summaryrefslogtreecommitdiff
path: root/include/linux/flex_array.h
diff options
context:
space:
mode:
authorJames Morris <jmorris@namei.org>2009-08-06 02:55:03 +0400
committerJames Morris <jmorris@namei.org>2009-08-06 02:55:03 +0400
commit012a5299a29672039f42944a37984558393ef769 (patch)
treede0815c67cf4156c32c8b552cd7448387cc391b0 /include/linux/flex_array.h
parentda34d4248bd2013ee64ce51e63ec0ebd1f32b46c (diff)
parent90bc1a658a53f8832ee799685703977a450e5af9 (diff)
downloadlinux-012a5299a29672039f42944a37984558393ef769.tar.xz
Merge branch 'master' into next
Diffstat (limited to 'include/linux/flex_array.h')
-rw-r--r--include/linux/flex_array.h47
1 files changed, 47 insertions, 0 deletions
diff --git a/include/linux/flex_array.h b/include/linux/flex_array.h
new file mode 100644
index 000000000000..23c1ec79a31b
--- /dev/null
+++ b/include/linux/flex_array.h
@@ -0,0 +1,47 @@
+#ifndef _FLEX_ARRAY_H
+#define _FLEX_ARRAY_H
+
+#include <linux/types.h>
+#include <asm/page.h>
+
+#define FLEX_ARRAY_PART_SIZE PAGE_SIZE
+#define FLEX_ARRAY_BASE_SIZE PAGE_SIZE
+
+struct flex_array_part;
+
+/*
+ * This is meant to replace cases where an array-like
+ * structure has gotten too big to fit into kmalloc()
+ * and the developer is getting tempted to use
+ * vmalloc().
+ */
+
+struct flex_array {
+ union {
+ struct {
+ int element_size;
+ int total_nr_elements;
+ struct flex_array_part *parts[0];
+ };
+ /*
+ * This little trick makes sure that
+ * sizeof(flex_array) == PAGE_SIZE
+ */
+ char padding[FLEX_ARRAY_BASE_SIZE];
+ };
+};
+
+#define FLEX_ARRAY_INIT(size, total) { { {\
+ .element_size = (size), \
+ .total_nr_elements = (total), \
+} } }
+
+struct flex_array *flex_array_alloc(int element_size, int total, gfp_t flags);
+int flex_array_prealloc(struct flex_array *fa, int start, int end, gfp_t flags);
+void flex_array_free(struct flex_array *fa);
+void flex_array_free_parts(struct flex_array *fa);
+int flex_array_put(struct flex_array *fa, int element_nr, void *src,
+ gfp_t flags);
+void *flex_array_get(struct flex_array *fa, int element_nr);
+
+#endif /* _FLEX_ARRAY_H */