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Commit c20f326a authored by Takashi Yoshii's avatar Takashi Yoshii Committed by Paul Mundt
Browse files

sh: Fix up T-bit error handling in SH-4A mutex fastpath. 



This corrects a deadlock encountered on ap325 in the cases where the
mutex is contended and the slow-path needs to be fallen back upon.

Signed-off-by: default avatarTakashi YOSHII <yoshii.takashi@renesas.com>
Signed-off-by: default avatarKuninori Morimoto <morimoto.kuninori@renesas.com>
Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
parent 03f07876

arch/sh/include/asm/mutex-llsc.h

+9 −12
Original line number Diff line number Diff line
@@ -21,38 +21,36 @@ 
static inline void

__mutex_fastpath_lock(atomic_t *count, void (*fail_fn)(atomic_t *))

{

	int __ex_flag, __res;

	int __done, __res;



	__asm__ __volatile__ (

		"movli.l	@%2, %0	\n"

		"add		#-1, %0	\n"

		"movco.l	%0, @%2	\n"

		"movt		%1	\n"

		: "=&z" (__res), "=&r" (__ex_flag)

		: "=&z" (__res), "=&r" (__done)

		: "r" (&(count)->counter)

		: "t");



	__res |= !__ex_flag;

	if (unlikely(__res != 0))

	if (unlikely(!__done || __res != 0))

		fail_fn(count);

}



static inline int

__mutex_fastpath_lock_retval(atomic_t *count, int (*fail_fn)(atomic_t *))

{

	int __ex_flag, __res;

	int __done, __res;



	__asm__ __volatile__ (

		"movli.l	@%2, %0	\n"

		"add		#-1, %0	\n"

		"movco.l	%0, @%2	\n"

		"movt		%1	\n"

		: "=&z" (__res), "=&r" (__ex_flag)

		: "=&z" (__res), "=&r" (__done)

		: "r" (&(count)->counter)

		: "t");



	__res |= !__ex_flag;

	if (unlikely(__res != 0))

	if (unlikely(!__done || __res != 0))

		__res = fail_fn(count);



	return __res;
@@ -61,19 +59,18 @@ __mutex_fastpath_lock_retval(atomic_t *count, int (*fail_fn)(atomic_t *)) 
static inline void

__mutex_fastpath_unlock(atomic_t *count, void (*fail_fn)(atomic_t *))

{

	int __ex_flag, __res;

	int __done, __res;



	__asm__ __volatile__ (

		"movli.l	@%2, %0	\n\t"

		"add		#1, %0	\n\t"

		"movco.l	%0, @%2 \n\t"

		"movt		%1	\n\t"

		: "=&z" (__res), "=&r" (__ex_flag)

		: "=&z" (__res), "=&r" (__done)

		: "r" (&(count)->counter)

		: "t");



	__res |= !__ex_flag;

	if (unlikely(__res <= 0))

	if (unlikely(!__done || __res <= 0))

		fail_fn(count);

}