404

[ Avaa Bypassed ]




Upload:

Command:

botdev@3.14.251.36: ~ $
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_HASH_H
#define _ASM_HASH_H

/*
 * The later H8SX models have a 32x32-bit multiply, but the H8/300H
 * and H8S have only 16x16->32.  Since it's tolerably compact, this is
 * basically an inlined version of the __mulsi3 code.  Since the inputs
 * are not expected to be small, it's also simplfied by skipping the
 * early-out checks.
 *
 * (Since neither CPU has any multi-bit shift instructions, a
 * shift-and-add version is a non-starter.)
 *
 * TODO: come up with an arch-specific version of the hashing in fs/namei.c,
 * since that is heavily dependent on rotates.  Which, as mentioned, suck
 * horribly on H8.
 */

#if defined(CONFIG_CPU_H300H) || defined(CONFIG_CPU_H8S)

#define HAVE_ARCH__HASH_32 1

/*
 * Multiply by k = 0x61C88647.  Fitting this into three registers requires
 * one extra instruction, but reducing register pressure will probably
 * make that back and then some.
 *
 * GCC asm note: %e1 is the high half of operand %1, while %f1 is the
 * low half.  So if %1 is er4, then %e1 is e4 and %f1 is r4.
 *
 * This has been designed to modify x in place, since that's the most
 * common usage, but preserve k, since hash_64() makes two calls in
 * quick succession.
 */
static inline u32 __attribute_const__ __hash_32(u32 x)
{
	u32 temp;

	asm(   "mov.w	%e1,%f0"
	"\n	mulxu.w	%f2,%0"		/* klow * xhigh */
	"\n	mov.w	%f0,%e1"	/* The extra instruction */
	"\n	mov.w	%f1,%f0"
	"\n	mulxu.w	%e2,%0"		/* khigh * xlow */
	"\n	add.w	%e1,%f0"
	"\n	mulxu.w	%f2,%1"		/* klow * xlow */
	"\n	add.w	%f0,%e1"
	: "=&r" (temp), "=r" (x)
	: "%r" (GOLDEN_RATIO_32), "1" (x));
	return x;
}

#endif
#endif /* _ASM_HASH_H */

Filemanager

Name Type Size Permission Actions
Kbuild File 1.13 KB 0644
atomic.h File 2.47 KB 0644
bitops.h File 4.45 KB 0644
bug.h File 263 B 0644
byteorder.h File 148 B 0644
cache.h File 281 B 0644
cmpxchg.h File 1.49 KB 0644
dma-mapping.h File 269 B 0644
elf.h File 2.66 KB 0644
flat.h File 1.1 KB 0644
hash.h File 1.63 KB 0644
io.h File 1.44 KB 0644
irq.h File 555 B 0644
irqflags.h File 1.88 KB 0644
kgdb.h File 1.04 KB 0644
page.h File 485 B 0644
page_offset.h File 37 B 0644
pci.h File 421 B 0644
pgtable.h File 1.7 KB 0644
processor.h File 3.17 KB 0644
ptrace.h File 1.03 KB 0644
segment.h File 886 B 0644
signal.h File 520 B 0644
smp.h File 32 B 0644
string.h File 389 B 0644
switch_to.h File 1.72 KB 0644
syscall.h File 1.03 KB 0644
thread_info.h File 3.26 KB 0644
tlb.h File 166 B 0644
traps.h File 1.06 KB 0644
uaccess.h File 1.02 KB 0644
user.h File 3.34 KB 0644