Commit f08fcced authored by Corentin Labbe's avatar Corentin Labbe Committed by Herbert Xu
Browse files

crypto: allwinner - Add sun8i-ss cryptographic offloader 



The Security System is an hardware cryptographic offloader present
on Allwinner SoCs A80 and A83T.
It is different from the previous sun4i-ss.

This driver supports AES cipher in CBC and ECB mode.

Acked-by: default avatarMaxime Ripard <mripard@kernel.org>
Signed-off-by: default avatarCorentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent a1afe274

drivers/crypto/allwinner/Kconfig

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Original line number Diff line number Diff line
@@ -58,3 +58,30 @@ config CRYPTO_DEV_SUN8I_CE_DEBUG 
	  Say y to enable sun8i-ce debug stats.

	  This will create /sys/kernel/debug/sun8i-ce/stats for displaying

	  the number of requests per flow and per algorithm.



config CRYPTO_DEV_SUN8I_SS

	tristate "Support for Allwinner Security System cryptographic offloader"

	select CRYPTO_BLKCIPHER

	select CRYPTO_ENGINE

	select CRYPTO_ECB

	select CRYPTO_CBC

	select CRYPTO_AES

	select CRYPTO_DES

	depends on CRYPTO_DEV_ALLWINNER

	depends on PM

	help

	  Select y here to have support for the Security System available on

	  Allwinner SoC A80, A83T.

	  The Security System handle AES/3DES ciphers in ECB/CBC mode.



	  To compile this driver as a module, choose M here: the module

	  will be called sun8i-ss.



config CRYPTO_DEV_SUN8I_SS_DEBUG

	bool "Enable sun8i-ss stats"

	depends on CRYPTO_DEV_SUN8I_SS

	depends on DEBUG_FS

	help

	  Say y to enable sun8i-ss debug stats.

	  This will create /sys/kernel/debug/sun8i-ss/stats for displaying

	  the number of requests per flow and per algorithm.

drivers/crypto/allwinner/Makefile

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Original line number Diff line number Diff line 
obj-$(CONFIG_CRYPTO_DEV_SUN4I_SS) += sun4i-ss/

obj-$(CONFIG_CRYPTO_DEV_SUN8I_CE) += sun8i-ce/

obj-$(CONFIG_CRYPTO_DEV_SUN8I_SS) += sun8i-ss/

drivers/crypto/allwinner/sun8i-ss/Makefile

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+2 −0
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obj-$(CONFIG_CRYPTO_DEV_SUN8I_SS) += sun8i-ss.o

sun8i-ss-y += sun8i-ss-core.o sun8i-ss-cipher.o

drivers/crypto/allwinner/sun8i-ss/sun8i-ss-cipher.c

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// SPDX-License-Identifier: GPL-2.0

/*

 * sun8i-ss-cipher.c - hardware cryptographic offloader for

 * Allwinner A80/A83T SoC

 *

 * Copyright (C) 2016-2019 Corentin LABBE <clabbe.montjoie@gmail.com>

 *

 * This file add support for AES cipher with 128,192,256 bits keysize in

 * CBC and ECB mode.

 *

 * You could find a link for the datasheet in Documentation/arm/sunxi/README

 */



#include <linux/crypto.h>

#include <linux/dma-mapping.h>

#include <linux/io.h>

#include <linux/pm_runtime.h>

#include <crypto/scatterwalk.h>

#include <crypto/internal/skcipher.h>

#include "sun8i-ss.h"



static bool sun8i_ss_need_fallback(struct skcipher_request *areq)

{

	struct scatterlist *in_sg = areq->src;

	struct scatterlist *out_sg = areq->dst;

	struct scatterlist *sg;



	if (areq->cryptlen == 0 || areq->cryptlen % 16)

		return true;



	if (sg_nents(areq->src) > 8 || sg_nents(areq->dst) > 8)

		return true;



	sg = areq->src;

	while (sg) {

		if ((sg->length % 16) != 0)

			return true;

		if ((sg_dma_len(sg) % 16) != 0)

			return true;

		if (!IS_ALIGNED(sg->offset, 16))

			return true;

		sg = sg_next(sg);

