// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Shared crypto simd helpers
 *
 * Copyright (c) 2012 Jussi Kivilinna <jussi.kivilinna@mbnet.fi>
 * Copyright (c) 2016 Herbert Xu <herbert@gondor.apana.org.au>
 * Copyright (c) 2019 Google LLC
 *
 * Based on aesni-intel_glue.c by:
 *  Copyright (C) 2008, Intel Corp.
 *    Author: Huang Ying <ying.huang@intel.com>
 */

/*
 * Shared crypto SIMD helpers.  These functions dynamically create and register
 * an skcipher or AEAD algorithm that wraps another, internal algorithm.  The
 * wrapper ensures that the internal algorithm is only executed in a context
 * where SIMD instructions are usable, i.e. where may_use_simd() returns true.
 * If SIMD is already usable, the wrapper directly calls the internal algorithm.
 * Otherwise it defers execution to a workqueue via cryptd.
 *
 * This is an alternative to the internal algorithm implementing a fallback for
 * the !may_use_simd() case itself.
 *
 * Note that the wrapper algorithm is asynchronous, i.e. it has the
 * CRYPTO_ALG_ASYNC flag set.  Therefore it won't be found by users who
 * explicitly allocate a synchronous algorithm.
 */

#include <crypto/cryptd.h>
#include <crypto/internal/aead.h>
#include <crypto/internal/simd.h>
#include <crypto/internal/skcipher.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/preempt.h>
#include <asm/simd.h>

/* skcipher support */

struct simd_skcipher_alg {
        const char *ialg_name;
        struct skcipher_alg alg;
};

struct simd_skcipher_ctx {
        struct cryptd_skcipher *cryptd_tfm;
};

static int simd_skcipher_setkey(struct crypto_skcipher *tfm, const u8 *key,
                                unsigned int key_len)
{
        struct simd_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm);
        struct crypto_skcipher *child = &ctx->cryptd_tfm->base;

        crypto_skcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
        crypto_skcipher_set_flags(child, crypto_skcipher_get_flags(tfm) &
                                         CRYPTO_TFM_REQ_MASK);
        return crypto_skcipher_setkey(child, key, key_len);
}

static int simd_skcipher_encrypt(struct skcipher_request *req)
{
        struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
        struct simd_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm);
        struct skcipher_request *subreq;
        struct crypto_skcipher *child;

        subreq = skcipher_request_ctx(req);
        *subreq = *req;

        if (!crypto_simd_usable() ||
            (in_atomic() && cryptd_skcipher_queued(ctx->cryptd_tfm)))
                child = &ctx->cryptd_tfm->base;
        else
                child = cryptd_skcipher_child(ctx->cryptd_tfm);

        skcipher_request_set_tfm(subreq, child);

        return crypto_skcipher_encrypt(subreq);
}

static int simd_skcipher_decrypt(struct skcipher_request *req)
{
        struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
        struct simd_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm);
        struct skcipher_request *subreq;
        struct crypto_skcipher *child;

        subreq = skcipher_request_ctx(req);
        *subreq = *req;

        if (!crypto_simd_usable() ||
            (in_atomic() && cryptd_skcipher_queued(ctx->cryptd_tfm)))
                child = &ctx->cryptd_tfm->base;
        else
                child = cryptd_skcipher_child(ctx->cryptd_tfm);

        skcipher_request_set_tfm(subreq, child);

        return crypto_skcipher_decrypt(subreq);
}

static void simd_skcipher_exit(struct crypto_skcipher *tfm)
{
        struct simd_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm);

        cryptd_free_skcipher(ctx->cryptd_tfm);
}

static int simd_skcipher_init(struct crypto_skcipher *tfm)
{
        struct simd_skcipher_ctx *ctx = crypto_skcipher_ctx(tfm);
        struct cryptd_skcipher *cryptd_tfm;
        struct simd_skcipher_alg *salg;
        struct skcipher_alg *alg;
        unsigned reqsize;

        alg = crypto_skcipher_alg(tfm);
        salg = container_of(alg, struct simd_skcipher_alg, alg);

