|author||David S. Miller <email@example.com>||2010-04-13 01:50:43 -0700|
|committer||David S. Miller <firstname.lastname@example.org>||2010-04-13 01:50:43 -0700|
sparc64: Add some more commentary to __raw_local_irq_save()
Suggested by Peter Zijlstra Signed-off-by: David S. Miller <email@example.com>
Diffstat (limited to 'arch/sparc/include')
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
@@ -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.
"rdpr %%pil, %0\n\t"