[PATCH v2 1/3] x86/percpu: Fix x86_this_cpu_variable_test_bit() asm template

[Uros Bizjak]

Fix x86_this_cpu_variable_test_bit(), which is implemented with
wrong asm template, where argument 2 (count argument) is considered
as percpu variable. However, x86_this_cpu_test_bit() is currently
used exclusively with constant bit number argument, so the called
x86_this_cpu_variable_test_bit() function is never instantiated.
The fix introduces named assembler operands to prevent this kind
of errors.

Signed-off-by: Uros Bizjak <ubizjak@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
---
v2: Split from the original v1 patch.
---
 arch/x86/include/asm/percpu.h | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h
index 20696df5d567..cbfbbe836ee2 100644
--- a/arch/x86/include/asm/percpu.h
+++ b/arch/x86/include/asm/percpu.h
@@ -586,10 +586,11 @@ static inline bool x86_this_cpu_variable_test_bit(int nr,
 {
 	bool oldbit;
 
-	asm volatile("btl "__percpu_arg(2)",%1"
+	asm volatile("btl %[nr], " __percpu_arg([var])
 			CC_SET(c)
 			: CC_OUT(c) (oldbit)
-			: "m" (*__my_cpu_ptr((unsigned long __percpu *)(addr))), "Ir" (nr));
+			: [var] "m" (*__my_cpu_ptr((unsigned long __percpu *)(addr))),
+			  [nr] "Ir" (nr));
 
 	return oldbit;
 }
-- 
2.44.0