Initial import

1 files changed, 250 insertions, 0 deletions

diff --git a/arch/mips/include/asm/cmpxchg.h b/arch/mips/include/asm/cmpxchg.h
new file mode 100644
index 000000000..412f945f1
--- /dev/null
+++ b/arch/mips/include/asm/cmpxchg.h
@@ -0,0 +1,250 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2003, 06, 07 by Ralf Baechle (ralf@linux-mips.org)
+ */
+#ifndef __ASM_CMPXCHG_H
+#define __ASM_CMPXCHG_H
+
+#include <linux/bug.h>
+#include <linux/irqflags.h>
+#include <asm/compiler.h>
+#include <asm/war.h>
+
+static inline unsigned long __xchg_u32(volatile int * m, unsigned int val)
+{
+	__u32 retval;
+
+	smp_mb__before_llsc();
+
+	if (kernel_uses_llsc && R10000_LLSC_WAR) {
+		unsigned long dummy;
+
+		__asm__ __volatile__(
+		"	.set	arch=r4000				\n"
+		"1:	ll	%0, %3			# xchg_u32	\n"
+		"	.set	mips0					\n"
+		"	move	%2, %z4					\n"
+		"	.set	arch=r4000				\n"
+		"	sc	%2, %1					\n"
+		"	beqzl	%2, 1b					\n"
+		"	.set	mips0					\n"
+		: "=&r" (retval), "=" GCC_OFF_SMALL_ASM() (*m), "=&r" (dummy)
+		: GCC_OFF_SMALL_ASM() (*m), "Jr" (val)
+		: "memory");
+	} else if (kernel_uses_llsc) {
+		unsigned long dummy;
+
+		do {
+			__asm__ __volatile__(
+			"	.set	"MIPS_ISA_ARCH_LEVEL"		\n"
+			"	ll	%0, %3		# xchg_u32	\n"
+			"	.set	mips0				\n"
+			"	move	%2, %z4				\n"
+			"	.set	"MIPS_ISA_ARCH_LEVEL"		\n"
+			"	sc	%2, %1				\n"
+			"	.set	mips0				\n"
+			: "=&r" (retval), "=" GCC_OFF_SMALL_ASM() (*m),
+			  "=&r" (dummy)
+			: GCC_OFF_SMALL_ASM() (*m), "Jr" (val)
+			: "memory");
+		} while (unlikely(!dummy));
+	} else {
+		unsigned long flags;
+
+		raw_local_irq_save(flags);
+		retval = *m;
+		*m = val;
+		raw_local_irq_restore(flags);	/* implies memory barrier  */
+	}
+
+	smp_llsc_mb();
+
+	return retval;
+}
+
+#ifdef CONFIG_64BIT
+static inline __u64 __xchg_u64(volatile __u64 * m, __u64 val)
+{
+	__u64 retval;
+
+	smp_mb__before_llsc();
+
+	if (kernel_uses_llsc && R10000_LLSC_WAR) {
+		unsigned long dummy;
+
+		__asm__ __volatile__(
+		"	.set	arch=r4000				\n"
+		"1:	lld	%0, %3			# xchg_u64	\n"
+		"	move	%2, %z4					\n"
+		"	scd	%2, %1					\n"
+		"	beqzl	%2, 1b					\n"
+		"	.set	mips0					\n"
+		: "=&r" (retval), "=" GCC_OFF_SMALL_ASM() (*m), "=&r" (dummy)
+		: GCC_OFF_SMALL_ASM() (*m), "Jr" (val)
+		: "memory");
+	} else if (kernel_uses_llsc) {
+		unsigned long dummy;
+
+		do {
+			__asm__ __volatile__(
+			"	.set	"MIPS_ISA_ARCH_LEVEL"		\n"
+			"	lld	%0, %3		# xchg_u64	\n"
+			"	move	%2, %z4				\n"
+			"	scd	%2, %1				\n"
+			"	.set	mips0				\n"
+			: "=&r" (retval), "=" GCC_OFF_SMALL_ASM() (*m),
+			  "=&r" (dummy)
+			: GCC_OFF_SMALL_ASM() (*m), "Jr" (val)
+			: "memory");
+		} while (unlikely(!dummy));
+	} else {
+		unsigned long flags;
+
+		raw_local_irq_save(flags);
+		retval = *m;
+		*m = val;
+		raw_local_irq_restore(flags);	/* implies memory barrier  */
+	}
+
+	smp_llsc_mb();
+
+	return retval;
+}
+#else
+extern __u64 __xchg_u64_unsupported_on_32bit_kernels(volatile __u64 * m, __u64 val);
+#define __xchg_u64 __xchg_u64_unsupported_on_32bit_kernels
+#endif
+
+static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
+{
+	switch (size) {
+	case 4:
+		return __xchg_u32(ptr, x);
+	case 8:
+		return __xchg_u64(ptr, x);
+	}
+
+	return x;
+}
+
+#define xchg(ptr, x)							\
