Introduce PSCI Library Interface

This patch introduces the PSCI Library interface. The major changes
introduced are as follows:

* Earlier BL31 was responsible for Architectural initialization during cold
boot via bl31_arch_setup() whereas PSCI was responsible for the same during
warm boot. This functionality is now consolidated by the PSCI library
and it does Architectural initialization via psci_arch_setup() during both
cold and warm boots.

* Earlier the warm boot entry point was always `psci_entrypoint()`. This was
not flexible enough as a library interface. Now PSCI expects the runtime
firmware to provide the entry point via `psci_setup()`. A new function
`bl31_warm_entrypoint` is introduced in BL31 and the previous
`psci_entrypoint()` is deprecated.

* The `smc_helpers.h` is reorganized to separate the SMC Calling Convention
defines from the Trusted Firmware SMC helpers. The former is now in a new
header file `smcc.h` and the SMC helpers are moved to Architecture specific
header.

* The CPU context is used by PSCI for context initialization and
restoration after power down (PSCI Context). It is also used by BL31 for SMC
handling and context management during Normal-Secure world switch (SMC
Context). The `psci_smc_handler()` interface is redefined to not use SMC
helper macros thus enabling to decouple the PSCI context from EL3 runtime
firmware SMC context. This enables PSCI to be integrated with other runtime
firmware using a different SMC context.

NOTE: With this patch the architectural setup done in `bl31_arch_setup()`
is done as part of `psci_setup()` and hence `bl31_platform_setup()` will be
invoked prior to architectural setup. It is highly unlikely that the platform
setup will depend on architectural setup and cause any failure. Please be
be aware of this change in sequence.

Change-Id: I7f497a08d33be234bbb822c28146250cb20dab73

1 files changed, 5 insertions, 13 deletions

diff --git a/services/std_svc/std_svc_setup.c b/services/std_svc/std_svc_setup.c
index 992a6005..06647e00 100644
--- a/services/std_svc/std_svc_setup.c
+++ b/services/std_svc/std_svc_setup.c
@@ -31,6 +31,7 @@
 #include <debug.h>
 #include <psci.h>
 #include <runtime_svc.h>
+#include <smcc_helpers.h>
 #include <std_svc.h>
 #include <stdint.h>
 #include <uuid.h>
@@ -40,16 +41,6 @@ DEFINE_SVC_UUID(arm_svc_uid,
 		0x108d905b, 0xf863, 0x47e8, 0xae, 0x2d,
 		0xc0, 0xfb, 0x56, 0x41, 0xf6, 0xe2);
 
-/* Setup Standard Services */
-static int32_t std_svc_setup(void)
-{
-	/*
-	 * PSCI is the only specification implemented as a Standard Service.
-	 * Invoke PSCI setup from here
-	 */
-	return psci_setup();
-}
-
 /*
  * Top-level Standard Service SMC handler. This handler will in turn dispatch
  * calls to PSCI SMC handler
@@ -68,8 +59,9 @@ uintptr_t std_svc_smc_handler(uint32_t smc_fid,
 	 * value
 	 */
 	if (is_psci_fid(smc_fid)) {
-		return psci_smc_handler(smc_fid, x1, x2, x3, x4, cookie,
-				handle, flags);
+		SMC_RET1(handle,
+			psci_smc_handler(smc_fid, x1, x2, x3, x4,
+					cookie, handle, flags));
 	}
 
 	switch (smc_fid) {
@@ -101,6 +93,6 @@ DECLARE_RT_SVC(
 		OEN_STD_START,
 		OEN_STD_END,
 		SMC_TYPE_FAST,
-		std_svc_setup,
+		NULL,
 		std_svc_smc_handler
 );