crypto/async_tx/async_xor.c - kernel/msm - Gitiles

 /*
  * xor offload engine api
  *
  * 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/interrupt.h>
 #include <linux/mm.h>
 #include <linux/dma-mapping.h>
 #include <linux/raid/xor.h>
 #include <linux/async_tx.h>

 static void
 do_async_xor(struct dma_async_tx_descriptor *tx, struct dma_device *device,
 	struct dma_chan *chan, struct page *dest, struct page **src_list,
 	unsigned int offset, unsigned int src_cnt, size_t len,
 	enum async_tx_flags flags, struct dma_async_tx_descriptor *depend_tx,
 	dma_async_tx_callback cb_fn, void *cb_param)
 {
 	dma_addr_t dma_addr;
 	enum dma_data_direction dir;
 	int i;

 	pr_debug("%s: len: %zu\n", __FUNCTION__, len);

 	dir = (flags & ASYNC_TX_ASSUME_COHERENT) ?
 		DMA_NONE : DMA_FROM_DEVICE;

 	dma_addr = dma_map_page(device->dev, dest, offset, len, dir);
 	tx->tx_set_dest(dma_addr, tx, 0);

 	dir = (flags & ASYNC_TX_ASSUME_COHERENT) ?
 		DMA_NONE : DMA_TO_DEVICE;

 	for (i = 0; i < src_cnt; i++) {
 		dma_addr = dma_map_page(device->dev, src_list[i],
 			offset, len, dir);
 		tx->tx_set_src(dma_addr, tx, i);
 	}

 	async_tx_submit(chan, tx, flags, depend_tx, cb_fn, cb_param);
 }

 static void
 do_sync_xor(struct page *dest, struct page **src_list, unsigned int offset,
 	unsigned int src_cnt, size_t len, enum async_tx_flags flags,
 	struct dma_async_tx_descriptor *depend_tx,
 	dma_async_tx_callback cb_fn, void *cb_param)
 {
 	void *_dest;
 	int i;

 	pr_debug("%s: len: %zu\n", __FUNCTION__, len);

 	/* reuse the 'src_list' array to convert to buffer pointers */
 	for (i = 0; i < src_cnt; i++)
 		src_list[i] = (struct page *)
 			(page_address(src_list[i]) + offset);

 	/* set destination address */
 	_dest = page_address(dest) + offset;

 	if (flags & ASYNC_TX_XOR_ZERO_DST)
 		memset(_dest, 0, len);

 	xor_blocks(src_cnt, len, _dest,
 		(void **) src_list);

 	async_tx_sync_epilog(flags, depend_tx, cb_fn, cb_param);
 }

 /**
  * async_xor - attempt to xor a set of blocks with a dma engine.
  *	xor_blocks always uses the dest as a source so the ASYNC_TX_XOR_ZERO_DST
  *	flag must be set to not include dest data in the calculation.  The
  *	assumption with dma eninges is that they only use the destination
  *	buffer as a source when it is explicity specified in the source list.
  * @dest: destination page
  * @src_list: array of source pages (if the dest is also a source it must be
  *	at index zero).  The contents of this array may be overwritten.
  * @offset: offset in pages to start transaction
  * @src_cnt: number of source pages
  * @len: length in bytes
  * @flags: ASYNC_TX_XOR_ZERO_DST, ASYNC_TX_XOR_DROP_DEST,
  *	ASYNC_TX_ASSUME_COHERENT, ASYNC_TX_ACK, ASYNC_TX_DEP_ACK
  * @depend_tx: xor depends on the result of this transaction.
  * @cb_fn: function to call when the xor completes
  * @cb_param: parameter to pass to the callback routine
  */
 struct dma_async_tx_descriptor *
 async_xor(struct page *dest, struct page **src_list, unsigned int offset,
 	int src_cnt, 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_XOR);
 	struct dma_device *device = chan ? chan->device : NULL;
 	struct dma_async_tx_descriptor *tx = NULL;
 	dma_async_tx_callback _cb_fn;
 	void *_cb_param;
 	unsigned long local_flags;
 	int xor_src_cnt;
 	int i = 0, src_off = 0, int_en;

