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-rw-r--r--Documentation/core-api/xarray.rst8
-rw-r--r--include/linux/xarray.h2
-rw-r--r--lib/test_xarray.c34
-rw-r--r--lib/xarray.c97
4 files changed, 139 insertions, 2 deletions
diff --git a/Documentation/core-api/xarray.rst b/Documentation/core-api/xarray.rst
index 463e4c798ec1..a4e705108f42 100644
--- a/Documentation/core-api/xarray.rst
+++ b/Documentation/core-api/xarray.rst
@@ -98,6 +98,13 @@ the XArray by calling :c:func:`xa_for_each`. You may prefer to use
:c:func:`xa_find` or :c:func:`xa_find_after` to move to the next present
entry in the XArray.
+Calling :c:func:`xa_store_range` stores the same entry in a range
+of indices. If you do this, some of the other operations will behave
+in a slightly odd way. For example, marking the entry at one index
+may result in the entry being marked at some, but not all of the other
+indices. Storing into one index may result in the entry retrieved by
+some, but not all of the other indices changing.
+
Finally, you can remove all entries from an XArray by calling
:c:func:`xa_destroy`. If the XArray entries are pointers, you may wish
to free the entries first. You can do this by iterating over all present
@@ -156,6 +163,7 @@ Takes xa_lock internally:
* :c:func:`xa_erase_bh`
* :c:func:`xa_erase_irq`
* :c:func:`xa_cmpxchg`
+ * :c:func:`xa_store_range`
* :c:func:`xa_alloc`
* :c:func:`xa_alloc_bh`
* :c:func:`xa_alloc_irq`
diff --git a/include/linux/xarray.h b/include/linux/xarray.h
index e0b57af52e9b..d9514928ddac 100644
--- a/include/linux/xarray.h
+++ b/include/linux/xarray.h
@@ -292,6 +292,8 @@ 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_reserve(struct xarray *, unsigned long index, 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);
void xa_set_mark(struct xarray *, unsigned long index, xa_mark_t);
void xa_clear_mark(struct xarray *, unsigned long index, xa_mark_t);
diff --git a/lib/test_xarray.c b/lib/test_xarray.c
index 0f06a93b4d0e..aa47754150ce 100644
--- a/lib/test_xarray.c
+++ b/lib/test_xarray.c
@@ -1039,6 +1039,39 @@ static noinline void check_create_range(struct xarray *xa)
check_create_range_3();
}
+static noinline void __check_store_range(struct xarray *xa, unsigned long first,
+ unsigned long last)
+{
+#ifdef CONFIG_XARRAY_MULTI
+ xa_store_range(xa, first, last, xa_mk_value(first), GFP_KERNEL);
+
+ XA_BUG_ON(xa, xa_load(xa, first) != xa_mk_value(first));
+ XA_BUG_ON(xa, xa_load(xa, last) != xa_mk_value(first));
+ XA_BUG_ON(xa, xa_load(xa, first - 1) != NULL);
+ XA_BUG_ON(xa, xa_load(xa, last + 1) != NULL);
+
+ xa_store_range(xa, first, last, NULL, GFP_KERNEL);
+#endif
+
+ XA_BUG_ON(xa, !xa_empty(xa));
+}
+
+static noinline void check_store_range(struct xarray *xa)
+{
+ unsigned long i, j;
+
+ for (i = 0; i < 128; i++) {
+ for (j = i; j < 128; j++) {
+ __check_store_range(xa, i, j);
+ __check_store_range(xa, 128 + i, 128 + j);
+ __check_store_range(xa, 4095 + i, 4095 + j);
+ __check_store_range(xa, 4096 + i, 4096 + j);
+ __check_store_range(xa, 123456 + i, 123456 + j);
+ __check_store_range(xa, UINT_MAX + i, UINT_MAX + j);
+ }
+ }
+}
+
static LIST_HEAD(shadow_nodes);
static void test_update_node(struct xa_node *node)
@@ -1184,6 +1217,7 @@ static int xarray_checks(void)
check_destroy(&array);
check_move(&array);
check_create_range(&array);
+ check_store_range(&array);
check_store_iter(&array);
check_workingset(&array, 0);
