vexpress_spc_get_nb_cpus(cluster));
 
 	local_irq_save(flags);
 	arch_spin_lock(&tc2_pm_lock);
@@ -232,7 +237,9 @@ static void __init tc2_pm_usage_count_init(void)
 	cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
 
 	pr_debug("%s: cpu %u cluster %u\n", __func__, cpu, cluster);
-	BUG_ON(cpu >= 3 || cluster >= 2);
+	BUG_ON(cluster >= TC2_MAX_CLUSTERS ||
+	       cpu >= vexpress_spc_get_nb_cpus(cluster));
+
 	tc2_pm_use_count[cpu][cluster] = 1;
 }
 
@@ -242,6 +249,12 @@ static int __init tc2_pm_init(void)
 {
 	int ret;
 
+	ret = psci_probe();
+	if (!ret) {
+		pr_debug("psci found. Aborting native init\n");
+		return -ENODEV;
+	}
+
 	if (!vexpress_spc_check_loaded())
 		return -ENODEV;
 

arch/arm/mach-vexpress/tc2_pm_psci.c

@@ -0,0 +1,173 @@
+/*
+ * arch/arm/mach-vexpress/tc2_pm_psci.c - TC2 PSCI support
+ *
+ * Created by: Achin Gupta, December 2012
+ * Copyright:  (C) 2012  ARM Limited
+ *
+ * Some portions of this file were originally written by Nicolas Pitre
+ * Copyright:   (C) 2012  Linaro Limited
+ *
+ * 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/init.h>
+#include <linux/kernel.h>
+#include <linux/spinlock.h>
+#include <linux/errno.h>
+
+#include <asm/mcpm.h>
+#include <asm/proc-fns.h>
+#include <asm/cacheflush.h>
+#include <asm/psci.h>
+#include <asm/atomic.h>
+#include <asm/cputype.h>
+#include <asm/cp15.h>
+
+#include <mach/motherboard.h>
+#include <mach/tc2.h>
+
+#include <linux/vexpress.h>
+
+/*
+ * Platform specific state id understood by the firmware and used to
+ * program the power controller
+ */
+#define PSCI_POWER_STATE_ID           0
+
+static atomic_t tc2_pm_use_count[TC2_MAX_CPUS][TC2_MAX_CLUSTERS];
+
+static int tc2_pm_psci_power_up(unsigned int cpu, unsigned int cluster)
+{
+	unsigned int mpidr = (cluster << 8) | cpu;
+	int ret = 0;
+
+	BUG_ON(!psci_ops.cpu_on);
+
+	switch (atomic_inc_return(&tc2_pm_use_count[cpu][cluster])) {
+	case 1:
+		/*
+		 * This is a request to power up a cpu that linux thinks has
+		 * been powered down. Retries are needed if the firmware has
+		 * seen the power down request as yet.
+		 */
+		do
+			ret = psci_ops.cpu_on(mpidr,
+					      virt_to_phys(mcpm_entry_point));
+		while (ret == -EAGAIN);
+
+		return ret;
+	case 2:
+		/* This power up request has overtaken a power down request */
+		return ret;
+	default:
+		/* Any other value is a bug */
+		BUG();
+	}
+}
+
+static void tc2_pm_psci_power_down(void)
+{
+	struct psci_power_state power_state;
+	unsigned int mpidr, cpu, cluster;
+
+	mpidr = read_cpuid_mpidr();
+	cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
+	cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
+
+	BUG_ON(!psci_ops.cpu_off);
+
+	switch (atomic_dec_return(&tc2_pm_use_count[cpu][cluster])) {
+	case 1:
+		/*
+		 * Overtaken by a power up. Flush caches, exit coherency,
+		 * return & fake a reset
+		 */
+		set_cr(get_cr() & ~CR_C);
+
+		flush_cache_louis();
+
+		asm volatile ("clrex");
+		set_auxcr(get_auxcr() & ~(1 << 6));
+
+		return;
+	case 0:
+		/* A normal request to possibly power down the cluster */
+		power_state.id = PSCI_POWER_STATE_ID;
+		power_state.type = PSCI_POWER_STATE_TYPE_POWER_DOWN;
+		power_state.affinity_level = PSCI_POWER_STATE_AFFINITY_LEVEL1;
+
+		psci_ops.cpu_off(power_state);
+
+		/* On success this function never returns */
+	default:
+		/* Any other value is a bug */
+		BUG();
+	}
+}
+
+static void tc2_pm_psci_suspend(u64 unused)
+{
+	struct psci_power_state power_state;
+
+	BUG_ON(!psci_ops.cpu_suspend);
+
+	/* On TC2 always attempt to power down the cluster */
+	power_state.id = PSCI_POWER_STATE_ID;
+	power_state.type = PSCI_POWER_STATE_TYPE_POWER_DOWN;
+	power_state.affinity_level = PSCI_POWER_STATE_AFFINITY_LEVEL1;
+
+	psci_ops.cpu_suspend(power_state, virt_to_phys(mcpm_entry_point));
+
+	/* On success this function never returns */
+	BUG();
+}
+
+static const struct mcpm_platform_ops tc2_pm_power_ops = {
+	.power_up      = tc2_pm_psci_power_up,
+	.power_down    = tc2_pm_psci_power_down,
+	.suspend       = tc2_pm_psci_suspend,
+};
+
+static void __init tc2_pm_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(cluster >= TC2_MAX_CLUSTERS ||
+	       cpu >= vexpress_spc_get_nb_cpus(cluster));
+
+	atomic_set(&tc2_pm_use_count[cpu][cluster], 1);
+}
+
+static int __init tc2_pm_psci_init(void)
+{
+	int ret;
+
+	ret = psci_probe();
+	if (ret) {
+		pr_debug("psci not found. Aborting psci init\n");
+		return -ENODEV;
+	}
+
+	if (!vexpress_spc_check_loaded()) {
+		pr_debug("spc not found. Aborting psci init\n");
+		return -ENODEV;
+	}
+
+	tc2_pm_usage_count_init();
+
+	ret = mcpm_platform_register(&tc2_pm_power_ops);
+	if (!ret)
+		ret = mcpm_sync_init(NULL);
+	if (!ret)
+		pr_info("TC2 power management initialized\n");
+	return ret;
+}
+
+early_initcall(tc2_pm_psci_init);