lib/crypto: x86: Move arch/x86/lib/crypto/ into lib/crypto/

Move the contents of arch/x86/lib/crypto/ into lib/crypto/x86/.

The new code organization makes a lot more sense for how this code
actually works and is developed.  In particular, it makes it possible to
build each algorithm as a single module, with better inlining and dead
code elimination.  For a more detailed explanation, see the patchset
which did this for the CRC library code:
https://lore.kernel.org/r/20250607200454.73587-1-ebiggers@kernel.org/.
Also see the patchset which did this for SHA-512:
https://lore.kernel.org/linux-crypto/20250616014019.415791-1-ebiggers@kernel.org/

This is just a preparatory commit, which does the move to get the files
into their new location but keeps them building the same way as before.
Later commits will make the actual improvements to the way the
arch-optimized code is integrated for each algorithm.

Add a gitignore entry for the removed directory arch/x86/lib/crypto/ so
that people don't accidentally commit leftover generated files.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Sohil Mehta <sohil.mehta@intel.com>
Link: https://lore.kernel.org/r/20250619191908.134235-9-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>

1 files changed, 129 insertions, 0 deletions

diff --git a/lib/crypto/x86/poly1305_glue.c b/lib/crypto/x86/poly1305_glue.c
new file mode 100644
index 0000000000000..b7e78a583e07f
--- /dev/null
+++ b/lib/crypto/x86/poly1305_glue.c
@@ -0,0 +1,129 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+/*
+ * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
+ */
+
+#include <asm/cpu_device_id.h>
+#include <asm/fpu/api.h>
+#include <crypto/internal/poly1305.h>
+#include <linux/jump_label.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/sizes.h>
+#include <linux/unaligned.h>
+
+struct poly1305_arch_internal {
+	union {
+		struct {
+			u32 h[5];
+			u32 is_base2_26;
+		};
+		u64 hs[3];
+	};
+	u64 r[2];
+	u64 pad;
+	struct { u32 r2, r1, r4, r3; } rn[9];
+};
+
+asmlinkage void poly1305_block_init_arch(
+	struct poly1305_block_state *state,
+	const u8 raw_key[POLY1305_BLOCK_SIZE]);
+EXPORT_SYMBOL_GPL(poly1305_block_init_arch);
+asmlinkage void poly1305_blocks_x86_64(struct poly1305_arch_internal *ctx,
+				       const u8 *inp,
+				       const size_t len, const u32 padbit);
+asmlinkage void poly1305_emit_x86_64(const struct poly1305_state *ctx,
+				     u8 mac[POLY1305_DIGEST_SIZE],
+				     const u32 nonce[4]);
+asmlinkage void poly1305_emit_avx(const struct poly1305_state *ctx,
+				  u8 mac[POLY1305_DIGEST_SIZE],
+				  const u32 nonce[4]);
+asmlinkage void poly1305_blocks_avx(struct poly1305_arch_internal *ctx,
+				    const u8 *inp, const size_t len,
+				    const u32 padbit);
+asmlinkage void poly1305_blocks_avx2(struct poly1305_arch_internal *ctx,
+				     const u8 *inp, const size_t len,
+				     const u32 padbit);
+asmlinkage void poly1305_blocks_avx512(struct poly1305_arch_internal *ctx,
+				       const u8 *inp,
+				       const size_t len, const u32 padbit);
+
+static __ro_after_init DEFINE_STATIC_KEY_FALSE(poly1305_use_avx);
+static __ro_after_init DEFINE_STATIC_KEY_FALSE(poly1305_use_avx2);
+static __ro_after_init DEFINE_STATIC_KEY_FALSE(poly1305_use_avx512);
+
+void poly1305_blocks_arch(struct poly1305_block_state *state, const u8 *inp,
+			  unsigned int len, u32 padbit)
+{
+	struct poly1305_arch_internal *ctx =
+		container_of(&state->h.h, struct poly1305_arch_internal, h);
+
+	/* SIMD disables preemption, so relax after processing each page. */
+	BUILD_BUG_ON(SZ_4K < POLY1305_BLOCK_SIZE ||
+		     SZ_4K % POLY1305_BLOCK_SIZE);
+
+	if (!static_branch_likely(&poly1305_use_avx)) {
+		poly1305_blocks_x86_64(ctx, inp, len, padbit);
+		return;
+	}
+
+	do {
+		const unsigned int bytes = min(len, SZ_4K);
+
+		kernel_fpu_begin();
+		if (static_branch_likely(&poly1305_use_avx512))
+			poly1305_blocks_avx512(ctx, inp, bytes, padbit);
+		else if (static_branch_likely(&poly1305_use_avx2))
+			poly1305_blocks_avx2(ctx, inp, bytes, padbit);
+		else
+			poly1305_blocks_avx(ctx, inp, bytes, padbit);
+		kernel_fpu_end();
+
+		len -= bytes;
+		inp += bytes;
+	} while (len);
+}
+EXPORT_SYMBOL_GPL(poly1305_blocks_arch);
+
+void poly1305_emit_arch(const struct poly1305_state *ctx,
+			u8 mac[POLY1305_DIGEST_SIZE], const u32 nonce[4])
+{
+	if (!static_branch_likely(&poly1305_use_avx))
+		poly1305_emit_x86_64(ctx, mac, nonce);
+	else
+		poly1305_emit_avx(ctx, mac, nonce);
+}
+EXPORT_SYMBOL_GPL(poly1305_emit_arch);
+
+bool poly1305_is_arch_optimized(void)
+{
+	return static_key_enabled(&poly1305_use_avx);
+}
+EXPORT_SYMBOL(poly1305_is_arch_optimized);
+
+static int __init poly1305_simd_mod_init(void)
+{
+	if (boot_cpu_has(X86_FEATURE_AVX) &&
+	    cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM, NULL))
+		static_branch_enable(&poly1305_use_avx);
+	if (boot_cpu_has(X86_FEATURE_AVX) && boot_cpu_has(X86_FEATURE_AVX2) &&
+	    cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM, NULL))
+		static_branch_enable(&poly1305_use_avx2);
+	if (boot_cpu_has(X86_FEATURE_AVX) && boot_cpu_has(X86_FEATURE_AVX2) &&
+	    boot_cpu_has(X86_FEATURE_AVX512F) &&
+	    cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM | XFEATURE_MASK_AVX512, NULL) &&
+	    /* Skylake downclocks unacceptably much when using zmm, but later generations are fast. */
+	    boot_cpu_data.x86_vfm != INTEL_SKYLAKE_X)
+		static_branch_enable(&poly1305_use_avx512);
+	return 0;
+}
+subsys_initcall(poly1305_simd_mod_init);
+
+static void __exit poly1305_simd_mod_exit(void)
+{
+}
+module_exit(poly1305_simd_mod_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Jason A. Donenfeld <Jason@zx2c4.com>");
+MODULE_DESCRIPTION("Poly1305 authenticator");