drivers/misc/tegra-cryptodev.c - kernel/tegra - Git at Google

 /*
  * drivers/misc/tegra-cryptodev.c
  *
  * crypto dev node for NVIDIA tegra aes hardware
  *
  * Copyright (c) 2010, NVIDIA Corporation.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  * more details.
  *
  * You should have received a copy of the GNU General Public License along
  * with this program; if not, write to the Free Software Foundation, Inc.,
  * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  */

 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/errno.h>
 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/fs.h>
 #include <linux/miscdevice.h>
 #include <linux/crypto.h>
 #include <linux/scatterlist.h>
 #include <linux/uaccess.h>
 #include <crypto/rng.h>

 #include "tegra-cryptodev.h"

 #define NBUFS 2

 struct tegra_crypto_ctx {
 	struct crypto_ablkcipher *ecb_tfm;
 	struct crypto_ablkcipher *cbc_tfm;
 	struct crypto_rng *rng;
 	u8 seed[TEGRA_CRYPTO_RNG_SEED_SIZE];
 	int use_ssk;
 };

 struct tegra_crypto_completion {
 	struct completion restart;
 	int req_err;
 };

 static int alloc_bufs(unsigned long *buf[NBUFS])
 {
 	int i;

 	for (i = 0; i < NBUFS; i++) {
 		buf[i] = (void *)__get_free_page(GFP_KERNEL);
 		if (!buf[i])
 			goto err_free_buf;
 	}

 	return 0;

 err_free_buf:
 	while (i-- > 0)
 		free_page((unsigned long)buf[i]);

 	return -ENOMEM;
 }

 static void free_bufs(unsigned long *buf[NBUFS])
 {
 	int i;

 	for (i = 0; i < NBUFS; i++)
 		free_page((unsigned long)buf[i]);
 }

 static int tegra_crypto_dev_open(struct inode *inode, struct file *filp)
 {
 	struct tegra_crypto_ctx *ctx;
 	int ret = 0;

 	ctx = kzalloc(sizeof(struct tegra_crypto_ctx), GFP_KERNEL);
 	if (!ctx) {
 		pr_err("no memory for context\n");
 		return -ENOMEM;
 	}

 	ctx->ecb_tfm = crypto_alloc_ablkcipher("ecb-aes-tegra",
 		CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC, 0);
 	if (IS_ERR(ctx->ecb_tfm)) {
 		pr_err("Failed to load transform for ecb-aes-tegra: %ld\n",
 			PTR_ERR(ctx->ecb_tfm));
 		ret = PTR_ERR(ctx->ecb_tfm);
 		goto fail_ecb;
 	}

 	ctx->cbc_tfm = crypto_alloc_ablkcipher("cbc-aes-tegra",
 		CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC, 0);
 	if (IS_ERR(ctx->cbc_tfm)) {
 		pr_err("Failed to load transform for cbc-aes-tegra: %ld\n",
 			PTR_ERR(ctx->cbc_tfm));
 		ret = PTR_ERR(ctx->cbc_tfm);
 		goto fail_cbc;
 	}

 	ctx->rng = crypto_alloc_rng("rng-aes-tegra", CRYPTO_ALG_TYPE_RNG, 0);
 	if (IS_ERR(ctx->rng)) {
 		pr_err("Failed to load transform for tegra rng: %ld\n",
 			PTR_ERR(ctx->rng));
 		ret = PTR_ERR(ctx->rng);
 		goto fail_rng;
 	}

 	filp->private_data = ctx;
 	return ret;

 fail_rng:
 	crypto_free_ablkcipher(ctx->cbc_tfm);

 fail_cbc:
 	crypto_free_ablkcipher(ctx->ecb_tfm);

 fail_ecb:
 	kfree(ctx);
 	return ret;
 }

 static int tegra_crypto_dev_release(struct inode *inode, struct file *filp)
 {
 	struct tegra_crypto_ctx *ctx = filp->private_data;

 	crypto_free_ablkcipher(ctx->ecb_tfm);
 	crypto_free_ablkcipher(ctx->cbc_tfm);
 	crypto_free_rng(ctx->rng);
 	kfree(ctx);
 	filp->private_data = NULL;
 	return 0;
 }

 static void tegra_crypt_complete(struct crypto_async_request *req, int err)
 {
 	struct tegra_crypto_completion *done = req->data;

 	if (err != -EINPROGRESS) {
 		done->req_err = err;
 		complete(&done->restart);
 	}
 }

