1 files changed, 84 insertions, 0 deletions
diff --git a/include/asm-powerpc/futex.h b/include/asm-powerpc/futex.h
new file mode 100644
index 00000000000..37c94e52ab6
--- /dev/null
+++ b/include/asm-powerpc/futex.h
@@ -0,0 +1,84 @@
+#ifndef _ASM_POWERPC_FUTEX_H
+#define _ASM_POWERPC_FUTEX_H
+
+#ifdef __KERNEL__
+
+#include <linux/futex.h>
+#include <asm/errno.h>
+#include <asm/synch.h>
+#include <asm/uaccess.h>
+#include <asm/ppc_asm.h>
+
+#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
+  __asm__ __volatile ( \
+	SYNC_ON_SMP \
+"1:	lwarx	%0,0,%2\n" \
+	insn \
+"2:	stwcx.	%1,0,%2\n" \
+	"bne-	1b\n" \
+	"li	%1,0\n" \
+"3:	.section .fixup,\"ax\"\n" \
+"4:	li	%1,%3\n" \
+	"b	3b\n" \
+	".previous\n" \
+	".section __ex_table,\"a\"\n" \
+	".align 3\n" \
+	DATAL " 1b,4b,2b,4b\n" \
+	".previous" \
+	: "=&r" (oldval), "=&r" (ret) \
+	: "b" (uaddr), "i" (-EFAULT), "1" (oparg) \
+	: "cr0", "memory")
+
+static inline int futex_atomic_op_inuser (int encoded_op, int __user *uaddr)
+{
+	int op = (encoded_op >> 28) & 7;
+	int cmp = (encoded_op >> 24) & 15;
+	int oparg = (encoded_op << 8) >> 20;
+	int cmparg = (encoded_op << 20) >> 20;
+	int oldval = 0, ret;
+	if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
+		oparg = 1 << oparg;
+
+	if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int)))
+		return -EFAULT;
+
+	inc_preempt_count();
+
+	switch (op) {
+	case FUTEX_OP_SET:
+		__futex_atomic_op("", ret, oldval, uaddr, oparg);
+		break;
+	case FUTEX_OP_ADD:
+		__futex_atomic_op("add %1,%0,%1\n", ret, oldval, uaddr, oparg);
+		break;
+	case FUTEX_OP_OR:
+		__futex_atomic_op("or %1,%0,%1\n", ret, oldval, uaddr, oparg);
+		break;
+	case FUTEX_OP_ANDN:
+		__futex_atomic_op("andc %1,%0,%1\n", ret, oldval, uaddr, oparg);
+		break;
+	case FUTEX_OP_XOR:
+		__futex_atomic_op("xor %1,%0,%1\n", ret, oldval, uaddr, oparg);
+		break;
+	default:
+		ret = -ENOSYS;
+	}
+
+	dec_preempt_count();
+
+	if (!ret) {
+		switch (cmp) {
+		case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
+		case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
+		case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
+		case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
+		case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
+		case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
+		default: ret = -ENOSYS;
+		}
+	}
+	return ret;
+}
+
+#endif /* __KERNEL__ */
+#endif /* _ASM_POWERPC_FUTEX_H */