CSS: Allow system suspend only via PSCI SYSTEM_SUSPEND API
The CSS power management layer previously allowed to suspend system
power domain level via both PSCI CPU_SUSPEND and PSCI SYSTEM_SUSPEND
APIs. System suspend via PSCI CPU_SUSPEND was always problematic to
support because of issues with targeting wakeup interrupts to
suspended cores before the per-cpu GIC initialization is done. This
is not the case for PSCI SYSTEM_SUSPEND API because all the other
cores are expected to be offlined prior to issuing system suspend and
PSCI CPU_ON explicit calls will be made to power them on. Hence the Juno
platform used to downgrade the PSCI CPU_SUSPEND request for system
power domain level to cluster level by overriding the default
`plat_psci_pm_ops` exported by CSS layer.
Given the direction the new CSS platforms are evolving, it is best to
limit the system suspend only via PSCI SYSTEM_SUSPEND API for all
CSS platforms. This patch makes changes to allow system suspend
only via PSCI SYSTEM_SUSPEND API. The override of `plat_psci_ops`
for Juno is removed.
Change-Id: Idb30eaad04890dd46074e9e888caeedc50a4b533
Signed-off-by: Soby Mathew <soby.mathew@arm.com>
diff --git a/include/plat/arm/css/common/css_pm.h b/include/plat/arm/css/common/css_pm.h
index 489275e..1e1bab7 100644
--- a/include/plat/arm/css/common/css_pm.h
+++ b/include/plat/arm/css/common/css_pm.h
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2015-2016, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2015-2017, ARM Limited and Contributors. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
@@ -35,11 +35,15 @@
#include <psci.h>
#include <types.h>
+/* System power domain at level 2, as currently implemented by CSS platforms */
+#define CSS_SYSTEM_PWR_DMN_LVL ARM_PWR_LVL2
+
/* Macros to read the CSS power domain state */
#define CSS_CORE_PWR_STATE(state) (state)->pwr_domain_state[ARM_PWR_LVL0]
#define CSS_CLUSTER_PWR_STATE(state) (state)->pwr_domain_state[ARM_PWR_LVL1]
-#define CSS_SYSTEM_PWR_STATE(state) ((PLAT_MAX_PWR_LVL > ARM_PWR_LVL1) ?\
- (state)->pwr_domain_state[ARM_PWR_LVL2] : 0)
+#define CSS_SYSTEM_PWR_STATE(state) \
+ ((PLAT_MAX_PWR_LVL == CSS_SYSTEM_PWR_DMN_LVL) ?\
+ (state)->pwr_domain_state[CSS_SYSTEM_PWR_DMN_LVL] : 0)
int css_pwr_domain_on(u_register_t mpidr);
void css_pwr_domain_on_finish(const psci_power_state_t *target_state);
diff --git a/plat/arm/board/juno/juno_pm.c b/plat/arm/board/juno/juno_pm.c
deleted file mode 100644
index c0fa628..0000000
--- a/plat/arm/board/juno/juno_pm.c
+++ /dev/null
@@ -1,93 +0,0 @@
-/*
- * Copyright (c) 2015-2016, ARM Limited and Contributors. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *
- * Redistributions of source code must retain the above copyright notice, this
- * list of conditions and the following disclaimer.
- *
- * Redistributions in binary form must reproduce the above copyright notice,
- * this list of conditions and the following disclaimer in the documentation
- * and/or other materials provided with the distribution.
- *
- * Neither the name of ARM nor the names of its contributors may be used
- * to endorse or promote products derived from this software without specific
- * prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
- * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
- * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
- * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
- * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGE.
- */
-#include <css_pm.h>
-#include <plat_arm.h>
-
-/*
- * Custom `validate_power_state` handler for Juno. According to PSCI
- * Specification, interrupts targeted to cores in PSCI CPU SUSPEND should
- * be able to resume it. On Juno, when the system power domain is suspended,
- * the GIC is also powered down. The SCP resumes the final core to be suspend
- * when an external wake-up event is received. But the other cores cannot be
- * woken up by a targeted interrupt, because GIC doesn't forward these
- * interrupts to the SCP. Due to this hardware limitation, we down-grade PSCI
- * CPU SUSPEND requests targeted to the system power domain level
- * to cluster power domain level.
- *
- * The system power domain suspend on Juno is only supported only via
- * PSCI SYSTEM SUSPEND API.
- */
-static int juno_validate_power_state(unsigned int power_state,
- psci_power_state_t *req_state)
-{
- int rc;
- rc = arm_validate_power_state(power_state, req_state);
-
- /*
- * Ensure that the system power domain level is never suspended
- * via PSCI CPU SUSPEND API. Currently system suspend is only
- * supported via PSCI SYSTEM SUSPEND API.
- */
- req_state->pwr_domain_state[ARM_PWR_LVL2] = ARM_LOCAL_STATE_RUN;
- return rc;
-}
-
-/*
- * Custom `translate_power_state_by_mpidr` handler for Juno. Unlike in the
- * `juno_validate_power_state`, we do not down-grade the system power
- * domain level request in `power_state` as it will be used to query the
- * PSCI_STAT_COUNT/RESIDENCY at the system power domain level.
- */
-static int juno_translate_power_state_by_mpidr(u_register_t mpidr,
- unsigned int power_state,
- psci_power_state_t *output_state)
-{
- return arm_validate_power_state(power_state, output_state);
-}
-
-/*******************************************************************************
- * Export the platform handlers via plat_arm_psci_pm_ops. The ARM Standard
- * platform will take care of registering the handlers with PSCI.
