1 files changed, 53 insertions, 0 deletions

diff --git a/include/asm-generic/futex.h b/include/asm-generic/futex.h
new file mode 100644
index 000000000000..3ae2c7347549
--- /dev/null
+++ b/include/asm-generic/futex.h
@@ -0,0 +1,53 @@
+#ifndef _ASM_GENERIC_FUTEX_H
+#define _ASM_GENERIC_FUTEX_H
+
+#ifdef __KERNEL__
+
+#include <linux/futex.h>
+#include <asm/errno.h>
+#include <asm/uaccess.h>
+
+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:
+        case FUTEX_OP_ADD:
+        case FUTEX_OP_OR:
+        case FUTEX_OP_ANDN:
+        case FUTEX_OP_XOR:
+        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
+#endif