Rework the PSCI migrate APIs

This patch reworks the PSCI MIGRATE, MIGRATE_INFO_TYPE and
MIGRATE_INFO_UP_CPU support for Trusted Firmware. The
implementation does the appropriate validation of parameters
and invokes the appropriate hook exported by the SPD.

The TSP is a MP Trusted OS. Hence the ability to actually
migrate a Trusted OS has not been implemented. The
corresponding function is not populated in the spd_pm_hooks
structure for the TSPD.

The `spd_pm_ops_t` has undergone changes with this patch.
SPD PORTS MAY NEED TO BE UPDATED.

Fixes ARM-software/tf-issues#249

Change-Id: Iabd87521bf7c530a5e4506b6d3bfd4f1bf87604f

include/bl31/services/psci.h

@@ -191,8 +191,8 @@ typedef struct spd_pm_ops {
 	void (*svc_suspend)(uint64_t __unused);
 	void (*svc_on_finish)(uint64_t __unused);
 	void (*svc_suspend_finish)(uint64_t suspend_level);
-	void (*svc_migrate)(uint64_t __unused1, uint64_t __unused2);
-	int32_t (*svc_migrate_info)(uint64_t *__unused);
+	int32_t (*svc_migrate)(uint64_t from_cpu, uint64_t to_cpu);
+	int32_t (*svc_migrate_info)(uint64_t *resident_cpu);
 	void (*svc_system_off)(void);
 	void (*svc_system_reset)(void);
 } spd_pm_ops_t;
@@ -202,9 +202,9 @@ typedef struct spd_pm_ops {
  ******************************************************************************/
 unsigned int psci_version(void);
 int psci_affinity_info(unsigned long, unsigned int);
-int psci_migrate(unsigned int);
-unsigned int psci_migrate_info_type(void);
-unsigned long psci_migrate_info_up_cpu(void);
+int psci_migrate(unsigned long);
+int psci_migrate_info_type(void);
+long psci_migrate_info_up_cpu(void);
 int psci_cpu_on(unsigned long,
 		unsigned long,
 		unsigned long);

services/std_svc/psci/psci_common.c

@@ -561,6 +561,29 @@ void psci_register_spd_pm_hook(const spd_pm_ops_t *pm)
 	psci_spd_pm = pm;
 }
 
+/*******************************************************************************
+ * This function invokes the migrate info hook in the spd_pm_ops. It performs
+ * the necessary return value validation. If the Secure Payload is UP and
+ * migrate capable, it returns the mpidr of the CPU on which the Secure payload
+ * is resident through the mpidr parameter. Else the value of the parameter on
+ * return is undefined.
+ ******************************************************************************/
+int psci_spd_migrate_info(uint64_t *mpidr)
+{
+	int rc;
+
+	if (!psci_spd_pm || !psci_spd_pm->svc_migrate_info)
+		return PSCI_E_NOT_SUPPORTED;
+
+	rc = psci_spd_pm->svc_migrate_info(mpidr);
+
+	assert(rc == PSCI_TOS_UP_MIG_CAP || rc == PSCI_TOS_NOT_UP_MIG_CAP \
+		|| rc == PSCI_TOS_NOT_PRESENT_MP || rc == PSCI_E_NOT_SUPPORTED);
+
+	return rc;
+}
+
+
 /*******************************************************************************
  * This function prints the state of all affinity instances present in the
  * system

services/std_svc/psci/psci_main.c

@@ -219,25 +219,57 @@ int psci_affinity_info(unsigned long target_affinity,
 	return rc;
 }
 
-/* Unimplemented */
-int psci_migrate(unsigned int target_cpu)
+int psci_migrate(unsigned long target_cpu)
 {
-	return PSCI_E_NOT_SUPPORTED;
+	int rc;
+	unsigned long resident_cpu_mpidr;
+
+	rc = psci_spd_migrate_info(&resident_cpu_mpidr);
+	if (rc != PSCI_TOS_UP_MIG_CAP)
+		return (rc == PSCI_TOS_NOT_UP_MIG_CAP) ?
+			  PSCI_E_DENIED : PSCI_E_NOT_SUPPORTED;
+
+	/*
+	 * Migrate should only be invoked on the CPU where
+	 * the Secure OS is resident.
+	 */
+	if (resident_cpu_mpidr != read_mpidr_el1())
+		return PSCI_E_NOT_PRESENT;
+
+	/* Check the validity of the specified target cpu */
+	rc = psci_validate_mpidr(target_cpu, MPIDR_AFFLVL0);
+	if (rc != PSCI_E_SUCCESS)
+		return PSCI_E_INVALID_PARAMS;
+
+	assert(psci_spd_pm && psci_spd_pm->svc_migrate);
+
+	rc = psci_spd_pm->svc_migrate(read_mpidr_el1(), target_cpu);
+	assert(rc == PSCI_E_SUCCESS || rc == PSCI_E_INTERN_FAIL);
+
+	return rc;
 }
 
-/* Unimplemented */
-unsigned int psci_migrate_info_type(void)
+int psci_migrate_info_type(void)
 {
-	return PSCI_TOS_NOT_PRESENT_MP;
+	unsigned long resident_cpu_mpidr;
+
+	return psci_spd_migrate_info(&resident_cpu_mpidr);
 }
 
-unsigned long psci_migrate_info_up_cpu(void)
+long psci_migrate_info_up_cpu(void)
 {
+	unsigned long resident_cpu_mpidr;
+	int rc;
+
 	/*
-	 * Return value of this currently unsupported call depends upon
-	 * what psci_migrate_info_type() returns.
+	 * Return value of this depends upon what
+	 * psci_spd_migrate_info() returns.
 	 */
-	return PSCI_E_SUCCESS;
+	rc = psci_spd_migrate_info(&resident_cpu_mpidr);
+	if (rc != PSCI_TOS_NOT_UP_MIG_CAP && rc != PSCI_TOS_UP_MIG_CAP)
+		return PSCI_E_INVALID_PARAMS;
+
+	return resident_cpu_mpidr;
 }
 
 /*******************************************************************************

services/std_svc/psci/psci_private.h

@@ -120,6 +120,7 @@ void psci_set_max_phys_off_afflvl(uint32_t afflvl);
 uint32_t psci_find_max_phys_off_afflvl(uint32_t start_afflvl,
 				       uint32_t end_afflvl,
 				       aff_map_node_t *mpidr_nodes[]);
+int psci_spd_migrate_info(uint64_t *mpidr);
 
 /* Private exported functions from psci_setup.c */
 int psci_get_aff_map_nodes(unsigned long mpidr,