 	BUG_ON(src_cnt <= 1);

 	while (src_cnt) {
 		local_flags = flags;
 		if (device) { /* run the xor asynchronously */
 			xor_src_cnt = min(src_cnt, device->max_xor);
 			/* if we are submitting additional xors
 			 * only set the callback on the last transaction
 			 */
 			if (src_cnt > xor_src_cnt) {
 				local_flags &= ~ASYNC_TX_ACK;
 				_cb_fn = NULL;
 				_cb_param = NULL;
 			} else {
 				_cb_fn = cb_fn;
 				_cb_param = cb_param;
 			}

 			int_en = _cb_fn ? 1 : 0;

 			tx = device->device_prep_dma_xor(
 				chan, xor_src_cnt, len, int_en);

 			if (tx) {
 				do_async_xor(tx, device, chan, dest,
 				&src_list[src_off], offset, xor_src_cnt, len,
 				local_flags, depend_tx, _cb_fn,
 				_cb_param);
 			} else /* fall through */
 				goto xor_sync;
 		} else { /* run the xor synchronously */
 xor_sync:
 			/* in the sync case the dest is an implied source
 			 * (assumes the dest is at the src_off index)
 			 */
 			if (flags & ASYNC_TX_XOR_DROP_DST) {
 				src_cnt--;
 				src_off++;
 			}

 			/* process up to 'MAX_XOR_BLOCKS' sources */
 			xor_src_cnt = min(src_cnt, MAX_XOR_BLOCKS);

 			/* if we are submitting additional xors
 			 * only set the callback on the last transaction
 			 */
 			if (src_cnt > xor_src_cnt) {
 				local_flags &= ~ASYNC_TX_ACK;
 				_cb_fn = NULL;
 				_cb_param = NULL;
 			} else {
 				_cb_fn = cb_fn;
 				_cb_param = cb_param;
 			}

 			/* 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__);
 			}

 			do_sync_xor(dest, &src_list[src_off], offset,
 				xor_src_cnt, len, local_flags, depend_tx,
 				_cb_fn, _cb_param);
 		}

 		/* the previous tx is hidden from the client,
 		 * so ack it
 		 */
 		if (i && depend_tx)
 			async_tx_ack(depend_tx);

 		depend_tx = tx;

 		if (src_cnt > xor_src_cnt) {
 			/* drop completed sources */
 			src_cnt -= xor_src_cnt;
 			src_off += xor_src_cnt;

 			/* unconditionally preserve the destination */
 			flags &= ~ASYNC_TX_XOR_ZERO_DST;

 			/* use the intermediate result a source, but remember
 			 * it's dropped, because it's implied, in the sync case
 			 */
 			src_list[--src_off] = dest;
 			src_cnt++;
 			flags |= ASYNC_TX_XOR_DROP_DST;
 		} else
 			src_cnt = 0;
 		i++;
 	}

 	return tx;
 }
 EXPORT_SYMBOL_GPL(async_xor);

 static int page_is_zero(struct page *p, unsigned int offset, size_t len)
 {
 	char *a = page_address(p) + offset;
 	return ((*(u32 *) a) == 0 &&
 		memcmp(a, a + 4, len - 4) == 0);
 }

 /**
  * async_xor_zero_sum - attempt a xor parity check with a dma engine.
  * @dest: destination page used if the xor is performed synchronously
  * @src_list: array of source pages.  The dest page must be listed as a source
  * 	at index zero.  The contents of this array may be overwritten.
  * @offset: offset in pages to start transaction
  * @src_cnt: number of source pages
  * @len: length in bytes
  * @result: 0 if sum == 0 else non-zero
  * @flags: ASYNC_TX_ASSUME_COHERENT, ASYNC_TX_ACK, ASYNC_TX_DEP_ACK
  * @depend_tx: xor depends on the result of this transaction.
  * @cb_fn: function to call when the xor completes
  * @cb_param: parameter to pass to the callback routine
  */
 struct dma_async_tx_descriptor *
 async_xor_zero_sum(struct page *dest, struct page **src_list,
 	unsigned int offset, int src_cnt, size_t len,
 	u32 *result, 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_ZERO_SUM);
 	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_zero_sum(chan, src_cnt, len, result,
 			int_en) : NULL;
 	int i;

