reset2: Add PSCI system_reset2 function

This patch implements PSCI_SYSTEM_RESET2 API as defined in PSCI
v1.1 specification. The specification allows architectural and
vendor-specific resets via this API. In the current specification,
there is only one architectural reset, the warm reset. This reset is
intended to provide a fast reboot path that guarantees not to reset
system main memory.

Change-Id: I057bb81a60cd0fe56465dbb5791d8e1cca025bd3
Signed-off-by: Roberto Vargas <roberto.vargas@arm.com>

include/lib/psci/psci.h

@@ -65,6 +65,8 @@
 #define PSCI_STAT_RESIDENCY_AARCH64	U(0xc4000010)
 #define PSCI_STAT_COUNT_AARCH32		U(0x84000011)
 #define PSCI_STAT_COUNT_AARCH64		U(0xc4000011)
+#define PSCI_SYSTEM_RESET2_AARCH32	U(0x84000012)
+#define PSCI_SYSTEM_RESET2_AARCH64	U(0xc4000012)
 #define PSCI_MEM_PROTECT		U(0x84000013)
 #define PSCI_MEM_CHK_RANGE_AARCH32	U(0x84000014)
 #define PSCI_MEM_CHK_RANGE_AARCH64	U(0xc4000014)
@@ -167,6 +169,14 @@
 
 #define PSCI_INVALID_MPIDR	~((u_register_t)0)
 
+/*
+ * SYSTEM_RESET2 macros
+ */
+#define PSCI_RESET2_TYPE_VENDOR_SHIFT	31
+#define PSCI_RESET2_TYPE_VENDOR		(1U << PSCI_RESET2_TYPE_VENDOR_SHIFT)
+#define PSCI_RESET2_TYPE_ARCH		(0U << PSCI_RESET2_TYPE_VENDOR_SHIFT)
+#define PSCI_RESET2_SYSTEM_WARM_RESET	(PSCI_RESET2_TYPE_ARCH | 0)
+
 #ifndef __ASSEMBLY__
 
 #include <stdint.h>
@@ -294,6 +304,8 @@ typedef struct plat_psci_ops {
 	int (*mem_protect_chk)(uintptr_t base, u_register_t length);
 	int (*read_mem_protect)(int *val);
 	int (*write_mem_protect)(int val);
+	int (*system_reset2)(int is_vendor,
+				int reset_type, u_register_t cookie);
 } plat_psci_ops_t;
 
 /*******************************************************************************

lib/psci/psci_main.c

@@ -414,6 +414,10 @@ u_register_t psci_smc_handler(uint32_t smc_fid,
 		case PSCI_MEM_CHK_RANGE_AARCH32:
 			return psci_mem_chk_range(x1, x2);
 
+		case PSCI_SYSTEM_RESET2_AARCH32:
+			/* We should never return from psci_system_reset2() */
+			return psci_system_reset2(x1, x2);
+
 		default:
 			break;
 		}
@@ -453,6 +457,9 @@ u_register_t psci_smc_handler(uint32_t smc_fid,
 		case PSCI_MEM_CHK_RANGE_AARCH64:
 			return psci_mem_chk_range(x1, x2);
 
+		case PSCI_SYSTEM_RESET2_AARCH64:
+			/* We should never return from psci_system_reset2() */
+			return psci_system_reset2(x1, x2);
 
 		default:
 			break;

lib/psci/psci_private.h

@@ -89,7 +89,8 @@
 			define_psci_cap(PSCI_NODE_HW_STATE_AARCH64) |	\
 			define_psci_cap(PSCI_SYSTEM_SUSPEND_AARCH64) |	\
 			define_psci_cap(PSCI_STAT_RESIDENCY_AARCH64) |	\
-			define_psci_cap(PSCI_STAT_COUNT_AARCH64))
+			define_psci_cap(PSCI_STAT_COUNT_AARCH64) |	\
+			define_psci_cap(PSCI_SYSTEM_RESET2_AARCH64))
 
 /*
  * Helper macros to get/set the fields of PSCI per-cpu data.
@@ -258,6 +259,7 @@ void psci_do_pwrup_cache_maintenance(void);
 /* Private exported functions from psci_system_off.c */
 void __dead2 psci_system_off(void);
 void __dead2 psci_system_reset(void);
+int psci_system_reset2(uint32_t reset_type, u_register_t cookie);
 
 /* Private exported functions from psci_stat.c */
 void psci_stats_update_pwr_down(unsigned int end_pwrlvl,

lib/psci/psci_setup.c

@@ -248,6 +248,8 @@ int psci_setup(const psci_lib_args_t *lib_args)
 		psci_caps |= define_psci_cap(PSCI_MEM_PROTECT);
 	if (psci_plat_pm_ops->mem_protect_chk)
 		psci_caps |= define_psci_cap(PSCI_MEM_CHK_RANGE_AARCH64);
+	if (psci_plat_pm_ops->system_reset2)
+		psci_caps |= define_psci_cap(PSCI_SYSTEM_RESET2_AARCH64);
 
 #if ENABLE_PSCI_STAT
 	psci_caps |=  define_psci_cap(PSCI_STAT_RESIDENCY_AARCH64);

lib/psci/psci_system_off.c

@@ -49,3 +49,33 @@ void __dead2 psci_system_reset(void)
 
 	/* This function does not return. We should never get here */
 }
+
+int psci_system_reset2(uint32_t reset_type, u_register_t cookie)
+{
+	int is_vendor;
+
+	psci_print_power_domain_map();
+
+	assert(psci_plat_pm_ops->system_reset2);
+
+	is_vendor = (reset_type >> PSCI_RESET2_TYPE_VENDOR_SHIFT) & 1;
+	if (!is_vendor) {
+		/*
+		 * Only WARM_RESET is allowed for architectural type resets.
+		 */
+		if (reset_type != PSCI_RESET2_SYSTEM_WARM_RESET)
+			return PSCI_E_INVALID_PARAMS;
+		if (psci_plat_pm_ops->write_mem_protect &&
+		    psci_plat_pm_ops->write_mem_protect(0) < 0) {
+			return PSCI_E_NOT_SUPPORTED;
+		}
+	}
+
+	/* Notify the Secure Payload Dispatcher */
+	if (psci_spd_pm && psci_spd_pm->svc_system_reset) {
+		psci_spd_pm->svc_system_reset();
+	}
+	console_flush();
+
+	return psci_plat_pm_ops->system_reset2(is_vendor, reset_type, cookie);
+}