diff options
| -rw-r--r-- | include/linux/xarray.h | 80 | ||||
| -rw-r--r-- | lib/test_xarray.c | 86 | ||||
| -rw-r--r-- | lib/xarray.c | 29 |
3 files changed, 135 insertions, 60 deletions
diff --git a/include/linux/xarray.h b/include/linux/xarray.h index 99dd0838b4ba..883bb958e462 100644 --- a/include/linux/xarray.h +++ b/include/linux/xarray.h @@ -200,6 +200,27 @@ static inline int xa_err(void *entry) return 0; } +/** + * struct xa_limit - Represents a range of IDs. + * @min: The lowest ID to allocate (inclusive). + * @max: The maximum ID to allocate (inclusive). + * + * This structure is used either directly or via the XA_LIMIT() macro + * to communicate the range of IDs that are valid for allocation. + * Two common ranges are predefined for you: + * * xa_limit_32b - [0 - UINT_MAX] + * * xa_limit_31b - [0 - INT_MAX] + */ +struct xa_limit { + u32 max; + u32 min; +}; + +#define XA_LIMIT(_min, _max) (struct xa_limit) { .min = _min, .max = _max } + +#define xa_limit_32b XA_LIMIT(0, UINT_MAX) +#define xa_limit_31b XA_LIMIT(0, INT_MAX) + typedef unsigned __bitwise xa_mark_t; #define XA_MARK_0 ((__force xa_mark_t)0U) #define XA_MARK_1 ((__force xa_mark_t)1U) @@ -476,7 +497,8 @@ 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); int __xa_insert(struct xarray *, unsigned long index, void *entry, gfp_t); -int __xa_alloc(struct xarray *, u32 *id, u32 max, void *entry, gfp_t); +int __must_check __xa_alloc(struct xarray *, u32 *id, void *entry, + struct xa_limit, gfp_t); int __xa_reserve(struct xarray *, unsigned long index, gfp_t); void __xa_set_mark(struct xarray *, unsigned long index, xa_mark_t); void __xa_clear_mark(struct xarray *, unsigned long index, xa_mark_t); @@ -753,26 +775,26 @@ static inline int xa_insert_irq(struct xarray *xa, unsigned long index, * xa_alloc() - Find somewhere to store this entry in the XArray. * @xa: XArray. * @id: Pointer to ID. - * @max: Maximum ID to allocate (inclusive). * @entry: New entry. + * @limit: Range of ID to allocate. * @gfp: Memory allocation flags. * - * Allocates an unused ID in the range specified by @id and @max. - * Updates the @id pointer with the index, then stores the entry at that - * index. A concurrent lookup will not see an uninitialised @id. + * Finds an empty entry in @xa between @limit.min and @limit.max, + * stores the index into the @id pointer, then stores the entry at + * that index. A concurrent lookup will not see an uninitialised @id. * - * Context: Process context. Takes and releases the xa_lock. May sleep if + * Context: Any context. Takes and releases the xa_lock. May sleep if * the @gfp flags permit. - * Return: 0 on success, -ENOMEM if memory allocation fails or -ENOSPC if - * there is no more space in the XArray. + * Return: 0 on success, -ENOMEM if memory could not be allocated or + * -EBUSY if there are no free entries in @limit. */ -static inline int xa_alloc(struct xarray *xa, u32 *id, u32 max, void *entry, - gfp_t gfp) +static inline __must_check int xa_alloc(struct xarray *xa, u32 *id, + void *entry, struct xa_limit limit, gfp_t gfp) { int err; xa_lock(xa); - err = __xa_alloc(xa, id, max, entry, gfp); + err = __xa_alloc(xa, id, entry, limit, gfp); xa_unlock(xa); return err; @@ -782,26 +804,26 @@ static inline int xa_alloc(struct xarray *xa, u32 *id, u32 max, void *entry, * xa_alloc_bh() - Find somewhere to store this entry in the XArray. * @xa: XArray. * @id: Pointer to ID. - * @max: Maximum ID to allocate (inclusive). * @entry: New entry. + * @limit: Range of ID to allocate. * @gfp: Memory allocation flags. * - * Allocates an unused ID in the range specified by @id and @max. - * Updates the @id pointer with the index, then stores the entry at that - * index. A concurrent lookup will not see an uninitialised @id. + * Finds an empty entry in @xa between @limit.min and @limit.max, + * stores the index into the @id pointer, then stores the entry at + * that index. A concurrent lookup will not see an uninitialised @id. * * Context: Any context. Takes and releases the xa_lock while * disabling softirqs. May sleep if the @gfp flags permit. - * Return: 0 on success, -ENOMEM if memory allocation fails or -ENOSPC if - * there is no more space in the XArray. + * Return: 0 on success, -ENOMEM if memory could not be allocated or + * -EBUSY if there are no free entries in @limit. */ -static inline int xa_alloc_bh(struct xarray *xa, u32 *id, u32 max, void *entry, - gfp_t gfp) +static inline int __must_check xa_alloc_bh(struct xarray *xa, u32 *id, + void *entry, struct xa_limit limit, gfp_t gfp) { int err; xa_lock_bh(xa); - err = __xa_alloc(xa, id, max, entry, gfp); + err = __xa_alloc(xa, id, entry, limit, gfp); xa_unlock_bh(xa); return err; @@ -811,26 +833,26 @@ static inline int xa_alloc_bh(struct xarray *xa, u32 *id, u32 max, void *entry, * xa_alloc_irq() - Find somewhere to store this entry in the XArray. * @xa: XArray. * @id: Pointer to ID. - * @max: Maximum ID to allocate (inclusive). * @entry: New entry. + * @limit: Range of ID to allocate. * @gfp: Memory allocation flags. * - * Allocates an unused ID in the range specified by @id and @max. - * Updates the @id pointer with the index, then stores the entry at that - * index. A concurrent lookup will not see an uninitialised @id. + * Finds an empty entry in @xa between @limit.min and @limit.max, + * stores the index into the @id pointer, then stores the entry at + * that index. A concurrent lookup will not see an uninitialised @id. * * Context: Process context. Takes and releases the xa_lock while * disabling interrupts. May sleep if the @gfp flags permit. - * Return: 0 on success, -ENOMEM if memory allocation fails or -ENOSPC if - * there is no more space in the XArray. + * Return: 0 on success, -ENOMEM if memory could not be allocated or + * -EBUSY if there are no free entries in @limit. */ -static inline int xa_alloc_irq(struct xarray *xa, u32 *id, u32 max, void *entry, - gfp_t gfp) +static inline int __must_check xa_alloc_irq(struct xarray *xa, u32 *id, + void *entry, struct xa_limit limit, gfp_t gfp) { int err; xa_lock_irq(xa); - err = __xa_alloc(xa, id, max, entry, gfp); + err = __xa_alloc(xa, id, entry, limit, gfp); xa_unlock_irq(xa); return err; diff --git a/lib/test_xarray.c b/lib/test_xarray.c index cd74f8f32abe..b5a6b981454d 100644 --- a/lib/test_xarray.c +++ b/lib/test_xarray.c @@ -40,9 +40,9 @@ static void *xa_store_index(struct xarray *xa, unsigned long index, gfp_t gfp) static void xa_alloc_index(struct xarray *xa, unsigned long index, gfp_t gfp) { - u32 id = 0; + u32 id; - XA_BUG_ON(xa, xa_alloc(xa, &id, UINT_MAX, xa_mk_index(index), + XA_BUG_ON(xa, xa_alloc(xa, &id, xa_mk_index(index), xa_limit_32b, gfp) != 0); XA_BUG_ON(xa, id != index); } @@ -640,28 +640,81 @@ static noinline void check_xa_alloc_1(struct xarray *xa, unsigned int base) xa_destroy(xa); /* Check that we fail properly at the limit of allocation */ - id = 0xfffffffeU; - XA_BUG_ON(xa, xa_alloc(xa, &id, UINT_MAX, xa_mk_index(id), + XA_BUG_ON(xa, xa_alloc(xa, &id, xa_mk_index(UINT_MAX - 1), + XA_LIMIT(UINT_MAX - 1, UINT_MAX), GFP_KERNEL) != 0); XA_BUG_ON(xa, id != 0xfffffffeU); - XA_BUG_ON(xa, xa_alloc(xa, &id, UINT_MAX, xa_mk_index(id), + XA_BUG_ON(xa, xa_alloc(xa, &id, xa_mk_index(UINT_MAX), + XA_LIMIT(UINT_MAX - 1, UINT_MAX), GFP_KERNEL) != 0); XA_BUG_ON(xa, id != 0xffffffffU); - XA_BUG_ON(xa, xa_alloc(xa, &id, UINT_MAX, xa_mk_index(id), - GFP_KERNEL) != -ENOSPC); - XA_BUG_ON(xa, id != 0xffffffffU); + id = 3; + XA_BUG_ON(xa, xa_alloc(xa, &id, xa_mk_index(0), + XA_LIMIT(UINT_MAX - 1, UINT_MAX), + GFP_KERNEL) != -EBUSY); + XA_BUG_ON(xa, id != 3); xa_destroy(xa); - id = 10; - XA_BUG_ON(xa, xa_alloc(xa, &id, 5, xa_mk_index(id), - GFP_KERNEL) != -ENOSPC); + XA_BUG_ON(xa, xa_alloc(xa, &id, xa_mk_index(10), XA_LIMIT(10, 5), + GFP_KERNEL) != -EBUSY); XA_BUG_ON(xa, xa_store_index(xa, 3, GFP_KERNEL) != 0); - XA_BUG_ON(xa, xa_alloc(xa, &id, 5, xa_mk_index(id), - GFP_KERNEL) != -ENOSPC); + XA_BUG_ON(xa, xa_alloc(xa, &id, xa_mk_index(10), XA_LIMIT(10, 5), + GFP_KERNEL) != -EBUSY); xa_erase_index(xa, 3); XA_BUG_ON(xa, !xa_empty(xa)); } +static noinline void check_xa_alloc_2(struct xarray *xa, unsigned int base) +{ + unsigned int i, id; + unsigned long index; + void *entry; + + /* Allocate and free a NULL and check xa_empty() behaves */ + XA_BUG_ON(xa, !xa_empty(xa)); + XA_BUG_ON(xa, xa_alloc(xa, &id, NULL, xa_limit_32b, GFP_KERNEL) != 0); + XA_BUG_ON(xa, id != base); + XA_BUG_ON(xa, xa_empty(xa)); + XA_BUG_ON(xa, xa_erase(xa, id) != NULL); + XA_BUG_ON(xa, !xa_empty(xa)); + + /* Ditto, but check destroy instead of erase */ + XA_BUG_ON(xa, !xa_empty(xa)); + XA_BUG_ON(xa, xa_alloc(xa, &id, NULL, xa_limit_32b, GFP_KERNEL) != 0); + XA_BUG_ON(xa, id != base); + XA_BUG_ON(xa, xa_empty(xa)); + xa_destroy(xa); + XA_BUG_ON(xa, !xa_empty(xa)); + + for (i = base; i < base + 10; i++) { + XA_BUG_ON(xa, xa_alloc(xa, &id, NULL, xa_limit_32b, + GFP_KERNEL) != 0); + XA_BUG_ON(xa, id != i); + } + + XA_BUG_ON(xa, xa_store(xa, 3, xa_mk_index(3), GFP_KERNEL) != NULL); + XA_BUG_ON(xa, xa_store(xa, 4, xa_mk_index(4), GFP_KERNEL) != NULL); + XA_BUG_ON(xa, xa_store(xa, 4, NULL, GFP_KERNEL) != xa_mk_index(4)); + XA_BUG_ON(xa, xa_erase(xa, 5) != NULL); + XA_BUG_ON(xa, xa_alloc(xa, &id, NULL, xa_limit_32b, GFP_KERNEL) != 0); + XA_BUG_ON(xa, id != 