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xtensa: enable kernel preemption 

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>
hifive-unleashed-5.1
Max Filippov 2013-08-26 15:16:23 +04:00 committed by Chris Zankel
parent aea8e7c80a
commit 16c5becf39
1 changed files with 17 additions and 28 deletions
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45
arch/xtensa/kernel/entry.S
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@ -31,7 +31,6 @@
/* Unimplemented features. */
#undef KERNEL_STACK_OVERFLOW_CHECK
#undef PREEMPTIBLE_KERNEL
#undef ALLOCA_EXCEPTION_IN_IRAM
/* Not well tested.
@ -429,7 +428,9 @@ common_exception_return:
/* Jump if we are returning from kernel exceptions. */
l32i a3, a1, PT_PS
_bbci.l a3, PS_UM_BIT, 4f
GET_THREAD_INFO(a2, a1)
l32i a4, a2, TI_FLAGS
_bbci.l a3, PS_UM_BIT, 6f
/* Specific to a user exception exit:
* We need to check some flags for signal handling and rescheduling,
@ -438,9 +439,6 @@ common_exception_return:
* Note that we don't disable interrupts here.
*/
GET_THREAD_INFO(a2,a1)
l32i a4, a2, TI_FLAGS
_bbsi.l a4, TIF_NEED_RESCHED, 3f
_bbsi.l a4, TIF_NOTIFY_RESUME, 2f
_bbci.l a4, TIF_SIGPENDING, 5f
@ -463,6 +461,19 @@ common_exception_return:
callx4 a4
j 1b
#ifdef CONFIG_PREEMPT
6:
_bbci.l a4, TIF_NEED_RESCHED, 4f
/* Check current_thread_info->preempt_count */
l32i a4, a2, TI_PRE_COUNT
bnez a4, 4f
movi a4, preempt_schedule_irq
callx4 a4
j 1b
#endif
5:
#ifdef CONFIG_DEBUG_TLB_SANITY
l32i a4, a1, PT_DEPC
@ -470,6 +481,7 @@ common_exception_return:
movi a4, check_tlb_sanity
callx4 a4
#endif
6:
4:
#ifdef CONFIG_TRACE_IRQFLAGS
l32i a4, a1, PT_DEPC
@ -573,29 +585,6 @@ user_exception_exit:
kernel_exception_exit:
#ifdef PREEMPTIBLE_KERNEL
#ifdef CONFIG_PREEMPT
/*
* Note: We've just returned from a call4, so we have
* at least 4 addt'l regs.
*/
/* Check current_thread_info->preempt_count */
GET_THREAD_INFO(a2)
l32i a3, a2, TI_PREEMPT
bnez a3, 1f
l32i a2, a2, TI_FLAGS
1:
#endif
#endif
/* Check if we have to do a movsp.
*
* We only have to do a movsp if the previous window-frame has