Add standby state support in PSCI cpu_suspend api
This patch adds support in the generic PSCI implementation to call a
platform specific function to enter a standby state using an example
implementation in ARM FVP port
Fixes ARM-software/tf-issues#94
Change-Id: Ic1263fcf25f28e09162ad29dca954125f9aa8cc9
diff --git a/include/psci.h b/include/psci.h
index 6fe1d8a..5c66789 100644
--- a/include/psci.h
+++ b/include/psci.h
@@ -74,6 +74,9 @@
#define PSTATE_TYPE_MASK 0x1
#define PSTATE_AFF_LVL_MASK 0x3
+#define PSTATE_TYPE_STANDBY 0x0
+#define PSTATE_TYPE_POWERDOWN 0x1
+
#define psci_get_pstate_id(pstate) (pstate >> PSTATE_ID_SHIFT) & \
PSTATE_ID_MASK
#define psci_get_pstate_type(pstate) (pstate >> PSTATE_TYPE_SHIFT) & \
diff --git a/plat/fvp/plat_pm.c b/plat/fvp/plat_pm.c
index dd7a4b3..7b51476 100644
--- a/plat/fvp/plat_pm.c
+++ b/plat/fvp/plat_pm.c
@@ -44,6 +44,29 @@
#include <psci.h>
/*******************************************************************************
+ * FVP handler called when an affinity instance is about to enter standby.
+ ******************************************************************************/
+int fvp_affinst_standby(unsigned int power_state)
+{
+ unsigned int target_afflvl;
+
+ /* Sanity check the requested state */
+ target_afflvl = psci_get_pstate_afflvl(power_state);
+
+ /*
+ * It's possible to enter standby only on affinity level 0 i.e. a cpu
+ * on the FVP. Ignore any other affinity level.
+ */
+ if (target_afflvl != MPIDR_AFFLVL0)
+ return PSCI_E_INVALID_PARAMS;
+
+ /* Enter standby state */
+ wfi();
+
+ return PSCI_E_SUCCESS;
+}
+
+/*******************************************************************************
* FVP handler called when an affinity instance is about to be turned on. The
* level and mpidr determine the affinity instance.
******************************************************************************/
@@ -372,7 +395,7 @@
* Export the platform handlers to enable psci to invoke them
******************************************************************************/
static plat_pm_ops fvp_plat_pm_ops = {
- 0,
+ fvp_affinst_standby,
fvp_affinst_on,
fvp_affinst_off,
fvp_affinst_suspend,
diff --git a/services/std_svc/psci/psci_main.c b/services/std_svc/psci/psci_main.c
index 6bf0583..2d61ec0 100644
--- a/services/std_svc/psci/psci_main.c
+++ b/services/std_svc/psci/psci_main.c
@@ -85,31 +85,28 @@
unsigned long mpidr;
unsigned int target_afflvl, pstate_type;
- /* TODO: Standby states are not supported at the moment */
- pstate_type = psci_get_pstate_type(power_state);
- if (pstate_type == 0) {
- rc = PSCI_E_INVALID_PARAMS;
- goto exit;
- }
-
/* Sanity check the requested state */
target_afflvl = psci_get_pstate_afflvl(power_state);
- if (target_afflvl > MPIDR_MAX_AFFLVL) {
- rc = PSCI_E_INVALID_PARAMS;
- goto exit;
+ if (target_afflvl > MPIDR_MAX_AFFLVL)
+ return PSCI_E_INVALID_PARAMS;
+
+ pstate_type = psci_get_pstate_type(power_state);
+ if (pstate_type == PSTATE_TYPE_STANDBY) {
+ if (psci_plat_pm_ops->affinst_standby)
+ rc = psci_plat_pm_ops->affinst_standby(power_state);
+ else
+ return PSCI_E_INVALID_PARAMS;
+ } else {
+ mpidr = read_mpidr();
+ rc = psci_afflvl_suspend(mpidr,
+ entrypoint,
+ context_id,
+ power_state,
+ MPIDR_AFFLVL0,
+ target_afflvl);
}
- mpidr = read_mpidr();
- rc = psci_afflvl_suspend(mpidr,
- entrypoint,
- context_id,
- power_state,
- MPIDR_AFFLVL0,
- target_afflvl);
-
-exit:
- if (rc != PSCI_E_SUCCESS)
- assert(rc == PSCI_E_INVALID_PARAMS);
+ assert(rc == PSCI_E_INVALID_PARAMS || rc == PSCI_E_SUCCESS);
return rc;
}