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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>
146 lines
3.3 KiB
C
146 lines
3.3 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef BTRFS_MISC_H
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#define BTRFS_MISC_H
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#include <linux/sched.h>
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#include <linux/wait.h>
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#include <linux/math64.h>
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#include <linux/rbtree.h>
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#define in_range(b, first, len) ((b) >= (first) && (b) < (first) + (len))
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/*
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* Enumerate bits using enum autoincrement. Define the @name as the n-th bit.
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*/
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#define ENUM_BIT(name) \
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__ ## name ## _BIT, \
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name = (1U << __ ## name ## _BIT), \
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__ ## name ## _SEQ = __ ## name ## _BIT
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static inline void cond_wake_up(struct wait_queue_head *wq)
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{
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/*
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* This implies a full smp_mb barrier, see comments for
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* waitqueue_active why.
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*/
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if (wq_has_sleeper(wq))
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wake_up(wq);
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}
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static inline void cond_wake_up_nomb(struct wait_queue_head *wq)
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{
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/*
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* Special case for conditional wakeup where the barrier required for
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* waitqueue_active is implied by some of the preceding code. Eg. one
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* of such atomic operations (atomic_dec_and_return, ...), or a
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* unlock/lock sequence, etc.
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*/
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if (waitqueue_active(wq))
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wake_up(wq);
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}
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static inline u64 mult_perc(u64 num, u32 percent)
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{
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return div_u64(num * percent, 100);
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}
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/* Copy of is_power_of_two that is 64bit safe */
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static inline bool is_power_of_two_u64(u64 n)
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{
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return n != 0 && (n & (n - 1)) == 0;
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}
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static inline bool has_single_bit_set(u64 n)
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{
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return is_power_of_two_u64(n);
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}
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/*
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* Simple bytenr based rb_tree relate structures
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*
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* Any structure wants to use bytenr as single search index should have their
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* structure start with these members.
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*/
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struct rb_simple_node {
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struct rb_node rb_node;
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u64 bytenr;
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};
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static inline struct rb_node *rb_simple_search(struct rb_root *root, u64 bytenr)
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{
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struct rb_node *node = root->rb_node;
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struct rb_simple_node *entry;
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while (node) {
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entry = rb_entry(node, struct rb_simple_node, rb_node);
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if (bytenr < entry->bytenr)
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node = node->rb_left;
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else if (bytenr > entry->bytenr)
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node = node->rb_right;
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else
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return node;
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}
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return NULL;
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}
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/*
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* Search @root from an entry that starts or comes after @bytenr.
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*
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* @root: the root to search.
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* @bytenr: bytenr to search from.
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*
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* Return the rb_node that start at or after @bytenr. If there is no entry at
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* or after @bytner return NULL.
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*/
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static inline struct rb_node *rb_simple_search_first(struct rb_root *root,
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u64 bytenr)
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{
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struct rb_node *node = root->rb_node, *ret = NULL;
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struct rb_simple_node *entry, *ret_entry = NULL;
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while (node) {
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entry = rb_entry(node, struct rb_simple_node, rb_node);
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if (bytenr < entry->bytenr) {
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if (!ret || entry->bytenr < ret_entry->bytenr) {
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ret = node;
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ret_entry = entry;
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}
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node = node->rb_left;
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} else if (bytenr > entry->bytenr) {
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node = node->rb_right;
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} else {
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return node;
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}
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}
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return ret;
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}
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static inline struct rb_node *rb_simple_insert(struct rb_root *root, u64 bytenr,
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struct rb_node *node)
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{
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struct rb_node **p = &root->rb_node;
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struct rb_node *parent = NULL;
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struct rb_simple_node *entry;
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while (*p) {
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parent = *p;
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entry = rb_entry(parent, struct rb_simple_node, rb_node);
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if (bytenr < entry->bytenr)
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p = &(*p)->rb_left;
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else if (bytenr > entry->bytenr)
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p = &(*p)->rb_right;
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else
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return parent;
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}
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rb_link_node(node, parent, p);
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rb_insert_color(node, root);
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return NULL;
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}
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#endif
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