feat(hw_crc): add support for HW computed CRC

Added support for HW computed CRC using Arm ACLE intrinsics.
These are built-in intrinsics available for ARMv8.1-A, and
onwards.
These intrinsics are enabled via '-march=armv8-a+crc' compile
switch for ARMv8-A (supports CRC instructions optionally).

HW CRC support is enabled unconditionally in BL2 for all Arm
platforms.

HW CRC calculation is verified offline to ensure a similar
result as its respective ZLib utility function.

HW CRC calculation support will be used in the upcoming
firmware update patches.

Change-Id: Ia2ae801f62d2003e89a9c3e6d77469b5312614b3
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
This commit is contained in:
Manish V Badarkhe 2021-04-22 14:41:27 +01:00
parent 1e13c500a0
commit a1cedadf73
4 changed files with 70 additions and 0 deletions

44
common/hw_crc32.c Normal file
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@ -0,0 +1,44 @@
/*
* Copyright (c) 2021, Arm Limited. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <stdarg.h>
#include <assert.h>
#include <arm_acle.h>
#include <common/debug.h>
/* hw_crc32 - compute CRC using Arm intrinsic function
*
* This function is useful for the platforms with the CPU ARMv8.0
* (with CRC instructions supported), and onwards.
* Platforms with CPU ARMv8.0 should make sure to add a compile switch
* '-march=armv8-a+crc" for successful compilation of this file.
*
* @crc: previous accumulated CRC
* @buf: buffer base address
* @size: the size of the buffer
*
* Return calculated CRC value
*/
uint32_t hw_crc32(uint32_t crc, const unsigned char *buf, size_t size)
{
assert(buf != NULL);
uint32_t calc_crc = ~crc;
const unsigned char *local_buf = buf;
size_t local_size = size;
/*
* calculate CRC over byte data
*/
while (local_size != 0UL) {
calc_crc = __crc32b(calc_crc, *local_buf);
local_buf++;
local_size--;
}
return ~calc_crc;
}

16
include/common/hw_crc32.h Normal file
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@ -0,0 +1,16 @@
/*
* Copyright (c) 2021, Arm Limited. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#ifndef HW_CRC32_H
#define HW_CRC32_H
#include <stddef.h>
#include <stdint.h>
/* compute CRC using Arm intrinsic function */
uint32_t hw_crc32(uint32_t crc, const unsigned char *buf, size_t size);
#endif /* HW_CRC32_H */

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@ -14,8 +14,10 @@
#define ARM_ACLE_H
#if !defined(__aarch64__) || defined(__clang__)
# define __crc32b __builtin_arm_crc32b
# define __crc32w __builtin_arm_crc32w
#else
# define __crc32b __builtin_aarch64_crc32b
# define __crc32w __builtin_aarch64_crc32w
#endif

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@ -178,6 +178,13 @@ ifeq (${ARM_GPT_SUPPORT}, 1)
drivers/partition/partition.c
endif
# Enable CRC instructions via extension for ARMv8-A CPUs.
# For ARMv8.1-A, and onwards CRC instructions are default enabled.
# Enable HW computed CRC support unconditionally in BL2 component.
ifeq (${ARM_ARCH_MINOR},0)
BL2_CPPFLAGS += -march=armv8-a+crc
endif
ifeq (${ARCH}, aarch64)
PLAT_INCLUDES += -Iinclude/plat/arm/common/aarch64
endif
@ -223,6 +230,7 @@ BL2_SOURCES += drivers/delay_timer/delay_timer.c \
drivers/io/io_storage.c \
plat/arm/common/arm_bl2_setup.c \
plat/arm/common/arm_err.c \
common/hw_crc32.c \
${ARM_IO_SOURCES}
# Firmware Configuration Framework sources