/*
* crc32-arm64.c - CRC32 and CRC32C using optional ARMv8 instructions
*
* Module based on crypto/crc32c_generic.c
*
* CRC32 loop taken from Ed Nevill's Hadoop CRC patch
* http://mail-archives.apache.org/mod_mbox/hadoop-common-dev/201406.mbox/%3C1403687030.3355.19.camel%40localhost.localdomain%3E
*
* Using inline assembly instead of intrinsics in order to be backwards
* compatible with older compilers.
*
* Copyright (C) 2014 Linaro Ltd <yazen.ghannam@linaro.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/unaligned/access_ok.h>
#include <linux/cpufeature.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/string.h>
#include <crypto/internal/hash.h>
MODULE_AUTHOR("Yazen Ghannam <yazen.ghannam@linaro.org>");
MODULE_DESCRIPTION("CRC32 and CRC32C using optional ARMv8 instructions");
MODULE_LICENSE("GPL v2");
#define CRC32X(crc, value) __asm__("crc32x %w[c], %w[c], %x[v]":[c]"+r"(crc):[v]"r"(value))
#define CRC32W(crc, value) __asm__("crc32w %w[c], %w[c], %w[v]":[c]"+r"(crc):[v]"r"(value))
#define CRC32H(crc, value) __asm__("crc32h %w[c], %w[c], %w[v]":[c]"+r"(crc):[v]"r"(value))
#define CRC32B(crc, value) __asm__("crc32b %w[c], %w[c], %w[v]":[c]"+r"(crc):[v]"r"(value))
#define CRC32CX(crc, value) __asm__("crc32cx %w[c], %w[c], %x[v]":[c]"+r"(crc):[v]"r"(value))
#define CRC32CW(crc, value) __asm__("crc32cw %w[c], %w[c], %w[v]":[c]"+r"(crc):[v]"r"(value))
#define CRC32CH(crc, value) __asm__("crc32ch %w[c], %w[c], %w[v]":[c]"+r"(crc):[v]"r"(value))
#define CRC32CB(crc, value) __asm__("crc32cb %w[c], %w[c], %w[v]":[c]"+r"(crc):[v]"r"(value))
static u32 crc32_arm64_le_hw(u32 crc, const u8 *p, unsigned int len)
{
s64 length = len;
while ((length -= sizeof(u64)) >= 0) {
CRC32X(crc, get_unaligned_le64(p));
p += sizeof(u64);
}
/* The following is more efficient than the straight loop */
if (length & sizeof(u32)) {
CRC32W(crc, get_unaligned_le32(p));
p += sizeof(u32);
}
if (length & sizeof(u16)) {
CRC32H(crc, get_unaligned_le16(p));
p += sizeof(u16);
}
if (length & sizeof(u8))
CRC32B(crc, *p);
return crc;
}
static u32 crc32c_arm64_le_hw(u32 crc, const u8 *p, unsigned int len)
{
s64 length = len;
while ((length -= sizeof(u64)) >= 0) {
CRC32CX(crc, get_unaligned_le64(p));
p += sizeof(u64);
}
/* The following is more efficient than the straight loop */
if (length & sizeof(u32)) {
CRC32CW(crc, get_unaligned_le32(p));
p += sizeof(u32);
}
if (length & sizeof(u16)) {
CRC32CH(crc, get_unaligned_le16(p));
p += sizeof(u16);
}
if (length & sizeof(u8))
CRC32CB(crc, *p);
return crc;
}
#define CHKSUM_BLOCK_SIZE 1
#define CHKSUM_DIGEST_SIZE 4
struct chksum_ctx {
u32 key;
};
struct chksum_desc_ctx {
u32 crc;
};
static int chksum_init(struct shash_desc *desc)
{
struct chksum_ctx *mctx = crypto_shash_ctx(desc->tfm);
struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
ctx->crc = mctx->key;
return 0;
}
/*
* Setting the seed allows arbitrary accumulators and flexible XOR policy
* If your algorithm starts with ~0, then XOR with ~0 before you set
* the seed.
