1 files changed, 123 insertions, 0 deletions
diff --git a/arch/arm/kernel/psci_smp.c b/arch/arm/kernel/psci_smp.c
new file mode 100644
index 000000000..d4392e177
--- /dev/null
+++ b/arch/arm/kernel/psci_smp.c
@@ -0,0 +1,123 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *
+ * Copyright (C) 2012 ARM Limited
+ *
+ * Author: Will Deacon <will.deacon@arm.com>
+ */
+
+#include <linux/init.h>
+#include <linux/smp.h>
+#include <linux/of.h>
+#include <linux/delay.h>
+#include <linux/psci.h>
+
+#include <uapi/linux/psci.h>
+
+#include <asm/psci.h>
+#include <asm/smp_plat.h>
+
+/*
+ * psci_smp assumes that the following is true about PSCI:
+ *
+ * cpu_suspend   Suspend the execution on a CPU
+ * @state        we don't currently describe affinity levels, so just pass 0.
+ * @entry_point  the first instruction to be executed on return
+ * returns 0  success, < 0 on failure
+ *
+ * cpu_off       Power down a CPU
+ * @state        we don't currently describe affinity levels, so just pass 0.
+ * no return on successful call
+ *
+ * cpu_on        Power up a CPU
+ * @cpuid        cpuid of target CPU, as from MPIDR
+ * @entry_point  the first instruction to be executed on return
+ * returns 0  success, < 0 on failure
+ *
+ * migrate       Migrate the context to a different CPU
+ * @cpuid        cpuid of target CPU, as from MPIDR
+ * returns 0  success, < 0 on failure
+ *
+ */
+
+extern void secondary_startup(void);
+
+static int psci_boot_secondary(unsigned int cpu, struct task_struct *idle)
+{
+	if (psci_ops.cpu_on)
+		return psci_ops.cpu_on(cpu_logical_map(cpu),
+					virt_to_idmap(&secondary_startup));
+	return -ENODEV;
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+static int psci_cpu_disable(unsigned int cpu)
+{
+	/* Fail early if we don't have CPU_OFF support */
+	if (!psci_ops.cpu_off)
+		return -EOPNOTSUPP;
+
+	/* Trusted OS will deny CPU_OFF */
+	if (psci_tos_resident_on(cpu))
+		return -EPERM;
+
+	return 0;
+}
+
+static void psci_cpu_die(unsigned int cpu)
+{
+	u32 state = PSCI_POWER_STATE_TYPE_POWER_DOWN <<
+		    PSCI_0_2_POWER_STATE_TYPE_SHIFT;
+
+	if (psci_ops.cpu_off)
+		psci_ops.cpu_off(state);
+
+	/* We should never return */
+	panic("psci: cpu %d failed to shutdown\n", cpu);
+}
+
+static int psci_cpu_kill(unsigned int cpu)
+{
+	int err, i;
+
+	if (!psci_ops.affinity_info)
+		return 1;
+	/*
+	 * cpu_kill could race with cpu_die and we can
+	 * potentially end up declaring this cpu undead
+	 * while it is dying. So, try again a few times.
+	 */
+
+	for (i = 0; i < 10; i++) {
+		err = psci_ops.affinity_info(cpu_logical_map(cpu), 0);
+		if (err == PSCI_0_2_AFFINITY_LEVEL_OFF) {
+			pr_info("CPU%d killed.\n", cpu);
+			return 1;
+		}
+
+		msleep(10);
+		pr_info("Retrying again to check for CPU kill\n");
+	}
+
+	pr_warn("CPU%d may not have shut down cleanly (AFFINITY_INFO reports %d)\n",
+			cpu, err);
+	/* Make platform_cpu_kill() fail. */
+	return 0;
+}
+
+#endif
+
+bool __init psci_smp_available(void)
+{
+	/* is cpu_on available at least? */
+	return (psci_ops.cpu_on != NULL);
+}
+
+const struct smp_operations psci_smp_ops __initconst = {
+	.smp_boot_secondary	= psci_boot_secondary,
+#ifdef CONFIG_HOTPLUG_CPU
+	.cpu_disable		= psci_cpu_disable,
+	.cpu_die		= psci_cpu_die,
+	.cpu_kill		= psci_cpu_kill,
+#endif
+};