Reorganise PSCI PM handler setup on ARM Standard platforms

This patch does the following reorganization to psci power management (PM)
handler setup for ARM standard platform ports :

1. The mailbox programming required during `plat_setup_psci_ops()` is identical
   for all ARM platforms. Hence the implementation of this API is now moved
   to the common `arm_pm.c` file. Each ARM platform now must define the
   PLAT_ARM_TRUSTED_MAILBOX_BASE macro, which in current platforms is the same
   as ARM_SHARED_RAM_BASE.

2. The PSCI PM handler callback structure, `plat_psci_ops`, must now be
   exported via `plat_arm_psci_pm_ops`. This allows the common implementation
   of `plat_setup_psci_ops()` to return a platform specific `plat_psci_ops`.
   In the case of CSS platforms, a default weak implementation of the same is
   provided in `css_pm.c` which can be overridden by each CSS platform.

3. For CSS platforms, the PSCI PM handlers defined in `css_pm.c` are now
   made library functions and a new header file `css_pm.h` is added to export
   these generic PM handlers. This allows the platform to reuse the
   adequate CSS PM handlers and redefine others which need to be customized
   when overriding the default `plat_arm_psci_pm_ops` in `css_pm.c`.

Change-Id: I277910f609e023ee5d5ff0129a80ecfce4356ede

9 files changed, 116 insertions, 73 deletions

diff --git a/include/plat/arm/css/common/css_def.h b/include/plat/arm/css/common/css_def.h
index 38ff9ddd..98b69cb3 100644
--- a/include/plat/arm/css/common/css_def.h
+++ b/include/plat/arm/css/common/css_def.h
@@ -39,8 +39,6 @@
  *************************************************************************/
 #define MHU_PAYLOAD_CACHED		0
 
-#define TRUSTED_MAILBOX_BASE		ARM_TRUSTED_SRAM_BASE
-
 #define NSROM_BASE			0x1f000000
 #define NSROM_SIZE			0x00001000
 
@@ -116,4 +114,8 @@
 /* System timer related constants */
 #define PLAT_ARM_NSTIMER_FRAME_ID	1
 
+/* Trusted mailbox base address common to all CSS */
+#define PLAT_ARM_TRUSTED_MAILBOX_BASE	ARM_TRUSTED_SRAM_BASE
+
+
 #endif /* __CSS_DEF_H__ */
diff --git a/include/plat/arm/css/common/css_pm.h b/include/plat/arm/css/common/css_pm.h
new file mode 100644
index 00000000..c19df92b
--- /dev/null
+++ b/include/plat/arm/css/common/css_pm.h
@@ -0,0 +1,48 @@
+/*
+ * 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 __CSS_PM_H__
+#define __CSS_PM_H__
+
+#include <cdefs.h>
+#include <psci.h>
+#include <types.h>
+
+int css_pwr_domain_on(u_register_t mpidr);
+void css_pwr_domain_on_finish(const psci_power_state_t *target_state);
+void css_pwr_domain_off(const psci_power_state_t *target_state);
+void css_pwr_domain_suspend(const psci_power_state_t *target_state);
+void css_pwr_domain_suspend_finish(
+				const psci_power_state_t *target_state);
+void __dead2 css_system_off(void);
+void __dead2 css_system_reset(void);
+void css_cpu_standby(plat_local_state_t cpu_state);
+
+#endif /* __CSS_PM_H__ */
diff --git a/plat/arm/board/fvp/aarch64/fvp_helpers.S b/plat/arm/board/fvp/aarch64/fvp_helpers.S
index 42e5b70c..865c615a 100644
--- a/plat/arm/board/fvp/aarch64/fvp_helpers.S
+++ b/plat/arm/board/fvp/aarch64/fvp_helpers.S
@@ -140,7 +140,7 @@ warm_reset:
 	 * it here with SO attributes.
 	 * ---------------------------------------------------------------------
 	 */
-	mov_imm	x0, MBOX_BASE
+	mov_imm	x0, PLAT_ARM_TRUSTED_MAILBOX_BASE
 	ldr	x0, [x0]
 	cbz	x0, _panic
 	ret
diff --git a/plat/arm/board/fvp/fvp_def.h b/plat/arm/board/fvp/fvp_def.h
index 9a9eebfc..3af4db68 100644
--- a/plat/arm/board/fvp/fvp_def.h
+++ b/plat/arm/board/fvp/fvp_def.h
@@ -134,12 +134,4 @@
 #define FVP_NSAID_HDLCD0		2
 #define FVP_NSAID_CLCD			7
 
