This commit refactors the FPU handling code on the Xtensa port of Amazon SMP
FreeRTOS in the following ways:
Auto-pinning via XT_RTOS_CP_EXC_HOOK
------------------------------------
The "_xt_coproc_exc" exception would previously automatically pin a task that
uses the FPU to the current core (to ensure that we can lazy save the task's FPU
context). However, this would mean that "xtensa_vectors.S" would need to be
OS-aware (to read the task's TCB structure).
This is now refactored so that "_xt_coproc_exc" calls a CP exception hook
function ("XT_RTOS_CP_EXC_HOOK") implemented in "portasm.S", thus allowing
"xtensa_vectors.S" to remain OS agnostic.
Using macros to acquire owner spinlock
--------------------------------------
The taking and relasing of the "_xt_coproc_owner_sa_lock" is now mostly
abstracted as the "spinlock_take" and "spinlock_release" macro. As a result,
"_xt_coproc_release" and "_xt_coproc_exc" are refactored so that:
- They are closer to their upstream (original) versions
- The spinlock is only taken when building for multicore
- The spinlock held region is shortened (now only protects the instructions
that access the "_xt_coproc_owner_sa" array
Other Changes
-------------
- Updated placing and comments of various "offset_..." constants used by
portasm.S
- Update description of "get_cpsa_from_tcb" assembly macro
- Tidied up some typos in the ".S" files
The llvm asm pasrser doesn't support some gnu asm extensions,
like using "&" with macro arguments. So, replace such code with
code which could be compiled by llvm.
This commit disables portUSING_MPU_WRAPPERS for the FreeRTOS SMP xtensa port.
This was previously enabled due to the need to keep a CPSA (coprocessor save
area pointer) in the TCB. The CPSA pointer is now calculated at run time.
This commit updates the copied Xtensa port to support the new porting interfaces
of the FreeRTOS SMP kernel. These modifications are mainly contained in
- FreeRTOSConfig.h
- FreeRTOSConfig_smp.h
- portmacro.h
- port.c
Some porting interfaces have changed in FreeRTOS SMP. In order to allow building
with IDF, compatibility interfaces have been added.
This commit copies over ESP-IDF Xtensa portable files to the
FreeRTOS-Kernel-SMP directory. No changes were made, this commit
only copies the portable source files.
Notes:
- This commit WILL NOT compile
- Some SPDX header dates were updated to pass pre-commit check
