cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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crc32c-vpmsum_glue.c (4051B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2#include <linux/crc32.h>
      3#include <crypto/internal/hash.h>
      4#include <crypto/internal/simd.h>
      5#include <linux/init.h>
      6#include <linux/module.h>
      7#include <linux/string.h>
      8#include <linux/kernel.h>
      9#include <linux/cpufeature.h>
     10#include <asm/simd.h>
     11#include <asm/switch_to.h>
     12
     13#define CHKSUM_BLOCK_SIZE	1
     14#define CHKSUM_DIGEST_SIZE	4
     15
     16#define VMX_ALIGN		16
     17#define VMX_ALIGN_MASK		(VMX_ALIGN-1)
     18
     19#define VECTOR_BREAKPOINT	512
     20
     21u32 __crc32c_vpmsum(u32 crc, unsigned char const *p, size_t len);
     22
     23static u32 crc32c_vpmsum(u32 crc, unsigned char const *p, size_t len)
     24{
     25	unsigned int prealign;
     26	unsigned int tail;
     27
     28	if (len < (VECTOR_BREAKPOINT + VMX_ALIGN) || !crypto_simd_usable())
     29		return __crc32c_le(crc, p, len);
     30
     31	if ((unsigned long)p & VMX_ALIGN_MASK) {
     32		prealign = VMX_ALIGN - ((unsigned long)p & VMX_ALIGN_MASK);
     33		crc = __crc32c_le(crc, p, prealign);
     34		len -= prealign;
     35		p += prealign;
     36	}
     37
     38	if (len & ~VMX_ALIGN_MASK) {
     39		preempt_disable();
     40		pagefault_disable();
     41		enable_kernel_altivec();
     42		crc = __crc32c_vpmsum(crc, p, len & ~VMX_ALIGN_MASK);
     43		disable_kernel_altivec();
     44		pagefault_enable();
     45		preempt_enable();
     46	}
     47
     48	tail = len & VMX_ALIGN_MASK;
     49	if (tail) {
     50		p += len & ~VMX_ALIGN_MASK;
     51		crc = __crc32c_le(crc, p, tail);
     52	}
     53
     54	return crc;
     55}
     56
     57static int crc32c_vpmsum_cra_init(struct crypto_tfm *tfm)
     58{
     59	u32 *key = crypto_tfm_ctx(tfm);
     60
     61	*key = ~0;
     62
     63	return 0;
     64}
     65
     66/*
     67 * Setting the seed allows arbitrary accumulators and flexible XOR policy
     68 * If your algorithm starts with ~0, then XOR with ~0 before you set
     69 * the seed.
     70 */
     71static int crc32c_vpmsum_setkey(struct crypto_shash *hash, const u8 *key,
     72			       unsigned int keylen)
     73{
     74	u32 *mctx = crypto_shash_ctx(hash);
     75
     76	if (keylen != sizeof(u32))
     77		return -EINVAL;
     78	*mctx = le32_to_cpup((__le32 *)key);
     79	return 0;
     80}
     81
     82static int crc32c_vpmsum_init(struct shash_desc *desc)
     83{
     84	u32 *mctx = crypto_shash_ctx(desc->tfm);
     85	u32 *crcp = shash_desc_ctx(desc);
     86
     87	*crcp = *mctx;
     88
     89	return 0;
     90}
     91
     92static int crc32c_vpmsum_update(struct shash_desc *desc, const u8 *data,
     93			       unsigned int len)
     94{
     95	u32 *crcp = shash_desc_ctx(desc);
     96
     97	*crcp = crc32c_vpmsum(*crcp, data, len);
     98
     99	return 0;
    100}
    101
    102static int __crc32c_vpmsum_finup(u32 *crcp, const u8 *data, unsigned int len,
    103				u8 *out)
    104{
    105	*(__le32 *)out = ~cpu_to_le32(crc32c_vpmsum(*crcp, data, len));
    106
    107	return 0;
    108}
    109
    110static int crc32c_vpmsum_finup(struct shash_desc *desc, const u8 *data,
    111			      unsigned int len, u8 *out)
    112{
    113	return __crc32c_vpmsum_finup(shash_desc_ctx(desc), data, len, out);
    114}
    115
    116static int crc32c_vpmsum_final(struct shash_desc *desc, u8 *out)
    117{
    118	u32 *crcp = shash_desc_ctx(desc);
    119
    120	*(__le32 *)out = ~cpu_to_le32p(crcp);
    121
    122	return 0;
    123}
    124
    125static int crc32c_vpmsum_digest(struct shash_desc *desc, const u8 *data,
    126			       unsigned int len, u8 *out)
    127{
    128	return __crc32c_vpmsum_finup(crypto_shash_ctx(desc->tfm), data, len,
    129				     out);
    130}
    131
    132static struct shash_alg alg = {
    133	.setkey		= crc32c_vpmsum_setkey,
    134	.init		= crc32c_vpmsum_init,
    135	.update		= crc32c_vpmsum_update,
    136	.final		= crc32c_vpmsum_final,
    137	.finup		= crc32c_vpmsum_finup,
    138	.digest		= crc32c_vpmsum_digest,
    139	.descsize	= sizeof(u32),
    140	.digestsize	= CHKSUM_DIGEST_SIZE,
    141	.base		= {
    142		.cra_name		= "crc32c",
    143		.cra_driver_name	= "crc32c-vpmsum",
    144		.cra_priority		= 200,
    145		.cra_flags		= CRYPTO_ALG_OPTIONAL_KEY,
    146		.cra_blocksize		= CHKSUM_BLOCK_SIZE,
    147		.cra_ctxsize		= sizeof(u32),
    148		.cra_module		= THIS_MODULE,
    149		.cra_init		= crc32c_vpmsum_cra_init,
    150	}
    151};
    152
    153static int __init crc32c_vpmsum_mod_init(void)
    154{
    155	if (!cpu_has_feature(CPU_FTR_ARCH_207S))
    156		return -ENODEV;
    157
    158	return crypto_register_shash(&alg);
    159}
    160
    161static void __exit crc32c_vpmsum_mod_fini(void)
    162{
    163	crypto_unregister_shash(&alg);
    164}
    165
    166module_cpu_feature_match(PPC_MODULE_FEATURE_VEC_CRYPTO, crc32c_vpmsum_mod_init);
    167module_exit(crc32c_vpmsum_mod_fini);
    168
    169MODULE_AUTHOR("Anton Blanchard <anton@samba.org>");
    170MODULE_DESCRIPTION("CRC32C using vector polynomial multiply-sum instructions");
    171MODULE_LICENSE("GPL");
    172MODULE_ALIAS_CRYPTO("crc32c");
    173MODULE_ALIAS_CRYPTO("crc32c-vpmsum");