+({									\
+	BUILD_BUG_ON(sizeof(*(ptr)) & ~0xc);				\
+									\
+	((__typeof__(*(ptr)))						\
+		__xchg((unsigned long)(x), (ptr), sizeof(*(ptr))));	\
+})
+
+#define __HAVE_ARCH_CMPXCHG 1
+
+#define __cmpxchg_asm(ld, st, m, old, new)				\
+({									\
+	__typeof(*(m)) __ret;						\
+									\
+	if (kernel_uses_llsc && R10000_LLSC_WAR) {			\
+		__asm__ __volatile__(					\
+		"	.set	push				\n"	\
+		"	.set	noat				\n"	\
+		"	.set	arch=r4000			\n"	\
+		"1:	" ld "	%0, %2		# __cmpxchg_asm \n"	\
+		"	bne	%0, %z3, 2f			\n"	\
+		"	.set	mips0				\n"	\
+		"	move	$1, %z4				\n"	\
+		"	.set	arch=r4000			\n"	\
+		"	" st "	$1, %1				\n"	\
+		"	beqzl	$1, 1b				\n"	\
+		"2:						\n"	\
+		"	.set	pop				\n"	\
+		: "=&r" (__ret), "=" GCC_OFF_SMALL_ASM() (*m)		\
+		: GCC_OFF_SMALL_ASM() (*m), "Jr" (old), "Jr" (new)		\
+		: "memory");						\
+	} else if (kernel_uses_llsc) {					\
+		__asm__ __volatile__(					\
+		"	.set	push				\n"	\
+		"	.set	noat				\n"	\
+		"	.set	"MIPS_ISA_ARCH_LEVEL"		\n"	\
+		"1:	" ld "	%0, %2		# __cmpxchg_asm \n"	\
+		"	bne	%0, %z3, 2f			\n"	\
+		"	.set	mips0				\n"	\
+		"	move	$1, %z4				\n"	\
+		"	.set	"MIPS_ISA_ARCH_LEVEL"		\n"	\
+		"	" st "	$1, %1				\n"	\
+		"	beqz	$1, 1b				\n"	\
+		"	.set	pop				\n"	\
+		"2:						\n"	\
+		: "=&r" (__ret), "=" GCC_OFF_SMALL_ASM() (*m)		\
+		: GCC_OFF_SMALL_ASM() (*m), "Jr" (old), "Jr" (new)		\
+		: "memory");						\
+	} else {							\
+		unsigned long __flags;					\
+									\
+		raw_local_irq_save(__flags);				\
+		__ret = *m;						\
+		if (__ret == old)					\
+			*m = new;					\
+		raw_local_irq_restore(__flags);				\
+	}								\
+									\
+	__ret;								\
+})
+
+/*
+ * This function doesn't exist, so you'll get a linker error
+ * if something tries to do an invalid cmpxchg().
+ */
+extern void __cmpxchg_called_with_bad_pointer(void);
+
+#define __cmpxchg(ptr, old, new, pre_barrier, post_barrier)		\
+({									\
+	__typeof__(ptr) __ptr = (ptr);					\
+	__typeof__(*(ptr)) __old = (old);				\
+	__typeof__(*(ptr)) __new = (new);				\
+	__typeof__(*(ptr)) __res = 0;					\
+									\
+	pre_barrier;							\
+									\
+	switch (sizeof(*(__ptr))) {					\
+	case 4:								\
+		__res = __cmpxchg_asm("ll", "sc", __ptr, __old, __new); \
+		break;							\
+	case 8:								\
+		if (sizeof(long) == 8) {				\
+			__res = __cmpxchg_asm("lld", "scd", __ptr,	\
+					   __old, __new);		\
+			break;						\
+		}							\
+	default:							\
+		__cmpxchg_called_with_bad_pointer();			\
+		break;							\
+	}								\
+									\
+	post_barrier;							\
+									\
+	__res;								\
+})
+
+#define cmpxchg(ptr, old, new)		__cmpxchg(ptr, old, new, smp_mb__before_llsc(), smp_llsc_mb())
+#define cmpxchg_local(ptr, old, new)	__cmpxchg(ptr, old, new, , )
+
+#ifdef CONFIG_64BIT
+#define cmpxchg64_local(ptr, o, n)					\
+  ({									\
+	BUILD_BUG_ON(sizeof(*(ptr)) != 8);				\
+	cmpxchg_local((ptr), (o), (n));					\
+  })
+
+#define cmpxchg64(ptr, o, n)						\
+  ({									\
+	BUILD_BUG_ON(sizeof(*(ptr)) != 8);				\
+	cmpxchg((ptr), (o), (n));					\
+  })
+#else
+#include <asm-generic/cmpxchg-local.h>
+#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
+#define cmpxchg64(ptr, o, n) cmpxchg64_local((ptr), (o), (n))
+#endif
+
+#endif /* __ASM_CMPXCHG_H */