linux-kernel - [PATCH 2/6] x86: Convert some devices to use DIE

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Date:	Thu,  6 Jan 2011 16:18:48 -0500
From:	Don Zickus <dzickus@...hat.com>
To:	x86@...nel.org
Cc:	Peter Zijlstra <peterz@...radead.org>,
	Robert Richter <robert.richter@....com>, ying.huang@...el.com,
	gorcunov@...il.com, LKML <linux-kernel@...r.kernel.org>,
	Don Zickus <dzickus@...hat.com>, Russ Anderson <rja@....com>,
	Corey Minyard <minyard@....org>,
	openipmi-developer@...ts.sourceforge.net,
	dann frazier <dannf@...com>
Subject: [PATCH 2/6] x86: Convert some devices to use DIE_NMIUNKNOWN

They are a handful of places in the code that register a die_notifier
as a catch all in case no claims the NMI.  Unfortunately, they trigger
on events like DIE_NMI and DIE_NMI_IPI, which depending on when they
registered may collide with other handlers that have the ability to
determine if the NMI is theirs or not.

The function unknown_nmi_error() makes one last effort to walk the
die_chain when no one else has claimed the NMI before spitting out
messages that the NMI is unknown.

This is a better spot for these devices to execute any code without
colliding with the other handlers.

The two drivers modified are only compiled on x86 arches I believe, so
they shouldn't be affected by other arches that may not have
DIE_NMIUNKNOWN defined.

CC: Russ Anderson <rja@....com>
CC: Corey Minyard <minyard@....org>
CC: openipmi-developer@...ts.sourceforge.net
CC: dann frazier <dannf@...com>
Signed-off-by: Don Zickus <dzickus@...hat.com>
---
 arch/x86/kernel/apic/x2apic_uv_x.c |    2 +-
 drivers/char/ipmi/ipmi_watchdog.c  |    2 +-
 drivers/watchdog/hpwdt.c           |    2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c
index e6cde91..7b0d2f6 100644
--- a/arch/x86/kernel/apic/x2apic_uv_x.c
+++ b/arch/x86/kernel/apic/x2apic_uv_x.c
@@ -642,7 +642,7 @@ void __cpuinit uv_cpu_init(void)
  */
 int uv_handle_nmi(struct notifier_block *self, unsigned long reason, void *data)
 {
-	if (reason != DIE_NMI_IPI)
+	if (reason != DIE_NMIUNKNOWN)
 		return NOTIFY_OK;
 
 	if (in_crash_kexec)
diff --git a/drivers/char/ipmi/ipmi_watchdog.c b/drivers/char/ipmi/ipmi_watchdog.c
index f4d334f..320668f 100644
--- a/drivers/char/ipmi/ipmi_watchdog.c
+++ b/drivers/char/ipmi/ipmi_watchdog.c
@@ -1081,7 +1081,7 @@ ipmi_nmi(struct notifier_block *self, unsigned long val, void *data)
 {
 	struct die_args *args = data;
 
-	if (val != DIE_NMI)
+	if (val != DIE_NMIUNKNOWN)
 		return NOTIFY_OK;
 
 	/* Hack, if it's a memory or I/O error, ignore it. */
diff --git a/drivers/watchdog/hpwdt.c b/drivers/watchdog/hpwdt.c
index dea7b5b..24b966d 100644
--- a/drivers/watchdog/hpwdt.c
+++ b/drivers/watchdog/hpwdt.c
@@ -469,7 +469,7 @@ static int hpwdt_pretimeout(struct notifier_block *nb, unsigned long ulReason,
 	unsigned long rom_pl;
 	static int die_nmi_called;
 
-	if (ulReason != DIE_NMI && ulReason != DIE_NMI_IPI)
+	if (ulReason != DIE_NMIUNKNOWN)
 		goto out;
 
 	if (!hpwdt_nmi_decoding)
-- 
1.7.3.4

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