2021-05-13 20:29:44 +08:00

108 lines
3.3 KiB
C

/*
* Copyright (c) 2020 Institute of Parallel And Distributed Systems (IPADS), Shanghai Jiao Tong University (SJTU)
* OS-Lab-2020 (i.e., ChCore) is licensed under the Mulan PSL v1.
* You can use this software according to the terms and conditions of the Mulan PSL v1.
* You may obtain a copy of Mulan PSL v1 at:
* http://license.coscl.org.cn/MulanPSL
* THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND, EITHER EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT, MERCHANTABILITY OR FIT FOR A PARTICULAR
* PURPOSE.
* See the Mulan PSL v1 for more details.
*/
#pragma once
#define BITS_PER_BYTE 8
#define BITS_PER_LONG (sizeof(unsigned long) * BITS_PER_BYTE)
#define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_LONG)
#define get_bit_in_slot(u64slot, bit) ((u64slot) & (1UL<<(bit)))
#define clear_bit_in_slot(u64slot, bit) ((u64slot) = (u64slot) & ~(1UL<<(bit)))
#define set_bit_in_slot(u64slot, bit) ((u64slot) = (u64slot) | (1UL<<(bit)))
/* set No'nr bit to 1 in slot pointed by p */
static inline void set_bit(unsigned int nr, volatile unsigned long *p)
{
unsigned nlongs = nr / BITS_PER_LONG;
unsigned ilongs = nr % BITS_PER_LONG;
p[nlongs] |= 1UL << ilongs;
}
/* get No'nr bit in slot pointed by p */
static inline int get_bit(unsigned int nr, volatile unsigned long *p)
{
unsigned nlongs = nr / BITS_PER_LONG;
unsigned ilongs = nr % BITS_PER_LONG;
return (p[nlongs] >> ilongs) & 0x1;
}
/* clear No'nr bit in slot pointed by p */
static inline void clear_bit(unsigned int nr, volatile unsigned long *p)
{
unsigned nlongs = nr / BITS_PER_LONG;
unsigned ilongs = nr % BITS_PER_LONG;
p[nlongs] &= ~(1UL << ilongs);
}
/* return the first zero bit start from the lowerst bit */
static inline int ctzl(unsigned long x)
{
return x == 0 ? sizeof(x) * BITS_PER_BYTE : __builtin_ctzl(x);
}
static inline int find_next_bit_helper(unsigned long *p, unsigned long size,
unsigned long start, int invert)
{
long cur_elem_index, cur_bit,
max_elem_index, max_bit, cur_bit_value, res = 0;
max_elem_index = (size - 1) / BITS_PER_LONG;
cur_elem_index = start / BITS_PER_LONG;
cur_bit = start % BITS_PER_LONG;
res = start;
while (cur_elem_index <= max_elem_index) {
if (cur_elem_index < max_elem_index)
max_bit = BITS_PER_LONG - 1;
else
max_bit = (size - 1) % BITS_PER_LONG;
for (; cur_bit <= max_bit; cur_bit++, res++) {
cur_bit_value =
get_bit_in_slot(p[cur_elem_index], cur_bit);
if (invert ? !cur_bit_value : cur_bit_value)
return res;
}
cur_elem_index++;
cur_bit = 0;
}
return size;
}
/*
* From lowest bit side, starting from 'start',
* this function find the first zero bit of the slot pointed by p.
*/
static inline int find_next_zero_bit(unsigned long *p, unsigned long size,
unsigned long start)
{
return find_next_bit_helper(p, size, start, 1);
}
/*
* From lowest bit side, starting from 'start',
* this function find the first bit of the slot pointed by p.
*/
static inline int find_next_bit(unsigned long *p, unsigned long size,
unsigned long start)
{
return find_next_bit_helper(p, size, start, 0);
}
/* From the first 1 bit to the last 1 bit in slot pointed by addr */
#define for_each_set_bit(pos, addr, size) \
for ((pos) = find_next_bit((addr), (size), 0); \
(pos) < (size); \
(pos) = find_next_bit((addr), (size), (pos) + 1))