linux/arch/sh/include/asm/word-at-a-time.h
Tanzir Hasan 66a5c40f60 kernel.h: removed REPEAT_BYTE from kernel.h
This patch creates wordpart.h and includes it in asm/word-at-a-time.h
for all architectures. WORD_AT_A_TIME_CONSTANTS depends on kernel.h
because of REPEAT_BYTE. Moving this to another header and including it
where necessary allows us to not include the bloated kernel.h. Making
this implicit dependency on REPEAT_BYTE explicit allows for later
improvements in the lib/string.c inclusion list.

Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Suggested-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Tanzir Hasan <tanzirh@google.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20231226-libstringheader-v6-1-80aa08c7652c@google.com
Signed-off-by: Kees Cook <keescook@chromium.org>
2024-02-01 09:47:59 -08:00

57 lines
1.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_SH_WORD_AT_A_TIME_H
#define __ASM_SH_WORD_AT_A_TIME_H
#ifdef CONFIG_CPU_BIG_ENDIAN
# include <asm-generic/word-at-a-time.h>
#else
#include <linux/bitops.h>
#include <linux/wordpart.h>
/*
* Little-endian version cribbed from x86.
*/
struct word_at_a_time {
const unsigned long one_bits, high_bits;
};
#define WORD_AT_A_TIME_CONSTANTS { REPEAT_BYTE(0x01), REPEAT_BYTE(0x80) }
/* Carl Chatfield / Jan Achrenius G+ version for 32-bit */
static inline long count_masked_bytes(long mask)
{
/* (000000 0000ff 00ffff ffffff) -> ( 1 1 2 3 ) */
long a = (0x0ff0001+mask) >> 23;
/* Fix the 1 for 00 case */
return a & mask;
}
/* Return nonzero if it has a zero */
static inline unsigned long has_zero(unsigned long a, unsigned long *bits, const struct word_at_a_time *c)
{
unsigned long mask = ((a - c->one_bits) & ~a) & c->high_bits;
*bits = mask;
return mask;
}
static inline unsigned long prep_zero_mask(unsigned long a, unsigned long bits, const struct word_at_a_time *c)
{
return bits;
}
static inline unsigned long create_zero_mask(unsigned long bits)
{
bits = (bits - 1) & ~bits;
return bits >> 7;
}
/* The mask we created is directly usable as a bytemask */
#define zero_bytemask(mask) (mask)
static inline unsigned long find_zero(unsigned long mask)
{
return count_masked_bytes(mask);
}
#endif
#endif