1 files changed, 80 insertions, 0 deletions
diff --git a/arch/x86/lib/crypto/sha256.c b/arch/x86/lib/crypto/sha256.c
new file mode 100644
index 000000000000..80380f8fdcee
--- /dev/null
+++ b/arch/x86/lib/crypto/sha256.c
@@ -0,0 +1,80 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * SHA-256 optimized for x86_64
+ *
+ * Copyright 2025 Google LLC
+ */
+#include <asm/fpu/api.h>
+#include <crypto/internal/sha2.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/static_call.h>
+
+asmlinkage void sha256_transform_ssse3(u32 state[SHA256_STATE_WORDS],
+				       const u8 *data, size_t nblocks);
+asmlinkage void sha256_transform_avx(u32 state[SHA256_STATE_WORDS],
+				     const u8 *data, size_t nblocks);
+asmlinkage void sha256_transform_rorx(u32 state[SHA256_STATE_WORDS],
+				      const u8 *data, size_t nblocks);
+asmlinkage void sha256_ni_transform(u32 state[SHA256_STATE_WORDS],
+				    const u8 *data, size_t nblocks);
+
+static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_sha256_x86);
+
+DEFINE_STATIC_CALL(sha256_blocks_x86, sha256_transform_ssse3);
+
+void sha256_blocks_simd(u32 state[SHA256_STATE_WORDS],
+			const u8 *data, size_t nblocks)
+{
+	if (static_branch_likely(&have_sha256_x86)) {
+		kernel_fpu_begin();
+		static_call(sha256_blocks_x86)(state, data, nblocks);
+		kernel_fpu_end();
+	} else {
+		sha256_blocks_generic(state, data, nblocks);
+	}
+}
+EXPORT_SYMBOL_GPL(sha256_blocks_simd);
+
+void sha256_blocks_arch(u32 state[SHA256_STATE_WORDS],
+			const u8 *data, size_t nblocks)
+{
+	sha256_blocks_generic(state, data, nblocks);
+}
+EXPORT_SYMBOL_GPL(sha256_blocks_arch);
+
+bool sha256_is_arch_optimized(void)
+{
+	return static_key_enabled(&have_sha256_x86);
+}
+EXPORT_SYMBOL_GPL(sha256_is_arch_optimized);
+
+static int __init sha256_x86_mod_init(void)
+{
+	if (boot_cpu_has(X86_FEATURE_SHA_NI)) {
+		static_call_update(sha256_blocks_x86, sha256_ni_transform);
+	} else if (cpu_has_xfeatures(XFEATURE_MASK_SSE |
+				     XFEATURE_MASK_YMM, NULL) &&
+		   boot_cpu_has(X86_FEATURE_AVX)) {
+		if (boot_cpu_has(X86_FEATURE_AVX2) &&
+		    boot_cpu_has(X86_FEATURE_BMI2))
+			static_call_update(sha256_blocks_x86,
+					   sha256_transform_rorx);
+		else
+			static_call_update(sha256_blocks_x86,
+					   sha256_transform_avx);
+	} else if (!boot_cpu_has(X86_FEATURE_SSSE3)) {
+		return 0;
+	}
+	static_branch_enable(&have_sha256_x86);
+	return 0;
+}
+subsys_initcall(sha256_x86_mod_init);
+
+static void __exit sha256_x86_mod_exit(void)
+{
+}
+module_exit(sha256_x86_mod_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("SHA-256 optimized for x86_64");