From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Date: Tue, 13 Apr 2010 09:48:58 +0200
> Care to enlighten the curious amongst us as to what exactly you're
> doing in the sparc code?
>From 0c25e9e6cbe7b233bb91d14d0e2c258bf8e6ec83 Mon Sep 17 00:00:00 2001
From: David S. Miller <davem@xxxxxxxxxxxxx>
Date: Mon, 12 Apr 2010 22:21:52 -0700
Subject: [PATCH 2/2] sparc64: Adjust __raw_local_irq_save() to cooperate in NMIs.
If we are in an NMI then doing a plain raw_local_irq_disable() will
write PIL_NORMAL_MAX into %pil, which is lower than PIL_NMI, and thus
we'll re-enable NMIs and recurse.
Doing a simple:
%pil = %pil | PIL_NORMAL_MAX
does what we want, if we're already at PIL_NMI (15) we leave it at
that setting, else we set it to PIL_NORMAL_MAX (14).
This should get the function tracer working on sparc64.
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
---
arch/sparc/include/asm/irqflags_64.h | 14 ++++++++++++--
1 files changed, 12 insertions(+), 2 deletions(-)
diff --git a/arch/sparc/include/asm/irqflags_64.h b/arch/sparc/include/asm/irqflags_64.h
index 8b49bf9..a16e94c 100644
--- a/arch/sparc/include/asm/irqflags_64.h
+++ b/arch/sparc/include/asm/irqflags_64.h
@@ -76,9 +76,19 @@ static inline int raw_irqs_disabled(void)
*/
static inline unsigned long __raw_local_irq_save(void)
{
- unsigned long flags = __raw_local_save_flags();
+ unsigned long flags, tmp;
- raw_local_irq_disable();
+ /* Disable interrupts to PIL_NORMAL_MAX unless we already
+ * are using PIL_NMI, in which case PIL_NMI is retained.
+ */
+ __asm__ __volatile__(
+ "rdpr %%pil, %0\n\t"
+ "or %0, %2, %1\n\t"
+ "wrpr %1, 0x0, %%pil"
+ : "=r" (flags), "=r" (tmp)
+ : "i" (PIL_NORMAL_MAX)
+ : "memory"
+ );
return flags;
}
--
1.7.0.4
--
To unsubscribe from this list: send the line "unsubscribe sparclinux" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