-/*******************************************************************************
- *  Shared Data
- ******************************************************************************/
-
-/* Entrypoint mailboxes */
-#define MBOX_BASE			ARM_SHARED_RAM_BASE
-
-
 #endif /* __FVP_DEF_H__ */
diff --git a/plat/arm/board/fvp/fvp_pm.c b/plat/arm/board/fvp/fvp_pm.c
index 9d6ab9ce..21ad14fa 100644
--- a/plat/arm/board/fvp/fvp_pm.c
+++ b/plat/arm/board/fvp/fvp_pm.c
@@ -66,17 +66,6 @@ const unsigned int arm_pm_idle_states[] = {
 #endif
 
 /*******************************************************************************
- * Private FVP function to program the mailbox for a cpu before it is released
- * from reset.
- ******************************************************************************/
-static void fvp_program_mailbox(uintptr_t address)
-{
-	uintptr_t *mailbox = (void *) MBOX_BASE;
-	*mailbox = address;
-	flush_dcache_range((uintptr_t) mailbox, sizeof(*mailbox));
-}
-
-/*******************************************************************************
  * Function which implements the common FVP specific operations to power down a
  * cpu in response to a CPU_OFF or CPU_SUSPEND request.
  ******************************************************************************/
@@ -293,9 +282,10 @@ static void __dead2 fvp_system_reset(void)
 }
 
 /*******************************************************************************
- * Export the platform handlers to enable psci to invoke them
+ * Export the platform handlers via plat_arm_psci_pm_ops. The ARM Standard
+ * platform layer will take care of registering the handlers with PSCI.
  ******************************************************************************/
-static const plat_psci_ops_t fvp_plat_psci_ops = {
+const plat_psci_ops_t plat_arm_psci_pm_ops = {
 	.cpu_standby = fvp_cpu_standby,
 	.pwr_domain_on = fvp_pwr_domain_on,
 	.pwr_domain_off = fvp_pwr_domain_off,
@@ -307,16 +297,3 @@ static const plat_psci_ops_t fvp_plat_psci_ops = {
 	.validate_power_state = arm_validate_power_state,
 	.validate_ns_entrypoint = arm_validate_ns_entrypoint
 };
-
-/*******************************************************************************
- * Export the platform specific psci ops & initialize the fvp power controller
- ******************************************************************************/
-int plat_setup_psci_ops(uintptr_t sec_entrypoint,
-				const plat_psci_ops_t **psci_ops)
-{
-	*psci_ops = &fvp_plat_psci_ops;
-
-	/* Program the jump address */
-	fvp_program_mailbox(sec_entrypoint);
-	return 0;
-}
diff --git a/plat/arm/board/fvp/include/platform_def.h b/plat/arm/board/fvp/include/platform_def.h
index 155216a8..840676ce 100644
--- a/plat/arm/board/fvp/include/platform_def.h
+++ b/plat/arm/board/fvp/include/platform_def.h
@@ -88,6 +88,10 @@
 /* System timer related constants */
 #define PLAT_ARM_NSTIMER_FRAME_ID		1
 
