summaryrefslogtreecommitdiff
path: root/lib
diff options
context:
space:
mode:
Diffstat (limited to 'lib')
-rw-r--r--lib/Kconfig.debug3
-rw-r--r--lib/Makefile1
-rw-r--r--lib/radix-tree.c43
-rw-r--r--lib/test_xarray.c87
-rw-r--r--lib/xarray.c195
5 files changed, 286 insertions, 43 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 4966c4fbe7f7..091155e12422 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1813,6 +1813,9 @@ config TEST_BITFIELD
config TEST_UUID
tristate "Test functions located in the uuid module at runtime"
+config TEST_XARRAY
+ tristate "Test the XArray code at runtime"
+
config TEST_OVERFLOW
tristate "Test check_*_overflow() functions at runtime"
diff --git a/lib/Makefile b/lib/Makefile
index 057385f1f145..e6f809556af5 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -68,6 +68,7 @@ obj-$(CONFIG_TEST_PRINTF) += test_printf.o
obj-$(CONFIG_TEST_BITMAP) += test_bitmap.o
obj-$(CONFIG_TEST_BITFIELD) += test_bitfield.o
obj-$(CONFIG_TEST_UUID) += test_uuid.o
+obj-$(CONFIG_TEST_XARRAY) += test_xarray.o
obj-$(CONFIG_TEST_PARMAN) += test_parman.o
obj-$(CONFIG_TEST_KMOD) += test_kmod.o
obj-$(CONFIG_TEST_DEBUG_VIRTUAL) += test_debug_virtual.o
diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 8a568cea1237..b8e961428484 100644
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -256,49 +256,6 @@ static unsigned long next_index(unsigned long index,
}
#ifndef __KERNEL__
-static void dump_node(struct radix_tree_node *node, unsigned long index)
-{
- unsigned long i;
-
- pr_debug("radix node: %p offset %d indices %lu-%lu parent %p tags %lx %lx %lx shift %d count %d nr_values %d\n",
- node, node->offset, index, index | node_maxindex(node),
- node->parent,
- node->tags[0][0], node->tags[1][0], node->tags[2][0],
- node->shift, node->count, node->nr_values);
-
- for (i = 0; i < RADIX_TREE_MAP_SIZE; i++) {
- unsigned long first = index | (i << node->shift);
- unsigned long last = first | ((1UL << node->shift) - 1);
- void *entry = node->slots[i];
- if (!entry)
- continue;
- if (entry == RADIX_TREE_RETRY) {
- pr_debug("radix retry offset %ld indices %lu-%lu parent %p\n",
- i, first, last, node);
- } else if (!radix_tree_is_internal_node(entry)) {
- pr_debug("radix entry %p offset %ld indices %lu-%lu parent %p\n",
- entry, i, first, last, node);
- } else if (xa_is_sibling(entry)) {
- pr_debug("radix sblng %p offset %ld indices %lu-%lu parent %p val %p\n",
- entry, i, first, last, node,
- node->slots[xa_to_sibling(entry)]);
- } else {
- dump_node(entry_to_node(entry), first);
- }
- }
-}
-
-/* For debug */
-static void radix_tree_dump(struct radix_tree_root *root)
-{
- pr_debug("radix root: %p xa_head %p tags %x\n",
- root, root->xa_head,
- root->xa_flags >> ROOT_TAG_SHIFT);
- if (!radix_tree_is_internal_node(root->xa_head))
- return;
- dump_node(entry_to_node(root->xa_head), 0);
-}
-
static void dump_ida_node(void *entry, unsigned long index)
{
unsigned long i;
diff --git a/lib/test_xarray.c b/lib/test_xarray.c
new file mode 100644
index 000000000000..a7248b87617f
--- /dev/null
+++ b/lib/test_xarray.c
@@ -0,0 +1,87 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * test_xarray.c: Test the XArray API
+ * Copyright (c) 2017-2018 Microsoft Corporation
+ * Author: Matthew Wilcox <willy@infradead.org>
+ */
+
+#include <linux/xarray.h>
+#include <linux/module.h>
+
+static unsigned int tests_run;
+static unsigned int tests_passed;
+
+#ifndef XA_DEBUG
+# ifdef __KERNEL__
+void xa_dump(const struct xarray *xa) { }
+# endif
+#undef XA_BUG_ON
+#define XA_BUG_ON(xa, x) do { \
+ tests_run++; \
+ if (x) { \
+ printk("BUG at %s:%d\n", __func__, __LINE__); \
+ xa_dump(xa); \
+ dump_stack(); \
+ } else { \
+ tests_passed++; \
+ } \
