From 8a635ffb142125c6637fe71d5cbce25e7dfa275e Mon Sep 17 00:00:00 2001
From: Tony Luck <tony.luck@intel.com>
Date: Wed, 15 May 2019 18:04:14 -0700
Subject: [PATCH] ia64: Make sure that we have a mmiowb function real early
Generic kernels feed many operation through the "machvec" logic to get
the correct form of the operation for the current system. "mmiowb()" is
one of those operations.
Although machvec is initialized very early in boot, it isn't early
enough for a recent upstream kernel change that added mmiowb to the
spin_unlock() path.
Statically initialize the mmiowb field of machvec so that we won't die
with a call through a NULL pointer. This should be safe because we do
the real initialization of machvec before bringing up any addtional CPUs
or doing any I/O.
Fixes: 49ca6462fc9e ("ia64/mmiowb: Add unconditional mmiowb() to arch_spin_unlock()")
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
arch/ia64/kernel/machvec.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/arch/ia64/kernel/machvec.c b/arch/ia64/kernel/machvec.c
index 1b604d02250be..ebd82535f51b7 100644
--- a/arch/ia64/kernel/machvec.c
+++ b/arch/ia64/kernel/machvec.c
@@ -10,7 +10,9 @@
#include <asm/page.h>
-struct ia64_machine_vector ia64_mv;
+struct ia64_machine_vector ia64_mv = {
+ .mmiowb = ___ia64_mmiowb
+};
EXPORT_SYMBOL(ia64_mv);
static struct ia64_machine_vector * __init
--
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