PSCI: Introduce new platform and CM helper APIs

This patch introduces new platform APIs and context management helper APIs
to support the new topology framework based on linear core position. This
framework will be introduced in the follwoing patch and it removes the
assumption that the MPIDR based affinity levels map directly to levels
in a power domain tree. The new platforms APIs and context management
helpers based on core position are as described below:

* plat_my_core_pos() and plat_core_pos_by_mpidr()

These 2 new mandatory platform APIs are meant to replace the existing
'platform_get_core_pos()' API. The 'plat_my_core_pos()' API returns the
linear index of the calling core and 'plat_core_pos_by_mpidr()' returns
the linear index of a core specified by its MPIDR. The latter API will also
validate the MPIDR passed as an argument and will return an error code (-1)
if an invalid MPIDR is passed as the argument. This enables the caller to
safely convert an MPIDR of another core to its linear index without querying
the PSCI topology tree e.g. during a call to PSCI CPU_ON.

Since the 'plat_core_pos_by_mpidr()' API verifies an MPIDR, which is always
platform specific, it is no longer possible to maintain a default implementation
of this API. Also it might not be possible for a platform port to verify an
MPIDR before the C runtime has been setup or the topology has been initialized.
This would prevent 'plat_core_pos_by_mpidr()' from being callable prior to
topology setup. As a result, the generic Trusted Firmware code does not call
this API before the topology setup has been done.

The 'plat_my_core_pos' API should be able to run without a C runtime.
Since this API needs to return a core position which is equal to the one
returned by 'plat_core_pos_by_mpidr()' API for the corresponding MPIDR,
this too cannot have default implementation and is a mandatory API for
platform ports. These APIs will be implemented by the ARM reference platform
ports later in the patch stack.

* plat_get_my_stack() and plat_set_my_stack()

These APIs are the stack management APIs which set/return stack addresses
appropriate for the calling core. These replace the 'platform_get_stack()' and
'platform_set_stack()' APIs. A default weak MP version and a global UP version
of these APIs are provided for the platforms.

* Context management helpers based on linear core position

A set of new context management(CM) helpers viz cm_get_context_by_index(),
cm_set_context_by_index(), cm_init_my_context() and cm_init_context_by_index()
are defined which are meant to replace the old helpers which took MPIDR
as argument. The old CM helpers are implemented based on the new helpers to
allow for code consolidation and will be deprecated once the switch to the new
framework is done.

Change-Id: I89758632b370c2812973a4b2efdd9b81a41f9b69

1 files changed, 3 insertions, 2 deletions

diff --git a/include/plat/common/psci1.0/platform.h b/include/plat/common/psci1.0/platform.h
index 50af4f85..059320f1 100644
--- a/include/plat/common/psci1.0/platform.h
+++ b/include/plat/common/psci1.0/platform.h
@@ -59,6 +59,8 @@ int plat_get_image_source(unsigned int image_id,
 			uintptr_t *dev_handle,
 			uintptr_t *image_spec);
 unsigned long plat_get_ns_image_entrypoint(void);
+unsigned int plat_my_core_pos(void);
+int plat_core_pos_by_mpidr(unsigned long mpidr);
 
 /*******************************************************************************
  * Mandatory interrupt management functions
@@ -74,8 +76,7 @@ uint32_t plat_interrupt_type_to_line(uint32_t type,
 /*******************************************************************************
  * Optional common functions (may be overridden)
  ******************************************************************************/
-unsigned int platform_get_core_pos(unsigned long mpidr);
-unsigned long platform_get_stack(unsigned long mpidr);
+unsigned long plat_get_my_stack(void);
 void plat_report_exception(unsigned long);
 int plat_crash_console_init(void);
 int plat_crash_console_putc(int c);