linux_dsm_epyc7002/arch/sparc/include/asm/pil.h
David S. Miller b4f4372f96 sparc64: Make %pil level 15 a pseudo-NMI.
So that we can profile code even in a local_irq_disable() section,
only write 14 (instead of 15) into the %pil register to disable IRQs.

This allows PIL level 15 to serve as a pseudo NMI.

Signed-off-by: David S. Miller <davem@davemloft.net>
2008-12-04 09:17:02 -08:00

30 lines
1.0 KiB
C

#ifndef _SPARC64_PIL_H
#define _SPARC64_PIL_H
/* To avoid some locking problems, we hard allocate certain PILs
* for SMP cross call messages that must do a etrap/rtrap.
*
* A local_irq_disable() does not block the cross call delivery, so
* when SMP locking is an issue we reschedule the event into a PIL
* interrupt which is blocked by local_irq_disable().
*
* In fact any XCALL which has to etrap/rtrap has a problem because
* it is difficult to prevent rtrap from running BH's, and that would
* need to be done if the XCALL arrived while %pil==PIL_NORMAL_MAX.
*
* Finally, in order to handle profiling events even when a
* local_irq_disable() is in progress, we only disable up to level 14
* interrupts. Profile counter overflow interrupts arrive at level
* 15.
*/
#define PIL_SMP_CALL_FUNC 1
#define PIL_SMP_RECEIVE_SIGNAL 2
#define PIL_SMP_CAPTURE 3
#define PIL_SMP_CTX_NEW_VERSION 4
#define PIL_DEVICE_IRQ 5
#define PIL_SMP_CALL_FUNC_SNGL 6
#define PIL_NORMAL_MAX 14
#define PIL_NMI 15
#endif /* !(_SPARC64_PIL_H) */