        cryptd_tfm = cryptd_alloc_skcipher(salg->ialg_name,
                                           CRYPTO_ALG_INTERNAL,
                                           CRYPTO_ALG_INTERNAL);
        if (IS_ERR(cryptd_tfm))
                return PTR_ERR(cryptd_tfm);

        ctx->cryptd_tfm = cryptd_tfm;

        reqsize = crypto_skcipher_reqsize(cryptd_skcipher_child(cryptd_tfm));
        reqsize = max(reqsize, crypto_skcipher_reqsize(&cryptd_tfm->base));
        reqsize += sizeof(struct skcipher_request);

        crypto_skcipher_set_reqsize(tfm, reqsize);

        return 0;
}

struct simd_skcipher_alg *simd_skcipher_create_compat(struct skcipher_alg *ialg,
                                                      const char *algname,
                                                      const char *drvname,
                                                      const char *basename)
{
        struct simd_skcipher_alg *salg;
        struct skcipher_alg *alg;
        int err;

        salg = kzalloc_obj(*salg);
        if (!salg) {
                salg = ERR_PTR(-ENOMEM);
                goto out;
        }

        salg->ialg_name = basename;
        alg = &salg->alg;

        err = -ENAMETOOLONG;
        if (snprintf(alg->base.cra_name, CRYPTO_MAX_ALG_NAME, "%s", algname) >=
            CRYPTO_MAX_ALG_NAME)
                goto out_free_salg;

        if (snprintf(alg->base.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s",
                     drvname) >= CRYPTO_MAX_ALG_NAME)
                goto out_free_salg;

        alg->base.cra_flags = CRYPTO_ALG_ASYNC |
                (ialg->base.cra_flags & CRYPTO_ALG_INHERITED_FLAGS);
        alg->base.cra_priority = ialg->base.cra_priority;
        alg->base.cra_blocksize = ialg->base.cra_blocksize;
        alg->base.cra_alignmask = ialg->base.cra_alignmask;
        alg->base.cra_module = ialg->base.cra_module;
        alg->base.cra_ctxsize = sizeof(struct simd_skcipher_ctx);

        alg->ivsize = ialg->ivsize;
        alg->chunksize = ialg->chunksize;
        alg->min_keysize = ialg->min_keysize;
        alg->max_keysize = ialg->max_keysize;

        alg->init = simd_skcipher_init;
        alg->exit = simd_skcipher_exit;

        alg->setkey = simd_skcipher_setkey;
        alg->encrypt = simd_skcipher_encrypt;
        alg->decrypt = simd_skcipher_decrypt;

        err = crypto_register_skcipher(alg);
        if (err)
                goto out_free_salg;

out:
        return salg;

out_free_salg:
        kfree(salg);
        salg = ERR_PTR(err);
        goto out;
}
EXPORT_SYMBOL_GPL(simd_skcipher_create_compat);

void simd_skcipher_free(struct simd_skcipher_alg *salg)
{
        crypto_unregister_skcipher(&salg->alg);
        kfree(salg);
}
EXPORT_SYMBOL_GPL(simd_skcipher_free);

int simd_register_skciphers_compat(struct skcipher_alg *algs, int count,
                                   struct simd_skcipher_alg **simd_algs)
{
        int err;
        int i;
        const char *algname;
        const char *drvname;
        const char *basename;
        struct simd_skcipher_alg *simd;

        err = crypto_register_skciphers(algs, count);
        if (err)
                return err;

        for (i = 0; i < count; i++) {
                WARN_ON(strncmp(algs[i].base.cra_name, "__", 2));
                WARN_ON(strncmp(algs[i].base.cra_driver_name, "__", 2));
                algname = algs[i].base.cra_name + 2;
                drvname = algs[i].base.cra_driver_name + 2;
                basename = algs[i].base.cra_driver_name;
                simd = simd_skcipher_create_compat(algs + i, algname, drvname, basename);
                err = PTR_ERR(simd);
                if (IS_ERR(simd))
                        goto err_unregister;
                simd_algs[i] = simd;
        }
        return 0;

err_unregister:
        simd_unregister_skciphers(algs, count, simd_algs);
        return err;
}
EXPORT_SYMBOL_GPL(simd_register_skciphers_compat);

void simd_unregister_skciphers(struct skcipher_alg *algs, int count,
                               struct simd_skcipher_alg **simd_algs)
{
        int i;

        crypto_unregister_skciphers(algs, count);

        for (i = 0; i < count; i++) {
                if (simd_algs[i]) {
                        simd_skcipher_free(simd_algs[i]);
                        simd_algs[i] = NULL;
                }
        }
}
EXPORT_SYMBOL_GPL(simd_unregister_skciphers);

