net: Add Wireguard support

This patch was created via the create-patch.sh script from the
wiregaurd-compat repo at

https://git.zx2c4.com/wireguard-linux-compat,
commit 3d3c92b4711b42169137b2ddf42ed4382e2babdf

Change-Id: I74f7eb09028152f71f78ae7ce20254d94ad0e256
diff --git a/net/wireguard/crypto/zinc/selftest/run.h b/net/wireguard/crypto/zinc/selftest/run.h
new file mode 100644
index 0000000..4ffaf60
--- /dev/null
+++ b/net/wireguard/crypto/zinc/selftest/run.h
@@ -0,0 +1,48 @@
+/* SPDX-License-Identifier: GPL-2.0 OR MIT */
+/*
+ * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ */
+
+#ifndef _ZINC_SELFTEST_RUN_H
+#define _ZINC_SELFTEST_RUN_H
+
+#include <linux/kernel.h>
+#include <linux/printk.h>
+#include <linux/bug.h>
+
+static inline bool selftest_run(const char *name, bool (*selftest)(void),
+				bool *const nobs[], unsigned int nobs_len)
+{
+	unsigned long set = 0, subset = 0, largest_subset = 0;
+	unsigned int i;
+
+	BUILD_BUG_ON(!__builtin_constant_p(nobs_len) ||
+		     nobs_len >= BITS_PER_LONG);
+
+	if (!IS_ENABLED(CONFIG_ZINC_SELFTEST))
+		return true;
+
+	for (i = 0; i < nobs_len; ++i)
+		set |= ((unsigned long)*nobs[i]) << i;
+
+	do {
+		for (i = 0; i < nobs_len; ++i)
+			*nobs[i] = BIT(i) & subset;
+		if (selftest())
+			largest_subset = max(subset, largest_subset);
+		else
+			pr_err("%s self-test combination 0x%lx: FAIL\n", name,
+			       subset);
+		subset = (subset - set) & set;
+	} while (subset);
+
+	for (i = 0; i < nobs_len; ++i)
+		*nobs[i] = BIT(i) & largest_subset;
+
+	if (largest_subset == set)
+		pr_info("%s self-tests: pass\n", name);
+
+	return !WARN_ON(largest_subset != set);
+}
+
+#endif