*/
static int chksum_setkey(struct crypto_shash *tfm, const u8 *key,
unsigned int keylen)
{
struct chksum_ctx *mctx = crypto_shash_ctx(tfm);
if (keylen != sizeof(mctx->key)) {
crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
return -EINVAL;
}
mctx->key = get_unaligned_le32(key);
return 0;
}
static int chksum_update(struct shash_desc *desc, const u8 *data,
unsigned int length)
{
struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
ctx->crc = crc32_arm64_le_hw(ctx->crc, data, length);
return 0;
}
static int chksumc_update(struct shash_desc *desc, const u8 *data,
unsigned int length)
{
struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
ctx->crc = crc32c_arm64_le_hw(ctx->crc, data, length);
return 0;
}
static int chksum_final(struct shash_desc *desc, u8 *out)
{
struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
put_unaligned_le32(ctx->crc, out);
return 0;
}
static int chksumc_final(struct shash_desc *desc, u8 *out)
{
struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
put_unaligned_le32(~ctx->crc, out);
return 0;
}
static int __chksum_finup(u32 crc, const u8 *data, unsigned int len, u8 *out)
{
put_unaligned_le32(crc32_arm64_le_hw(crc, data, len), out);
return 0;
}
static int __chksumc_finup(u32 crc, const u8 *data, unsigned int len, u8 *out)
{
put_unaligned_le32(~crc32c_arm64_le_hw(crc, data, len), out);
return 0;
}
static int chksum_finup(struct shash_desc *desc, const u8 *data,
unsigned int len, u8 *out)
{
struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
return __chksum_finup(ctx->crc, data, len, out);
}
static int chksumc_finup(struct shash_desc *desc, const u8 *data,
unsigned int len, u8 *out)
{
struct chksum_desc_ctx *ctx = shash_desc_ctx(desc);
return __chksumc_finup(ctx->crc, data, len, out);
}
static int chksum_digest(struct shash_desc *desc, const u8 *data,
unsigned int length, u8 *out)
{
struct chksum_ctx *mctx = crypto_shash_ctx(desc->tfm);
return __chksum_finup(mctx->key, data, length, out);
}
static int chksumc_digest(struct shash_desc *desc, const u8 *data,
unsigned int length, u8 *out)
{
struct chksum_ctx *mctx = crypto_shash_ctx(desc->tfm);
return __chksumc_finup(mctx->key, data, length, out);
}
static int crc32_cra_init(struct crypto_tfm *tfm)
{
struct chksum_ctx *mctx = crypto_tfm_ctx(tfm);
mctx->key = 0;
return 0;
}
static int crc32c_cra_init(struct crypto_tfm *tfm)
{
struct chksum_ctx *mctx = crypto_tfm_ctx(tfm);
mctx->key = ~0;
return 0;
}
static struct shash_alg crc32_alg = {
.digestsize = CHKSUM_DIGEST_SIZE,
.setkey = chksum_setkey,
.init = chksum_init,
.update = chksum_update,
.final = chksum_final,
.finup = chksum_finup,
.digest = chksum_digest,
.descsize = sizeof(struct chksum_desc_ctx),
.base = {
.cra_name = "crc32",
.cra_driver_name = "crc32-arm64-hw",
.cra_priority = 300,
.cra_blocksize = CHKSUM_BLOCK_SIZE,
.cra_alignmask = 0,
.cra_ctxsize = sizeof(struct chksum_ctx),
.cra_module = THIS_MODULE,
.cra_init = crc32_cra_init,
}
};
static struct shash_alg crc32c_alg = {
.digestsize = CHKSUM_DIGEST_SIZE,
.setkey = chksum_setkey,
.init = chksum_init,
.update = chksumc_update,
.final = chksumc_final,
.finup = chksumc_finup,
.digest = chksumc_digest,
.descsize = sizeof(struct chksum_desc_ctx),
.base = {
.cra_name = "crc32c",
.cra_driver_name = "crc32c-arm64-hw",
.cra_priority = 300,
.cra_blocksize = CHKSUM_BLOCK_SIZE,
.cra_alignmask = 0,
.cra_ctxsize = sizeof(struct chksum_ctx),
.cra_module = THIS_MODULE,
.cra_init = crc32c_cra_init,
}
};
static int __init crc32_mod_init(void)
{
int err;
err = crypto_register_shash(&crc32_alg);
if (err)
return err;
err = crypto_register_shash(&crc32c_alg);
if (err) {
crypto_unregister_shash(&crc32_alg);
return err;
}
return 0;
}
static void __exit crc32_mod_exit(void)
{
crypto_unregister_shash(&crc32_alg);
crypto_unregister_shash(&crc32c_alg);
}
module_cpu_feature_match(CRC32, crc32_mod_init);
module_exit(crc32_mod_exit);
