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authorRabin Vincent <rabin@rab.in>2010-01-25 19:43:03 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2010-02-15 21:39:50 +0000
commitc5113b61baf7a9a8616eca83e20847e7fecdc679 (patch)
treea7109d04a3dc00b7e6063a9a69fe5afcf3eb85d8
parent24b44a66fa240f6fc63343623ca730d39754047e (diff)
ARM: 5897/1: spinlock: don't use deprecated barriers on ARMv7
On ARMv7, the use of the cp15 operations for barriers is deprecated in favour of the isb, dsb, and dmb instructions. Change the locking functions to use the appropriate type of dsb for the architecture being built for. Signed-off-by: Rabin Vincent <rabin@rab.in> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
-rw-r--r--arch/arm/include/asm/spinlock.h36
1 files changed, 23 insertions, 13 deletions
diff --git a/arch/arm/include/asm/spinlock.h b/arch/arm/include/asm/spinlock.h
index c91c64cab92..17eb355707d 100644
--- a/arch/arm/include/asm/spinlock.h
+++ b/arch/arm/include/asm/spinlock.h
@@ -5,6 +5,22 @@
#error SMP not supported on pre-ARMv6 CPUs
#endif
+static inline void dsb_sev(void)
+{
+#if __LINUX_ARM_ARCH__ >= 7
+ __asm__ __volatile__ (
+ "dsb\n"
+ "sev"
+ );
+#elif defined(CONFIG_CPU_32v6K)
+ __asm__ __volatile__ (
+ "mcr p15, 0, %0, c7, c10, 4\n"
+ "sev"
+ : : "r" (0)
+ );
+#endif
+}
+
/*
* ARMv6 Spin-locking.
*
@@ -69,13 +85,11 @@ static inline void arch_spin_unlock(arch_spinlock_t *lock)
__asm__ __volatile__(
" str %1, [%0]\n"
-#ifdef CONFIG_CPU_32v6K
-" mcr p15, 0, %1, c7, c10, 4\n" /* DSB */
-" sev"
-#endif
:
: "r" (&lock->lock), "r" (0)
: "cc");
+
+ dsb_sev();
}
/*
@@ -132,13 +146,11 @@ static inline void arch_write_unlock(arch_rwlock_t *rw)
__asm__ __volatile__(
"str %1, [%0]\n"
-#ifdef CONFIG_CPU_32v6K
-" mcr p15, 0, %1, c7, c10, 4\n" /* DSB */
-" sev\n"
-#endif
:
: "r" (&rw->lock), "r" (0)
: "cc");
+
+ dsb_sev();
}
/* write_can_lock - would write_trylock() succeed? */
@@ -188,14 +200,12 @@ static inline void arch_read_unlock(arch_rwlock_t *rw)
" strex %1, %0, [%2]\n"
" teq %1, #0\n"
" bne 1b"
-#ifdef CONFIG_CPU_32v6K
-"\n cmp %0, #0\n"
-" mcreq p15, 0, %0, c7, c10, 4\n"
-" seveq"
-#endif
: "=&r" (tmp), "=&r" (tmp2)
: "r" (&rw->lock)
: "cc");
+
+ if (tmp == 0)
+ dsb_sev();
}
static inline int arch_read_trylock(arch_rwlock_t *rw)