rocksdb/util/crc32c_arm64.cc
Yuqi Gu 29f7bbef99 Fix RocksDB SIGILL error on Raspberry PI 4 (#7233)
Summary:
Issue:https://github.com/facebook/rocksdb/issues/7042

No PMULL runtime check will lead to SIGILL on a Raspberry pi 4.

Leverage 'getauxval' to get Hardware-Cap to detect whether target
platform does support PMULL or not in runtime.

Consider the condition that the target platform does support crc32 but not support PMULL.
In this condition, the code should leverage the crc32 instruction
rather than skip all hardware crc32 instruction.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7233

Reviewed By: jay-zhuang

Differential Revision: D23790116

fbshipit-source-id: a3ebd821fbd4a38dd2f59064adbb7c3013ee8140
2020-09-22 10:41:19 -07:00

166 lines
4.3 KiB
C++

// Copyright (c) 2018, Arm Limited and affiliates. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
#include "util/crc32c_arm64.h"
#if defined(__linux__) && defined(HAVE_ARM64_CRC)
#include <asm/hwcap.h>
#ifdef ROCKSDB_AUXV_GETAUXVAL_PRESENT
#include <sys/auxv.h>
#endif
#ifndef HWCAP_CRC32
#define HWCAP_CRC32 (1 << 7)
#endif
#ifndef HWCAP_PMULL
#define HWCAP_PMULL (1 << 4)
#endif
#ifdef HAVE_ARM64_CRYPTO
/* unfolding to compute 8 * 3 = 24 bytes parallelly */
#define CRC32C24BYTES(ITR) \
crc1 = crc32c_u64(crc1, *(buf64 + BLK_LENGTH + (ITR))); \
crc2 = crc32c_u64(crc2, *(buf64 + BLK_LENGTH * 2 + (ITR))); \
crc0 = crc32c_u64(crc0, *(buf64 + (ITR)));
/* unfolding to compute 24 * 7 = 168 bytes parallelly */
#define CRC32C7X24BYTES(ITR) \
do { \
CRC32C24BYTES((ITR)*7 + 0) \
CRC32C24BYTES((ITR)*7 + 1) \
CRC32C24BYTES((ITR)*7 + 2) \
CRC32C24BYTES((ITR)*7 + 3) \
CRC32C24BYTES((ITR)*7 + 4) \
CRC32C24BYTES((ITR)*7 + 5) \
CRC32C24BYTES((ITR)*7 + 6) \
} while (0)
#endif
extern bool pmull_runtime_flag;
uint32_t crc32c_runtime_check(void) {
#ifdef ROCKSDB_AUXV_GETAUXVAL_PRESENT
uint64_t auxv = getauxval(AT_HWCAP);
return (auxv & HWCAP_CRC32) != 0;
#else
return 0;
#endif
}
bool crc32c_pmull_runtime_check(void) {
#ifdef ROCKSDB_AUXV_GETAUXVAL_PRESENT
uint64_t auxv = getauxval(AT_HWCAP);
return (auxv & HWCAP_PMULL) != 0;
#else
return false;
#endif
}
#ifdef ROCKSDB_UBSAN_RUN
#if defined(__clang__)
__attribute__((__no_sanitize__("alignment")))
#elif defined(__GNUC__)
__attribute__((__no_sanitize_undefined__))
#endif
#endif
uint32_t crc32c_arm64(uint32_t crc, unsigned char const *data,
unsigned len) {
const uint8_t *buf8;
const uint64_t *buf64 = (uint64_t *)data;
int length = (int)len;
crc ^= 0xffffffff;
/*
* Pmull runtime check here.
* Raspberry Pi supports crc32 but doesn't support pmull.
* Skip Crc32c Parallel computation if no crypto extension available.
*/
if (pmull_runtime_flag) {
/* Macro (HAVE_ARM64_CRYPTO) is used for compiling check */
#ifdef HAVE_ARM64_CRYPTO
/* Crc32c Parallel computation
* Algorithm comes from Intel whitepaper:
* crc-iscsi-polynomial-crc32-instruction-paper
*
* Input data is divided into three equal-sized blocks
* Three parallel blocks (crc0, crc1, crc2) for 1024 Bytes
* One Block: 42(BLK_LENGTH) * 8(step length: crc32c_u64) bytes
*/
#define BLK_LENGTH 42
while (length >= 1024) {
uint64_t t0, t1;
uint32_t crc0 = 0, crc1 = 0, crc2 = 0;
/* Parallel Param:
* k0 = CRC32(x ^ (42 * 8 * 8 * 2 - 1));
* k1 = CRC32(x ^ (42 * 8 * 8 - 1));
*/
uint32_t k0 = 0xe417f38a, k1 = 0x8f158014;
/* Prefetch data for following block to avoid cache miss */
PREF1KL1((uint8_t *)buf64, 1024);
/* First 8 byte for better pipelining */
crc0 = crc32c_u64(crc, *buf64++);
/* 3 blocks crc32c parallel computation
* Macro unfolding to compute parallelly
* 168 * 6 = 1008 (bytes)
*/
CRC32C7X24BYTES(0);
CRC32C7X24BYTES(1);
CRC32C7X24BYTES(2);
CRC32C7X24BYTES(3);
CRC32C7X24BYTES(4);
CRC32C7X24BYTES(5);
buf64 += (BLK_LENGTH * 3);
/* Last 8 bytes */
crc = crc32c_u64(crc2, *buf64++);
t0 = (uint64_t)vmull_p64(crc0, k0);
t1 = (uint64_t)vmull_p64(crc1, k1);
/* Merge (crc0, crc1, crc2) -> crc */
crc1 = crc32c_u64(0, t1);
crc ^= crc1;
crc0 = crc32c_u64(0, t0);
crc ^= crc0;
length -= 1024;
}
if (length == 0) return crc ^ (0xffffffffU);
#endif
} // if Pmull runtime check here
buf8 = (const uint8_t *)buf64;
while (length >= 8) {
crc = crc32c_u64(crc, *(const uint64_t *)buf8);
buf8 += 8;
length -= 8;
}
/* The following is more efficient than the straight loop */
if (length >= 4) {
crc = crc32c_u32(crc, *(const uint32_t *)buf8);
buf8 += 4;
length -= 4;
}
if (length >= 2) {
crc = crc32c_u16(crc, *(const uint16_t *)buf8);
buf8 += 2;
length -= 2;
}
if (length >= 1) crc = crc32c_u8(crc, *buf8);
crc ^= 0xffffffff;
return crc;
}
#endif