[193/205] [IA64] Fix spinaphore down_spin()

[Greg KH]

2.6.34-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Tony Luck <tony.luck@xxxxxxxxx>

commit b70f4e85bfc4d7000036355b714a92d5c574f1be upstream.

Typo in down_spin() meant it only read the low 32 bits of the
"serve" value, instead of the full 64 bits. This results in the
system hanging when the values in ticket/serve get larger than
32-bits. A big enough system running the right test can hit this
in a just a few hours.

Broken since 883a3acf5b0d4782ac35981227a0d094e8b44850
    [IA64] Re-implement spinaphores using ticket lock concepts

Reported via IRC by Bjorn Helgaas

Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 arch/ia64/mm/tlb.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/ia64/mm/tlb.c
+++ b/arch/ia64/mm/tlb.c
@@ -121,7 +121,7 @@ static inline void down_spin(struct spin
 	ia64_invala();
 
 	for (;;) {
-		asm volatile ("ld4.c.nc %0=[%1]" : "=r"(serve) : "r"(&ss->serve) : "memory");
+		asm volatile ("ld8.c.nc %0=[%1]" : "=r"(serve) : "r"(&ss->serve) : "memory");
 		if (time_before(t, serve))
 			return;
 		cpu_relax();


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