linux_dsm_epyc7002/arch/s390/include/asm/irqflags.h
Christian Borntraeger 204ee2c564 s390/irqflags: optimize irq restore
The ssm instruction takes longer that stnsm/stosm as it is often
used to modify DAT and PER. We know that irqsave/irqrestore only
deals with external and I/O interrupts and we know that irqrestore
can transition only from disabled->disabled or disabled->enabled,
so we can use the faster stosm.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
2016-01-19 12:14:01 +01:00

78 lines
1.7 KiB
C

/*
* Copyright IBM Corp. 2006, 2010
* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
*/
#ifndef __ASM_IRQFLAGS_H
#define __ASM_IRQFLAGS_H
#include <linux/types.h>
#define ARCH_IRQ_ENABLED (3UL << (BITS_PER_LONG - 8))
/* store then OR system mask. */
#define __arch_local_irq_stosm(__or) \
({ \
unsigned long __mask; \
asm volatile( \
" stosm %0,%1" \
: "=Q" (__mask) : "i" (__or) : "memory"); \
__mask; \
})
/* store then AND system mask. */
#define __arch_local_irq_stnsm(__and) \
({ \
unsigned long __mask; \
asm volatile( \
" stnsm %0,%1" \
: "=Q" (__mask) : "i" (__and) : "memory"); \
__mask; \
})
/* set system mask. */
static inline notrace void __arch_local_irq_ssm(unsigned long flags)
{
asm volatile("ssm %0" : : "Q" (flags) : "memory");
}
static inline notrace unsigned long arch_local_save_flags(void)
{
return __arch_local_irq_stnsm(0xff);
}
static inline notrace unsigned long arch_local_irq_save(void)
{
return __arch_local_irq_stnsm(0xfc);
}
static inline notrace void arch_local_irq_disable(void)
{
arch_local_irq_save();
}
static inline notrace void arch_local_irq_enable(void)
{
__arch_local_irq_stosm(0x03);
}
/* This only restores external and I/O interrupt state */
static inline notrace void arch_local_irq_restore(unsigned long flags)
{
/* only disabled->disabled and disabled->enabled is valid */
if (flags & ARCH_IRQ_ENABLED)
arch_local_irq_enable();
}
static inline notrace bool arch_irqs_disabled_flags(unsigned long flags)
{
return !(flags & ARCH_IRQ_ENABLED);
}
static inline notrace bool arch_irqs_disabled(void)
{
return arch_irqs_disabled_flags(arch_local_save_flags());
}
#endif /* __ASM_IRQFLAGS_H */