Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2)  * CRC32 using the polynomial from IEEE-802.3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4)  * Authors: Lasse Collin <lasse.collin@tukaani.org>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5)  *          Igor Pavlov <https://7-zip.org/>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7)  * This file has been put into the public domain.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8)  * You can do whatever you want with this file.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12)  * This is not the fastest implementation, but it is pretty compact.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13)  * The fastest versions of xz_crc32() on modern CPUs without hardware
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)  * accelerated CRC instruction are 3-5 times as fast as this version,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15)  * but they are bigger and use more memory for the lookup table.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include "xz_private.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21)  * STATIC_RW_DATA is used in the pre-boot environment on some architectures.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22)  * See <linux/decompress/mm.h> for details.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) #ifndef STATIC_RW_DATA
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) #	define STATIC_RW_DATA static
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) STATIC_RW_DATA uint32_t xz_crc32_table[256];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) XZ_EXTERN void xz_crc32_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) 	const uint32_t poly = CRC32_POLY_LE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) 	uint32_t i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) 	uint32_t j;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) 	uint32_t r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) 	for (i = 0; i < 256; ++i) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) 		r = i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) 		for (j = 0; j < 8; ++j)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) 			r = (r >> 1) ^ (poly & ~((r & 1) - 1));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) 		xz_crc32_table[i] = r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) 	return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) XZ_EXTERN uint32_t xz_crc32(const uint8_t *buf, size_t size, uint32_t crc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) 	crc = ~crc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) 	while (size != 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) 		crc = xz_crc32_table[*buf++ ^ (crc & 0xFF)] ^ (crc >> 8);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) 		--size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) 	return ~crc;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) }