Implement PSCI_FEATURES API

This patch implements the PSCI_FEATURES function which is a mandatory
API in the PSCI 1.0 specification. A capability variable is
constructed during initialization by examining the plat_pm_ops and
spd_pm_ops exported by the platform and the Secure Payload Dispatcher.
This is used by the PSCI FEATURES function to determine which
PSCI APIs are supported by the platform.

Change-Id: I147ffc1bd5d90b469bd3cc4bbe0a20e95c247df7

include/bl31/runtime_svc.h

@@ -176,6 +176,14 @@ typedef int32_t (*rt_svc_init_t)(void);
 #define SMC_SET_EL3(_h, _e, _v) \
 	write_ctx_reg(get_el3state_ctx(_h), (_e), (_v));
 
+/* The macro below is used to identify a Standard Service SMC call */
+#define is_std_svc_call(_fid)		((((_fid) >> FUNCID_OEN_SHIFT) & \
+					   FUNCID_OEN_MASK) == OEN_STD_START)
+
+/* The macro below is used to identify a valid Fast SMC call */
+#define is_valid_fast_smc(_fid)		((!(((_fid) >> 16) & 0xff)) && \
+					   (GET_SMC_TYPE(_fid) == SMC_TYPE_FAST))
+
 /*
  * Prototype for runtime service SMC handler function. x0 (SMC Function ID) to
  * x4 are as passed by the caller. Rest of the arguments to SMC and the context

include/bl31/services/psci.h

@@ -61,11 +61,15 @@
 #define PSCI_MIG_INFO_UP_CPU_AARCH64	0xc4000007
 #define PSCI_SYSTEM_OFF			0x84000008
 #define PSCI_SYSTEM_RESET		0x84000009
+#define PSCI_FEATURES			0x8400000A
+
+/* Macro to help build the psci capabilities bitfield */
+#define define_psci_cap(x)		(1 << (x & 0x1f))
 
 /*
  * Number of PSCI calls (above) implemented
  */
-#define PSCI_NUM_CALLS			15
+#define PSCI_NUM_CALLS			16
 
 /*******************************************************************************
  * PSCI Migrate and friends
@@ -96,6 +100,18 @@
 #define psci_get_pstate_afflvl(pstate)	((pstate >> PSTATE_AFF_LVL_SHIFT) & \
 					PSTATE_AFF_LVL_MASK)
 
+/*******************************************************************************
+ * PSCI CPU_FEATURES feature flag specific defines
+ ******************************************************************************/
+/* Features flags for CPU SUSPEND power state parameter format. Bits [1:1] */
+#define FF_PSTATE_SHIFT		1
+#define FF_PSTATE_ORIG		0
+#define FF_PSTATE_EXTENDED	1
+
+/* Features flags for CPU SUSPEND OS Initiated mode support. Bits [0:0] */
+#define FF_MODE_SUPPORT_SHIFT		0
+#define FF_SUPPORTS_OS_INIT_MODE	1
+
 /*******************************************************************************
  * PSCI version
  ******************************************************************************/

services/std_svc/psci/psci_common.c

@@ -558,7 +558,15 @@ void psci_afflvl_power_on_finish(int start_afflvl,
  ******************************************************************************/
 void psci_register_spd_pm_hook(const spd_pm_ops_t *pm)
 {
+	assert(pm);
 	psci_spd_pm = pm;
+
+	if (pm->svc_migrate)
+		psci_caps |= define_psci_cap(PSCI_MIG_AARCH64);
+
+	if (pm->svc_migrate_info)
+		psci_caps |= define_psci_cap(PSCI_MIG_INFO_UP_CPU_AARCH64)
+				| define_psci_cap(PSCI_MIG_INFO_TYPE);
 }
 
 /*******************************************************************************

services/std_svc/psci/psci_main.c

@@ -32,6 +32,7 @@
 #include <arch_helpers.h>
 #include <assert.h>
 #include <runtime_svc.h>
+#include <std_svc.h>
 #include <debug.h>
 #include "psci_private.h"
 
@@ -272,6 +273,39 @@ long psci_migrate_info_up_cpu(void)
 	return resident_cpu_mpidr;
 }
 
