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[PATCH V2 6/8] MIPS: Add NMI notifier

To: Ralf Baechle <ralf@linux-mips.org>
Subject: [PATCH V2 6/8] MIPS: Add NMI notifier
From: Kevin Cernekee <cernekee@gmail.com>
Date: Thu, 10 Nov 2011 22:30:29 -0800
Cc: linux-mips@linux-mips.org
In-reply-to: <5f9666eb295ce196b2a9688afab07dea@localhost>
References: <5f9666eb295ce196b2a9688afab07dea@localhost>
Sender: linux-mips-bounce@linux-mips.org
User-agent: vim 7.2
Allow the board support code to register a raw notifier callback for
NMI, similar to what is done for CU2 exceptions.

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
---

V2:

Use a raw notifier instead of a function pointer for NMI events.


 arch/mips/include/asm/traps.h |   12 ++++++++++++
 arch/mips/kernel/traps.c      |    9 +++++++++
 2 files changed, 21 insertions(+), 0 deletions(-)

diff --git a/arch/mips/include/asm/traps.h b/arch/mips/include/asm/traps.h
index 90ff2f4..4edab87 100644
--- a/arch/mips/include/asm/traps.h
+++ b/arch/mips/include/asm/traps.h
@@ -25,4 +25,16 @@ extern void (*board_nmi_handler_setup)(void);
 extern void (*board_ejtag_handler_setup)(void);
 extern void (*board_bind_eic_interrupt)(int irq, int regset);
 
+extern int register_nmi_notifier(struct notifier_block *nb);
+
+#define nmi_notifier(fn, pri)                                          \
+({                                                                     \
+       static struct notifier_block fn##_nb = {                        \
+               .notifier_call = fn,                                    \
+               .priority = pri                                         \
+       };                                                              \
+                                                                       \
+       register_nmi_notifier(&fn##_nb);                                \
+})
+
 #endif /* _ASM_TRAPS_H */
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 5c8a49d..33945aa 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -1339,9 +1339,18 @@ void ejtag_exception_handler(struct pt_regs *regs)
 
 /*
  * NMI exception handler.
+ * No lock; only written during early bootup by CPU 0.
  */
+static RAW_NOTIFIER_HEAD(nmi_chain);
+
+int register_nmi_notifier(struct notifier_block *nb)
+{
+       return raw_notifier_chain_register(&nmi_chain, nb);
+}
+
 NORET_TYPE void ATTRIB_NORET nmi_exception_handler(struct pt_regs *regs)
 {
+       raw_notifier_call_chain(&nmi_chain, 0, regs);
        bust_spinlocks(1);
        printk("NMI taken!!!!\n");
        die("NMI", regs);
-- 
1.7.6.3


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