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xtensa: mask interrupts earlier

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When coming out of an exception, we need to mask interrupts
to avoid races when decrementing the nested count. Move
the instruction that does this earlier.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This commit is contained in:
Andrew Boie 2019-08-13 15:37:18 -07:00 • committed by Andrew Boie
commit dafd3485bf
1 changed files with 7 additions and 5 deletions
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12
arch/xtensa/include/xtensa-asm2-s.h
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@ -291,6 +291,12 @@ _switch_stacks_\@:
_do_call_\@: _do_call_\@:
CROSS_STACK_CALL CROSS_STACK_CALL
/* Mask interrupts (which have been unmasked during the handler
* execution) while we muck with the windows and decrement the nested
* count. The restore will unmask them correctly.
*/
rsil a0, XCHAL_NMILEVEL
/* Decrement nest count */ /* Decrement nest count */
rsr.\SR a3 rsr.\SR a3
l32i a0, a3, \NEST_OFF l32i a0, a3, \NEST_OFF
@ -303,13 +309,9 @@ _do_call_\@:
* register spill before restoring, for obvious reasons. * register spill before restoring, for obvious reasons.
* Remember to restore the A1 stack pointer as it existed at * Remember to restore the A1 stack pointer as it existed at
* interrupt time so the caller of the interrupted function * interrupt time so the caller of the interrupted function
* spills to the right place. Also mask interrupts (which * spills to the right place.
* have been unmasked during the handler execution) while we
* muck with the windows. The restore will unmask them
* correctly.
*/ */
beq a6, a1, _restore_\@ beq a6, a1, _restore_\@
rsil a0, XCHAL_NMILEVEL
l32i a1, a1, 0 l32i a1, a1, 0
addi a1, a1, BASE_SAVE_AREA_SIZE addi a1, a1, BASE_SAVE_AREA_SIZE
SPILL_ALL_WINDOWS SPILL_ALL_WINDOWS