From c011f80ba0912486fe51dd2b3f71d9b33a151188 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Tue, 13 Apr 2010 01:50:43 -0700 Subject: sparc64: Add some more commentary to __raw_local_irq_save() Suggested by Peter Zijlstra Signed-off-by: David S. Miller --- arch/sparc/include/asm/irqflags_64.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'arch/sparc') diff --git a/arch/sparc/include/asm/irqflags_64.h b/arch/sparc/include/asm/irqflags_64.h index a16e94c4b149..bfa1ea45b4cd 100644 --- a/arch/sparc/include/asm/irqflags_64.h +++ b/arch/sparc/include/asm/irqflags_64.h @@ -80,6 +80,13 @@ static inline unsigned long __raw_local_irq_save(void) /* Disable interrupts to PIL_NORMAL_MAX unless we already * are using PIL_NMI, in which case PIL_NMI is retained. + * + * The only values we ever program into the %pil are 0, + * PIL_NORMAL_MAX and PIL_NMI. + * + * Since PIL_NMI is the largest %pil value and all bits are + * set in it (0xf), it doesn't matter what PIL_NORMAL_MAX + * actually is. */ __asm__ __volatile__( "rdpr %%pil, %0\n\t" -- cgit v1.2.3