cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

crct10dif-vpmsum_glue.c (2940B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * Calculate a CRC T10-DIF with vpmsum acceleration
      4 *
      5 * Copyright 2017, Daniel Axtens, IBM Corporation.
      6 * [based on crc32c-vpmsum_glue.c]
      7 */
      8
      9#include <linux/crc-t10dif.h>
     10#include <crypto/internal/hash.h>
     11#include <crypto/internal/simd.h>
     12#include <linux/init.h>
     13#include <linux/module.h>
     14#include <linux/string.h>
     15#include <linux/kernel.h>
     16#include <linux/cpufeature.h>
     17#include <asm/simd.h>
     18#include <asm/switch_to.h>
     19
     20#define VMX_ALIGN		16
     21#define VMX_ALIGN_MASK		(VMX_ALIGN-1)
     22
     23#define VECTOR_BREAKPOINT	64
     24
     25u32 __crct10dif_vpmsum(u32 crc, unsigned char const *p, size_t len);
     26
     27static u16 crct10dif_vpmsum(u16 crci, unsigned char const *p, size_t len)
     28{
     29	unsigned int prealign;
     30	unsigned int tail;
     31	u32 crc = crci;
     32
     33	if (len < (VECTOR_BREAKPOINT + VMX_ALIGN) || !crypto_simd_usable())
     34		return crc_t10dif_generic(crc, p, len);
     35
     36	if ((unsigned long)p & VMX_ALIGN_MASK) {
     37		prealign = VMX_ALIGN - ((unsigned long)p & VMX_ALIGN_MASK);
     38		crc = crc_t10dif_generic(crc, p, prealign);
     39		len -= prealign;
     40		p += prealign;
     41	}
     42
     43	if (len & ~VMX_ALIGN_MASK) {
     44		crc <<= 16;
     45		preempt_disable();
     46		pagefault_disable();
     47		enable_kernel_altivec();
     48		crc = __crct10dif_vpmsum(crc, p, len & ~VMX_ALIGN_MASK);
     49		disable_kernel_altivec();
     50		pagefault_enable();
     51		preempt_enable();
     52		crc >>= 16;
     53	}
     54
     55	tail = len & VMX_ALIGN_MASK;
     56	if (tail) {
     57		p += len & ~VMX_ALIGN_MASK;
     58		crc = crc_t10dif_generic(crc, p, tail);
     59	}
     60
     61	return crc & 0xffff;
     62}
     63
     64static int crct10dif_vpmsum_init(struct shash_desc *desc)
     65{
     66	u16 *crc = shash_desc_ctx(desc);
     67
     68	*crc = 0;
     69	return 0;
     70}
     71
     72static int crct10dif_vpmsum_update(struct shash_desc *desc, const u8 *data,
     73			    unsigned int length)
     74{
     75	u16 *crc = shash_desc_ctx(desc);
     76
     77	*crc = crct10dif_vpmsum(*crc, data, length);
     78
     79	return 0;
     80}
     81
     82
     83static int crct10dif_vpmsum_final(struct shash_desc *desc, u8 *out)
     84{
     85	u16 *crcp = shash_desc_ctx(desc);
     86
     87	*(u16 *)out = *crcp;
     88	return 0;
     89}
     90
     91static struct shash_alg alg = {
     92	.init		= crct10dif_vpmsum_init,
     93	.update		= crct10dif_vpmsum_update,
     94	.final		= crct10dif_vpmsum_final,
     95	.descsize	= CRC_T10DIF_DIGEST_SIZE,
     96	.digestsize	= CRC_T10DIF_DIGEST_SIZE,
     97	.base		= {
     98		.cra_name		= "crct10dif",
     99		.cra_driver_name	= "crct10dif-vpmsum",
    100		.cra_priority		= 200,
    101		.cra_blocksize		= CRC_T10DIF_BLOCK_SIZE,
    102		.cra_module		= THIS_MODULE,
    103	}
    104};
    105
    106static int __init crct10dif_vpmsum_mod_init(void)
    107{
    108	if (!cpu_has_feature(CPU_FTR_ARCH_207S))
    109		return -ENODEV;
    110
    111	return crypto_register_shash(&alg);
    112}
    113
    114static void __exit crct10dif_vpmsum_mod_fini(void)
    115{
    116	crypto_unregister_shash(&alg);
    117}
    118
    119module_cpu_feature_match(PPC_MODULE_FEATURE_VEC_CRYPTO, crct10dif_vpmsum_mod_init);
    120module_exit(crct10dif_vpmsum_mod_fini);
    121
    122MODULE_AUTHOR("Daniel Axtens <dja@axtens.net>");
    123MODULE_DESCRIPTION("CRCT10DIF using vector polynomial multiply-sum instructions");
    124MODULE_LICENSE("GPL");
    125MODULE_ALIAS_CRYPTO("crct10dif");
    126MODULE_ALIAS_CRYPTO("crct10dif-vpmsum");