/* * 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 #include #include #include #include #include #include #include #include #include #include #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");