diff options
author | Palmer Dabbelt <palmer@dabbelt.com> | 2017-07-11 04:03:19 +0300 |
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committer | Palmer Dabbelt <palmer@dabbelt.com> | 2017-09-27 01:26:45 +0300 |
commit | 5d8544e2d0075a5f3c9a2cf27152354d54360da1 (patch) | |
tree | 56169c3eaeff96fe1d8547c3bac7cfa658af9d60 /arch/riscv/include/asm/word-at-a-time.h | |
parent | fab957c11efe2f405e08b9f0d080524bc2631428 (diff) | |
download | linux-5d8544e2d0075a5f3c9a2cf27152354d54360da1.tar.xz |
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>
Diffstat (limited to 'arch/riscv/include/asm/word-at-a-time.h')
-rw-r--r-- | arch/riscv/include/asm/word-at-a-time.h | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/arch/riscv/include/asm/word-at-a-time.h b/arch/riscv/include/asm/word-at-a-time.h new file mode 100644 index 000000000000..aa6238791d3e --- /dev/null +++ b/arch/riscv/include/asm/word-at-a-time.h @@ -0,0 +1,55 @@ +/* + * 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 */ |