- ******************************************************************************/
-plat_psci_ops_t plat_arm_psci_pm_ops = {
- .pwr_domain_on = css_pwr_domain_on,
- .pwr_domain_on_finish = css_pwr_domain_on_finish,
- .pwr_domain_off = css_pwr_domain_off,
- .cpu_standby = css_cpu_standby,
- .pwr_domain_suspend = css_pwr_domain_suspend,
- .pwr_domain_suspend_finish = css_pwr_domain_suspend_finish,
- .system_off = css_system_off,
- .system_reset = css_system_reset,
- .validate_power_state = juno_validate_power_state,
- .validate_ns_entrypoint = arm_validate_ns_entrypoint,
- .get_sys_suspend_power_state = css_get_sys_suspend_power_state,
- .translate_power_state_by_mpidr = juno_translate_power_state_by_mpidr,
- .get_node_hw_state = css_node_hw_state
-};
diff --git a/plat/arm/board/juno/platform.mk b/plat/arm/board/juno/platform.mk
index 0855438..e29f8c8 100644
--- a/plat/arm/board/juno/platform.mk
+++ b/plat/arm/board/juno/platform.mk
@@ -73,7 +73,6 @@
BL31_SOURCES += lib/cpus/aarch64/cortex_a53.S \
lib/cpus/aarch64/cortex_a57.S \
lib/cpus/aarch64/cortex_a72.S \
- plat/arm/board/juno/juno_pm.c \
plat/arm/board/juno/juno_topology.c \
${JUNO_GIC_SOURCES} \
${JUNO_INTERCONNECT_SOURCES} \
diff --git a/plat/arm/css/common/css_pm.c b/plat/arm/css/common/css_pm.c
index d4dd0af..21ce865 100644
--- a/plat/arm/css/common/css_pm.c
+++ b/plat/arm/css/common/css_pm.c
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2015-2016, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2015-2017, ARM Limited and Contributors. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
@@ -75,6 +75,13 @@
CASSERT(PLAT_MAX_PWR_LVL >= ARM_PWR_LVL1,
assert_max_pwr_lvl_supported_mismatch);
+/*
+ * Ensure that the PLAT_MAX_PWR_LVL is not greater than CSS_SYSTEM_PWR_DMN_LVL
+ * assumed by the CSS layer.
+ */
+CASSERT(PLAT_MAX_PWR_LVL <= CSS_SYSTEM_PWR_DMN_LVL,
+ assert_max_pwr_lvl_higher_than_css_sys_lvl);
+
/*******************************************************************************
* Handler called when a power domain is about to be turned on. The
* level and mpidr determine the affinity instance.
@@ -243,7 +250,7 @@
* System Suspend is supported only if the system power domain node
* is implemented.
*/
- assert(PLAT_MAX_PWR_LVL >= ARM_PWR_LVL2);
+ assert(PLAT_MAX_PWR_LVL == CSS_SYSTEM_PWR_DMN_LVL);
for (i = ARM_PWR_LVL0; i <= PLAT_MAX_PWR_LVL; i++)
req_state->pwr_domain_state[i] = ARM_LOCAL_STATE_OFF;
@@ -257,6 +264,39 @@
return css_scp_get_power_state(mpidr, power_level);
}
+/*
+ * The system power domain suspend is only supported only via
+ * PSCI SYSTEM_SUSPEND API. PSCI CPU_SUSPEND request to system power domain
+ * will be downgraded to the lower level.
+ */
+static int css_validate_power_state(unsigned int power_state,
+ psci_power_state_t *req_state)
+{
+ int rc;
+ rc = arm_validate_power_state(power_state, req_state);
+
+ /*
+ * Ensure that the system power domain level is never suspended
+ * via PSCI CPU SUSPEND API. Currently system suspend is only
+ * supported via PSCI SYSTEM SUSPEND API.
+ */
+ req_state->pwr_domain_state[CSS_SYSTEM_PWR_DMN_LVL] = ARM_LOCAL_STATE_RUN;
+ return rc;
+}
+
+/*
+ * Custom `translate_power_state_by_mpidr` handler for CSS. Unlike in the
+ * `css_validate_power_state`, we do not downgrade the system power
+ * domain level request in `power_state` as it will be used to query the
+ * PSCI_STAT_COUNT/RESIDENCY at the system power domain level.
+ */
+static int css_translate_power_state_by_mpidr(u_register_t mpidr,
+ unsigned int power_state,
+ psci_power_state_t *output_state)
+{
+ return arm_validate_power_state(power_state, output_state);
+}
+
/*******************************************************************************
* Export the platform handlers via plat_arm_psci_pm_ops. The ARM Standard
* platform will take care of registering the handlers with PSCI.
@@ -270,7 +310,9 @@
.pwr_domain_suspend_finish = css_pwr_domain_suspend_finish,
.system_off = css_system_off,
.system_reset = css_system_reset,
- .validate_power_state = arm_validate_power_state,
+ .validate_power_state = css_validate_power_state,
.validate_ns_entrypoint = arm_validate_ns_entrypoint,
- .get_node_hw_state = css_node_hw_state
+ .translate_power_state_by_mpidr = css_translate_power_state_by_mpidr,
+ .get_node_hw_state = css_node_hw_state,
+ .get_sys_suspend_power_state = css_get_sys_suspend_power_state
};
