PSCI: Demonstrate support for composite power states
This patch adds support to the Juno and FVP ports for composite power states
with both the original and extended state-id power-state formats. Both the
platform ports use the recommended state-id encoding as specified in
Section 6.5 of the PSCI specification (ARM DEN 0022C). The platform build flag
ARM_RECOM_STATE_ID_ENC is used to include this support.
By default, to maintain backwards compatibility, the original power state
parameter format is used and the state-id field is expected to be zero.
Change-Id: Ie721b961957eaecaca5bf417a30952fe0627ef10
diff --git a/docs/user-guide.md b/docs/user-guide.md
index 5be3c3d..b9b69b3 100644
--- a/docs/user-guide.md
+++ b/docs/user-guide.md
@@ -394,6 +394,14 @@
this option, `arm_rotprivk_rsa.pem` must be specified as `ROT_KEY` when
creating the certificates.
+* `ARM_RECOM_STATE_ID_ENC`: The PSCI1.0 specification recommends an encoding
+ for the construction of composite state-ID in the power-state parameter.
+ The existing PSCI clients currently do not support this encoding of
+ State-ID yet. Hence this flag is used to configure whether to use the
+ recommended State-ID encoding or not. The default value of this flag is 0,
+ in which case the platform is configured to expect NULL in the State-ID
+ field of power-state parameter.
+
#### ARM CSS platform specific build options
* `CSS_DETECT_PRE_1_7_0_SCP`: Boolean flag to detect SCP version
diff --git a/include/plat/arm/common/plat_arm.h b/include/plat/arm/common/plat_arm.h
index 29f1c90..56b5eda 100644
--- a/include/plat/arm/common/plat_arm.h
+++ b/include/plat/arm/common/plat_arm.h
@@ -148,6 +148,35 @@
#endif /* IMAGE_BL31 */
+#if ARM_RECOM_STATE_ID_ENC
+/*
+ * Macros used to parse state information from State-ID if it is using the
+ * recommended encoding for State-ID.
+ */
+#define ARM_LOCAL_PSTATE_WIDTH 4
+#define ARM_LOCAL_PSTATE_MASK ((1 << ARM_LOCAL_PSTATE_WIDTH) - 1)
+
+/* Macros to construct the composite power state */
+
+/* Make composite power state parameter till power level 0 */
+#if PSCI_EXTENDED_STATE_ID
+
+#define arm_make_pwrstate_lvl0(lvl0_state, pwr_lvl, type) \
+ (((lvl0_state) << PSTATE_ID_SHIFT) | ((type) << PSTATE_TYPE_SHIFT))
+#else
+#define arm_make_pwrstate_lvl0(lvl0_state, pwr_lvl, type) \
+ (((lvl0_state) << PSTATE_ID_SHIFT) | \
+ ((pwr_lvl) << PSTATE_PWR_LVL_SHIFT) | \
+ ((type) << PSTATE_TYPE_SHIFT))
+#endif /* __PSCI_EXTENDED_STATE_ID__ */
+
+/* Make composite power state parameter till power level 1 */
+#define arm_make_pwrstate_lvl1(lvl1_state, lvl0_state, pwr_lvl, type) \
+ (((lvl1_state) << ARM_LOCAL_PSTATE_WIDTH) | \
+ arm_make_pwrstate_lvl0(lvl0_state, pwr_lvl, type))
+
+#endif /* __ARM_RECOM_STATE_ID_ENC__ */
+
/* CCI utility functions */
void arm_cci_init(void);
diff --git a/plat/arm/board/fvp/fvp_pm.c b/plat/arm/board/fvp/fvp_pm.c
index c59ffd1..56d6502 100644
--- a/plat/arm/board/fvp/fvp_pm.c
+++ b/plat/arm/board/fvp/fvp_pm.c
@@ -49,6 +49,27 @@
unsigned long value __aligned(CACHE_WRITEBACK_GRANULE);
} mailbox_t;
+#if ARM_RECOM_STATE_ID_ENC
+/*
+ * The table storing the valid idle power states. Ensure that the
+ * array entries are populated in ascending order of state-id to
+ * enable us to use binary search during power state validation.
+ * The table must be terminated by a NULL entry.
+ */
+const unsigned int arm_pm_idle_states[] = {
+ /* State-id - 0x01 */
+ arm_make_pwrstate_lvl1(ARM_LOCAL_STATE_RUN, ARM_LOCAL_STATE_RET,
+ ARM_PWR_LVL0, PSTATE_TYPE_STANDBY),
+ /* State-id - 0x02 */
+ arm_make_pwrstate_lvl1(ARM_LOCAL_STATE_RUN, ARM_LOCAL_STATE_OFF,
+ ARM_PWR_LVL0, PSTATE_TYPE_POWERDOWN),
+ /* State-id - 0x22 */
+ arm_make_pwrstate_lvl1(ARM_LOCAL_STATE_OFF, ARM_LOCAL_STATE_OFF,
+ ARM_PWR_LVL1, PSTATE_TYPE_POWERDOWN),
+ 0,
+};
+#endif
+
/*******************************************************************************
* Private FVP function to program the mailbox for a cpu before it is released
* from reset.
diff --git a/plat/arm/common/arm_common.mk b/plat/arm/common/arm_common.mk
index eb2f750..1234619 100644
--- a/plat/arm/common/arm_common.mk
+++ b/plat/arm/common/arm_common.mk
@@ -46,6 +46,23 @@
# Process flags
$(eval $(call add_define,ARM_TSP_RAM_LOCATION_ID))
+# For the original power-state parameter format, the State-ID can be encoded
+# according to the recommended encoding or zero. This flag determines which
+# State-ID encoding to be parsed.