+} while (0)
+#endif
+
+static void *xa_store_index(struct xarray *xa, unsigned long index, gfp_t gfp)
+{
+ radix_tree_insert(xa, index, xa_mk_value(index));
+ return NULL;
+}
+
+static void xa_erase_index(struct xarray *xa, unsigned long index)
+{
+ radix_tree_delete(xa, index);
+}
+
+static noinline void check_xa_load(struct xarray *xa)
+{
+ unsigned long i, j;
+
+ for (i = 0; i < 1024; i++) {
+ for (j = 0; j < 1024; j++) {
+ void *entry = xa_load(xa, j);
+ if (j < i)
+ XA_BUG_ON(xa, xa_to_value(entry) != j);
+ else
+ XA_BUG_ON(xa, entry);
+ }
+ XA_BUG_ON(xa, xa_store_index(xa, i, GFP_KERNEL) != NULL);
+ }
+
+ for (i = 0; i < 1024; i++) {
+ for (j = 0; j < 1024; j++) {
+ void *entry = xa_load(xa, j);
+ if (j >= i)
+ XA_BUG_ON(xa, xa_to_value(entry) != j);
+ else
+ XA_BUG_ON(xa, entry);
+ }
+ xa_erase_index(xa, i);
+ }
+ XA_BUG_ON(xa, !xa_empty(xa));
+}
+
+static RADIX_TREE(array, GFP_KERNEL);
+
+static int xarray_checks(void)
+{
+ check_xa_load(&array);
+
+ printk("XArray: %u of %u tests passed\n", tests_passed, tests_run);
+ return (tests_run == tests_passed) ? 0 : -EINVAL;
+}
+
+static void xarray_exit(void)
+{
+}
+
+module_init(xarray_checks);
+module_exit(xarray_exit);
+MODULE_AUTHOR("Matthew Wilcox <willy@infradead.org>");
+MODULE_LICENSE("GPL");
diff --git a/lib/xarray.c b/lib/xarray.c
index 862f4c64c754..19cfcbc69a68 100644
--- a/lib/xarray.c
+++ b/lib/xarray.c
@@ -24,6 +24,100 @@
* @entry refers to something stored in a slot in the xarray
*/
+/* extracts the offset within this node from the index */
+static unsigned int get_offset(unsigned long index, struct xa_node *node)
+{
+ return (index >> node->shift) & XA_CHUNK_MASK;
+}
+
+/* move the index either forwards (find) or backwards (sibling slot) */
+static void xas_move_index(struct xa_state *xas, unsigned long offset)
+{
+ unsigned int shift = xas->xa_node->shift;
+ xas->xa_index &= ~XA_CHUNK_MASK << shift;
+ xas->xa_index += offset << shift;
+}
+
+static void *set_bounds(struct xa_state *xas)
+{
+ xas->xa_node = XAS_BOUNDS;
+ return NULL;
+}
+
+/*
+ * Starts a walk. If the @xas is already valid, we assume that it's on
+ * the right path and just return where we've got to. If we're in an
+ * error state, return NULL. If the index is outside the current scope
+ * of the xarray, return NULL without changing @xas->xa_node. Otherwise
+ * set @xas->xa_node to NULL and return the current head of the array.
+ */
+static void *xas_start(struct xa_state *xas)
+{
+ void *entry;
+
+ if (xas_valid(xas))
+ return xas_reload(xas);
+ if (xas_error(xas))
+ return NULL;
+
+ entry = xa_head(xas->xa);
+ if (!xa_is_node(entry)) {
+ if (xas->xa_index)
+ return set_bounds(xas);
+ } else {
+ if ((xas->xa_index >> xa_to_node(entry)->shift) > XA_CHUNK_MASK)
+ return set_bounds(xas);
+ }
+
+ xas->xa_node = NULL;
+ return entry;
+}
+
+static void *xas_descend(struct xa_state *xas, struct xa_node *node)
+{
+ unsigned int offset = get_offset(xas->xa_index, node);
+ void *entry = xa_entry(xas->xa, node, offset);
+
+ xas->xa_node = node;
+ if (xa_is_sibling(entry)) {
+ offset = xa_to_sibling(entry);
+ entry = xa_entry(xas->xa, node, offset);
+ }
+
+ xas->xa_offset = offset;
+ return entry;
+}
+
+/**
+ * xas_load() - Load an entry from the XArray (advanced).
+ * @xas: XArray operation state.
+ *
+ * Usually walks the @xas to the appropriate state to load the entry
+ * stored at xa_index. However, it will do nothing and return %NULL if
+ * @xas is in an error state. xas_load() will never expand the tree.
+ *
+ * If the xa_state is set up to operate on a multi-index entry, xas_load()
+ * may return %NULL or an internal entry, even if there are entries
+ * present within the range specified by @xas.
