1 files changed, 90 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..3849f71e6
--- /dev/null
+++ b/arch/arm/mach-shmobile/platsmp-scu.c
@@ -0,0 +1,90 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * SMP support for SoCs with SCU covered by mach-shmobile
+ *
+ * Copyright (C) 2013  Magnus Damm
+ */
+#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 phys_addr_t shmobile_scu_base_phys;
+static void __iomem *shmobile_scu_base;
+
+static int shmobile_scu_cpu_prepare(unsigned int cpu)
+{
+	/* For this particular CPU register SCU SMP boot vector */
+	shmobile_smp_hook(cpu, __pa_symbol(shmobile_boot_scu),
+			  shmobile_scu_base_phys);
+	return 0;
+}
+
+void __init shmobile_smp_scu_prepare_cpus(phys_addr_t scu_base_phys,
+					  unsigned int max_cpus)
+{
+	/* install boot code shared by all CPUs */
+	shmobile_boot_fn = __pa_symbol(shmobile_smp_boot);
+
+	/* enable SCU and cache coherency on booting CPU */
+	shmobile_scu_base_phys = scu_base_phys;
+	shmobile_scu_base = ioremap(scu_base_phys, PAGE_SIZE);
+	scu_enable(shmobile_scu_base);
+	scu_power_mode(shmobile_scu_base, SCU_PM_NORMAL);
+
+	/* Use CPU notifier for reset vector control */
+	cpuhp_setup_state_nocalls(CPUHP_ARM_SHMOBILE_SCU_PREPARE,
+				  "arm/shmobile-scu:prepare",
+				  shmobile_scu_cpu_prepare, NULL);
+}
+
+#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 ((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