+/* Mailbox base address */
+#define PLAT_ARM_TRUSTED_MAILBOX_BASE	ARM_TRUSTED_SRAM_BASE
+
+
 /* TrustZone controller related constants
  *
  * Currently only filters 0 and 2 are connected on Base FVP.
diff --git a/plat/arm/common/arm_pm.c b/plat/arm/common/arm_pm.c
index b2251700..2497588f 100644
--- a/plat/arm/common/arm_pm.c
+++ b/plat/arm/common/arm_pm.c
@@ -33,13 +33,16 @@
 #include <assert.h>
 #include <errno.h>
 #include <plat_arm.h>
+#include <platform_def.h>
 #include <psci.h>
 
+/* Standard ARM platforms are expected to export plat_arm_psci_pm_ops */
+extern const plat_psci_ops_t plat_arm_psci_pm_ops;
+
 #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
@@ -144,3 +147,42 @@ int arm_validate_ns_entrypoint(uintptr_t entrypoint)
 
 	return PSCI_E_INVALID_ADDRESS;
 }
+
+/*******************************************************************************
+ * Private function to program the mailbox for a cpu before it is released
+ * from reset. This function assumes that the Trusted mail box base is within
+ * the ARM_SHARED_RAM region
+ ******************************************************************************/
+static void arm_program_trusted_mailbox(uintptr_t address)
+{
+	uintptr_t *mailbox = (void *) PLAT_ARM_TRUSTED_MAILBOX_BASE;
+
+	*mailbox = address;
+
+	/*
+	 * Ensure that the PLAT_ARM_TRUSTED_MAILBOX_BASE is within
+	 * ARM_SHARED_RAM region.
+	 */
+	assert((PLAT_ARM_TRUSTED_MAILBOX_BASE >= ARM_SHARED_RAM_BASE) &&
+		((PLAT_ARM_TRUSTED_MAILBOX_BASE + sizeof(*mailbox)) <= \
+				(ARM_SHARED_RAM_BASE + ARM_SHARED_RAM_SIZE)));
+
+	/* Flush data cache if the mail box shared RAM is cached */
+#if PLAT_ARM_SHARED_RAM_CACHED
+	flush_dcache_range((uintptr_t) mailbox, sizeof(*mailbox));
+#endif
+}
+
+/*******************************************************************************
+ * The ARM Standard platform definition of platform porting API
+ * `plat_setup_psci_ops`.
+ ******************************************************************************/
+int plat_setup_psci_ops(uintptr_t sec_entrypoint,
+				const plat_psci_ops_t **psci_ops)
+{
+	*psci_ops = &plat_arm_psci_pm_ops;
+
+	/* Setup mailbox with entry point. */
+	arm_program_trusted_mailbox(sec_entrypoint);
+	return 0;
+}
diff --git a/plat/arm/css/common/aarch64/css_helpers.S b/plat/arm/css/common/aarch64/css_helpers.S
index 05bd8647..1137a492 100644
--- a/plat/arm/css/common/aarch64/css_helpers.S
+++ b/plat/arm/css/common/aarch64/css_helpers.S
@@ -67,7 +67,7 @@ endfunc plat_secondary_cold_boot_setup
 	 * ---------------------------------------------------------------------
 	 */
 func plat_get_my_entrypoint
-	mov_imm	x0, TRUSTED_MAILBOX_BASE
+	mov_imm	x0, PLAT_ARM_TRUSTED_MAILBOX_BASE
 	ldr	x0, [x0]
 	ret
 endfunc plat_get_my_entrypoint
diff --git a/plat/arm/css/common/css_pm.c b/plat/arm/css/common/css_pm.c
index cc64bf8b..c0c615b9 100644
--- a/plat/arm/css/common/css_pm.c
+++ b/plat/arm/css/common/css_pm.c
@@ -28,19 +28,20 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include <assert.h>
 #include <arch_helpers.h>
+#include <assert.h>
 #include <arm_gic.h>
 #include <cci.h>
-#include <css_def.h>
+#include <css_pm.h>
 #include <debug.h>
 #include <errno.h>
 #include <plat_arm.h>
 #include <platform.h>
 #include <platform_def.h>
-#include <psci.h>
 #include "css_scpi.h"
 
