fix(psci): add optional pwr_domain_validate_suspend to plat_psci_ops_t
This patch adds a new optional member `pwr_domain_validate_suspend` to
the `plat_psci_ops_t` structure that allows a platform to optionally
perform platform specific validations in OS-initiated mode. This is
conditionally compiled into the build depending on the value of the
`PSCI_OS_INIT_MODE` build option.
In https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/17682,
the return type of the `pwr_domain_suspend` handler was updated from
`void` to `int` to allow a platform to optionally perform platform
specific validations in OS-initiated mode. However, when an error code
other than `PSCI_E_SUCCESS` is returned, the current exit path does not
undo the operations in `psci_suspend_to_pwrdown_start`, and as a result,
the system ends up in an unexpected state.
The fix in this patch prevents the need to undo the operations in
`psci_suspend_to_pwrdown_start`, by allowing the platform to first
perform any necessary platform specific validations before the PSCI
generic code proceeds to the point of no return where the CPU_SUSPEND
request is expected to complete successfully.
Change-Id: I05d92c7ea3f5364da09af630d44d78252185db20
Signed-off-by: Wing Li <wingers@google.com>
diff --git a/docs/design_documents/psci_osi_mode.rst b/docs/design_documents/psci_osi_mode.rst
index 3296e27..a6e1bdf 100644
--- a/docs/design_documents/psci_osi_mode.rst
+++ b/docs/design_documents/psci_osi_mode.rst
@@ -4,7 +4,7 @@
:Author: Maulik Shah & Wing Li
:Organization: Qualcomm Innovation Center, Inc. & Google LLC
:Contact: Maulik Shah <quic_mkshah@quicinc.com> & Wing Li <wingers@google.com>
-:Status: RFC
+:Status: Accepted
.. contents:: Table of Contents
@@ -367,9 +367,11 @@
``psci_validate_state_coordination``. If validation fails, propagate the
error up the call stack.
-* Update the return type of the platform specific ``pwr_domain_suspend``
- handler from ``void`` to ``int``, to allow the platform to optionally perform
- validations based on hardware states.
+* Add a new optional member ``pwr_domain_validate_suspend`` to
+ ``plat_psci_ops_t`` to allow the platform to optionally perform validations
+ based on hardware states.
+
+* The platform specific ``pwr_domain_suspend`` handler remains unchanged.
.. image:: ../resources/diagrams/psci-osi-mode.png
diff --git a/docs/porting-guide.rst b/docs/porting-guide.rst
index 1250071..8182f91 100644
--- a/docs/porting-guide.rst
+++ b/docs/porting-guide.rst
@@ -2818,6 +2818,17 @@
for the higher power domain levels depending on the result of state
coordination. The generic code expects the handler to succeed.
+plat_psci_ops.pwr_domain_validate_suspend() [optional]
+......................................................
+
+This is an optional function that is only compiled into the build if the build
+option ``PSCI_OS_INIT_MODE`` is enabled.
+
+If implemented, this function allows the platform to perform platform specific
+validations based on hardware states. The generic code expects this function to
+return PSCI_E_SUCCESS on success, or either PSCI_E_DENIED or
+PSCI_E_INVALID_PARAMS as appropriate for any invalid requests.
+
plat_psci_ops.pwr_domain_suspend_pwrdown_early() [optional]
...........................................................
@@ -2876,10 +2887,6 @@
data, for example in DRAM. The Distributor can then be powered down using an
implementation-defined sequence.
-If the build option ``PSCI_OS_INIT_MODE`` is enabled, the generic code expects
-the platform to return PSCI_E_SUCCESS on success, or either PSCI_E_DENIED or
-PSCI_E_INVALID_PARAMS as appropriate for any invalid requests.
-
plat_psci_ops.pwr_domain_pwr_down_wfi()
.......................................
diff --git a/docs/resources/diagrams/psci-osi-mode.png b/docs/resources/diagrams/psci-osi-mode.png
index d322953..09175e5 100644
--- a/docs/resources/diagrams/psci-osi-mode.png
+++ b/docs/resources/diagrams/psci-osi-mode.png
Binary files differ
diff --git a/include/lib/psci/psci.h b/include/lib/psci/psci.h
index 4d7e58e..01dc3cb 100644
--- a/include/lib/psci/psci.h
+++ b/include/lib/psci/psci.h
@@ -319,13 +319,13 @@
int (*pwr_domain_on)(u_register_t mpidr);
void (*pwr_domain_off)(const psci_power_state_t *target_state);
int (*pwr_domain_off_early)(const psci_power_state_t *target_state);
+#if PSCI_OS_INIT_MODE
+ int (*pwr_domain_validate_suspend)(
+ const psci_power_state_t *target_state);
+#endif
void (*pwr_domain_suspend_pwrdown_early)(
const psci_power_state_t *target_state);
-#if PSCI_OS_INIT_MODE
- int (*pwr_domain_suspend)(const psci_power_state_t *target_state);
-#else
void (*pwr_domain_suspend)(const psci_power_state_t *target_state);
-#endif
void (*pwr_domain_on_finish)(const psci_power_state_t *target_state);
void (*pwr_domain_on_finish_late)(
const psci_power_state_t *target_state);
diff --git a/lib/psci/psci_common.c b/lib/psci/psci_common.c
index c893476..bfc09cc 100644
--- a/lib/psci/psci_common.c
+++ b/lib/psci/psci_common.c
@@ -451,8 +451,8 @@
* enter. This function will be called after coordination of requested power
* states has been done for each power level.
