Initial import

1 files changed, 97 insertions, 0 deletions

diff --git a/arch/arm/mach-shmobile/platsmp-scu.c b/arch/arm/mach-shmobile/platsmp-scu.c
new file mode 100644
index 000000000..64663110a
--- /dev/null
+++ b/arch/arm/mach-shmobile/platsmp-scu.c
@@ -0,0 +1,97 @@
+/*
+ * SMP support for SoCs with SCU covered by mach-shmobile
+ *
+ * Copyright (C) 2013  Magnus Damm
+ *
+ * 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/cpu.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/smp.h>
+#include <asm/cacheflush.h>
+#include <asm/smp_plat.h>
+#include <asm/smp_scu.h>
+#include "common.h"
+
+static int shmobile_smp_scu_notifier_call(struct notifier_block *nfb,
+					  unsigned long action, void *hcpu)
+{
+	unsigned int cpu = (long)hcpu;
+
+	switch (action) {
+	case CPU_UP_PREPARE:
+		/* For this particular CPU register SCU SMP boot vector */
+		shmobile_smp_hook(cpu, virt_to_phys(shmobile_boot_scu),
+				  (unsigned long)shmobile_scu_base);
+		break;
+	};
+
+	return NOTIFY_OK;
+}
+
+static struct notifier_block shmobile_smp_scu_notifier = {
+	.notifier_call = shmobile_smp_scu_notifier_call,
+};
+
+void __init shmobile_smp_scu_prepare_cpus(unsigned int max_cpus)
+{
+	/* install boot code shared by all CPUs */
+	shmobile_boot_fn = virt_to_phys(shmobile_smp_boot);
+	shmobile_boot_arg = MPIDR_HWID_BITMASK;
+
+	/* enable SCU and cache coherency on booting CPU */
+	scu_enable(shmobile_scu_base);
+	scu_power_mode(shmobile_scu_base, SCU_PM_NORMAL);
+
+	/* Use CPU notifier for reset vector control */
+	register_cpu_notifier(&shmobile_smp_scu_notifier);
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+void shmobile_smp_scu_cpu_die(unsigned int cpu)
+{
+	/* For this particular CPU deregister boot vector */
+	shmobile_smp_hook(cpu, 0, 0);
+
+	dsb();
+	flush_cache_all();
+
+	/* disable cache coherency */
+	scu_power_mode(shmobile_scu_base, SCU_PM_POWEROFF);
+
+	/* jump to shared mach-shmobile sleep / reset code */
+	shmobile_smp_sleep();
+}
+
+static int shmobile_smp_scu_psr_core_disabled(int cpu)
+{
+	unsigned long mask = SCU_PM_POWEROFF << (cpu * 8);
+
+	if ((__raw_readl(shmobile_scu_base + 8) & mask) == mask)
+		return 1;
+
+	return 0;
+}
+
+int shmobile_smp_scu_cpu_kill(unsigned int cpu)
+{
+	int k;
+
+	/* this function is running on another CPU than the offline target,
+	 * here we need wait for shutdown code in platform_cpu_die() to
+	 * finish before asking SoC-specific code to power off the CPU core.
+	 */
+	for (k = 0; k < 1000; k++) {
+		if (shmobile_smp_scu_psr_core_disabled(cpu))
+			return 1;
+
+		mdelay(1);
+	}
+
+	return 0;
+}
+#endif