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SDEI: Unconditionally resume Secure if it was interrupted 

Secure world execution nearly always expect a controlled exit to
Non-secure world. SDEI interrupts, although targets EL3, occur on behalf
of Non-secure world, and may have higher priority than Secure world
interrupts. Therefore they might preempt Secure execution, and yield
execution to Non-secure SDEI handler. Upon completion of SDEI event
handling (regardless of whether it's COPLETE or COMPLETE_AND_RESUME), we
must resume Secure execution if it was preempted.

Change-Id: I6edd991032588588427ba2fe6c3d7668f7080e3d
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>
This commit is contained in:
Jeenu Viswambharan 2018-10-11 09:50:26 +01:00
parent 98aab97484
commit 90a9213bfb
1 changed files with 2 additions and 3 deletions
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5
services/std_svc/sdei/sdei_intr_mgmt.c
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@ -485,15 +485,14 @@ int sdei_intr_handler(uint32_t intr_raw, uint32_t flags, void *handle,
/*
* We reach here when client completes the event.
*
* If the cause of dispatch originally interrupted the Secure world, and
* if Non-secure world wasn't allowed to preempt Secure execution,
* If the cause of dispatch originally interrupted the Secure world,
* resume Secure.
*
* No need to save the Non-secure context ahead of a world switch: the
* Non-secure context was fully saved before dispatch, and has been
* returned to its pre-dispatch state.
*/
if ((sec_state == SECURE) && (ehf_is_ns_preemption_allowed() == 0U))
if (sec_state == SECURE)
restore_and_resume_secure_context();
/*