5); + + xa_for_each(xa, index, entry) { + xa_erase_index(xa, index); + } + + for (i = base; i < base + 9; i++) { + XA_BUG_ON(xa, xa_erase(xa, i) != NULL); + XA_BUG_ON(xa, xa_empty(xa)); + } + XA_BUG_ON(xa, xa_erase(xa, 8) != NULL); + XA_BUG_ON(xa, xa_empty(xa)); + XA_BUG_ON(xa, xa_erase(xa, base + 9) != NULL); + XA_BUG_ON(xa, !xa_empty(xa)); + + xa_destroy(xa); +} + static DEFINE_XARRAY_ALLOC(xa0); static DEFINE_XARRAY_ALLOC1(xa1); @@ -669,6 +722,8 @@ static noinline void check_xa_alloc(void) { check_xa_alloc_1(&xa0, 0); check_xa_alloc_1(&xa1, 1); + check_xa_alloc_2(&xa0, 0); + check_xa_alloc_2(&xa1, 1); } static noinline void __check_store_iter(struct xarray *xa, unsigned long start, @@ -1219,9 +1274,8 @@ static void check_align_1(struct xarray *xa, char *name) void *entry; for (i = 0; i < 8; i++) { - id = 0; - XA_BUG_ON(xa, xa_alloc(xa, &id, UINT_MAX, name + i, GFP_KERNEL) - != 0); + XA_BUG_ON(xa, xa_alloc(xa, &id, name + i, xa_limit_32b, + GFP_KERNEL) != 0); XA_BUG_ON(xa, id != i); } xa_for_each(xa, index, entry) diff --git a/lib/xarray.c b/lib/xarray.c index 468fb7b7963f..c707388fb05e 100644 --- a/lib/xarray.c +++ b/lib/xarray.c @@ -1615,23 +1615,23 @@ EXPORT_SYMBOL(xa_store_range); * __xa_alloc() - Find somewhere to store this entry in the XArray. * @xa: XArray. * @id: Pointer to ID. - * @max: Maximum ID to allocate (inclusive). + * @limit: Range for allocated ID. * @entry: New entry. * @gfp: Memory allocation flags. * - * Allocates an unused ID in the range specified by @id and @max. - * Updates the @id pointer with the index, then stores the entry at that - * index. A concurrent lookup will not see an uninitialised @id. + * Finds an empty entry in @xa between @limit.min and @limit.max, + * stores the index into the @id pointer, then stores the entry at + * that index. A concurrent lookup will not see an uninitialised @id. * * Context: Any context. Expects xa_lock to be held on entry. May * release and reacquire xa_lock if @gfp flags permit. - * Return: 0 on success, -ENOMEM if memory allocation fails or -ENOSPC if - * there is no more space in the XArray. + * Return: 0 on success, -ENOMEM if memory could not be allocated or + * -EBUSY if there are no free entries in @limit. */ -int __xa_alloc(struct xarray *xa, u32 *id, u32 max, void *entry, gfp_t gfp) +int __xa_alloc(struct xarray *xa, u32 *id, void *entry, + struct xa_limit limit, gfp_t gfp) { XA_STATE(xas, xa, 0); - int err; if (WARN_ON_ONCE(xa_is_advanced(entry))) return -EINVAL; @@ -1642,18 +1642,17 @@ int __xa_alloc(struct xarray *xa, u32 *id, u32 max, void *entry, gfp_t gfp) entry = XA_ZERO_ENTRY; do { - xas.xa_index = *id; - xas_find_marked(&xas, max, XA_FREE_MARK); + xas.xa_index = limit.min; + xas_find_marked(&xas, limit.max, XA_FREE_MARK); if (xas.xa_node == XAS_RESTART) - xas_set_err(&xas, -ENOSPC); + xas_set_err(&xas, -EBUSY); + else + *id = xas.xa_index; xas_store(&xas, entry); xas_clear_mark(&xas, XA_FREE_MARK); } while (__xas_nomem(&xas, gfp)); - err = xas_error(&xas); - if (!err) - *id = xas.xa_index; - return err; + return xas_error(&xas); } EXPORT_SYMBOL(__xa_alloc); |