diff options
| author | David S. Miller <davem@davemloft.net> | 2010-04-13 01:50:43 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-04-13 01:50:43 -0700 |
| commit | c011f80ba0912486fe51dd2b3f71d9b33a151188 (patch) | |
| tree | f133e1b698f5a0eaca251bcdcc5a4f6397aa59d7 | |
| parent | 9343af084c7e8911897b0883042ee690cee3aaef (diff) | |
sparc64: Add some more commentary to __raw_local_irq_save()
Suggested by Peter Zijlstra
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | arch/sparc/include/asm/irqflags_64.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/sparc/include/asm/irqflags_64.h b/arch/sparc/include/asm/irqflags_64.h index a16e94c4b14..bfa1ea45b4c 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" |