diff --git a/lib/xarray.c b/lib/xarray.c
index 9a0d49d4b5f0..8b176f009c08 100644
--- a/lib/xarray.c
+++ b/lib/xarray.c
@@ -376,6 +376,14 @@ static void *xas_alloc(struct xa_state *xas, unsigned int shift)
return node;
}
+#ifdef CONFIG_XARRAY_MULTI
+/* Returns the number of indices covered by a given xa_state */
+static unsigned long xas_size(const struct xa_state *xas)
+{
+ return (xas->xa_sibs + 1UL) << xas->xa_shift;
+}
+#endif
+
/*
* Use this to calculate the maximum index that will need to be created
* in order to add the entry described by @xas. Because we cannot store a
@@ -388,8 +396,7 @@ static unsigned long xas_max(struct xa_state *xas)
#ifdef CONFIG_XARRAY_MULTI
if (xas->xa_shift || xas->xa_sibs) {
- unsigned long mask;
- mask = (((xas->xa_sibs + 1UL) << xas->xa_shift) - 1);
+ unsigned long mask = xas_size(xas) - 1;
max |= mask;
if (mask == max)
max++;
@@ -1517,6 +1524,92 @@ int xa_reserve(struct xarray *xa, unsigned long index, gfp_t gfp)
}
EXPORT_SYMBOL(xa_reserve);
+#ifdef CONFIG_XARRAY_MULTI
+static void xas_set_range(struct xa_state *xas, unsigned long first,
+ unsigned long last)
+{
+ unsigned int shift = 0;
+ unsigned long sibs = last - first;
+ unsigned int offset = XA_CHUNK_MASK;
+
+ xas_set(xas, first);
+
+ while ((first & XA_CHUNK_MASK) == 0) {
+ if (sibs < XA_CHUNK_MASK)
+ break;
+ if ((sibs == XA_CHUNK_MASK) && (offset < XA_CHUNK_MASK))
+ break;
+ shift += XA_CHUNK_SHIFT;
+ if (offset == XA_CHUNK_MASK)
+ offset = sibs & XA_CHUNK_MASK;
+ sibs >>= XA_CHUNK_SHIFT;
+ first >>= XA_CHUNK_SHIFT;
+ }
+
+ offset = first & XA_CHUNK_MASK;
+ if (offset + sibs > XA_CHUNK_MASK)
+ sibs = XA_CHUNK_MASK - offset;
+ if ((((first + sibs + 1) << shift) - 1) > last)
+ sibs -= 1;
+
+ xas->xa_shift = shift;
+ xas->xa_sibs = sibs;
+}
+
+/**
+ * xa_store_range() - Store this entry at a range of indices in the XArray.
+ * @xa: XArray.
+ * @first: First index to affect.
+ * @last: Last index to affect.
+ * @entry: New entry.
+ * @gfp: Memory allocation flags.
+ *
+ * After this function returns, loads from any index between @first and @last,
+ * inclusive will return @entry.
+ * Storing into an existing multislot entry updates the entry of every index.
+ * The marks associated with @index are unaffected unless @entry is %NULL.
+ *
+ * Context: Process context. Takes and releases the xa_lock. May sleep
+ * if the @gfp flags permit.
+ * Return: %NULL on success, xa_err(-EINVAL) if @entry cannot be stored in
+ * an XArray, or xa_err(-ENOMEM) if memory allocation failed.
+ */
+void *xa_store_range(struct xarray *xa, unsigned long first,
+ unsigned long last, void *entry, gfp_t gfp)
+{
+ XA_STATE(xas, xa, 0);
+
+ if (WARN_ON_ONCE(xa_is_internal(entry)))
+ return XA_ERROR(-EINVAL);
+ if (last < first)
+ return XA_ERROR(-EINVAL);
+
+ do {
+ xas_lock(&xas);
+ if (entry) {
+ unsigned int order = (last == ~0UL) ? 64 :
+ ilog2(last + 1);
+ xas_set_order(&xas, last, order);
+ xas_create(&xas);
+ if (xas_error(&xas))
+ goto unlock;
+ }
+ do {
+ xas_set_range(&xas, first, last);
+ xas_store(&xas, entry);
+ if (xas_error(&xas))
+ goto unlock;
+ first += xas_size(&xas);
+ } while (first <= last);
+unlock:
+ xas_unlock(&xas);
+ } while (xas_nomem(&xas, gfp));
+
+ return xas_result(&xas, NULL);
+}
+EXPORT_SYMBOL(xa_store_range);
+#endif /* CONFIG_XARRAY_MULTI */
+
/**
* __xa_alloc() - Find somewhere to store this entry in the XArray.
* @xa: XArray.