+int psci_features(unsigned int psci_fid)
+{
+	uint32_t local_caps = psci_caps;
+
+	/* Check if it is a 64 bit function */
+	if (((psci_fid >> FUNCID_CC_SHIFT) & FUNCID_CC_MASK) == SMC_64)
+		local_caps &= PSCI_CAP_64BIT_MASK;
+
+	/* Check for invalid fid */
+	if (!(is_std_svc_call(psci_fid) && is_valid_fast_smc(psci_fid)
+			&& is_psci_fid(psci_fid)))
+		return PSCI_E_NOT_SUPPORTED;
+
+
+	/* Check if the psci fid is supported or not */
+	if (!(local_caps & define_psci_cap(psci_fid)))
+		return PSCI_E_NOT_SUPPORTED;
+
+	/* Format the feature flags */
+	if (psci_fid == PSCI_CPU_SUSPEND_AARCH32 ||
+			psci_fid == PSCI_CPU_SUSPEND_AARCH64) {
+		/*
+		 * The trusted firmware uses the original power state format
+		 * and does not support OS Initiated Mode.
+		 */
+		return (FF_PSTATE_ORIG << FF_PSTATE_SHIFT) |
+			((!FF_SUPPORTS_OS_INIT_MODE) << FF_MODE_SUPPORT_SHIFT);
+	}
+
+	/* Return 0 for all other fid's */
+	return PSCI_E_SUCCESS;
+}
+
 /*******************************************************************************
  * PSCI top level handler for servicing SMCs.
  ******************************************************************************/
@@ -327,6 +361,9 @@ uint64_t psci_smc_handler(uint32_t smc_fid,
 			psci_system_reset();
 			/* We should never return from psci_system_reset() */
 
+		case PSCI_FEATURES:
+			SMC_RET1(handle, psci_features(x1));
+
 		default:
 			break;
 		}

services/std_svc/psci/psci_private.h

@@ -52,6 +52,26 @@
 						CPU_DATA_PSCI_LOCK_OFFSET)
 #endif
 
+/*
+ * The PSCI capability which are provided by the generic code but does not
+ * depend on the platform or spd capabilities.
+ */
+#define PSCI_GENERIC_CAP	\
+			(define_psci_cap(PSCI_VERSION) |		\
+			define_psci_cap(PSCI_AFFINITY_INFO_AARCH64) |	\
+			define_psci_cap(PSCI_FEATURES))
+
+/*
+ * The PSCI capabilities mask for 64 bit functions.
+ */
+#define PSCI_CAP_64BIT_MASK	\
+			(define_psci_cap(PSCI_CPU_SUSPEND_AARCH64) |	\
+			define_psci_cap(PSCI_CPU_ON_AARCH64) |		\
+			define_psci_cap(PSCI_AFFINITY_INFO_AARCH64) |	\
+			define_psci_cap(PSCI_MIG_AARCH64) |		\
+			define_psci_cap(PSCI_MIG_INFO_UP_CPU_AARCH64))
+
+
 /*******************************************************************************
  * The following two data structures hold the topology tree which in turn tracks
  * the state of the all the affinity instances supported by the platform.
@@ -82,6 +102,7 @@ typedef void (*afflvl_power_on_finisher_t)(aff_map_node_t *);
  ******************************************************************************/
 extern const plat_pm_ops_t *psci_plat_pm_ops;
 extern aff_map_node_t psci_aff_map[PSCI_NUM_AFFS];
+extern uint32_t psci_caps;
 
 /*******************************************************************************
  * SPD's power management hooks registered with PSCI

services/std_svc/psci/psci_setup.c

@@ -57,6 +57,12 @@ static cpu_context_t psci_ns_context[PLATFORM_CORE_COUNT];
  ******************************************************************************/
 static aff_limits_node_t psci_aff_limits[MPIDR_MAX_AFFLVL + 1];
 
+/******************************************************************************
+ * Define the psci capability variable.
+ *****************************************************************************/
+uint32_t psci_caps;
+
+
 /*******************************************************************************
  * Routines for retrieving the node corresponding to an affinity level instance
  * in the mpidr. The first one uses binary search to find the node corresponding
@@ -372,5 +378,19 @@ int32_t psci_setup(void)
 	platform_setup_pm(&psci_plat_pm_ops);
 	assert(psci_plat_pm_ops);
 
+	/* Initialize the psci capability */
+	psci_caps = PSCI_GENERIC_CAP;
+
+	if (psci_plat_pm_ops->affinst_off)
+		psci_caps |=  define_psci_cap(PSCI_CPU_OFF);
+	if (psci_plat_pm_ops->affinst_on && psci_plat_pm_ops->affinst_on_finish)
+		psci_caps |=  define_psci_cap(PSCI_CPU_ON_AARCH64);
+	if (psci_plat_pm_ops->affinst_suspend && psci_plat_pm_ops->affinst_suspend_finish)
+		psci_caps |=  define_psci_cap(PSCI_CPU_SUSPEND_AARCH64);
+	if (psci_plat_pm_ops->system_off)
+		psci_caps |=  define_psci_cap(PSCI_SYSTEM_OFF);
+	if (psci_plat_pm_ops->system_reset)
+		psci_caps |=  define_psci_cap(PSCI_SYSTEM_RESET);
+
 	return 0;
 }