/* AEAD support */

struct simd_aead_alg {
        const char *ialg_name;
        struct aead_alg alg;
};

struct simd_aead_ctx {
        struct cryptd_aead *cryptd_tfm;
};

static int simd_aead_setkey(struct crypto_aead *tfm, const u8 *key,
                                unsigned int key_len)
{
        struct simd_aead_ctx *ctx = crypto_aead_ctx(tfm);
        struct crypto_aead *child = &ctx->cryptd_tfm->base;

        crypto_aead_clear_flags(child, CRYPTO_TFM_REQ_MASK);
        crypto_aead_set_flags(child, crypto_aead_get_flags(tfm) &
                                     CRYPTO_TFM_REQ_MASK);
        return crypto_aead_setkey(child, key, key_len);
}

static int simd_aead_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
{
        struct simd_aead_ctx *ctx = crypto_aead_ctx(tfm);
        struct crypto_aead *child = &ctx->cryptd_tfm->base;

        return crypto_aead_setauthsize(child, authsize);
}

static int simd_aead_encrypt(struct aead_request *req)
{
        struct crypto_aead *tfm = crypto_aead_reqtfm(req);
        struct simd_aead_ctx *ctx = crypto_aead_ctx(tfm);
        struct aead_request *subreq;
        struct crypto_aead *child;

        subreq = aead_request_ctx(req);
        *subreq = *req;

        if (!crypto_simd_usable() ||
            (in_atomic() && cryptd_aead_queued(ctx->cryptd_tfm)))
                child = &ctx->cryptd_tfm->base;
        else
                child = cryptd_aead_child(ctx->cryptd_tfm);

        aead_request_set_tfm(subreq, child);

        return crypto_aead_encrypt(subreq);
}

static int simd_aead_decrypt(struct aead_request *req)
{
        struct crypto_aead *tfm = crypto_aead_reqtfm(req);
        struct simd_aead_ctx *ctx = crypto_aead_ctx(tfm);
        struct aead_request *subreq;
        struct crypto_aead *child;

        subreq = aead_request_ctx(req);
        *subreq = *req;

        if (!crypto_simd_usable() ||
            (in_atomic() && cryptd_aead_queued(ctx->cryptd_tfm)))
                child = &ctx->cryptd_tfm->base;
        else
                child = cryptd_aead_child(ctx->cryptd_tfm);

        aead_request_set_tfm(subreq, child);

        return crypto_aead_decrypt(subreq);
}

static void simd_aead_exit(struct crypto_aead *tfm)
{
        struct simd_aead_ctx *ctx = crypto_aead_ctx(tfm);

        cryptd_free_aead(ctx->cryptd_tfm);
}

static int simd_aead_init(struct crypto_aead *tfm)
{
        struct simd_aead_ctx *ctx = crypto_aead_ctx(tfm);
        struct cryptd_aead *cryptd_tfm;
        struct simd_aead_alg *salg;
        struct aead_alg *alg;
        unsigned reqsize;

        alg = crypto_aead_alg(tfm);
        salg = container_of(alg, struct simd_aead_alg, alg);

        cryptd_tfm = cryptd_alloc_aead(salg->ialg_name, CRYPTO_ALG_INTERNAL,
                                       CRYPTO_ALG_INTERNAL);
        if (IS_ERR(cryptd_tfm))
                return PTR_ERR(cryptd_tfm);

        ctx->cryptd_tfm = cryptd_tfm;

