/* SPDX-License-Identifier: GPL-2.0 OR MIT */
/*
 * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
 */

#include <asm/cpufeature.h>
#include <asm/fpu/api.h>
#include <asm/processor.h>
#include <asm/simd.h>
#include <linux/jump_label.h>
#include <linux/kernel.h>
#include <linux/sizes.h>

asmlinkage void blake2s_compress_ssse3(struct blake2s_ctx *ctx,
				       const u8 *data, size_t nblocks, u32 inc);
asmlinkage void blake2s_compress_avx512(struct blake2s_ctx *ctx,
					const u8 *data, size_t nblocks, u32 inc);

static __ro_after_init DEFINE_STATIC_KEY_FALSE(blake2s_use_ssse3);
static __ro_after_init DEFINE_STATIC_KEY_FALSE(blake2s_use_avx512);

static void blake2s_compress(struct blake2s_ctx *ctx,
			     const u8 *data, size_t nblocks, u32 inc)
{
	/* SIMD disables preemption, so relax after processing each page. */
	BUILD_BUG_ON(SZ_4K / BLAKE2S_BLOCK_SIZE < 8);

	if (!static_branch_likely(&blake2s_use_ssse3) || !may_use_simd()) {
		blake2s_compress_generic(ctx, data, nblocks, inc);
		return;
	}

	do {
		const size_t blocks = min_t(size_t, nblocks,
					    SZ_4K / BLAKE2S_BLOCK_SIZE);

		kernel_fpu_begin();
		if (static_branch_likely(&blake2s_use_avx512))
			blake2s_compress_avx512(ctx, data, blocks, inc);
		else
			blake2s_compress_ssse3(ctx, data, blocks, inc);
		kernel_fpu_end();

		data += blocks * BLAKE2S_BLOCK_SIZE;
		nblocks -= blocks;
	} while (nblocks);
}

#define blake2s_mod_init_arch blake2s_mod_init_arch
static void blake2s_mod_init_arch(void)
{
	if (boot_cpu_has(X86_FEATURE_SSSE3))
		static_branch_enable(&blake2s_use_ssse3);

	if (boot_cpu_has(X86_FEATURE_AVX) &&
	    boot_cpu_has(X86_FEATURE_AVX2) &&
	    boot_cpu_has(X86_FEATURE_AVX512F) &&
	    boot_cpu_has(X86_FEATURE_AVX512VL) &&
	    cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM |
			      XFEATURE_MASK_AVX512, NULL))
		static_branch_enable(&blake2s_use_avx512);
}