	}

	sg = areq->dst;

	while (sg) {

		if ((sg->length % 16) != 0)

			return true;

		if ((sg_dma_len(sg) % 16) != 0)

			return true;

		if (!IS_ALIGNED(sg->offset, 16))

			return true;

		sg = sg_next(sg);

	}



	/* SS need same numbers of SG (with same length) for source and destination */

	in_sg = areq->src;

	out_sg = areq->dst;

	while (in_sg && out_sg) {

		if (in_sg->length != out_sg->length)

			return true;

		in_sg = sg_next(in_sg);

		out_sg = sg_next(out_sg);

	}

	if (in_sg || out_sg)

		return true;

	return false;

}



static int sun8i_ss_cipher_fallback(struct skcipher_request *areq)

{

	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);

	struct sun8i_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);

	struct sun8i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);

	int err;



	SYNC_SKCIPHER_REQUEST_ON_STACK(subreq, op->fallback_tfm);

#ifdef CONFIG_CRYPTO_DEV_SUN8I_SS_DEBUG

	struct skcipher_alg *alg = crypto_skcipher_alg(tfm);

	struct sun8i_ss_alg_template *algt;



	algt = container_of(alg, struct sun8i_ss_alg_template, alg.skcipher);

	algt->stat_fb++;

#endif

	skcipher_request_set_sync_tfm(subreq, op->fallback_tfm);

	skcipher_request_set_callback(subreq, areq->base.flags, NULL, NULL);

	skcipher_request_set_crypt(subreq, areq->src, areq->dst,

				   areq->cryptlen, areq->iv);

	if (rctx->op_dir & SS_DECRYPTION)

		err = crypto_skcipher_decrypt(subreq);

	else

		err = crypto_skcipher_encrypt(subreq);

	skcipher_request_zero(subreq);

	return err;

}



static int sun8i_ss_cipher(struct skcipher_request *areq)

{

	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);

	struct sun8i_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);

	struct sun8i_ss_dev *ss = op->ss;

	struct sun8i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);

	struct skcipher_alg *alg = crypto_skcipher_alg(tfm);

	struct sun8i_ss_alg_template *algt;

	struct scatterlist *sg;

	unsigned int todo, len, offset, ivsize;

	void *backup_iv = NULL;

	int nr_sgs = 0;

	int nr_sgd = 0;

	int err = 0;

	int i;



	algt = container_of(alg, struct sun8i_ss_alg_template, alg.skcipher);



	dev_dbg(ss->dev, "%s %s %u %x IV(%p %u) key=%u\n", __func__,

		crypto_tfm_alg_name(areq->base.tfm),

		areq->cryptlen,

		rctx->op_dir, areq->iv, crypto_skcipher_ivsize(tfm),

		op->keylen);



#ifdef CONFIG_CRYPTO_DEV_SUN8I_SS_DEBUG

	algt->stat_req++;

#endif



	rctx->op_mode = ss->variant->op_mode[algt->ss_blockmode];

	rctx->method = ss->variant->alg_cipher[algt->ss_algo_id];

	rctx->keylen = op->keylen;



	rctx->p_key = dma_map_single(ss->dev, op->key, op->keylen, DMA_TO_DEVICE);

	if (dma_mapping_error(ss->dev, rctx->p_key)) {

		dev_err(ss->dev, "Cannot DMA MAP KEY\n");

		err = -EFAULT;

		goto theend;

	}



	ivsize = crypto_skcipher_ivsize(tfm);

	if (areq->iv && crypto_skcipher_ivsize(tfm) > 0) {

		rctx->ivlen = ivsize;

		rctx->biv = kzalloc(ivsize, GFP_KERNEL | GFP_DMA);

		if (!rctx->biv) {

			err = -ENOMEM;

			goto theend_key;

