ARM: psci: add support for PSCI invocations from the kernel

This patch adds support for the Power State Coordination Interface
defined by ARM, allowing Linux to request CPU-centric power-management
operations from firmware implementing the PSCI protocol.

Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
diff --git a/arch/arm/include/asm/psci.h b/arch/arm/include/asm/psci.h
new file mode 100644
index 0000000..ce0dbe7
--- /dev/null
+++ b/arch/arm/include/asm/psci.h
@@ -0,0 +1,36 @@
+/*
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * Copyright (C) 2012 ARM Limited
+ */
+
+#ifndef __ASM_ARM_PSCI_H
+#define __ASM_ARM_PSCI_H
+
+#define PSCI_POWER_STATE_TYPE_STANDBY		0
+#define PSCI_POWER_STATE_TYPE_POWER_DOWN	1
+
+struct psci_power_state {
+	u16	id;
+	u8	type;
+	u8	affinity_level;
+};
+
+struct psci_operations {
+	int (*cpu_suspend)(struct psci_power_state state,
+			   unsigned long entry_point);
+	int (*cpu_off)(struct psci_power_state state);
+	int (*cpu_on)(unsigned long cpuid, unsigned long entry_point);
+	int (*migrate)(unsigned long cpuid);
+};
+
+extern struct psci_operations psci_ops;
+
+#endif /* __ASM_ARM_PSCI_H */