+ARM_RECOM_STATE_ID_ENC := 0
+
+# If the PSCI_EXTENDED_STATE_ID is set, then the recommended state ID need to
+# be used. Else throw a build error.
+ifeq (${PSCI_EXTENDED_STATE_ID}, 1)
+ ifeq (${ARM_RECOM_STATE_ID_ENC}, 0)
+ $(error "Incompatible STATE_ID build option specified")
+ endif
+endif
+
+# Process ARM_RECOM_STATE_ID_ENC flag
+$(eval $(call assert_boolean,ARM_RECOM_STATE_ID_ENC))
+$(eval $(call add_define,ARM_RECOM_STATE_ID_ENC))
+
PLAT_INCLUDES += -Iinclude/common/tbbr \
-Iinclude/plat/arm/common \
-Iinclude/plat/arm/common/aarch64
diff --git a/plat/arm/common/arm_pm.c b/plat/arm/common/arm_pm.c
index 3f47309..71fbf9f 100644
--- a/plat/arm/common/arm_pm.c
+++ b/plat/arm/common/arm_pm.c
@@ -31,8 +31,15 @@
#include <arch_helpers.h>
#include <assert.h>
#include <errno.h>
+#include <plat_arm.h>
#include <psci.h>
+#if ARM_RECOM_STATE_ID_ENC
+extern unsigned int arm_pm_idle_states[];
+#endif /* __ARM_RECOM_STATE_ID_ENC__ */
+
+
+#if !ARM_RECOM_STATE_ID_ENC
/*******************************************************************************
* ARM standard platform handler called to check the validity of the power state
* parameter.
@@ -74,3 +81,45 @@
return PSCI_E_SUCCESS;
}
+
+#else
+/*******************************************************************************
+ * ARM standard platform handler called to check the validity of the power
+ * state parameter. The power state parameter has to be a composite power
+ * state.
+ ******************************************************************************/
+int arm_validate_power_state(unsigned int power_state,
+ psci_power_state_t *req_state)
+{
+ unsigned int state_id;
+ int i;
+
+ assert(req_state);
+
+ /*
+ * Currently we are using a linear search for finding the matching
+ * entry in the idle power state array. This can be made a binary
+ * search if the number of entries justify the additional complexity.
+ */
+ for (i = 0; !!arm_pm_idle_states[i]; i++) {
+ if (power_state == arm_pm_idle_states[i])
+ break;
+ }
+
+ /* Return error if entry not found in the idle state array */
+ if (!arm_pm_idle_states[i])
+ return PSCI_E_INVALID_PARAMS;
+
+ i = 0;
+ state_id = psci_get_pstate_id(power_state);
+
+ /* Parse the State ID and populate the state info parameter */
+ while (state_id) {
+ req_state->pwr_domain_state[i++] = state_id &
+ ARM_LOCAL_PSTATE_MASK;
+ state_id >>= ARM_LOCAL_PSTATE_WIDTH;
+ }
+
+ return PSCI_E_SUCCESS;
+}
+#endif /* __ARM_RECOM_STATE_ID_ENC__ */
diff --git a/plat/arm/css/common/css_pm.c b/plat/arm/css/common/css_pm.c
index 55b1703..49c364d 100644
--- a/plat/arm/css/common/css_pm.c
+++ b/plat/arm/css/common/css_pm.c
@@ -43,6 +43,27 @@
unsigned long wakeup_address;
+#if ARM_RECOM_STATE_ID_ENC
+/*
+ * The table storing the valid idle power states. Ensure that the
+ * array entries are populated in ascending order of state-id to
+ * enable us to use binary search during power state validation.
+ * The table must be terminated by a NULL entry.
+ */
+const unsigned int arm_pm_idle_states[] = {
+ /* State-id - 0x01 */
+ arm_make_pwrstate_lvl1(ARM_LOCAL_STATE_RUN, ARM_LOCAL_STATE_RET,
+ ARM_PWR_LVL0, PSTATE_TYPE_STANDBY),
+ /* State-id - 0x02 */
+ arm_make_pwrstate_lvl1(ARM_LOCAL_STATE_RUN, ARM_LOCAL_STATE_OFF,
+ ARM_PWR_LVL0, PSTATE_TYPE_POWERDOWN),
+ /* State-id - 0x22 */
+ arm_make_pwrstate_lvl1(ARM_LOCAL_STATE_OFF, ARM_LOCAL_STATE_OFF,
+ ARM_PWR_LVL1, PSTATE_TYPE_POWERDOWN),
+ 0,
+};
+#endif
+
/*******************************************************************************
* Private function to program the mailbox for a cpu before it is released
* from reset.
