mirror of
https://github.com/torvalds/linux.git
synced 2024-11-13 07:31:45 +00:00
428c8e0310
The div_factor* helpers calculate fraction or percentage fraction. The name is a bit confusing, we use it only for percentage calculations and there are two helpers. There's a helper mult_frac that's for general fractions, that tries to be accurate but we multiply and divide by small numbers so we can use the div_u64 helper. Rename the div_factor* helpers and use 1..100 percentage range, also drop the case checking for percentage == 100, it's never hit. The conversions: * div_factor calculates tenths and the numbers need to be adjusted * div_factor_fine is direct replacement Signed-off-by: David Sterba <dsterba@suse.com>
147 lines
3.3 KiB
C
147 lines
3.3 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
|
|
#ifndef BTRFS_MISC_H
|
|
#define BTRFS_MISC_H
|
|
|
|
#include <linux/sched.h>
|
|
#include <linux/wait.h>
|
|
#include <linux/math64.h>
|
|
#include <linux/rbtree.h>
|
|
|
|
#define in_range(b, first, len) ((b) >= (first) && (b) < (first) + (len))
|
|
|
|
/*
|
|
* Enumerate bits using enum autoincrement. Define the @name as the n-th bit.
|
|
*/
|
|
#define ENUM_BIT(name) \
|
|
__ ## name ## _BIT, \
|
|
name = (1U << __ ## name ## _BIT), \
|
|
__ ## name ## _SEQ = __ ## name ## _BIT
|
|
|
|
static inline void cond_wake_up(struct wait_queue_head *wq)
|
|
{
|
|
/*
|
|
* This implies a full smp_mb barrier, see comments for
|
|
* waitqueue_active why.
|
|
*/
|
|
if (wq_has_sleeper(wq))
|
|
wake_up(wq);
|
|
}
|
|
|
|
static inline void cond_wake_up_nomb(struct wait_queue_head *wq)
|
|
{
|
|
/*
|
|
* Special case for conditional wakeup where the barrier required for
|
|
* waitqueue_active is implied by some of the preceding code. Eg. one
|
|
* of such atomic operations (atomic_dec_and_return, ...), or a
|
|
* unlock/lock sequence, etc.
|
|
*/
|
|
if (waitqueue_active(wq))
|
|
wake_up(wq);
|
|
}
|
|
|
|
static inline u64 mult_perc(u64 num, u32 percent)
|
|
{
|
|
return div_u64(num * percent, 100);
|
|
}
|
|
/* Copy of is_power_of_two that is 64bit safe */
|
|
static inline bool is_power_of_two_u64(u64 n)
|
|
{
|
|
return n != 0 && (n & (n - 1)) == 0;
|
|
}
|
|
|
|
static inline bool has_single_bit_set(u64 n)
|
|
{
|
|
return is_power_of_two_u64(n);
|
|
}
|
|
|
|
/*
|
|
* Simple bytenr based rb_tree relate structures
|
|
*
|
|
* Any structure wants to use bytenr as single search index should have their
|
|
* structure start with these members.
|
|
*/
|
|
struct rb_simple_node {
|
|
struct rb_node rb_node;
|
|
u64 bytenr;
|
|
};
|
|
|
|
static inline struct rb_node *rb_simple_search(struct rb_root *root, u64 bytenr)
|
|
{
|
|
struct rb_node *node = root->rb_node;
|
|
struct rb_simple_node *entry;
|
|
|
|
while (node) {
|
|
entry = rb_entry(node, struct rb_simple_node, rb_node);
|
|
|
|
if (bytenr < entry->bytenr)
|
|
node = node->rb_left;
|
|
else if (bytenr > entry->bytenr)
|
|
node = node->rb_right;
|
|
else
|
|
return node;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* Search @root from an entry that starts or comes after @bytenr.
|
|
*
|
|
* @root: the root to search.
|
|
* @bytenr: bytenr to search from.
|
|
*
|
|
* Return the rb_node that start at or after @bytenr. If there is no entry at
|
|
* or after @bytner return NULL.
|
|
*/
|
|
static inline struct rb_node *rb_simple_search_first(struct rb_root *root,
|
|
u64 bytenr)
|
|
{
|
|
struct rb_node *node = root->rb_node, *ret = NULL;
|
|
struct rb_simple_node *entry, *ret_entry = NULL;
|
|
|
|
while (node) {
|
|
entry = rb_entry(node, struct rb_simple_node, rb_node);
|
|
|
|
if (bytenr < entry->bytenr) {
|
|
if (!ret || entry->bytenr < ret_entry->bytenr) {
|
|
ret = node;
|
|
ret_entry = entry;
|
|
}
|
|
|
|
node = node->rb_left;
|
|
} else if (bytenr > entry->bytenr) {
|
|
node = node->rb_right;
|
|
} else {
|
|
return node;
|
|
}
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static inline struct rb_node *rb_simple_insert(struct rb_root *root, u64 bytenr,
|
|
struct rb_node *node)
|
|
{
|
|
struct rb_node **p = &root->rb_node;
|
|
struct rb_node *parent = NULL;
|
|
struct rb_simple_node *entry;
|
|
|
|
while (*p) {
|
|
parent = *p;
|
|
entry = rb_entry(parent, struct rb_simple_node, rb_node);
|
|
|
|
if (bytenr < entry->bytenr)
|
|
p = &(*p)->rb_left;
|
|
else if (bytenr > entry->bytenr)
|
|
p = &(*p)->rb_right;
|
|
else
|
|
return parent;
|
|
}
|
|
|
|
rb_link_node(node, parent, p);
|
|
rb_insert_color(node, root);
|
|
return NULL;
|
|
}
|
|
|
|
#endif
|