 static int process_crypt_req(struct tegra_crypto_ctx *ctx, struct tegra_crypt_req *crypt_req)
 {
 	struct crypto_ablkcipher *tfm;
 	struct ablkcipher_request *req = NULL;
 	struct scatterlist in_sg;
 	struct scatterlist out_sg;
 	unsigned long *xbuf[NBUFS];
 	int ret = 0, size = 0;
 	unsigned long total = 0;
 	struct tegra_crypto_completion tcrypt_complete;
 	const u8 *key = NULL;

 	if (crypt_req->op & TEGRA_CRYPTO_ECB) {
 		req = ablkcipher_request_alloc(ctx->ecb_tfm, GFP_KERNEL);
 		tfm = ctx->ecb_tfm;
 	} else {
 		req = ablkcipher_request_alloc(ctx->cbc_tfm, GFP_KERNEL);
 		tfm = ctx->cbc_tfm;
 	}
 	if (!req) {
 		pr_err("%s: Failed to allocate request\n", __func__);
 		return -ENOMEM;
 	}

 	if ((crypt_req->keylen < 0) || (crypt_req->keylen > AES_MAX_KEY_SIZE))
 		return -EINVAL;

 	crypto_ablkcipher_clear_flags(tfm, ~0);

 	if (!ctx->use_ssk)
 		key = crypt_req->key;

 	ret = crypto_ablkcipher_setkey(tfm, key, crypt_req->keylen);
 	if (ret < 0) {
 		pr_err("setkey failed");
 		goto process_req_out;
 	}

 	ret = alloc_bufs(xbuf);
 	if (ret < 0) {
 		pr_err("alloc_bufs failed");
 		goto process_req_out;
 	}

 	init_completion(&tcrypt_complete.restart);

 	ablkcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
 		tegra_crypt_complete, &tcrypt_complete);

 	total = crypt_req->plaintext_sz;
 	while (total > 0) {
 		size = min(total, PAGE_SIZE);
 		ret = copy_from_user((void *)xbuf[0],
 			(void __user *)crypt_req->plaintext, size);
 		if (ret < 0) {
 			pr_debug("%s: copy_from_user failed (%d)\n", __func__, ret);
 			goto process_req_buf_out;
 		}
 		sg_init_one(&in_sg, xbuf[0], size);
 		sg_init_one(&out_sg, xbuf[1], size);

 		ablkcipher_request_set_crypt(req, &in_sg,
 			&out_sg, size, crypt_req->iv);

 		INIT_COMPLETION(tcrypt_complete.restart);
 		tcrypt_complete.req_err = 0;
 		ret = crypt_req->encrypt ?
 			crypto_ablkcipher_encrypt(req) :
 			crypto_ablkcipher_decrypt(req);

 		if ((ret == -EINPROGRESS) || (ret == -EBUSY)) {
 			/* crypto driver is asynchronous */
 			ret = wait_for_completion_interruptible(&tcrypt_complete.restart);

 			if (ret < 0)
 				goto process_req_buf_out;

 			if (tcrypt_complete.req_err < 0) {
 				ret = tcrypt_complete.req_err;
 				goto process_req_buf_out;
 			}
 		} else if (ret < 0) {
 			pr_debug("%scrypt failed (%d)\n",
 				crypt_req->encrypt ? "en" : "de", ret);
 			goto process_req_buf_out;
 		}

 		ret = copy_to_user((void __user *)crypt_req->result,
 			(const void *)xbuf[1], size);
 		if (ret < 0)
 			goto process_req_buf_out;

 		total -= size;
 		crypt_req->result += size;
 		crypt_req->plaintext += size;
 	}

 process_req_buf_out:
 	free_bufs(xbuf);
 process_req_out:
 	ablkcipher_request_free(req);

 	return ret;
 }

 static long tegra_crypto_dev_ioctl(struct file *filp,
 	unsigned int ioctl_num, unsigned long arg)
 {
 	struct tegra_crypto_ctx *ctx = filp->private_data;
 	struct tegra_crypt_req crypt_req;
 	struct tegra_rng_req rng_req;
 	char *rng;
 	int ret = 0;

 	switch (ioctl_num) {
 	case TEGRA_CRYPTO_IOCTL_NEED_SSK:
 		ctx->use_ssk = (int)arg;
 		break;

 	case TEGRA_CRYPTO_IOCTL_PROCESS_REQ:
 		ret = copy_from_user(&crypt_req, (void __user *)arg, sizeof(crypt_req));
 		if (ret < 0) {
 			pr_err("%s: copy_from_user fail(%d)\n", __func__, ret);
 			break;
 		}

