cregit-Linux how code gets into the kernel

Release 4.15 include/linux/list_bl.h

Directory: include/linux
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_LIST_BL_H

#define _LINUX_LIST_BL_H

#include <linux/list.h>
#include <linux/bit_spinlock.h>

/*
 * Special version of lists, where head of the list has a lock in the lowest
 * bit. This is useful for scalable hash tables without increasing memory
 * footprint overhead.
 *
 * For modification operations, the 0 bit of hlist_bl_head->first
 * pointer must be set.
 *
 * With some small modifications, this can easily be adapted to store several
 * arbitrary bits (not just a single lock bit), if the need arises to store
 * some fast and compact auxiliary data.
 */

#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)

#define LIST_BL_LOCKMASK	1UL
#else

#define LIST_BL_LOCKMASK	0UL
#endif

#ifdef CONFIG_DEBUG_LIST

#define LIST_BL_BUG_ON(x) BUG_ON(x)
#else

#define LIST_BL_BUG_ON(x)
#endif



struct hlist_bl_head {
	
struct hlist_bl_node *first;
};


struct hlist_bl_node {
	

struct hlist_bl_node *next, **pprev;
};

#define INIT_HLIST_BL_HEAD(ptr) \
	((ptr)->first = NULL)


static inline void INIT_HLIST_BL_NODE(struct hlist_bl_node *h) { h->next = NULL; h->pprev = NULL; }

Contributors

PersonTokensPropCommitsCommitProp
Nicholas Piggin24100.00%1100.00%
Total24100.00%1100.00%

#define hlist_bl_entry(ptr, type, member) container_of(ptr,type,member)
static inline bool hlist_bl_unhashed(const struct hlist_bl_node *h) { return !h->pprev; }

Contributors

PersonTokensPropCommitsCommitProp
Nicholas Piggin1894.74%150.00%
Chen Gang S15.26%150.00%
Total19100.00%2100.00%


static inline struct hlist_bl_node *hlist_bl_first(struct hlist_bl_head *h) { return (struct hlist_bl_node *) ((unsigned long)h->first & ~LIST_BL_LOCKMASK); }

Contributors

PersonTokensPropCommitsCommitProp
Nicholas Piggin33100.00%1100.00%
Total33100.00%1100.00%


static inline void hlist_bl_set_first(struct hlist_bl_head *h, struct hlist_bl_node *n) { LIST_BL_BUG_ON((unsigned long)n & LIST_BL_LOCKMASK); LIST_BL_BUG_ON(((unsigned long)h->first & LIST_BL_LOCKMASK) != LIST_BL_LOCKMASK); h->first = (struct hlist_bl_node *)((unsigned long)n | LIST_BL_LOCKMASK); }

Contributors

PersonTokensPropCommitsCommitProp
Nicholas Piggin64100.00%2100.00%
Total64100.00%2100.00%


static inline bool hlist_bl_empty(const struct hlist_bl_head *h) { return !((unsigned long)READ_ONCE(h->first) & ~LIST_BL_LOCKMASK); }

Contributors

PersonTokensPropCommitsCommitProp
Nicholas Piggin2787.10%133.33%
Paul E. McKenney39.68%133.33%
Chen Gang S13.23%133.33%
Total31100.00%3100.00%


static inline void hlist_bl_add_head(struct hlist_bl_node *n, struct hlist_bl_head *h) { struct hlist_bl_node *first = hlist_bl_first(h); n->next = first; if (first) first->pprev = &n->next; n->pprev = &h->first; hlist_bl_set_first(h, n); }

Contributors

PersonTokensPropCommitsCommitProp
Nicholas Piggin62100.00%1100.00%
Total62100.00%1100.00%


static inline void __hlist_bl_del(struct hlist_bl_node *n) { struct hlist_bl_node *next = n->next; struct hlist_bl_node **pprev = n->pprev; LIST_BL_BUG_ON((unsigned long)n & LIST_BL_LOCKMASK); /* pprev may be `first`, so be careful not to lose the lock bit */ WRITE_ONCE(*pprev, (struct hlist_bl_node *) ((unsigned long)next | ((unsigned long)*pprev & LIST_BL_LOCKMASK))); if (next) next->pprev = pprev; }

Contributors

PersonTokensPropCommitsCommitProp
Nicholas Piggin7995.18%150.00%
Paul E. McKenney44.82%150.00%
Total83100.00%2100.00%


static inline void hlist_bl_del(struct hlist_bl_node *n) { __hlist_bl_del(n); n->next = LIST_POISON1; n->pprev = LIST_POISON2; }

Contributors

PersonTokensPropCommitsCommitProp
Nicholas Piggin29100.00%1100.00%
Total29100.00%1100.00%


static inline void hlist_bl_del_init(struct hlist_bl_node *n) { if (!hlist_bl_unhashed(n)) { __hlist_bl_del(n); INIT_HLIST_BL_NODE(n); } }

Contributors

PersonTokensPropCommitsCommitProp
Nicholas Piggin32100.00%1100.00%
Total32100.00%1100.00%


static inline void hlist_bl_lock(struct hlist_bl_head *b) { bit_spin_lock(0, (unsigned long *)b); }

Contributors

PersonTokensPropCommitsCommitProp
Christoph Hellwig24100.00%1100.00%
Total24100.00%1100.00%


static inline void hlist_bl_unlock(struct hlist_bl_head *b) { __bit_spin_unlock(0, (unsigned long *)b); }

Contributors

PersonTokensPropCommitsCommitProp
Christoph Hellwig24100.00%1100.00%
Total24100.00%1100.00%


static inline bool hlist_bl_is_locked(struct hlist_bl_head *b) { return bit_spin_is_locked(0, (unsigned long *)b); }

Contributors

PersonTokensPropCommitsCommitProp
Steven Whitehouse25100.00%1100.00%
Total25100.00%1100.00%

/** * hlist_bl_for_each_entry - iterate over list of given type * @tpos: the type * to use as a loop cursor. * @pos: the &struct hlist_node to use as a loop cursor. * @head: the head for your list. * @member: the name of the hlist_node within the struct. * */ #define hlist_bl_for_each_entry(tpos, pos, head, member) \ for (pos = hlist_bl_first(head); \ pos && \ ({ tpos = hlist_bl_entry(pos, typeof(*tpos), member); 1;}); \ pos = pos->next) /** * hlist_bl_for_each_entry_safe - iterate over list of given type safe against removal of list entry * @tpos: the type * to use as a loop cursor. * @pos: the &struct hlist_node to use as a loop cursor. * @n: another &struct hlist_node to use as temporary storage * @head: the head for your list. * @member: the name of the hlist_node within the struct. */ #define hlist_bl_for_each_entry_safe(tpos, pos, n, head, member) \ for (pos = hlist_bl_first(head); \ pos && ({ n = pos->next; 1; }) && \ ({ tpos = hlist_bl_entry(pos, typeof(*tpos), member); 1;}); \ pos = n) #endif

Overall Contributors

PersonTokensPropCommitsCommitProp
Nicholas Piggin49384.42%222.22%
Christoph Hellwig518.73%111.11%
Steven Whitehouse254.28%111.11%
Paul E. McKenney71.20%222.22%
Russell King50.86%111.11%
Chen Gang S20.34%111.11%
Greg Kroah-Hartman10.17%111.11%
Total584100.00%9100.00%
Directory: include/linux
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