From 962033d55d0761e0716a01a715c6659c8c8dfc41 Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Wed, 20 Feb 2019 11:51:22 -0500 Subject: [PATCH] XArray: Use xa_cmpxchg to implement xa_reserve Jason feels this is clearer, and it saves a function and an exported symbol. Suggested-by: Jason Gunthorpe Signed-off-by: Matthew Wilcox --- Documentation/core-api/xarray.rst | 1 - include/linux/xarray.h | 25 +++------------------ lib/xarray.c | 36 ------------------------------- 3 files changed, 3 insertions(+), 59 deletions(-) diff --git a/Documentation/core-api/xarray.rst b/Documentation/core-api/xarray.rst index c7436da5c4ad..ef6f9f98f595 100644 --- a/Documentation/core-api/xarray.rst +++ b/Documentation/core-api/xarray.rst @@ -215,7 +215,6 @@ Assumes xa_lock held on entry: * :c:func:`__xa_erase` * :c:func:`__xa_cmpxchg` * :c:func:`__xa_alloc` - * :c:func:`__xa_reserve` * :c:func:`__xa_set_mark` * :c:func:`__xa_clear_mark` diff --git a/include/linux/xarray.h b/include/linux/xarray.h index 588733abd19d..0e01e6129145 100644 --- a/include/linux/xarray.h +++ b/include/linux/xarray.h @@ -525,7 +525,6 @@ int __must_check __xa_alloc(struct xarray *, u32 *id, void *entry, struct xa_limit, gfp_t); int __must_check __xa_alloc_cyclic(struct xarray *, u32 *id, void *entry, struct xa_limit, u32 *next, gfp_t); -int __must_check __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); @@ -1004,13 +1003,7 @@ static inline int xa_alloc_cyclic_irq(struct xarray *xa, u32 *id, void *entry, static inline __must_check int xa_reserve(struct xarray *xa, unsigned long index, gfp_t gfp) { - int ret; - - xa_lock(xa); - ret = __xa_reserve(xa, index, gfp); - xa_unlock(xa); - - return ret; + return xa_err(xa_cmpxchg(xa, index, NULL, XA_ZERO_ENTRY, gfp)); } /** @@ -1028,13 +1021,7 @@ int xa_reserve(struct xarray *xa, unsigned long index, gfp_t gfp) static inline __must_check int xa_reserve_bh(struct xarray *xa, unsigned long index, gfp_t gfp) { - int ret; - - xa_lock_bh(xa); - ret = __xa_reserve(xa, index, gfp); - xa_unlock_bh(xa); - - return ret; + return xa_err(xa_cmpxchg_bh(xa, index, NULL, XA_ZERO_ENTRY, gfp)); } /** @@ -1052,13 +1039,7 @@ int xa_reserve_bh(struct xarray *xa, unsigned long index, gfp_t gfp) static inline __must_check int xa_reserve_irq(struct xarray *xa, unsigned long index, gfp_t gfp) { - int ret; - - xa_lock_irq(xa); - ret = __xa_reserve(xa, index, gfp); - xa_unlock_irq(xa); - - return ret; + return xa_err(xa_cmpxchg_irq(xa, index, NULL, XA_ZERO_ENTRY, gfp)); } /** diff --git a/lib/xarray.c b/lib/xarray.c index b9a6cf42feee..3f10198f00b7 100644 --- a/lib/xarray.c +++ b/lib/xarray.c @@ -1484,42 +1484,6 @@ int __xa_insert(struct xarray *xa, unsigned long index, void *entry, gfp_t gfp) } EXPORT_SYMBOL(__xa_insert); -/** - * __xa_reserve() - Reserve this index in the XArray. - * @xa: XArray. - * @index: Index into array. - * @gfp: Memory allocation flags. - * - * Ensures there is somewhere to store an entry at @index in the array. - * If there is already something stored at @index, this function does - * nothing. If there was nothing there, the entry is marked as reserved. - * Loading from a reserved entry returns a %NULL pointer. - * - * If you do not use the entry that you have reserved, call xa_release() - * or xa_erase() to free any unnecessary memory. - * - * Context: Any context. Expects the xa_lock to be held on entry. May - * release the lock, sleep and reacquire the lock if the @gfp flags permit. - * Return: 0 if the reservation succeeded or -ENOMEM if it failed. - */ -int __xa_reserve(struct xarray *xa, unsigned long index, gfp_t gfp) -{ - XA_STATE(xas, xa, index); - void *curr; - - do { - curr = xas_load(&xas); - if (!curr) { - xas_store(&xas, XA_ZERO_ENTRY); - if (xa_track_free(xa)) - xas_clear_mark(&xas, XA_FREE_MARK); - } - } while (__xas_nomem(&xas, gfp)); - - return xas_error(&xas); -} -EXPORT_SYMBOL(__xa_reserve); - #ifdef CONFIG_XARRAY_MULTI static void xas_set_range(struct xa_state *xas, unsigned long first, unsigned long last) -- 2.45.2