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, 37 insertions, 0 deletions

diff --git a/target/linux/generic/backport-5.4/080-wireguard-0048-crypto-x86-poly1305-emit-does-base-conversion-itself.patch b/target/linux/generic/backport-5.4/080-wireguard-0048-crypto-x86-poly1305-emit-does-base-conversion-itself.patch
new file mode 100644
index 0000000000..68af53f52c
--- /dev/null
+++ b/target/linux/generic/backport-5.4/080-wireguard-0048-crypto-x86-poly1305-emit-does-base-conversion-itself.patch
@@ -0,0 +1,37 @@
+From 722ccb5da4bab4e142e4dc1eea10406a08547c7b Mon Sep 17 00:00:00 2001
+From: "Jason A. Donenfeld" <Jason@zx2c4.com>
+Date: Fri, 17 Jan 2020 11:42:22 +0100
+Subject: [PATCH 048/124] crypto: x86/poly1305 - emit does base conversion
+ itself
+
+commit f9e7fe32a792726186301423ff63a465d63386e1 upstream.
+
+The emit code does optional base conversion itself in assembly, so we
+don't need to do that here. Also, neither one of these functions uses
+simd instructions, so checking for that doesn't make sense either.
+
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
+Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
+---
+ arch/x86/crypto/poly1305_glue.c | 8 ++------
+ 1 file changed, 2 insertions(+), 6 deletions(-)
+
+--- a/arch/x86/crypto/poly1305_glue.c
++++ b/arch/x86/crypto/poly1305_glue.c
+@@ -123,13 +123,9 @@ static void poly1305_simd_blocks(void *c
+ static void poly1305_simd_emit(void *ctx, u8 mac[POLY1305_DIGEST_SIZE],
+ 			       const u32 nonce[4])
+ {
+-	struct poly1305_arch_internal *state = ctx;
+-
+-	if (!IS_ENABLED(CONFIG_AS_AVX) || !static_branch_likely(&poly1305_use_avx) ||
+-	    !state->is_base2_26 || !crypto_simd_usable()) {
+-		convert_to_base2_64(ctx);
++	if (!IS_ENABLED(CONFIG_AS_AVX) || !static_branch_likely(&poly1305_use_avx))
+ 		poly1305_emit_x86_64(ctx, mac, nonce);
+-	} else
++	else
+ 		poly1305_emit_avx(ctx, mac, nonce);
+ }
+