		}

		if (rctx->op_dir & SS_DECRYPTION) {

			backup_iv = kzalloc(ivsize, GFP_KERNEL);

			if (!backup_iv) {

				err = -ENOMEM;

				goto theend_key;

			}

			offset = areq->cryptlen - ivsize;

			scatterwalk_map_and_copy(backup_iv, areq->src, offset,

						 ivsize, 0);

		}

		memcpy(rctx->biv, areq->iv, ivsize);

		rctx->p_iv = dma_map_single(ss->dev, rctx->biv, rctx->ivlen,

					    DMA_TO_DEVICE);

		if (dma_mapping_error(ss->dev, rctx->p_iv)) {

			dev_err(ss->dev, "Cannot DMA MAP IV\n");

			err = -ENOMEM;

			goto theend_iv;

		}

	}

	if (areq->src == areq->dst) {

		nr_sgs = dma_map_sg(ss->dev, areq->src, sg_nents(areq->src),

				    DMA_BIDIRECTIONAL);

		if (nr_sgs <= 0 || nr_sgs > 8) {

			dev_err(ss->dev, "Invalid sg number %d\n", nr_sgs);

			err = -EINVAL;

			goto theend_iv;

		}

		nr_sgd = nr_sgs;

	} else {

		nr_sgs = dma_map_sg(ss->dev, areq->src, sg_nents(areq->src),

				    DMA_TO_DEVICE);

		if (nr_sgs <= 0 || nr_sgs > 8) {

			dev_err(ss->dev, "Invalid sg number %d\n", nr_sgs);

			err = -EINVAL;

			goto theend_iv;

		}

		nr_sgd = dma_map_sg(ss->dev, areq->dst, sg_nents(areq->dst),

				    DMA_FROM_DEVICE);

		if (nr_sgd <= 0 || nr_sgd > 8) {

			dev_err(ss->dev, "Invalid sg number %d\n", nr_sgd);

			err = -EINVAL;

			goto theend_sgs;

		}

	}



	len = areq->cryptlen;

	i = 0;

	sg = areq->src;

	while (i < nr_sgs && sg && len) {

		if (sg_dma_len(sg) == 0)

			goto sgs_next;

		rctx->t_src[i].addr = sg_dma_address(sg);

		todo = min(len, sg_dma_len(sg));

		rctx->t_src[i].len = todo / 4;

		dev_dbg(ss->dev, "%s total=%u SGS(%d %u off=%d) todo=%u\n", __func__,

			areq->cryptlen, i, rctx->t_src[i].len, sg->offset, todo);

		len -= todo;

		i++;

sgs_next:

		sg = sg_next(sg);

	}

	if (len > 0) {

		dev_err(ss->dev, "remaining len %d\n", len);

		err = -EINVAL;

		goto theend_sgs;

	}



	len = areq->cryptlen;

	i = 0;

	sg = areq->dst;

	while (i < nr_sgd && sg && len) {

		if (sg_dma_len(sg) == 0)

			goto sgd_next;

		rctx->t_dst[i].addr = sg_dma_address(sg);

		todo = min(len, sg_dma_len(sg));

		rctx->t_dst[i].len = todo / 4;

		dev_dbg(ss->dev, "%s total=%u SGD(%d %u off=%d) todo=%u\n", __func__,

			areq->cryptlen, i, rctx->t_dst[i].len, sg->offset, todo);

		len -= todo;

		i++;

sgd_next:

		sg = sg_next(sg);

	}

	if (len > 0) {

		dev_err(ss->dev, "remaining len %d\n", len);

		err = -EINVAL;

		goto theend_sgs;