 		ret = process_crypt_req(ctx, &crypt_req);
 		break;

 	case TEGRA_CRYPTO_IOCTL_SET_SEED:
 		if (copy_from_user(&rng_req, (void __user *)arg, sizeof(rng_req)))
 			return -EFAULT;

 		memcpy(ctx->seed, rng_req.seed, TEGRA_CRYPTO_RNG_SEED_SIZE);

 		ret = crypto_rng_reset(ctx->rng, ctx->seed,
 			crypto_rng_seedsize(ctx->rng));
 		break;

 	case TEGRA_CRYPTO_IOCTL_GET_RANDOM:
 		if (copy_from_user(&rng_req, (void __user *)arg, sizeof(rng_req)))
 			return -EFAULT;

 		rng = kzalloc(rng_req.nbytes, GFP_KERNEL);
 		if (!rng) {
 			pr_err("mem alloc for rng fail");
 			ret = -ENODATA;
 			goto rng_out;
 		}

 		ret = crypto_rng_get_bytes(ctx->rng, rng,
 			rng_req.nbytes);

 		if (ret != rng_req.nbytes) {
 			pr_err("rng failed");
 			ret = -ENODATA;
 			goto rng_out;
 		}

 		ret = copy_to_user((void __user *)rng_req.rdata,
 			(const void *)rng, rng_req.nbytes);
 		ret = (ret < 0) ? -ENODATA : 0;
 rng_out:
 		if (rng)
 			kfree(rng);
 		break;

 	default:
 		pr_debug("invalid ioctl code(%d)", ioctl_num);
 		ret = -EINVAL;
 	}

 	return ret;
 }

 struct file_operations tegra_crypto_fops = {
 	.owner = THIS_MODULE,
 	.open = tegra_crypto_dev_open,
 	.release = tegra_crypto_dev_release,
 	.unlocked_ioctl = tegra_crypto_dev_ioctl,
 };

 struct miscdevice tegra_crypto_device = {
 	.minor = MISC_DYNAMIC_MINOR,
 	.name = "tegra-crypto",
 	.fops = &tegra_crypto_fops,
 };

 static int __init tegra_crypto_dev_init(void)
 {
 	return misc_register(&tegra_crypto_device);
 }

 late_initcall(tegra_crypto_dev_init);

 MODULE_DESCRIPTION("Tegra AES hw device node.");
 MODULE_AUTHOR("NVIDIA Corporation");
 MODULE_LICENSE("GPLv2");
	/*
	* drivers/misc/tegra-cryptodev.c
	*
	* crypto dev node for NVIDIA tegra aes hardware
	*
	* Copyright (c) 2010, NVIDIA Corporation.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	* more details.
	*
	* You should have received a copy of the GNU General Public License along
	* with this program; if not, write to the Free Software Foundation, Inc.,
	* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
	*/

	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/errno.h>
	#include <linux/kernel.h>
	#include <linux/slab.h>
	#include <linux/fs.h>
	#include <linux/miscdevice.h>
	#include <linux/crypto.h>
	#include <linux/scatterlist.h>
	#include <linux/uaccess.h>
	#include <crypto/rng.h>

	#include "tegra-cryptodev.h"

	#define NBUFS 2

	struct tegra_crypto_ctx {
	struct crypto_ablkcipher *ecb_tfm;
	struct crypto_ablkcipher *cbc_tfm;
	struct crypto_rng *rng;
	u8 seed[TEGRA_CRYPTO_RNG_SEED_SIZE];
	int use_ssk;
	};

	struct tegra_crypto_completion {
	struct completion restart;
	int req_err;
	};

	static int alloc_bufs(unsigned long *buf[NBUFS])
	{
	int i;

	for (i = 0; i < NBUFS; i++) {
	buf[i] = (void *)__get_free_page(GFP_KERNEL);
	if (!buf[i])
	goto err_free_buf;
	}

	return 0;

	err_free_buf:
	while (i-- > 0)
	free_page((unsigned long)buf[i]);

	return -ENOMEM;
	}

	static void free_bufs(unsigned long *buf[NBUFS])
	{
	int i;

	for (i = 0; i < NBUFS; i++)
	free_page((unsigned long)buf[i]);
	}

	static int tegra_crypto_dev_open(struct inode inode, struct file filp)
	{
	struct tegra_crypto_ctx *ctx;
	int ret = 0;

	ctx = kzalloc(sizeof(struct tegra_crypto_ctx), GFP_KERNEL);
	if (!ctx) {
	pr_err("no memory for context\n");
	return -ENOMEM;
	}

