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authorMatthew Wilcox <matthew@wil.cx>2007-12-03 12:16:57 -0500
committerMatthew Wilcox <matthew@wil.cx>2007-12-04 10:39:57 -0500
commit6182a0943af2235756836ed7e021fa22b93ec68b (patch)
treee715aed99e16619e72649c9bb46de300eedff778
parent399154be2dcb6a58dbde9682162c38113cf3e40b (diff)
downloadlinux-stericsson-6182a0943af2235756836ed7e021fa22b93ec68b.tar.gz
dmapool: Tidy up includes and add comments
We were missing a copyright statement and license, so add GPLv2, David Brownell's copyright and my copyright. The asm/io.h include was superfluous, but we were missing a few other necessary includes. Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
-rw-r--r--mm/dmapool.c40
1 files changed, 30 insertions, 10 deletions
diff --git a/mm/dmapool.c b/mm/dmapool.c
index 744d541df866..e2ea4543abb4 100644
--- a/mm/dmapool.c
+++ b/mm/dmapool.c
@@ -1,19 +1,39 @@
+/*
+ * DMA Pool allocator
+ *
+ * Copyright 2001 David Brownell
+ * Copyright 2007 Intel Corporation
+ * Author: Matthew Wilcox <willy@linux.intel.com>
+ *
+ * This software may be redistributed and/or modified under the terms of
+ * the GNU General Public License ("GPL") version 2 as published by the
+ * Free Software Foundation.
+ *
+ * This allocator returns small blocks of a given size which are DMA-able by
+ * the given device. It uses the dma_alloc_coherent page allocator to get
+ * new pages, then splits them up into blocks of the required size.
+ * Many older drivers still have their own code to do this.
+ *
+ * The current design of this allocator is fairly simple. The pool is
+ * represented by the 'struct dma_pool' which keeps a doubly-linked list of
+ * allocated pages. Each page in the page_list is split into blocks of at
+ * least 'size' bytes.
+ */
#include <linux/device.h>
-#include <linux/mm.h>
-#include <asm/io.h> /* Needed for i386 to build */
#include <linux/dma-mapping.h>
#include <linux/dmapool.h>
-#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
#include <linux/module.h>
+#include <linux/mutex.h>
#include <linux/poison.h>
#include <linux/sched.h>
-
-/*
- * Pool allocator ... wraps the dma_alloc_coherent page allocator, so
- * small blocks are easily used by drivers for bus mastering controllers.
- * This should probably be sharing the guts of the slab allocator.
- */
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/wait.h>
struct dma_pool { /* the pool */
struct list_head page_list;
@@ -265,7 +285,7 @@ EXPORT_SYMBOL(dma_pool_destroy);
*
* This returns the kernel virtual address of a currently unused block,
* and reports its dma address through the handle.
- * If such a memory block can't be allocated, null is returned.
+ * If such a memory block can't be allocated, %NULL is returned.
*/
void *dma_pool_alloc(struct dma_pool *pool, gfp_t mem_flags,
dma_addr_t *handle)