1 files changed, 131 insertions, 0 deletions
diff --git a/crypto/async_tx/async_memcpy.c b/crypto/async_tx/async_memcpy.c
new file mode 100644
index 0000000..a973f4e
--- /dev/null
+++ b/crypto/async_tx/async_memcpy.c
@@ -0,0 +1,131 @@
+/*
+ * copy offload engine support
+ *
+ * Copyright © 2006, Intel Corporation.
+ *
+ *      Dan Williams <dan.j.williams@intel.com>
+ *
+ *      with architecture considerations by:
+ *      Neil Brown <neilb@suse.de>
+ *      Jeff Garzik <jeff@garzik.org>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+#include <linux/kernel.h>
+#include <linux/highmem.h>
+#include <linux/mm.h>
+#include <linux/dma-mapping.h>
+#include <linux/async_tx.h>
+
+/**
+ * async_memcpy - attempt to copy memory with a dma engine.
+ * @dest: destination page
+ * @src: src page
+ * @offset: offset in pages to start transaction
+ * @len: length in bytes
+ * @flags: ASYNC_TX_ASSUME_COHERENT, ASYNC_TX_ACK, ASYNC_TX_DEP_ACK,
+ *	ASYNC_TX_KMAP_SRC, ASYNC_TX_KMAP_DST
+ * @depend_tx: memcpy depends on the result of this transaction
+ * @cb_fn: function to call when the memcpy completes
+ * @cb_param: parameter to pass to the callback routine
+ */
+struct dma_async_tx_descriptor *
+async_memcpy(struct page *dest, struct page *src, unsigned int dest_offset,
+	unsigned int src_offset, size_t len, enum async_tx_flags flags,
+	struct dma_async_tx_descriptor *depend_tx,
+	dma_async_tx_callback cb_fn, void *cb_param)
+{
+	struct dma_chan *chan = async_tx_find_channel(depend_tx, DMA_MEMCPY);
+	struct dma_device *device = chan ? chan->device : NULL;
+	int int_en = cb_fn ? 1 : 0;
+	struct dma_async_tx_descriptor *tx = device ?
+		device->device_prep_dma_memcpy(chan, len,
+		int_en) : NULL;
+
+	if (tx) { /* run the memcpy asynchronously */
+		dma_addr_t addr;
+		enum dma_data_direction dir;
+
+		pr_debug("%s: (async) len: %zu\n", __FUNCTION__, len);
+
+		dir = (flags & ASYNC_TX_ASSUME_COHERENT) ?
+			DMA_NONE : DMA_FROM_DEVICE;
+
+		addr = dma_map_page(device->dev, dest, dest_offset, len, dir);
+		tx->tx_set_dest(addr, tx, 0);
+
+		dir = (flags & ASYNC_TX_ASSUME_COHERENT) ?
+			DMA_NONE : DMA_TO_DEVICE;
+
+		addr = dma_map_page(device->dev, src, src_offset, len, dir);
+		tx->tx_set_src(addr, tx, 0);
+
+		async_tx_submit(chan, tx, flags, depend_tx, cb_fn, cb_param);
+	} else { /* run the memcpy synchronously */
+		void *dest_buf, *src_buf;
+		pr_debug("%s: (sync) len: %zu\n", __FUNCTION__, len);
+
+		/* wait for any prerequisite operations */
+		if (depend_tx) {
+			/* if ack is already set then we cannot be sure
+			 * we are referring to the correct operation
+			 */
+			BUG_ON(depend_tx->ack);
+			if (dma_wait_for_async_tx(depend_tx) == DMA_ERROR)
+				panic("%s: DMA_ERROR waiting for depend_tx\n",
+					__FUNCTION__);
+		}
+
+		if (flags & ASYNC_TX_KMAP_DST)
+			dest_buf = kmap_atomic(dest, KM_USER0) + dest_offset;
+		else
+			dest_buf = page_address(dest) + dest_offset;
+
+		if (flags & ASYNC_TX_KMAP_SRC)
+			src_buf = kmap_atomic(src, KM_USER0) + src_offset;
+		else
+			src_buf = page_address(src) + src_offset;
+
+		memcpy(dest_buf, src_buf, len);
+
+		if (flags & ASYNC_TX_KMAP_DST)
+			kunmap_atomic(dest_buf, KM_USER0);
+
+		if (flags & ASYNC_TX_KMAP_SRC)
+			kunmap_atomic(src_buf, KM_USER0);
+
+		async_tx_sync_epilog(flags, depend_tx, cb_fn, cb_param);
+	}
+
+	return tx;
+}
+EXPORT_SYMBOL_GPL(async_memcpy);
+
+static int __init async_memcpy_init(void)
+{
+	return 0;
+}
+
+static void __exit async_memcpy_exit(void)
+{
+	do { } while (0);
+}
+
+module_init(async_memcpy_init);
+module_exit(async_memcpy_exit);
+
+MODULE_AUTHOR("Intel Corporation");
+MODULE_DESCRIPTION("asynchronous memcpy api");
+MODULE_LICENSE("GPL");