	}



	err = sun8i_ss_run_task(ss, rctx, crypto_tfm_alg_name(areq->base.tfm));



theend_sgs:

	if (areq->src == areq->dst) {

		dma_unmap_sg(ss->dev, areq->src, nr_sgs, DMA_BIDIRECTIONAL);

	} else {

		dma_unmap_sg(ss->dev, areq->src, nr_sgs, DMA_TO_DEVICE);

		dma_unmap_sg(ss->dev, areq->dst, nr_sgd, DMA_FROM_DEVICE);

	}



theend_iv:

	if (rctx->p_iv)

		dma_unmap_single(ss->dev, rctx->p_iv, rctx->ivlen,

				 DMA_TO_DEVICE);



	if (areq->iv && ivsize > 0) {

		if (rctx->biv) {

			offset = areq->cryptlen - ivsize;

			if (rctx->op_dir & SS_DECRYPTION) {

				memcpy(areq->iv, backup_iv, ivsize);

				memzero_explicit(backup_iv, ivsize);

				kzfree(backup_iv);

			} else {

				scatterwalk_map_and_copy(areq->iv, areq->dst, offset,

							 ivsize, 0);

			}

			kfree(rctx->biv);

		}

	}



theend_key:

	dma_unmap_single(ss->dev, rctx->p_key, op->keylen, DMA_TO_DEVICE);



theend:



	return err;

}



static int sun8i_ss_handle_cipher_request(struct crypto_engine *engine, void *areq)

{

	int err;

	struct skcipher_request *breq = container_of(areq, struct skcipher_request, base);



	err = sun8i_ss_cipher(breq);

	crypto_finalize_skcipher_request(engine, breq, err);



	return 0;

}



int sun8i_ss_skdecrypt(struct skcipher_request *areq)

{

	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);

	struct sun8i_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);

	struct sun8i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);

	struct crypto_engine *engine;

	int e;



	memset(rctx, 0, sizeof(struct sun8i_cipher_req_ctx));

	rctx->op_dir = SS_DECRYPTION;



	if (sun8i_ss_need_fallback(areq))

		return sun8i_ss_cipher_fallback(areq);



	e = sun8i_ss_get_engine_number(op->ss);

	engine = op->ss->flows[e].engine;

	rctx->flow = e;



	return crypto_transfer_skcipher_request_to_engine(engine, areq);

}



int sun8i_ss_skencrypt(struct skcipher_request *areq)

{

	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(areq);

	struct sun8i_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);

	struct sun8i_cipher_req_ctx *rctx = skcipher_request_ctx(areq);

	struct crypto_engine *engine;

	int e;



	memset(rctx, 0, sizeof(struct sun8i_cipher_req_ctx));

	rctx->op_dir = SS_ENCRYPTION;



	if (sun8i_ss_need_fallback(areq))

		return sun8i_ss_cipher_fallback(areq);



	e = sun8i_ss_get_engine_number(op->ss);

	engine = op->ss->flows[e].engine;

	rctx->flow = e;



	return crypto_transfer_skcipher_request_to_engine(engine, areq);

}



int sun8i_ss_cipher_init(struct crypto_tfm *tfm)

{

	struct sun8i_cipher_tfm_ctx *op = crypto_tfm_ctx(tfm);

	struct sun8i_ss_alg_template *algt;

	const char *name = crypto_tfm_alg_name(tfm);

	struct crypto_skcipher *sktfm = __crypto_skcipher_cast(tfm);

	struct skcipher_alg *alg = crypto_skcipher_alg(sktfm);

	int err;



	memset(op, 0, sizeof(struct sun8i_cipher_tfm_ctx));



	algt = container_of(alg, struct sun8i_ss_alg_template, alg.skcipher);

	op->ss = algt->ss;



	sktfm->reqsize = sizeof(struct sun8i_cipher_req_ctx);



	op->fallback_tfm = crypto_alloc_sync_skcipher(name, 0, CRYPTO_ALG_NEED_FALLBACK);

	if (IS_ERR(op->fallback_tfm)) {

		dev_err(op->ss->dev, "ERROR: Cannot allocate fallback for %s %ld\n",

			name, PTR_ERR(op->fallback_tfm));

		return PTR_ERR(op->fallback_tfm);

