diff options
Diffstat (limited to 'include/linux/xarray.h')
| -rw-r--r-- | include/linux/xarray.h | 36 |
1 files changed, 23 insertions, 13 deletions
diff --git a/include/linux/xarray.h b/include/linux/xarray.h index 687c150071a5..588733abd19d 100644 --- a/include/linux/xarray.h +++ b/include/linux/xarray.h @@ -131,6 +131,12 @@ static inline unsigned int xa_pointer_tag(void *entry) * xa_mk_internal() - Create an internal entry. * @v: Value to turn into an internal entry. * + * Internal entries are used for a number of purposes. Entries 0-255 are + * used for sibling entries (only 0-62 are used by the current code). 256 + * is used for the retry entry. 257 is used for the reserved / zero entry. + * Negative internal entries are used to represent errnos. Node pointers + * are also tagged as internal entries in some situations. + * * Context: Any context. * Return: An XArray internal entry corresponding to this value. */ @@ -163,6 +169,22 @@ static inline bool xa_is_internal(const void *entry) return ((unsigned long)entry & 3) == 2; } +#define XA_ZERO_ENTRY xa_mk_internal(257) + +/** + * xa_is_zero() - Is the entry a zero entry? + * @entry: Entry retrieved from the XArray + * + * The normal API will return NULL as the contents of a slot containing + * a zero entry. You can only see zero entries by using the advanced API. + * + * Return: %true if the entry is a zero entry. + */ +static inline bool xa_is_zero(const void *entry) +{ + return unlikely(entry == XA_ZERO_ENTRY); +} + /** * xa_is_err() - Report whether an XArray operation returned an error * @entry: Result from calling an XArray function @@ -1050,7 +1072,7 @@ int xa_reserve_irq(struct xarray *xa, unsigned long index, gfp_t gfp) */ static inline void xa_release(struct xarray *xa, unsigned long index) { - xa_cmpxchg(xa, index, NULL, NULL, 0); + xa_cmpxchg(xa, index, XA_ZERO_ENTRY, NULL, 0); } /* Everything below here is the Advanced API. Proceed with caution. */ @@ -1210,18 +1232,6 @@ static inline bool xa_is_sibling(const void *entry) } #define XA_RETRY_ENTRY xa_mk_internal(256) -#define XA_ZERO_ENTRY xa_mk_internal(257) - -/** - * xa_is_zero() - Is the entry a zero entry? - * @entry: Entry retrieved from the XArray - * - * Return: %true if the entry is a zero entry. - */ -static inline bool xa_is_zero(const void *entry) -{ - return unlikely(entry == XA_ZERO_ENTRY); -} /** * xa_is_retry() - Is the entry a retry entry? |