/* 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);
}