Пример #1
0
/*
 * Steps through buffer one byte at at time, calculates reflected 
 * crc using table.
 */
uint32_t crc32c_intel(unsigned char const *data, unsigned long length)
{
	unsigned int iquotient = length / SCALE_F;
	unsigned int iremainder = length % SCALE_F;
#if BITS_PER_LONG == 64
	uint64_t *ptmp = (uint64_t *) data;
#else
	uint32_t *ptmp = (uint32_t *) data;
#endif
	uint32_t crc = ~0;

	while (iquotient--) {
		__asm__ __volatile__(
			".byte 0xf2, " REX_PRE "0xf, 0x38, 0xf1, 0xf1;"
			:"=S"(crc)
			:"0"(crc), "c"(*ptmp)
		);
		ptmp++;
	}

	if (iremainder)
		crc = crc32c_intel_le_hw_byte(crc, (unsigned char *)ptmp,
				 iremainder);

	return crc;
}
static u32 __pure crc32c_intel_le_hw(u32 crc, unsigned char const *p, size_t len)
{
	unsigned int iquotient = len / SCALE_F;
	unsigned int iremainder = len % SCALE_F;
	unsigned long *ptmp = (unsigned long *)p;

	while (iquotient--) {
		__asm__ __volatile__(
			".byte 0xf2, " REX_PRE "0xf, 0x38, 0xf1, 0xf1;"
			:"=S"(crc)
			:"0"(crc), "c"(*ptmp)
		);
		ptmp++;
	}

	if (iremainder)
		crc = crc32c_intel_le_hw_byte(crc, (unsigned char *)ptmp,
				 iremainder);

	return crc;
}