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authorMatthew Wilcox <willy@infradead.org>2018-10-31 21:39:28 +0300
committerMatthew Wilcox <willy@infradead.org>2018-11-06 00:38:08 +0300
commitc5beb07e7a06b24f4f27304f6282b5dbd929543b (patch)
treedddd6ce81475ebd3ab56fff6e55efe60d0802393
parent4c0608f4a0e76dfb82d3accd20081f4bf47ed143 (diff)
downloadlinux-c5beb07e7a06b24f4f27304f6282b5dbd929543b.tar.xz
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>
-rw-r--r--include/linux/xarray.h113
-rw-r--r--lib/xarray.c41
2 files changed, 69 insertions, 85 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. */
/*
diff --git a/lib/xarray.c b/lib/xarray.c
index 9cab8cfef8a8..77671d4a7910 100644
--- a/lib/xarray.c
+++ b/lib/xarray.c
@@ -1407,47 +1407,6 @@ void *__xa_store(struct xarray *xa, unsigned long index, void *entry, gfp_t gfp)
EXPORT_SYMBOL(__xa_store);
/**
- * 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: Process 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.
- */
-void *xa_cmpxchg(struct xarray *xa, unsigned long index,
- void *old, void *entry, gfp_t gfp)
-{
- XA_STATE(xas, xa, index);
- void *curr;
-
- if (WARN_ON_ONCE(xa_is_internal(entry)))
- return XA_ERROR(-EINVAL);
-
- do {
- xas_lock(&xas);
- curr = xas_load(&xas);
- if (curr == XA_ZERO_ENTRY)
- curr = NULL;
- if (curr == old) {
- xas_store(&xas, entry);
- if (xa_track_free(xa) && entry)
- xas_clear_mark(&xas, XA_FREE_MARK);
- }
- xas_unlock(&xas);
- } while (xas_nomem(&xas, gfp));
-
- return xas_result(&xas, curr);
-}
-EXPORT_SYMBOL(xa_cmpxchg);
-
-/**
* __xa_cmpxchg() - Store this entry in the XArray.
* @xa: XArray.
* @index: Index into array.