xtensa: clean up stpill_registers

- remove unused asm parameters;
- fix EXCM bit setting in the PS SR during _spill_registers call.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
xtensa: add stacktrace support

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
xtensa: add irq flags trace support

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
xtensa: fix arch_irqs_disabled_flags implementation

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
xtensa: enable interrupts for do_notify_resume/schedule

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
xtensa: enable lockdep support

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
xtensa: run hardirqs with hardirqs off

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
xtensa: ISS: fix timer_lock usage in rs_open

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
xtensa: WIP: add SMP support

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
xtensa: fix __flush_dtlb_all isync/dsync

xtensa ISA says that IDTLB instruction must be separated from the
following translations possibly affected by the invalidation by the
DSYNC instruction, not the ISYNC. Replace ISYNC with DSYNC and rename
invalidate_dtlb_entry_no_isync to invalidate_dtlb_entry_no_dsync.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
xtensa: fix local_save_flags usage in local_flush_tlb*

local_save_flags looks meaningless in the context, replace them with
local_irq_save.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
xtensa: WIP: provide custom CALLER_ADDR* implementations

Definition of CALLER_ADDR* through __builtin_return_address makes
compiler insert calls to __xtensa_libgcc_window_spill, which in turn
makes syscall fast_syscall_spill_registers that clobbers registers.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>