kernel: 5.4: import wireguard backport

Rather than using the clunky, old, slower wireguard-linux-compat out of
tree module, this commit does a patch-by-patch backport of upstream's
wireguard to 5.4. This specific backport is in widespread use, being
part of SUSE's enterprise kernel, Oracle's enterprise kernel, Google's
Android kernel, Gentoo's distro kernel, and probably more I've forgotten
about. It's definately the "more proper" way of adding wireguard to a
kernel than the ugly compat.h hell of the wireguard-linux-compat repo.
And most importantly for OpenWRT, it allows using the same module
configuration code for 5.10 as for 5.4, with no need for bifurcation.

These patches are from the backport tree which is maintained in the
open here: https://git.zx2c4.com/wireguard-linux/log/?h=backport-5.4.y
I'll be sending PRs to update this as needed.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

1 files changed, 38 insertions, 0 deletions

diff --git a/target/linux/generic/backport-5.4/080-wireguard-0058-crypto-lib-chacha20poly1305-Add-missing-function-dec.patch b/target/linux/generic/backport-5.4/080-wireguard-0058-crypto-lib-chacha20poly1305-Add-missing-function-dec.patch
new file mode 100644
index 0000000000..0653e3a8ba
--- /dev/null
+++ b/target/linux/generic/backport-5.4/080-wireguard-0058-crypto-lib-chacha20poly1305-Add-missing-function-dec.patch
@@ -0,0 +1,38 @@
+From 58c2229461f888087fc3175650bc2e6aa70fd862 Mon Sep 17 00:00:00 2001
+From: Herbert Xu <herbert@gondor.apana.org.au>
+Date: Wed, 8 Jul 2020 12:41:13 +1000
+Subject: [PATCH 058/124] crypto: lib/chacha20poly1305 - Add missing function
+ declaration
+
+commit 06cc2afbbdf9a9e8df3e2f8db724997dd6e1b4ac upstream.
+
+This patch adds a declaration for chacha20poly1305_selftest to
+silence a sparse warning.
+
+Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+---
+ include/crypto/chacha20poly1305.h | 2 ++
+ lib/crypto/chacha20poly1305.c     | 2 --
+ 2 files changed, 2 insertions(+), 2 deletions(-)
+
+--- a/include/crypto/chacha20poly1305.h
++++ b/include/crypto/chacha20poly1305.h
+@@ -45,4 +45,6 @@ bool chacha20poly1305_decrypt_sg_inplace
+ 					 const u64 nonce,
+ 					 const u8 key[CHACHA20POLY1305_KEY_SIZE]);
+ 
++bool chacha20poly1305_selftest(void);
++
+ #endif /* __CHACHA20POLY1305_H */
+--- a/lib/crypto/chacha20poly1305.c
++++ b/lib/crypto/chacha20poly1305.c
+@@ -21,8 +21,6 @@
+ 
+ #define CHACHA_KEY_WORDS	(CHACHA_KEY_SIZE / sizeof(u32))
+ 
+-bool __init chacha20poly1305_selftest(void);
+-
+ static void chacha_load_key(u32 *k, const u8 *in)
+ {
+ 	k[0] = get_unaligned_le32(in);