	ctx->ecb_tfm = crypto_alloc_ablkcipher("ecb-aes-tegra",
	CRYPTO_ALG_TYPE_ABLKCIPHER \| CRYPTO_ALG_ASYNC, 0);
	if (IS_ERR(ctx->ecb_tfm)) {
	pr_err("Failed to load transform for ecb-aes-tegra: %ld\n",
	PTR_ERR(ctx->ecb_tfm));
	ret = PTR_ERR(ctx->ecb_tfm);
	goto fail_ecb;
	}

	ctx->cbc_tfm = crypto_alloc_ablkcipher("cbc-aes-tegra",
	CRYPTO_ALG_TYPE_ABLKCIPHER \| CRYPTO_ALG_ASYNC, 0);
	if (IS_ERR(ctx->cbc_tfm)) {
	pr_err("Failed to load transform for cbc-aes-tegra: %ld\n",
	PTR_ERR(ctx->cbc_tfm));
	ret = PTR_ERR(ctx->cbc_tfm);
	goto fail_cbc;
	}

	ctx->rng = crypto_alloc_rng("rng-aes-tegra", CRYPTO_ALG_TYPE_RNG, 0);
	if (IS_ERR(ctx->rng)) {
	pr_err("Failed to load transform for tegra rng: %ld\n",
	PTR_ERR(ctx->rng));
	ret = PTR_ERR(ctx->rng);
	goto fail_rng;
	}

	filp->private_data = ctx;
	return ret;

	fail_rng:
	crypto_free_ablkcipher(ctx->cbc_tfm);

	fail_cbc:
	crypto_free_ablkcipher(ctx->ecb_tfm);

	fail_ecb:
	kfree(ctx);
	return ret;
	}

	static int tegra_crypto_dev_release(struct inode inode, struct file filp)
	{
	struct tegra_crypto_ctx *ctx = filp->private_data;

	crypto_free_ablkcipher(ctx->ecb_tfm);
	crypto_free_ablkcipher(ctx->cbc_tfm);
	crypto_free_rng(ctx->rng);
	kfree(ctx);
	filp->private_data = NULL;
	return 0;
	}

	static void tegra_crypt_complete(struct crypto_async_request *req, int err)
	{
	struct tegra_crypto_completion *done = req->data;

	if (err != -EINPROGRESS) {
	done->req_err = err;
	complete(&done->restart);
	}
	}

	static int process_crypt_req(struct tegra_crypto_ctx ctx, struct tegra_crypt_req crypt_req)
	{
	struct crypto_ablkcipher *tfm;
	struct ablkcipher_request *req = NULL;
	struct scatterlist in_sg;
	struct scatterlist out_sg;
	unsigned long *xbuf[NBUFS];
	int ret = 0, size = 0;
	unsigned long total = 0;
	struct tegra_crypto_completion tcrypt_complete;
	const u8 *key = NULL;

	if (crypt_req->op & TEGRA_CRYPTO_ECB) {
	req = ablkcipher_request_alloc(ctx->ecb_tfm, GFP_KERNEL);
	tfm = ctx->ecb_tfm;
	} else {
	req = ablkcipher_request_alloc(ctx->cbc_tfm, GFP_KERNEL);
	tfm = ctx->cbc_tfm;
	}
	if (!req) {
	pr_err("%s: Failed to allocate request\n", __func__);
	return -ENOMEM;
	}

	if ((crypt_req->keylen < 0) \|\| (crypt_req->keylen > AES_MAX_KEY_SIZE))
	return -EINVAL;

	crypto_ablkcipher_clear_flags(tfm, ~0);

	if (!ctx->use_ssk)
	key = crypt_req->key;

	ret = crypto_ablkcipher_setkey(tfm, key, crypt_req->keylen);
	if (ret < 0) {
	pr_err("setkey failed");
	goto process_req_out;
	}

	ret = alloc_bufs(xbuf);
	if (ret < 0) {
	pr_err("alloc_bufs failed");
	goto process_req_out;
	}

	init_completion(&tcrypt_complete.restart);

	ablkcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
	tegra_crypt_complete, &tcrypt_complete);

	total = crypt_req->plaintext_sz;
	while (total > 0) {
	size = min(total, PAGE_SIZE);
	ret = copy_from_user((void *)xbuf[0],
	(void __user *)crypt_req->plaintext, size);
	if (ret < 0) {
	pr_debug("%s: copy_from_user failed (%d)\n", __func__, ret);
	goto process_req_buf_out;
	}
	sg_init_one(&in_sg, xbuf[0], size);
	sg_init_one(&out_sg, xbuf[1], size);

	ablkcipher_request_set_crypt(req, &in_sg,
	&out_sg, size, crypt_req->iv);