        reqsize = max(crypto_aead_reqsize(cryptd_aead_child(cryptd_tfm)),
                      crypto_aead_reqsize(&cryptd_tfm->base));
        reqsize += sizeof(struct aead_request);

        crypto_aead_set_reqsize(tfm, reqsize);

        return 0;
}

static struct simd_aead_alg *simd_aead_create_compat(struct aead_alg *ialg,
                                                     const char *algname,
                                                     const char *drvname,
                                                     const char *basename)
{
        struct simd_aead_alg *salg;
        struct aead_alg *alg;
        int err;

        salg = kzalloc_obj(*salg);
        if (!salg) {
                salg = ERR_PTR(-ENOMEM);
                goto out;
        }

        salg->ialg_name = basename;
        alg = &salg->alg;

        err = -ENAMETOOLONG;
        if (snprintf(alg->base.cra_name, CRYPTO_MAX_ALG_NAME, "%s", algname) >=
            CRYPTO_MAX_ALG_NAME)
                goto out_free_salg;

        if (snprintf(alg->base.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s",
                     drvname) >= CRYPTO_MAX_ALG_NAME)
                goto out_free_salg;

        alg->base.cra_flags = CRYPTO_ALG_ASYNC |
                (ialg->base.cra_flags & CRYPTO_ALG_INHERITED_FLAGS);
        alg->base.cra_priority = ialg->base.cra_priority;
        alg->base.cra_blocksize = ialg->base.cra_blocksize;
        alg->base.cra_alignmask = ialg->base.cra_alignmask;
        alg->base.cra_module = ialg->base.cra_module;
        alg->base.cra_ctxsize = sizeof(struct simd_aead_ctx);

        alg->ivsize = ialg->ivsize;
        alg->maxauthsize = ialg->maxauthsize;
        alg->chunksize = ialg->chunksize;

        alg->init = simd_aead_init;
        alg->exit = simd_aead_exit;

        alg->setkey = simd_aead_setkey;
        alg->setauthsize = simd_aead_setauthsize;
        alg->encrypt = simd_aead_encrypt;
        alg->decrypt = simd_aead_decrypt;

        err = crypto_register_aead(alg);
        if (err)
                goto out_free_salg;

out:
        return salg;

out_free_salg:
        kfree(salg);
        salg = ERR_PTR(err);
        goto out;
}

static void simd_aead_free(struct simd_aead_alg *salg)
{
        crypto_unregister_aead(&salg->alg);
        kfree(salg);
}

int simd_register_aeads_compat(struct aead_alg *algs, int count,
                               struct simd_aead_alg **simd_algs)
{
        int err;
        int i;
        const char *algname;
        const char *drvname;
        const char *basename;
        struct simd_aead_alg *simd;

        err = crypto_register_aeads(algs, count);
        if (err)
                return err;

        for (i = 0; i < count; i++) {
                WARN_ON(strncmp(algs[i].base.cra_name, "__", 2));
                WARN_ON(strncmp(algs[i].base.cra_driver_name, "__", 2));
                algname = algs[i].base.cra_name + 2;
                drvname = algs[i].base.cra_driver_name + 2;
                basename = algs[i].base.cra_driver_name;
                simd = simd_aead_create_compat(algs + i, algname, drvname, basename);
                err = PTR_ERR(simd);
                if (IS_ERR(simd))
                        goto err_unregister;
                simd_algs[i] = simd;
        }
        return 0;

err_unregister:
        simd_unregister_aeads(algs, count, simd_algs);
        return err;
}
EXPORT_SYMBOL_GPL(simd_register_aeads_compat);

void simd_unregister_aeads(struct aead_alg *algs, int count,
                           struct simd_aead_alg **simd_algs)
{
        int i;

        crypto_unregister_aeads(algs, count);

        for (i = 0; i < count; i++) {
                if (simd_algs[i]) {
                        simd_aead_free(simd_algs[i]);
                        simd_algs[i] = NULL;
                }
        }
}
EXPORT_SYMBOL_GPL(simd_unregister_aeads);

MODULE_DESCRIPTION("Shared crypto SIMD helpers");
MODULE_LICENSE("GPL");