+ *
+ * Context: Any context. The caller should hold the xa_lock or the RCU lock.
+ * Return: Usually an entry in the XArray, but see description for exceptions.
+ */
+void *xas_load(struct xa_state *xas)
+{
+ void *entry = xas_start(xas);
+
+ while (xa_is_node(entry)) {
+ struct xa_node *node = xa_to_node(entry);
+
+ if (xas->xa_shift > node->shift)
+ break;
+ entry = xas_descend(xas, node);
+ }
+ return entry;
+}
+EXPORT_SYMBOL_GPL(xas_load);
+
/**
* xa_init_flags() - Initialise an empty XArray with flags.
* @xa: XArray.
@@ -42,3 +136,104 @@ void xa_init_flags(struct xarray *xa, gfp_t flags)
xa->xa_head = NULL;
}
EXPORT_SYMBOL(xa_init_flags);
+
+/**
+ * xa_load() - Load an entry from an XArray.
+ * @xa: XArray.
+ * @index: index into array.
+ *
+ * Context: Any context. Takes and releases the RCU lock.
+ * Return: The entry at @index in @xa.
+ */
+void *xa_load(struct xarray *xa, unsigned long index)
+{
+ XA_STATE(xas, xa, index);
+ void *entry;
+
+ rcu_read_lock();
+ do {
+ entry = xas_load(&xas);
+ } while (xas_retry(&xas, entry));
+ rcu_read_unlock();
+
+ return entry;
+}
+EXPORT_SYMBOL(xa_load);
+
+#ifdef XA_DEBUG
+void xa_dump_node(const struct xa_node *node)
+{
+ unsigned i, j;
+
+ if (!node)
+ return;
+ if ((unsigned long)node & 3) {
+ pr_cont("node %px\n", node);
+ return;
+ }
+
+ pr_cont("node %px %s %d parent %px shift %d count %d values %d "
+ "array %px list %px %px marks",
+ node, node->parent ? "offset" : "max", node->offset,
+ node->parent, node->shift, node->count, node->nr_values,
+ node->array, node->private_list.prev, node->private_list.next);
+ for (i = 0; i < XA_MAX_MARKS; i++)
+ for (j = 0; j < XA_MARK_LONGS; j++)
+ pr_cont(" %lx", node->marks[i][j]);
+ pr_cont("\n");
+}
+
+void xa_dump_index(unsigned long index, unsigned int shift)
+{
+ if (!shift)
+ pr_info("%lu: ", index);
+ else if (shift >= BITS_PER_LONG)
+ pr_info("0-%lu: ", ~0UL);
+ else
+ pr_info("%lu-%lu: ", index, index | ((1UL << shift) - 1));
+}
+
+void xa_dump_entry(const void *entry, unsigned long index, unsigned long shift)
+{
+ if (!entry)
+ return;
+
+ xa_dump_index(index, shift);
+
+ if (xa_is_node(entry)) {
+ if (shift == 0) {
+ pr_cont("%px\n", entry);
+ } else {
+ unsigned long i;
+ struct xa_node *node = xa_to_node(entry);
+ xa_dump_node(node);
+ for (i = 0; i < XA_CHUNK_SIZE; i++)
+ xa_dump_entry(node->slots[i],
+ index + (i << node->shift), node->shift);
+ }
+ } else if (xa_is_value(entry))
+ pr_cont("value %ld (0x%lx) [%px]\n", xa_to_value(entry),
+ xa_to_value(entry), entry);
+ else if (!xa_is_internal(entry))
+ pr_cont("%px\n", entry);
+ else if (xa_is_retry(entry))
+ pr_cont("retry (%ld)\n", xa_to_internal(entry));
+ else if (xa_is_sibling(entry))
+ pr_cont("sibling (slot %ld)\n", xa_to_sibling(entry));
+ else
+ pr_cont("UNKNOWN ENTRY (%px)\n", entry);
+}
+
+void xa_dump(const struct xarray *xa)
+{
+ void *entry = xa->xa_head;
+ unsigned int shift = 0;
+
+ pr_info("xarray: %px head %px flags %x marks %d %d %d\n", xa, entry,
+ xa->xa_flags, radix_tree_tagged(xa, 0),
+ radix_tree_tagged(xa, 1), radix_tree_tagged(xa, 2));
+ if (xa_is_node(entry))
+ shift = xa_to_node(entry)->shift + XA_CHUNK_SHIFT;
+ xa_dump_entry(entry, 0, shift);
+}
+#endif
generated by cgit v1.2.3-58-ga151 (git 2.39.0) at 2024-11-28 18:25:33 +0000