diff options
Diffstat (limited to 'kernel/crypto/842.c')
| -rw-r--r-- | kernel/crypto/842.c | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/kernel/crypto/842.c b/kernel/crypto/842.c new file mode 100644 index 000000000..b48f4f108 --- /dev/null +++ b/kernel/crypto/842.c @@ -0,0 +1,183 @@ +/* + * Cryptographic API for the 842 compression algorithm. + * + * 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, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * + * Copyright (C) IBM Corporation, 2011 + * + * Authors: Robert Jennings <rcj@linux.vnet.ibm.com> + * Seth Jennings <sjenning@linux.vnet.ibm.com> + */ + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/crypto.h> +#include <linux/vmalloc.h> +#include <linux/nx842.h> +#include <linux/lzo.h> +#include <linux/timer.h> + +static int nx842_uselzo; + +struct nx842_ctx { + void *nx842_wmem; /* working memory for 842/lzo */ +}; + +enum nx842_crypto_type { + NX842_CRYPTO_TYPE_842, + NX842_CRYPTO_TYPE_LZO +}; + +#define NX842_SENTINEL 0xdeadbeef + +struct nx842_crypto_header { + unsigned int sentinel; /* debug */ + enum nx842_crypto_type type; +}; + +static int nx842_init(struct crypto_tfm *tfm) +{ + struct nx842_ctx *ctx = crypto_tfm_ctx(tfm); + int wmemsize; + + wmemsize = max_t(int, nx842_get_workmem_size(), LZO1X_MEM_COMPRESS); + ctx->nx842_wmem = kmalloc(wmemsize, GFP_NOFS); + if (!ctx->nx842_wmem) + return -ENOMEM; + + return 0; +} + +static void nx842_exit(struct crypto_tfm *tfm) +{ + struct nx842_ctx *ctx = crypto_tfm_ctx(tfm); + + kfree(ctx->nx842_wmem); +} + +static void nx842_reset_uselzo(unsigned long data) +{ + nx842_uselzo = 0; +} + +static DEFINE_TIMER(failover_timer, nx842_reset_uselzo, 0, 0); + +static int nx842_crypto_compress(struct crypto_tfm *tfm, const u8 *src, + unsigned int slen, u8 *dst, unsigned int *dlen) +{ + struct nx842_ctx *ctx = crypto_tfm_ctx(tfm); + struct nx842_crypto_header *hdr; + unsigned int tmp_len = *dlen; + size_t lzodlen; /* needed for lzo */ + int err; + + *dlen = 0; + hdr = (struct nx842_crypto_header *)dst; + hdr->sentinel = NX842_SENTINEL; /* debug */ + dst += sizeof(struct nx842_crypto_header); + tmp_len -= sizeof(struct nx842_crypto_header); + lzodlen = tmp_len; + + if (likely(!nx842_uselzo)) { + err = nx842_compress(src, slen, dst, &tmp_len, ctx->nx842_wmem); + + if (likely(!err)) { + hdr->type = NX842_CRYPTO_TYPE_842; + *dlen = tmp_len + sizeof(struct nx842_crypto_header); + return 0; + } + + /* hardware failed */ + nx842_uselzo = 1; + + /* set timer to check for hardware again in 1 second */ + mod_timer(&failover_timer, jiffies + msecs_to_jiffies(1000)); + } + + /* no hardware, use lzo */ + err = lzo1x_1_compress(src, slen, dst, &lzodlen, ctx->nx842_wmem); + if (err != LZO_E_OK) + return -EINVAL; + + hdr->type = NX842_CRYPTO_TYPE_LZO; + *dlen = lzodlen + sizeof(struct nx842_crypto_header); + return 0; +} + +static int nx842_crypto_decompress(struct crypto_tfm *tfm, const u8 *src, + unsigned int slen, u8 *dst, unsigned int *dlen) +{ + struct nx842_ctx *ctx = crypto_tfm_ctx(tfm); + struct nx842_crypto_header *hdr; + unsigned int tmp_len = *dlen; + size_t lzodlen; /* needed for lzo */ + int err; + + *dlen = 0; + hdr = (struct nx842_crypto_header *)src; + + if (unlikely(hdr->sentinel != NX842_SENTINEL)) + return -EINVAL; + + src += sizeof(struct nx842_crypto_header); + slen -= sizeof(struct nx842_crypto_header); + + if (likely(hdr->type == NX842_CRYPTO_TYPE_842)) { + err = nx842_decompress(src, slen, dst, &tmp_len, + ctx->nx842_wmem); + if (err) + return -EINVAL; + *dlen = tmp_len; + } else if (hdr->type == NX842_CRYPTO_TYPE_LZO) { + lzodlen = tmp_len; + err = lzo1x_decompress_safe(src, slen, dst, &lzodlen); + if (err != LZO_E_OK) + return -EINVAL; + *dlen = lzodlen; + } else + return -EINVAL; + + return 0; +} + +static struct crypto_alg alg = { + .cra_name = "842", + .cra_flags = CRYPTO_ALG_TYPE_COMPRESS, + .cra_ctxsize = sizeof(struct nx842_ctx), + .cra_module = THIS_MODULE, + .cra_init = nx842_init, + .cra_exit = nx842_exit, + .cra_u = { .compress = { + .coa_compress = nx842_crypto_compress, + .coa_decompress = nx842_crypto_decompress } } +}; + +static int __init nx842_mod_init(void) +{ + del_timer(&failover_timer); + return crypto_register_alg(&alg); +} + +static void __exit nx842_mod_exit(void) +{ + crypto_unregister_alg(&alg); +} + +module_init(nx842_mod_init); +module_exit(nx842_mod_exit); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("842 Compression Algorithm"); +MODULE_ALIAS_CRYPTO("842"); |