[tip:x86/urgent] x86/mce: Add notifier_block forward declaration

[tip-bot for Arnd Bergmann]

Commit-ID:  704ae091b061082b37a9968621af4c290c641d50
Gitweb:     https://git.kernel.org/tip/704ae091b061082b37a9968621af4c290c641d50
Author:     Arnd Bergmann <arnd@xxxxxxxx>
AuthorDate: Fri, 17 Aug 2018 12:01:36 +0200
Committer:  Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Mon, 20 Aug 2018 18:04:42 +0200

x86/mce: Add notifier_block forward declaration

Without linux/irq.h, there is no declaration of notifier_block, leading to
a build warning:

In file included from arch/x86/kernel/cpu/mcheck/threshold.c:10:
arch/x86/include/asm/mce.h:151:46: error: 'struct notifier_block' declared inside parameter list will not be visible outside of this definition or declaration [-Werror]

It's sufficient to declare the struct tag here, which avoids pulling in
more header files.

Fixes: 447ae3166702 ("x86: Don't include linux/irq.h from asm/hardirq.h")
Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Nicolai Stange <nstange@xxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxx>
Link: https://lkml.kernel.org/r/20180817100156.3009043-1-arnd@xxxxxxxx

---
 arch/x86/include/asm/mce.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h
index 8c7b3e5a2d01..3a17107594c8 100644
--- a/arch/x86/include/asm/mce.h
+++ b/arch/x86/include/asm/mce.h
@@ -148,6 +148,7 @@ enum mce_notifier_prios {
 	MCE_PRIO_LOWEST		= 0,
 };
 
+struct notifier_block;
 extern void mce_register_decode_chain(struct notifier_block *nb);
 extern void mce_unregister_decode_chain(struct notifier_block *nb);