	INIT_COMPLETION(tcrypt_complete.restart);
	tcrypt_complete.req_err = 0;
	ret = crypt_req->encrypt ?
	crypto_ablkcipher_encrypt(req) :
	crypto_ablkcipher_decrypt(req);

	if ((ret == -EINPROGRESS) \|\| (ret == -EBUSY)) {
	/* crypto driver is asynchronous */
	ret = wait_for_completion_interruptible(&tcrypt_complete.restart);

	if (ret < 0)
	goto process_req_buf_out;

	if (tcrypt_complete.req_err < 0) {
	ret = tcrypt_complete.req_err;
	goto process_req_buf_out;
	}
	} else if (ret < 0) {
	pr_debug("%scrypt failed (%d)\n",
	crypt_req->encrypt ? "en" : "de", ret);
	goto process_req_buf_out;
	}

	ret = copy_to_user((void __user *)crypt_req->result,
	(const void *)xbuf[1], size);
	if (ret < 0)
	goto process_req_buf_out;

	total -= size;
	crypt_req->result += size;
	crypt_req->plaintext += size;
	}

	process_req_buf_out:
	free_bufs(xbuf);
	process_req_out:
	ablkcipher_request_free(req);

	return ret;
	}

	static long tegra_crypto_dev_ioctl(struct file *filp,
	unsigned int ioctl_num, unsigned long arg)
	{
	struct tegra_crypto_ctx *ctx = filp->private_data;
	struct tegra_crypt_req crypt_req;
	struct tegra_rng_req rng_req;
	char *rng;
	int ret = 0;

	switch (ioctl_num) {
	case TEGRA_CRYPTO_IOCTL_NEED_SSK:
	ctx->use_ssk = (int)arg;
	break;

	case TEGRA_CRYPTO_IOCTL_PROCESS_REQ:
	ret = copy_from_user(&crypt_req, (void __user *)arg, sizeof(crypt_req));
	if (ret < 0) {
	pr_err("%s: copy_from_user fail(%d)\n", __func__, ret);
	break;
	}

	ret = process_crypt_req(ctx, &crypt_req);
	break;

	case TEGRA_CRYPTO_IOCTL_SET_SEED:
	if (copy_from_user(&rng_req, (void __user *)arg, sizeof(rng_req)))
	return -EFAULT;

	memcpy(ctx->seed, rng_req.seed, TEGRA_CRYPTO_RNG_SEED_SIZE);

	ret = crypto_rng_reset(ctx->rng, ctx->seed,
	crypto_rng_seedsize(ctx->rng));
	break;

	case TEGRA_CRYPTO_IOCTL_GET_RANDOM:
	if (copy_from_user(&rng_req, (void __user *)arg, sizeof(rng_req)))
	return -EFAULT;

	rng = kzalloc(rng_req.nbytes, GFP_KERNEL);
	if (!rng) {
	pr_err("mem alloc for rng fail");
	ret = -ENODATA;
	goto rng_out;
	}

	ret = crypto_rng_get_bytes(ctx->rng, rng,
	rng_req.nbytes);

	if (ret != rng_req.nbytes) {
	pr_err("rng failed");
	ret = -ENODATA;
	goto rng_out;
	}

	ret = copy_to_user((void __user *)rng_req.rdata,
	(const void *)rng, rng_req.nbytes);
	ret = (ret < 0) ? -ENODATA : 0;
	rng_out:
	if (rng)
	kfree(rng);
	break;

	default:
	pr_debug("invalid ioctl code(%d)", ioctl_num);
	ret = -EINVAL;
	}

	return ret;
	}

	struct file_operations tegra_crypto_fops = {
	.owner = THIS_MODULE,
	.open = tegra_crypto_dev_open,
	.release = tegra_crypto_dev_release,
	.unlocked_ioctl = tegra_crypto_dev_ioctl,
	};

	struct miscdevice tegra_crypto_device = {
	.minor = MISC_DYNAMIC_MINOR,
	.name = "tegra-crypto",
	.fops = &tegra_crypto_fops,
	};

	static int __init tegra_crypto_dev_init(void)
	{
	return misc_register(&tegra_crypto_device);
	}

	late_initcall(tegra_crypto_dev_init);

	MODULE_DESCRIPTION("Tegra AES hw device node.");
	MODULE_AUTHOR("NVIDIA Corporation");
	MODULE_LICENSE("GPLv2");