[PATCH] consolidate asm/futex.h

[firefly-linux-kernel-4.4.55.git] / include / asm-generic / futex.h

diff --git a/include/asm-generic/futex.h b/include/asm-generic/futex.h
new file mode 100644 (file)
index 0000000..3ae2c73
--- /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