 	BUG_ON(src_cnt <= 1);

 	if (tx) {
 		dma_addr_t dma_addr;
 		enum dma_data_direction dir;

 		pr_debug("%s: (async) len: %zu\n", __FUNCTION__, len);

 		dir = (flags & ASYNC_TX_ASSUME_COHERENT) ?
 			DMA_NONE : DMA_TO_DEVICE;

 		for (i = 0; i < src_cnt; i++) {
 			dma_addr = dma_map_page(device->dev, src_list[i],
 				offset, len, dir);
 			tx->tx_set_src(dma_addr, tx, i);
 		}

 		async_tx_submit(chan, tx, flags, depend_tx, cb_fn, cb_param);
 	} else {
 		unsigned long xor_flags = flags;

 		pr_debug("%s: (sync) len: %zu\n", __FUNCTION__, len);

 		xor_flags |= ASYNC_TX_XOR_DROP_DST;
 		xor_flags &= ~ASYNC_TX_ACK;

 		tx = async_xor(dest, src_list, offset, src_cnt, len, xor_flags,
 			depend_tx, NULL, NULL);

 		if (tx) {
 			if (dma_wait_for_async_tx(tx) == DMA_ERROR)
 				panic("%s: DMA_ERROR waiting for tx\n",
 					__FUNCTION__);
 			async_tx_ack(tx);
 		}

 		*result = page_is_zero(dest, offset, len) ? 0 : 1;

 		tx = NULL;

 		async_tx_sync_epilog(flags, depend_tx, cb_fn, cb_param);
 	}

 	return tx;
 }
 EXPORT_SYMBOL_GPL(async_xor_zero_sum);

 static int __init async_xor_init(void)
 {
 	return 0;
 }

 static void __exit async_xor_exit(void)
 {
 	do { } while (0);
 }

 module_init(async_xor_init);
 module_exit(async_xor_exit);

 MODULE_AUTHOR("Intel Corporation");
 MODULE_DESCRIPTION("asynchronous xor/xor-zero-sum api");
 MODULE_LICENSE("GPL");
	/*
	* xor offload engine api
	*
	* 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/interrupt.h>
	#include <linux/mm.h>
	#include <linux/dma-mapping.h>
	#include <linux/raid/xor.h>
	#include <linux/async_tx.h>

	static void
	do_async_xor(struct dma_async_tx_descriptor tx, struct dma_device device,
	struct dma_chan chan, struct page dest, struct page **src_list,
	unsigned int offset, unsigned int src_cnt, size_t len,
	enum async_tx_flags flags, struct dma_async_tx_descriptor *depend_tx,
	dma_async_tx_callback cb_fn, void *cb_param)
	{
	dma_addr_t dma_addr;
	enum dma_data_direction dir;
	int i;

	pr_debug("%s: len: %zu\n", __FUNCTION__, len);

	dir = (flags & ASYNC_TX_ASSUME_COHERENT) ?
	DMA_NONE : DMA_FROM_DEVICE;

	dma_addr = dma_map_page(device->dev, dest, offset, len, dir);
	tx->tx_set_dest(dma_addr, tx, 0);

	dir = (flags & ASYNC_TX_ASSUME_COHERENT) ?
	DMA_NONE : DMA_TO_DEVICE;

	for (i = 0; i < src_cnt; i++) {
	dma_addr = dma_map_page(device->dev, src_list[i],
	offset, len, dir);
	tx->tx_set_src(dma_addr, tx, i);
	}

	async_tx_submit(chan, tx, flags, depend_tx, cb_fn, cb_param);
	}

	static void
	do_sync_xor(struct page dest, struct page *src_list, unsigned int offset,
	unsigned int src_cnt, size_t len, enum async_tx_flags flags,
	struct dma_async_tx_descriptor *depend_tx,
	dma_async_tx_callback cb_fn, void *cb_param)
	{
	void *_dest;
	int i;

	pr_debug("%s: len: %zu\n", __FUNCTION__, len);