+/* Allow CSS platforms to override `plat_arm_psci_pm_ops` */
+#pragma weak plat_arm_psci_pm_ops
 
 #if ARM_RECOM_STATE_ID_ENC
 /*
@@ -64,17 +65,6 @@ const unsigned int arm_pm_idle_states[] = {
 #endif
 
 /*******************************************************************************
- * Private function to program the mailbox for a cpu before it is released
- * from reset.
- ******************************************************************************/
-static void css_program_mailbox(uintptr_t address)
-{
-	uintptr_t *mailbox = (void *) TRUSTED_MAILBOX_BASE;
-	*mailbox = address;
-	flush_dcache_range((uintptr_t) mailbox, sizeof(*mailbox));
-}
-
-/*******************************************************************************
  * Handler called when a power domain is about to be turned on. The
  * level and mpidr determine the affinity instance.
  ******************************************************************************/
@@ -149,7 +139,7 @@ static void css_power_down_common(const psci_power_state_t *target_state)
  * Handler called when a power domain is about to be turned off. The
  * target_state encodes the power state that each level should transition to.
  ******************************************************************************/
-static void css_pwr_domain_off(const psci_power_state_t *target_state)
+void css_pwr_domain_off(const psci_power_state_t *target_state)
 {
 	assert(target_state->pwr_domain_state[ARM_PWR_LVL0] ==
 						ARM_LOCAL_STATE_OFF);
@@ -161,7 +151,7 @@ static void css_pwr_domain_off(const psci_power_state_t *target_state)
  * Handler called when a power domain is about to be suspended. The
  * target_state encodes the power state that each level should transition to.
  ******************************************************************************/
-static void css_pwr_domain_suspend(const psci_power_state_t *target_state)
+void css_pwr_domain_suspend(const psci_power_state_t *target_state)
 {
 	/*
 	 * Juno has retention only at cpu level. Just return
@@ -184,7 +174,7 @@ static void css_pwr_domain_suspend(const psci_power_state_t *target_state)
  * TODO: At the moment we reuse the on finisher and reinitialize the secure
  * context. Need to implement a separate suspend finisher.
  ******************************************************************************/
-static void css_pwr_domain_suspend_finish(
+void css_pwr_domain_suspend_finish(
 				const psci_power_state_t *target_state)
 {
 	/*
@@ -200,7 +190,7 @@ static void css_pwr_domain_suspend_finish(
 /*******************************************************************************
  * Handlers to shutdown/reboot the system
  ******************************************************************************/
-static void __dead2 css_system_off(void)
+void __dead2 css_system_off(void)
 {
 	uint32_t response;
 
@@ -216,7 +206,7 @@ static void __dead2 css_system_off(void)
 	panic();
 }
 
-static void __dead2 css_system_reset(void)
+void __dead2 css_system_reset(void)
 {
 	uint32_t response;
 
@@ -256,9 +246,10 @@ void css_cpu_standby(plat_local_state_t cpu_state)
 }
 
 /*******************************************************************************
- * Export the platform handlers to enable psci to invoke them
+ * Export the platform handlers via plat_arm_psci_pm_ops. The ARM Standard
+ * platform will take care of registering the handlers with PSCI.
  ******************************************************************************/
-static const plat_psci_ops_t css_ops = {
+const 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,
@@ -270,16 +261,3 @@ static const plat_psci_ops_t css_ops = {
 	.validate_power_state	= arm_validate_power_state,
 	.validate_ns_entrypoint = arm_validate_ns_entrypoint
 };
-
-/*******************************************************************************
- * Export the platform specific psci ops.
- ******************************************************************************/
-int plat_setup_psci_ops(uintptr_t sec_entrypoint,
-				const plat_psci_ops_t **psci_ops)
-{
-	*psci_ops = &css_ops;
-
-	/* Setup mailbox with entry point. */
-	css_program_mailbox(sec_entrypoint);
-	return 0;
-}