support for migrate info - Tee-dev

3 Oct 2018

I am upstreaming TF-A support for the Renesas R-car gen3 platforms [1].
In order to prevent the boot cpu from being switched off (hotpluged)  I 
am having to work around the fact that OPTEE_OS does not support 
MIGRATE_INFO_TYPE or MIGRATE_INFO_UP_CPU.
Its SPD at TF-A level [2] returns that the TrustedOS if fully MP aware 
and has not special requirements for migration.
The work around I implemented (patch below and [3]) will query the 
platform whenever the opteed SPD indicates that it has no migration 
restrictions (which currently is always)
Is there any work ongoing on OPTEE_OS to support MIGRATE_INFO and update 
the TF-A SPD or am I missing some fundamental point?
thanks
Jorge
[1] https://github.com/ARM-software/arm-trusted-firmware/pull/1582
[2] 
https://github.com/ARM-software/arm-trusted-firmware/blob/master/services/sp...
[3] 
https://github.com/ARM-software/arm-trusted-firmware/pull/1582/commits/9a7fe...
psci: implement platform hook to migrate_info
---
  include/lib/psci/psci.h |  2 ++
  lib/psci/psci_main.c    | 35 ++++++++++++++++++++++++++++++++---
  2 files changed, 34 insertions(+), 3 deletions(-)

diff --git a/include/lib/psci/psci.h b/include/lib/psci/psci.h
index b27e481..e705a81 100644
--- a/include/lib/psci/psci.h
+++ b/include/lib/psci/psci.h
@@ -322,12 +322,14 @@ typedef struct plat_psci_ops {
         int (*write_mem_protect)(int val);
         int (*system_reset2)(int is_vendor,
                                 int reset_type, u_register_t cookie);
+       int (*migrate_info)(u_register_t *mpidr);
  } plat_psci_ops_t;
/*******************************************************************************
   * Function & Data prototypes
******************************************************************************/
  unsigned int psci_version(void);
+int psci_migrate_info(u_register_t *mpidr);
  int psci_cpu_on(u_register_t target_cpu,
                 uintptr_t entrypoint,
                 u_register_t context_id);
diff --git a/lib/psci/psci_main.c b/lib/psci/psci_main.c
index fd822bc..ce5419a 100644
--- a/lib/psci/psci_main.c
+++ b/lib/psci/psci_main.c
@@ -44,6 +44,23 @@ int psci_cpu_on(u_register_t target_cpu,
         return psci_cpu_on_start(target_cpu, &ep);
  }
+int psci_platform_migrate_info(u_register_t *mpidr)
+{
+       int rc;
+
+       if (psci_plat_pm_ops->migrate_info == NULL) {
+               /* no migrate restrictions */
+               return PSCI_TOS_NOT_PRESENT_MP;
+       }
+
+       rc = psci_plat_pm_ops->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;
+}
+
  unsigned int psci_version(void)
  {
         return PSCI_MAJOR_VER | PSCI_MINOR_VER;
@@ -276,8 +293,14 @@ int psci_migrate(u_register_t target_cpu)
  int psci_migrate_info_type(void)
  {
         u_register_t resident_cpu_mpidr;
+       int rc;
+
+       rc = psci_spd_migrate_info(&resident_cpu_mpidr);
+       if ((rc != PSCI_TOS_NOT_UP_MIG_CAP) && (rc != PSCI_TOS_UP_MIG_CAP))
+               return psci_platform_migrate_info(NULL);
+
+       return rc;
-       return psci_spd_migrate_info(&resident_cpu_mpidr);
  }
u_register_t psci_migrate_info_up_cpu(void)
@@ -290,8 +313,14 @@ u_register_t psci_migrate_info_up_cpu(void)
          * psci_spd_migrate_info() returns.
          */
         rc = psci_spd_migrate_info(&resident_cpu_mpidr);
-       if ((rc != PSCI_TOS_NOT_UP_MIG_CAP) && (rc != PSCI_TOS_UP_MIG_CAP))
-               return (u_register_t)(register_t) PSCI_E_INVALID_PARAMS;
+       if ((rc != PSCI_TOS_NOT_UP_MIG_CAP) && (rc != 
PSCI_TOS_UP_MIG_CAP)) {
+               rc = psci_platform_migrate_info(&resident_cpu_mpidr);
+               if ((rc != PSCI_TOS_NOT_UP_MIG_CAP) &&
+                   (rc != PSCI_TOS_UP_MIG_CAP))
+                       /* neither the SDP nor the platform have any 
migration
+                          restrictions: any core can be hotpluged */
+                       return (u_register_t)(register_t) 
PSCI_E_INVALID_PARAMS;
+       }
return resident_cpu_mpidr;
  }
-- 
2.7.4


    