	}



	dev_info(op->ss->dev, "Fallback for %s is %s\n",

		 crypto_tfm_alg_driver_name(&sktfm->base),

		 crypto_tfm_alg_driver_name(crypto_skcipher_tfm(&op->fallback_tfm->base)));



	op->enginectx.op.do_one_request = sun8i_ss_handle_cipher_request;

	op->enginectx.op.prepare_request = NULL;

	op->enginectx.op.unprepare_request = NULL;



	err = pm_runtime_get_sync(op->ss->dev);

	if (err < 0) {

		dev_err(op->ss->dev, "pm error %d\n", err);

		goto error_pm;

	}



	return 0;

error_pm:

	crypto_free_sync_skcipher(op->fallback_tfm);

	return err;

}



void sun8i_ss_cipher_exit(struct crypto_tfm *tfm)

{

	struct sun8i_cipher_tfm_ctx *op = crypto_tfm_ctx(tfm);



	if (op->key) {

		memzero_explicit(op->key, op->keylen);

		kfree(op->key);

	}

	crypto_free_sync_skcipher(op->fallback_tfm);

	pm_runtime_put_sync(op->ss->dev);

}



int sun8i_ss_aes_setkey(struct crypto_skcipher *tfm, const u8 *key,

			unsigned int keylen)

{

	struct sun8i_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);

	struct sun8i_ss_dev *ss = op->ss;



	switch (keylen) {

	case 128 / 8:

		break;

	case 192 / 8:

		break;

	case 256 / 8:

		break;

	default:

		dev_dbg(ss->dev, "ERROR: Invalid keylen %u\n", keylen);

		crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);

		return -EINVAL;

	}

	if (op->key) {

		memzero_explicit(op->key, op->keylen);

		kfree(op->key);

	}

	op->keylen = keylen;

	op->key = kmalloc(keylen, GFP_KERNEL | GFP_DMA);

	if (!op->key)

		return -ENOMEM;

	memcpy(op->key, key, keylen);



	crypto_sync_skcipher_clear_flags(op->fallback_tfm, CRYPTO_TFM_REQ_MASK);

	crypto_sync_skcipher_set_flags(op->fallback_tfm, tfm->base.crt_flags & CRYPTO_TFM_REQ_MASK);



	return crypto_sync_skcipher_setkey(op->fallback_tfm, key, keylen);

}



int sun8i_ss_des3_setkey(struct crypto_skcipher *tfm, const u8 *key,

			 unsigned int keylen)

{

	struct sun8i_cipher_tfm_ctx *op = crypto_skcipher_ctx(tfm);

	struct sun8i_ss_dev *ss = op->ss;



	if (unlikely(keylen != 3 * DES_KEY_SIZE)) {

		dev_dbg(ss->dev, "Invalid keylen %u\n", keylen);

		crypto_skcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);

		return -EINVAL;

	}



	if (op->key) {

		memzero_explicit(op->key, op->keylen);

		kfree(op->key);

	}

	op->keylen = keylen;

	op->key = kmalloc(keylen, GFP_KERNEL | GFP_DMA);

	if (!op->key)

		return -ENOMEM;

	memcpy(op->key, key, keylen);



	crypto_sync_skcipher_clear_flags(op->fallback_tfm, CRYPTO_TFM_REQ_MASK);

	crypto_sync_skcipher_set_flags(op->fallback_tfm, tfm->base.crt_flags & CRYPTO_TFM_REQ_MASK);



	return crypto_sync_skcipher_setkey(op->fallback_tfm, key, keylen);

}

drivers/crypto/allwinner/sun8i-ss/sun8i-ss-core.c

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File added.

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