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kernel
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linux
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: Takashi YOSHII <yoshii.takashi@renesas.com>
Signed-off-by: Kuninori Morimoto <morimoto.kuninori@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
authored by
Takashi Yoshii
and committed by
Paul Mundt
c20f326a
03f07876
+9
-12
+9
-12
arch/sh/include/asm/mutex-llsc.h
+9
-12
arch/sh/include/asm/mutex-llsc.h
···
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static inline void
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__mutex_fastpath_lock(atomic_t *count, void (*fail_fn)(atomic_t *))
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{
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-
int __ex_flag, __res;
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+
int __done, __res;
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__asm__ __volatile__ (
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"movli.l @%2, %0 \n"
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"add #-1, %0 \n"
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"movco.l %0, @%2 \n"
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"movt %1 \n"
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-
: "=&z" (__res), "=&r" (__ex_flag)
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: "=&z" (__res), "=&r" (__done)
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: "r" (&(count)->counter)
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: "t");
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-
__res |= !__ex_flag;
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if (unlikely(__res != 0))
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if (unlikely(!__done || __res != 0))
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fail_fn(count);
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}
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static inline int
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__mutex_fastpath_lock_retval(atomic_t *count, int (*fail_fn)(atomic_t *))
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{
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int __ex_flag, __res;
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int __done, __res;
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__asm__ __volatile__ (
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"movli.l @%2, %0 \n"
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"add #-1, %0 \n"
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"movco.l %0, @%2 \n"
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"movt %1 \n"
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: "=&z" (__res), "=&r" (__ex_flag)
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: "=&z" (__res), "=&r" (__done)
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: "r" (&(count)->counter)
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: "t");
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-
__res |= !__ex_flag;
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if (unlikely(__res != 0))
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if (unlikely(!__done || __res != 0))
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__res = fail_fn(count);
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return __res;
···
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static inline void
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__mutex_fastpath_unlock(atomic_t *count, void (*fail_fn)(atomic_t *))
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{
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int __ex_flag, __res;
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int __done, __res;
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__asm__ __volatile__ (
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"movli.l @%2, %0 \n\t"
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"add #1, %0 \n\t"
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"movco.l %0, @%2 \n\t"
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"movt %1 \n\t"
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: "=&z" (__res), "=&r" (__ex_flag)
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: "=&z" (__res), "=&r" (__done)
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: "r" (&(count)->counter)
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: "t");
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-
__res |= !__ex_flag;
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if (unlikely(__res <= 0))
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+
if (unlikely(!__done || __res <= 0))
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fail_fn(count);
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}
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