PSCI: Implement platform compatibility layer

The new PSCI topology framework and PSCI extended State framework introduces
a breaking change in the platform port APIs. To ease the migration of the
platform ports to the new porting interface, a compatibility layer is
introduced which essentially defines the new platform API in terms of the
old API. The old PSCI helpers to retrieve the power-state, its associated
fields and the highest coordinated physical OFF affinity level of a core
are also implemented for compatibility. This allows the existing
platform ports to work with the new PSCI framework without significant
rework. This layer will be enabled by default once the switch to the new
PSCI framework is done and is controlled by the build flag ENABLE_PLAT_COMPAT.

Change-Id: I4b17cac3a4f3375910a36dba6b03d8f1700d07e3

2 files changed, 115 insertions, 2 deletions

diff --git a/include/bl31/services/psci1.0/psci.h b/include/bl31/services/psci1.0/psci.h
index fe23711e..93611876 100644
--- a/include/bl31/services/psci1.0/psci.h
+++ b/include/bl31/services/psci1.0/psci.h
@@ -33,6 +33,9 @@
 
 #include <bakery_lock.h>
 #include <platform_def.h>	/* for PLAT_NUM_PWR_DOMAINS */
+#if ENABLE_PLAT_COMPAT
+#include <psci_compat.h>
+#endif
 
 /*******************************************************************************
  * Number of power domains whose state this psci imp. can track
@@ -316,8 +319,6 @@ uint64_t psci_smc_handler(uint32_t smc_fid,
 /* PSCI setup function */
 int32_t psci_setup(void);
 
-
 #endif /*__ASSEMBLY__*/
 
-
 #endif /* __PSCI_H__ */
diff --git a/include/bl31/services/psci1.0/psci_compat.h b/include/bl31/services/psci1.0/psci_compat.h
new file mode 100644
index 00000000..cc80ae30
--- /dev/null
+++ b/include/bl31/services/psci1.0/psci_compat.h
@@ -0,0 +1,112 @@
+/*
+ * Copyright (c) 2015, 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.
+ */
+
+#ifndef __PSCI_COMPAT_H__
+#define __PSCI_COMPAT_H__
+
+#include <arch.h>
+#include <platform_def.h>
+
+#ifndef __ASSEMBLY__
+/*
+ * The below declarations are to enable compatibility for the platform ports
+ * using the old platform interface and psci helpers.
+ */
+#define PLAT_MAX_PWR_LVL	PLATFORM_MAX_AFFLVL
+#define PLAT_NUM_PWR_DOMAINS	PLATFORM_NUM_AFFS
+
+/*******************************************************************************
+ * PSCI affinity related constants. An affinity instance could
+ * be present or absent physically to cater for asymmetric topologies.
+ ******************************************************************************/
+#define PSCI_AFF_ABSENT		0x0
+#define PSCI_AFF_PRESENT	0x1
+
+#define PSCI_STATE_ON		0x0
+#define PSCI_STATE_OFF		0x1
+#define PSCI_STATE_ON_PENDING	0x2
+#define PSCI_STATE_SUSPEND	0x3
+
+/*
+ * Using the compatibility platform interfaces means that the local states
+ * used in psci_power_state_t need to only convey whether its power down
+ * or standby state. The onus is on the platform port to do the right thing
+ * including the state coordination in case multiple power down states are
+ * involved. Hence if we assume 3 generic states viz, run, standby and
+ * power down, we can assign 1 and 2 to standby and power down respectively.
+ */
+#define PLAT_MAX_RET_STATE	1
+#define PLAT_MAX_OFF_STATE	2
+
+
+#define psci_get_pstate_afflvl(pstate)		psci_get_pstate_pwrlvl(pstate)
+
+/*
+ * This array stores the 'power_state' requests of each CPU during
+ * CPU_SUSPEND and SYSTEM_SUSPEND which will be populated by the
+ * compatibility layer when appropriate platform hooks are invoked.
+ */
+extern unsigned int psci_power_state_compat[PLATFORM_CORE_COUNT];
+
+/*******************************************************************************
+ * Structure populated by platform specific code to export routines which
+ * perform common low level pm functions
+ ******************************************************************************/
+typedef struct plat_pm_ops {
+	void (*affinst_standby)(unsigned int power_state);
+	int (*affinst_on)(unsigned long mpidr,
+			  unsigned long sec_entrypoint,
+			  unsigned int afflvl,
+			  unsigned int state);
+	void (*affinst_off)(unsigned int afflvl, unsigned int state);
+	void (*affinst_suspend)(unsigned long sec_entrypoint,
+			       unsigned int afflvl,
+			       unsigned int state);
+	void (*affinst_on_finish)(unsigned int afflvl, unsigned int state);
+	void (*affinst_suspend_finish)(unsigned int afflvl,
+				      unsigned int state);
+	void (*system_off)(void) __dead2;
+	void (*system_reset)(void) __dead2;
+	int (*validate_power_state)(unsigned int power_state);
+	int (*validate_ns_entrypoint)(unsigned long ns_entrypoint);
+	unsigned int (*get_sys_suspend_power_state)(void);
+} plat_pm_ops_t;
+
+/*******************************************************************************
+ * Function & Data prototypes to enable compatibility for older platform ports
+ ******************************************************************************/
+int psci_get_suspend_stateid_by_mpidr(unsigned long);
+int psci_get_suspend_stateid(void);
+int psci_get_suspend_powerstate(void);
+unsigned int psci_get_max_phys_off_afflvl(void);
+int psci_get_suspend_afflvl(void);
+
+#endif /* ____ASSEMBLY__ */
+#endif /* __PSCI_COMPAT_H__ */