From 962033d55d0761e0716a01a715c6659c8c8dfc41 Mon Sep 17 00:00:00 2001
From: Matthew Wilcox <willy@infradead.org>
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 <jgg@ziepe.ca>
Signed-off-by: Matthew Wilcox <willy@infradead.org>
---
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 c7436da5c4ad0..ef6f9f98f5957 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 588733abd19d7..0e01e61291455 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 b9a6cf42feeea..3f10198f00b77 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)
--
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