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author | Matthew Wilcox <willy@infradead.org> | 2018-10-31 14:39:28 -0400 |
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committer | Matthew Wilcox <willy@infradead.org> | 2018-11-05 16:38:08 -0500 |
commit | c5beb07e7a06b24f4f27304f6282b5dbd929543b (patch) | |
tree | dddd6ce81475ebd3ab56fff6e55efe60d0802393 /include/linux/xarray.h | |
parent | 4c0608f4a0e76dfb82d3accd20081f4bf47ed143 (diff) | |
download | linux-c5beb07e7a06b24f4f27304f6282b5dbd929543b.tar.gz linux-c5beb07e7a06b24f4f27304f6282b5dbd929543b.tar.bz2 linux-c5beb07e7a06b24f4f27304f6282b5dbd929543b.zip |
XArray: Unify xa_cmpxchg and __xa_cmpxchg
xa_cmpxchg() was one of the largest functions in the xarray
implementation. By turning it into a wrapper and having the callers
take the lock (like several other functions), we save 160 bytes on a
tinyconfig build and reduce the duplication in xarray.c.
Signed-off-by: Matthew Wilcox <willy@infradead.org>
Diffstat (limited to 'include/linux/xarray.h')
-rw-r--r-- | include/linux/xarray.h | 113 |
1 files changed, 69 insertions, 44 deletions
diff --git a/include/linux/xarray.h b/include/linux/xarray.h index c2cb0426c60c..8e59d4fbd55e 100644 --- a/include/linux/xarray.h +++ b/include/linux/xarray.h @@ -289,8 +289,6 @@ struct xarray { void xa_init_flags(struct xarray *, gfp_t flags); void *xa_load(struct xarray *, unsigned long index); void *xa_store(struct xarray *, unsigned long index, void *entry, gfp_t); -void *xa_cmpxchg(struct xarray *, unsigned long index, - void *old, void *entry, gfp_t); void *xa_store_range(struct xarray *, unsigned long first, unsigned long last, void *entry, gfp_t); bool xa_get_mark(struct xarray *, unsigned long index, xa_mark_t); @@ -360,48 +358,6 @@ static inline void *xa_erase(struct xarray *xa, unsigned long index) } /** - * xa_insert() - Store this entry in the XArray unless another entry is - * already present. - * @xa: XArray. - * @index: Index into array. - * @entry: New entry. - * @gfp: Memory allocation flags. - * - * If you would rather see the existing entry in the array, use xa_cmpxchg(). - * This function is for users who don't care what the entry is, only that - * one is present. - * - * Context: Process context. Takes and releases the xa_lock. - * May sleep if the @gfp flags permit. - * Return: 0 if the store succeeded. -EEXIST if another entry was present. - * -ENOMEM if memory could not be allocated. - */ -static inline int xa_insert(struct xarray *xa, unsigned long index, - void *entry, gfp_t gfp) -{ - void *curr = xa_cmpxchg(xa, index, NULL, entry, gfp); - if (!curr) - return 0; - if (xa_is_err(curr)) - return xa_err(curr); - return -EEXIST; -} - -/** - * xa_release() - Release a reserved entry. - * @xa: XArray. - * @index: Index of entry. - * - * After calling xa_reserve(), you can call this function to release the - * reservation. If the entry at @index has been stored to, this function - * will do nothing. - */ -static inline void xa_release(struct xarray *xa, unsigned long index) -{ - xa_cmpxchg(xa, index, NULL, NULL, 0); -} - -/** * xa_for_each() - Iterate over a portion of an XArray. * @xa: XArray. * @entry: Entry retrieved from array. @@ -535,6 +491,61 @@ static inline void *xa_erase_irq(struct xarray *xa, unsigned long index) } /** + * xa_cmpxchg() - Conditionally replace an entry in the XArray. + * @xa: XArray. + * @index: Index into array. + * @old: Old value to test against. + * @entry: New value to place in array. + * @gfp: Memory allocation flags. + * + * If the entry at @index is the same as @old, replace it with @entry. + * If the return value is equal to @old, then the exchange was successful. + * + * Context: Any context. Takes and releases the xa_lock. May sleep + * if the @gfp flags permit. + * Return: The old value at this index or xa_err() if an error happened. + */ +static inline void *xa_cmpxchg(struct xarray *xa, unsigned long index, + void *old, void *entry, gfp_t gfp) +{ + void *curr; + + xa_lock(xa); + curr = __xa_cmpxchg(xa, index, old, entry, gfp); + xa_unlock(xa); + + return curr; +} + +/** + * xa_insert() - Store this entry in the XArray unless another entry is + * already present. + * @xa: XArray. + * @index: Index into array. + * @entry: New entry. + * @gfp: Memory allocation flags. + * + * If you would rather see the existing entry in the array, use xa_cmpxchg(). + * This function is for users who don't care what the entry is, only that + * one is present. + * + * Context: Process context. Takes and releases the xa_lock. + * May sleep if the @gfp flags permit. + * Return: 0 if the store succeeded. -EEXIST if another entry was present. + * -ENOMEM if memory could not be allocated. + */ +static inline int xa_insert(struct xarray *xa, unsigned long index, + void *entry, gfp_t gfp) +{ + void *curr = xa_cmpxchg(xa, index, NULL, entry, gfp); + if (!curr) + return 0; + if (xa_is_err(curr)) + return xa_err(curr); + return -EEXIST; +} + +/** * xa_alloc() - Find somewhere to store this entry in the XArray. * @xa: XArray. * @id: Pointer to ID. @@ -699,6 +710,20 @@ int xa_reserve_irq(struct xarray *xa, unsigned long index, gfp_t gfp) return ret; } +/** + * xa_release() - Release a reserved entry. + * @xa: XArray. + * @index: Index of entry. + * + * After calling xa_reserve(), you can call this function to release the + * reservation. If the entry at @index has been stored to, this function + * will do nothing. + */ +static inline void xa_release(struct xarray *xa, unsigned long index) +{ + xa_cmpxchg(xa, index, NULL, NULL, 0); +} + /* Everything below here is the Advanced API. Proceed with caution. */ /* |