local_t: mips extension

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 124 insertions, 1 deletions

diff --git a/include/asm-mips/system.h b/include/asm-mips/system.h
index 290887077e4..d53dd724556 100644
--- a/include/asm-mips/system.h
+++ b/include/asm-mips/system.h
@@ -262,6 +262,58 @@ static inline unsigned long __cmpxchg_u32(volatile int * m, unsigned long old,
 	return retval;
 }
 
+static inline unsigned long __cmpxchg_u32_local(volatile int * m,
+	unsigned long old, unsigned long new)
+{
+	__u32 retval;
+
+	if (cpu_has_llsc && R10000_LLSC_WAR) {
+		__asm__ __volatile__(
+		"	.set	push					\n"
+		"	.set	noat					\n"
+		"	.set	mips3					\n"
+		"1:	ll	%0, %2			# __cmpxchg_u32	\n"
+		"	bne	%0, %z3, 2f				\n"
+		"	.set	mips0					\n"
+		"	move	$1, %z4					\n"
+		"	.set	mips3					\n"
+		"	sc	$1, %1					\n"
+		"	beqzl	$1, 1b					\n"
+		"2:							\n"
+		"	.set	pop					\n"
+		: "=&r" (retval), "=R" (*m)
+		: "R" (*m), "Jr" (old), "Jr" (new)
+		: "memory");
+	} else if (cpu_has_llsc) {
+		__asm__ __volatile__(
+		"	.set	push					\n"
+		"	.set	noat					\n"
+		"	.set	mips3					\n"
+		"1:	ll	%0, %2			# __cmpxchg_u32	\n"
+		"	bne	%0, %z3, 2f				\n"
+		"	.set	mips0					\n"
+		"	move	$1, %z4					\n"
+		"	.set	mips3					\n"
+		"	sc	$1, %1					\n"
+		"	beqz	$1, 1b					\n"
+		"2:							\n"
+		"	.set	pop					\n"
+		: "=&r" (retval), "=R" (*m)
+		: "R" (*m), "Jr" (old), "Jr" (new)
+		: "memory");
+	} else {
+		unsigned long flags;
+
+		local_irq_save(flags);
+		retval = *m;
+		if (retval == old)
+			*m = new;
+		local_irq_restore(flags);	/* implies memory barrier  */
+	}
+
+	return retval;
+}
+
 #ifdef CONFIG_64BIT
 static inline unsigned long __cmpxchg_u64(volatile int * m, unsigned long old,
 	unsigned long new)
@@ -315,10 +367,62 @@ static inline unsigned long __cmpxchg_u64(volatile int * m, unsigned long old,
 
 	return retval;
 }
+
+static inline unsigned long __cmpxchg_u64_local(volatile int * m,
+	unsigned long old, unsigned long new)
+{
+	__u64 retval;
+
+	if (cpu_has_llsc && R10000_LLSC_WAR) {
+		__asm__ __volatile__(
+		"	.set	push					\n"
+		"	.set	noat					\n"
+		"	.set	mips3					\n"
+		"1:	lld	%0, %2			# __cmpxchg_u64	\n"
+		"	bne	%0, %z3, 2f				\n"
+		"	move	$1, %z4					\n"
+		"	scd	$1, %1					\n"
+		"	beqzl	$1, 1b					\n"
+		"2:							\n"
+		"	.set	pop					\n"
+		: "=&r" (retval), "=R" (*m)
+		: "R" (*m), "Jr" (old), "Jr" (new)
+		: "memory");
+	} else if (cpu_has_llsc) {
+		__asm__ __volatile__(
+		"	.set	push					\n"
+		"	.set	noat					\n"
+		"	.set	mips3					\n"
+		"1:	lld	%0, %2			# __cmpxchg_u64	\n"
+		"	bne	%0, %z3, 2f				\n"
+		"	move	$1, %z4					\n"
+		"	scd	$1, %1					\n"
+		"	beqz	$1, 1b					\n"
+		"2:							\n"
+		"	.set	pop					\n"
+		: "=&r" (retval), "=R" (*m)
+		: "R" (*m), "Jr" (old), "Jr" (new)
+		: "memory");
+	} else {
+		unsigned long flags;
+
+		local_irq_save(flags);
+		retval = *m;
+		if (retval == old)
+			*m = new;
+		local_irq_restore(flags);	/* implies memory barrier  */
+	}
+
+	return retval;
+}
+
 #else
 extern unsigned long __cmpxchg_u64_unsupported_on_32bit_kernels(
 	volatile int * m, unsigned long old, unsigned long new);
 #define __cmpxchg_u64 __cmpxchg_u64_unsupported_on_32bit_kernels
+extern unsigned long __cmpxchg_u64_local_unsupported_on_32bit_kernels(
+	volatile int * m, unsigned long old, unsigned long new);
+#define __cmpxchg_u64_local __cmpxchg_u64_local_unsupported_on_32bit_kernels
 #endif
 
 /* This function doesn't exist, so you'll get a linker error
@@ -338,7 +442,26 @@ static inline unsigned long __cmpxchg(volatile void * ptr, unsigned long old,
 	return old;
 }
 
-#define cmpxchg(ptr,old,new) ((__typeof__(*(ptr)))__cmpxchg((ptr), (unsigned long)(old), (unsigned long)(new),sizeof(*(ptr))))
+static inline unsigned long __cmpxchg_local(volatile void * ptr,
+	unsigned long old, unsigned long new, int size)
+{
+	switch (size) {
+	case 4:
+		return __cmpxchg_u32_local(ptr, old, new);
+	case 8:
+		return __cmpxchg_u64_local(ptr, old, new);
+	}
+	__cmpxchg_called_with_bad_pointer();
+	return old;
+}
+
+#define cmpxchg(ptr,old,new) \
+	((__typeof__(*(ptr)))__cmpxchg((ptr), \
+		(unsigned long)(old), (unsigned long)(new),sizeof(*(ptr))))
+
+#define cmpxchg_local(ptr,old,new) \
+	((__typeof__(*(ptr)))__cmpxchg_local((ptr), \
+		(unsigned long)(old), (unsigned long)(new),sizeof(*(ptr))))
 
 extern void set_handler (unsigned long offset, void *addr, unsigned long len);
 extern void set_uncached_handler (unsigned long offset, void *addr, unsigned long len);