71 lines
1.6 KiB
C
71 lines
1.6 KiB
C
/*
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* T10 Data Integrity Field CRC16 calculation
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*
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* Copyright (c) 2007 Oracle Corporation. All rights reserved.
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* Written by Martin K. Petersen <martin.petersen@oracle.com>
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*
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* This source code is licensed under the GNU General Public License,
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* Version 2. See the file COPYING for more details.
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*/
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#include <linux/types.h>
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#include <linux/module.h>
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#include <linux/crc-t10dif.h>
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#include <linux/err.h>
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#include <linux/init.h>
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#include <crypto/hash.h>
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#include <linux/static_key.h>
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static struct crypto_shash *crct10dif_tfm;
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static struct static_key crct10dif_fallback __read_mostly;
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__u16 crc_t10dif_update(__u16 crc, const unsigned char *buffer, size_t len)
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{
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struct {
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struct shash_desc shash;
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char ctx[2];
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} desc;
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int err;
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if (static_key_false(&crct10dif_fallback))
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return crc_t10dif_generic(crc, buffer, len);
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desc.shash.tfm = crct10dif_tfm;
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desc.shash.flags = 0;
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*(__u16 *)desc.ctx = crc;
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err = crypto_shash_update(&desc.shash, buffer, len);
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BUG_ON(err);
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return *(__u16 *)desc.ctx;
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}
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EXPORT_SYMBOL(crc_t10dif_update);
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__u16 crc_t10dif(const unsigned char *buffer, size_t len)
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{
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return crc_t10dif_update(0, buffer, len);
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}
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EXPORT_SYMBOL(crc_t10dif);
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static int __init crc_t10dif_mod_init(void)
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{
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crct10dif_tfm = crypto_alloc_shash("crct10dif", 0, 0);
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if (IS_ERR(crct10dif_tfm)) {
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static_key_slow_inc(&crct10dif_fallback);
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crct10dif_tfm = NULL;
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}
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return 0;
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}
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static void __exit crc_t10dif_mod_fini(void)
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{
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crypto_free_shash(crct10dif_tfm);
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}
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module_init(crc_t10dif_mod_init);
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module_exit(crc_t10dif_mod_fini);
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MODULE_DESCRIPTION("T10 DIF CRC calculation");
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MODULE_LICENSE("GPL");
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MODULE_SOFTDEP("pre: crct10dif");
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