linux_dsm_epyc7002/arch/riscv/include/asm/word-at-a-time.h
Palmer Dabbelt 5d8544e2d0 RISC-V: Generic library routines and assembly
This patch contains code that is more specific to the RISC-V ISA than it
is to Linux.  It contains string and math operations, C wrappers for
various assembly instructions, stack walking code, and uaccess.

Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
2017-09-26 15:26:45 -07:00

56 lines
1.5 KiB
C

/*
* Copyright (C) 2012 Regents of the University of California
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
* Derived from arch/x86/include/asm/word-at-a-time.h
*/
#ifndef _ASM_RISCV_WORD_AT_A_TIME_H
#define _ASM_RISCV_WORD_AT_A_TIME_H
#include <linux/kernel.h>
struct word_at_a_time {
const unsigned long one_bits, high_bits;
};
#define WORD_AT_A_TIME_CONSTANTS { REPEAT_BYTE(0x01), REPEAT_BYTE(0x80) }
static inline unsigned long has_zero(unsigned long val,
unsigned long *bits, const struct word_at_a_time *c)
{
unsigned long mask = ((val - c->one_bits) & ~val) & c->high_bits;
*bits = mask;
return mask;
}
static inline unsigned long prep_zero_mask(unsigned long val,
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;
}
static inline unsigned long find_zero(unsigned long mask)
{
return fls64(mask) >> 3;
}
/* The mask we created is directly usable as a bytemask */
#define zero_bytemask(mask) (mask)
#endif /* _ASM_RISCV_WORD_AT_A_TIME_H */