	/* reuse the 'src_list' array to convert to buffer pointers */
	for (i = 0; i < src_cnt; i++)
	src_list[i] = (struct page *)
	(page_address(src_list[i]) + offset);

	/* set destination address */
	_dest = page_address(dest) + offset;

	if (flags & ASYNC_TX_XOR_ZERO_DST)
	memset(_dest, 0, len);

	xor_blocks(src_cnt, len, _dest,
	(void **) src_list);

	async_tx_sync_epilog(flags, depend_tx, cb_fn, cb_param);
	}

	/**
	* async_xor - attempt to xor a set of blocks with a dma engine.
	* xor_blocks always uses the dest as a source so the ASYNC_TX_XOR_ZERO_DST
	* flag must be set to not include dest data in the calculation. The
	* assumption with dma eninges is that they only use the destination
	* buffer as a source when it is explicity specified in the source list.
	* @dest: destination page
	* @src_list: array of source pages (if the dest is also a source it must be
	* at index zero). The contents of this array may be overwritten.
	* @offset: offset in pages to start transaction
	* @src_cnt: number of source pages
	* @len: length in bytes
	* @flags: ASYNC_TX_XOR_ZERO_DST, ASYNC_TX_XOR_DROP_DEST,
	* ASYNC_TX_ASSUME_COHERENT, ASYNC_TX_ACK, ASYNC_TX_DEP_ACK
	* @depend_tx: xor depends on the result of this transaction.
	* @cb_fn: function to call when the xor completes
	* @cb_param: parameter to pass to the callback routine
	*/
	struct dma_async_tx_descriptor *
	async_xor(struct page dest, struct page *src_list, unsigned int offset,
	int src_cnt, 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_XOR);
	struct dma_device *device = chan ? chan->device : NULL;
	struct dma_async_tx_descriptor *tx = NULL;
	dma_async_tx_callback _cb_fn;
	void *_cb_param;
	unsigned long local_flags;
	int xor_src_cnt;
	int i = 0, src_off = 0, int_en;

	BUG_ON(src_cnt <= 1);

	while (src_cnt) {
	local_flags = flags;
	if (device) { /* run the xor asynchronously */
	xor_src_cnt = min(src_cnt, device->max_xor);
	/* if we are submitting additional xors
	* only set the callback on the last transaction
	*/
	if (src_cnt > xor_src_cnt) {
	local_flags &= ~ASYNC_TX_ACK;
	_cb_fn = NULL;
	_cb_param = NULL;
	} else {
	_cb_fn = cb_fn;
	_cb_param = cb_param;
	}

	int_en = _cb_fn ? 1 : 0;

	tx = device->device_prep_dma_xor(
	chan, xor_src_cnt, len, int_en);

	if (tx) {
	do_async_xor(tx, device, chan, dest,
	&src_list[src_off], offset, xor_src_cnt, len,
	local_flags, depend_tx, _cb_fn,
	_cb_param);
	} else /* fall through */
	goto xor_sync;
	} else { /* run the xor synchronously */
	xor_sync:
	/* in the sync case the dest is an implied source
	* (assumes the dest is at the src_off index)
	*/
	if (flags & ASYNC_TX_XOR_DROP_DST) {
	src_cnt--;
	src_off++;
	}

	/* process up to 'MAX_XOR_BLOCKS' sources */
	xor_src_cnt = min(src_cnt, MAX_XOR_BLOCKS);

	/* if we are submitting additional xors
	* only set the callback on the last transaction
	*/
	if (src_cnt > xor_src_cnt) {
	local_flags &= ~ASYNC_TX_ACK;
	_cb_fn = NULL;
	_cb_param = NULL;
	} else {
	_cb_fn = cb_fn;
	_cb_param = cb_param;
	}

	/* 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__);
	}

	do_sync_xor(dest, &src_list[src_off], offset,
	xor_src_cnt, len, local_flags, depend_tx,
	_cb_fn, _cb_param);
	}

