zephyr/arch/xtensa/include
Andy Ross 865bbd6b69 xtensa-asm2: Handle alloca/movsp exceptions
Xtensa register windows have a special exception that happens when the
stack pointer needs to be moved, but the caller function has already
spilled its registers below it.

I thought these were unexercised in Zephyr code, but they turn out to
be thrown by the existing mem_pool tests when run in the 32-register
qemu environment (but not on 64-register hardwre).  Because the effect
of the exception is to unspill the caller, there is no good way to
handle this in a traditional handler.  Instead put a 5-instruction
stub in front of the user exception handler (i.e. incurring that cost
on every trap and every L1 interrupt) to test before doing the normal
entry.

Works, but would be nicer to optimize this in the future so that only
true alloca exceptions take that cost.

Signed-off-by: Andy Ross <andrew.j.ross@intel.com>
2018-02-16 10:44:29 -05:00
..
kernel_arch_data.h kernel: Add alternative _arch_switch context switch primitive 2018-02-16 10:44:29 -05:00
kernel_arch_func.h kernel, xtensa: Switch-specific thread return value 2018-02-16 10:44:29 -05:00
kernel_arch_thread.h doc: Fix misspellings in header/doxygen comments 2017-10-17 19:40:29 -04:00
kernel_event_logger_arch.h Xtensa port: Added Xtensa specific code (C + S) files. 2017-02-13 08:04:27 -08:00
offsets_short_arch.h xtensa port: Fixed crash on startup on CP enabled cores 2017-04-13 11:54:49 -07:00
xtensa-asm2-context.h xtensa: New asm layer to support SMP 2018-02-16 10:44:29 -05:00
xtensa-asm2-s.h xtensa-asm2: Handle alloca/movsp exceptions 2018-02-16 10:44:29 -05:00
xtensa-asm2.h xtensa: New asm layer to support SMP 2018-02-16 10:44:29 -05:00
xtensa_api.h xtensa: Implement _xt_ints_on/off for asm2 2018-02-16 10:44:29 -05:00
xtensa_config.h cleanup: rename fiber/task -> thread 2017-10-30 18:41:15 -04:00
xtensa_context.h xtensa port: Clear the CP descriptor of new created thread. 2017-04-20 16:01:55 +00:00
xtensa_rtos.h timer: xtensa_sys_timer: Tickless Kernel Implementation for Xtensa 2017-11-07 08:17:40 -05:00
xtensa_timer.h timer: xtensa_sys_timer: Tickless Kernel Implementation for Xtensa 2017-11-07 08:17:40 -05:00