*****************************************************************************/
-static void psci_set_target_local_pwr_states(unsigned int end_pwrlvl,
- const psci_power_state_t *target_state)
+void psci_set_target_local_pwr_states(unsigned int end_pwrlvl,
+ const psci_power_state_t *target_state)
{
unsigned int parent_idx, lvl;
const plat_local_state_t *pd_state = target_state->pwr_domain_state;
@@ -474,7 +474,6 @@
}
}
-
/*******************************************************************************
* PSCI helper function to get the parent nodes corresponding to a cpu_index.
******************************************************************************/
@@ -595,9 +594,6 @@
state_info->pwr_domain_state[lvl] = PSCI_LOCAL_STATE_RUN;
}
-
- /* Update the target state in the power domain nodes */
- psci_set_target_local_pwr_states(end_pwrlvl, state_info);
}
#if PSCI_OS_INIT_MODE
@@ -684,9 +680,6 @@
return rc;
}
- /* Update the target state in the power domain nodes */
- psci_set_target_local_pwr_states(end_pwrlvl, state_info);
-
return rc;
}
#endif
diff --git a/lib/psci/psci_off.c b/lib/psci/psci_off.c
index 9f36ac7..f83753f 100644
--- a/lib/psci/psci_off.c
+++ b/lib/psci/psci_off.c
@@ -104,6 +104,9 @@
*/
psci_do_state_coordination(end_pwrlvl, &state_info);
+ /* Update the target state in the power domain nodes */
+ psci_set_target_local_pwr_states(end_pwrlvl, &state_info);
+
#if ENABLE_PSCI_STAT
/* Update the last cpu for each level till end_pwrlvl */
psci_stats_update_pwr_down(end_pwrlvl, &state_info);
diff --git a/lib/psci/psci_private.h b/lib/psci/psci_private.h
index b9987fe..04f93bd 100644
--- a/lib/psci/psci_private.h
+++ b/lib/psci/psci_private.h
@@ -298,6 +298,8 @@
#endif
void psci_get_target_local_pwr_states(unsigned int end_pwrlvl,
psci_power_state_t *target_state);
+void psci_set_target_local_pwr_states(unsigned int end_pwrlvl,
+ const psci_power_state_t *target_state);
int psci_validate_entry_point(entry_point_info_t *ep,
uintptr_t entrypoint, u_register_t context_id);
void psci_get_parent_pwr_domain_nodes(unsigned int cpu_idx,
diff --git a/lib/psci/psci_suspend.c b/lib/psci/psci_suspend.c
index 861b875..d93e60d 100644
--- a/lib/psci/psci_suspend.c
+++ b/lib/psci/psci_suspend.c
@@ -219,6 +219,19 @@
}
#endif
+#if PSCI_OS_INIT_MODE
+ if (psci_plat_pm_ops->pwr_domain_validate_suspend != NULL) {
+ rc = psci_plat_pm_ops->pwr_domain_validate_suspend(state_info);
+ if (rc != PSCI_E_SUCCESS) {
+ skip_wfi = true;
+ goto exit;
+ }
+ }
+#endif
+
+ /* Update the target state in the power domain nodes */
+ psci_set_target_local_pwr_states(end_pwrlvl, state_info);
+
#if ENABLE_PSCI_STAT
/* Update the last cpu for each level till end_pwrlvl */
psci_stats_update_pwr_down(end_pwrlvl, state_info);
@@ -234,15 +247,7 @@
* program the power controller etc.
*/
-#if PSCI_OS_INIT_MODE
- rc = psci_plat_pm_ops->pwr_domain_suspend(state_info);
- if (rc != PSCI_E_SUCCESS) {
- skip_wfi = true;
- goto exit;
- }
-#else
psci_plat_pm_ops->pwr_domain_suspend(state_info);
-#endif
#if ENABLE_PSCI_STAT
plat_psci_stat_accounting_start(state_info);