	/* the previous tx is hidden from the client,
	* so ack it
	*/
	if (i && depend_tx)
	async_tx_ack(depend_tx);

	depend_tx = tx;

	if (src_cnt > xor_src_cnt) {
	/* drop completed sources */
	src_cnt -= xor_src_cnt;
	src_off += xor_src_cnt;

	/* unconditionally preserve the destination */
	flags &= ~ASYNC_TX_XOR_ZERO_DST;

	/* use the intermediate result a source, but remember
	* it's dropped, because it's implied, in the sync case
	*/
	src_list[--src_off] = dest;
	src_cnt++;
	flags \|= ASYNC_TX_XOR_DROP_DST;
	} else
	src_cnt = 0;
	i++;
	}

	return tx;
	}
	EXPORT_SYMBOL_GPL(async_xor);

	static int page_is_zero(struct page *p, unsigned int offset, size_t len)
	{
	char *a = page_address(p) + offset;
	return (((u32 ) a) == 0 &&
	memcmp(a, a + 4, len - 4) == 0);
	}

	/**
	* async_xor_zero_sum - attempt a xor parity check with a dma engine.
	* @dest: destination page used if the xor is performed synchronously
	* @src_list: array of source pages. The dest page must be listed as a source
	* at index zero. The contents of this array may be overwritten.
	* @offset: offset in pages to start transaction
	* @src_cnt: number of source pages
	* @len: length in bytes
	* @result: 0 if sum == 0 else non-zero
	* @flags: ASYNC_TX_ASSUME_COHERENT, ASYNC_TX_ACK, ASYNC_TX_DEP_ACK
	* @depend_tx: xor depends on the result of this transaction.
	* @cb_fn: function to call when the xor completes
	* @cb_param: parameter to pass to the callback routine
	*/
	struct dma_async_tx_descriptor *
	async_xor_zero_sum(struct page dest, struct page *src_list,
	unsigned int offset, int src_cnt, size_t len,
	u32 *result, 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_ZERO_SUM);
	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_zero_sum(chan, src_cnt, len, result,
	int_en) : NULL;
	int i;

	BUG_ON(src_cnt <= 1);

	if (tx) {
	dma_addr_t dma_addr;
	enum dma_data_direction dir;

	pr_debug("%s: (async) len: %zu\n", __FUNCTION__, len);

	dir = (flags & ASYNC_TX_ASSUME_COHERENT) ?
	DMA_NONE : DMA_TO_DEVICE;

	for (i = 0; i < src_cnt; i++) {
	dma_addr = dma_map_page(device->dev, src_list[i],
	offset, len, dir);
	tx->tx_set_src(dma_addr, tx, i);
	}

	async_tx_submit(chan, tx, flags, depend_tx, cb_fn, cb_param);
	} else {
	unsigned long xor_flags = flags;

	pr_debug("%s: (sync) len: %zu\n", __FUNCTION__, len);

	xor_flags \|= ASYNC_TX_XOR_DROP_DST;
	xor_flags &= ~ASYNC_TX_ACK;

	tx = async_xor(dest, src_list, offset, src_cnt, len, xor_flags,
	depend_tx, NULL, NULL);

	if (tx) {
	if (dma_wait_for_async_tx(tx) == DMA_ERROR)
	panic("%s: DMA_ERROR waiting for tx\n",
	__FUNCTION__);
	async_tx_ack(tx);
	}

	*result = page_is_zero(dest, offset, len) ? 0 : 1;

	tx = NULL;

	async_tx_sync_epilog(flags, depend_tx, cb_fn, cb_param);
	}

	return tx;
	}
	EXPORT_SYMBOL_GPL(async_xor_zero_sum);

	static int __init async_xor_init(void)
	{
	return 0;
	}

	static void __exit async_xor_exit(void)
	{
	do { } while (0);
	}

	module_init(async_xor_init);
	module_exit(async_xor_exit);

	MODULE_AUTHOR("Intel Corporation");
	MODULE_DESCRIPTION("asynchronous xor/xor-zero-sum api");
	MODULE_LICENSE("GPL");