[deliverable/linux.git] / crypto / async_tx / async_xor.c

/*
 * 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>

/* do_async_xor - dma map the pages and perform the xor with an engine */
static __async_inline struct dma_async_tx_descriptor *
do_async_xor(struct dma_chan *chan, struct page *dest, struct page **src_list,
	     unsigned int offset, int src_cnt, size_t len, dma_addr_t *dma_src,
	     struct async_submit_ctl *submit)
{
	struct dma_device *dma = chan->device;
	struct dma_async_tx_descriptor *tx = NULL;
	int src_off = 0;
	int i;
	dma_async_tx_callback cb_fn_orig = submit->cb_fn;
	void *cb_param_orig = submit->cb_param;
	enum async_tx_flags flags_orig = submit->flags;
	enum dma_ctrl_flags dma_flags;
	int xor_src_cnt;
	dma_addr_t dma_dest;

	/* map the dest bidrectional in case it is re-used as a source */
	dma_dest = dma_map_page(dma->dev, dest, offset, len, DMA_BIDIRECTIONAL);
	for (i = 0; i < src_cnt; i++) {
		/* only map the dest once */
		if (unlikely(src_list[i] == dest)) {
			dma_src[i] = dma_dest;
			continue;
		}
		dma_src[i] = dma_map_page(dma->dev, src_list[i], offset,
					  len, DMA_TO_DEVICE);
	}

	while (src_cnt) {
		submit->flags = flags_orig;
		dma_flags = 0;
		xor_src_cnt = min(src_cnt, (int)dma->max_xor);
		/* if we are submitting additional xors, leave the chain open,
		 * clear the callback parameters, and leave the destination
		 * buffer mapped
		 */
		if (src_cnt > xor_src_cnt) {
			submit->flags &= ~ASYNC_TX_ACK;
			dma_flags = DMA_COMPL_SKIP_DEST_UNMAP;
			submit->cb_fn = NULL;
			submit->cb_param = NULL;
		} else {
			submit->cb_fn = cb_fn_orig;
			submit->cb_param = cb_param_orig;
		}
		if (submit->cb_fn)
			dma_flags |= DMA_PREP_INTERRUPT;

		/* Since we have clobbered the src_list we are committed
		 * to doing this asynchronously.  Drivers force forward progress
		 * in case they can not provide a descriptor
		 */
		tx = dma->device_prep_dma_xor(chan, dma_dest, &dma_src[src_off],
					      xor_src_cnt, len, dma_flags);

		if (unlikely(!tx))
			async_tx_quiesce(&submit->depend_tx);

		/* spin wait for the preceeding transactions to complete */
		while (unlikely(!tx)) {
			dma_async_issue_pending(chan);
			tx = dma->device_prep_dma_xor(chan, dma_dest,
						      &dma_src[src_off],
						      xor_src_cnt, len,
						      dma_flags);
		}

		async_tx_submit(chan, tx, submit);
		submit->depend_tx = tx;

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

			/* use the intermediate result a source */
			dma_src[--src_off] = dma_dest;
			src_cnt++;
		} else
			break;
	}

	return tx;
}

static void
do_sync_xor(struct page *dest, struct page **src_list, unsigned int offset,
	    int src_cnt, size_t len, struct async_submit_ctl *submit)
{
	int i;
	int xor_src_cnt;
	int src_off = 0;
	void *dest_buf;
	void **srcs;

	if (submit->scribble)
		srcs = submit->scribble;
	else
		srcs = (void **) src_list;

	/* convert to buffer pointers */
	for (i = 0; i < src_cnt; i++)
		srcs[i] = page_address(src_list[i]) + offset;

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

	if (submit->flags & ASYNC_TX_XOR_ZERO_DST)
		memset(dest_buf, 0, len);

	while (src_cnt > 0) {
		/* process up to 'MAX_XOR_BLOCKS' sources */
		xor_src_cnt = min(src_cnt, MAX_XOR_BLOCKS);
		xor_blocks(xor_src_cnt, len, dest_buf, &srcs[src_off]);

		/* drop completed sources */
		src_cnt -= xor_src_cnt;
		src_off += xor_src_cnt;
	}

	async_tx_sync_epilog(submit);
}

/**
 * async_xor - attempt to xor a set of blocks with a dma engine.
 * @dest: destination page
 * @src_list: array of source pages
 * @offset: common src/dst offset to start transaction
 * @src_cnt: number of source pages
 * @len: length in bytes
 * @submit: submission / completion modifiers
 *
 * honored flags: ASYNC_TX_ACK, ASYNC_TX_XOR_ZERO_DST, ASYNC_TX_XOR_DROP_DST
 *
 * 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.
 *
 * src_list note: if the dest is also a source it must be at index zero.
 * The contents of this array will be overwritten if a scribble region
 * is not specified.
 */
struct dma_async_tx_descriptor *
async_xor(struct page *dest, struct page **src_list, unsigned int offset,
	  int src_cnt, size_t len, struct async_submit_ctl *submit)
{
	struct dma_chan *chan = async_tx_find_channel(submit, DMA_XOR,
						      &dest, 1, src_list,
						      src_cnt, len);
	dma_addr_t *dma_src = NULL;

	BUG_ON(src_cnt <= 1);

	if (submit->scribble)
		dma_src = submit->scribble;
	else if (sizeof(dma_addr_t) <= sizeof(struct page *))
		dma_src = (dma_addr_t *) src_list;

	if (dma_src && chan) {
		/* run the xor asynchronously */
		pr_debug("%s (async): len: %zu\n", __func__, len);

		return do_async_xor(chan, dest, src_list, offset, src_cnt, len,
				    dma_src, submit);
	} else {
		/* run the xor synchronously */
		pr_debug("%s (sync): len: %zu\n", __func__, len);
		WARN_ONCE(chan, "%s: no space for dma address conversion\n",
			  __func__);

		/* in the sync case the dest is an implied source
		 * (assumes the dest is the first source)
		 */
		if (submit->flags & ASYNC_TX_XOR_DROP_DST) {
			src_cnt--;
			src_list++;
		}

		/* wait for any prerequisite operations */
		async_tx_quiesce(&submit->depend_tx);

		do_sync_xor(dest, src_list, offset, src_cnt, len, submit);

		return NULL;
	}
}
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_val - 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
 * @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
 * @submit: submission / completion modifiers
 *
 * honored flags: ASYNC_TX_ACK
 *
 * src_list note: if the dest is also a source it must be at index zero.
 * The contents of this array will be overwritten if a scribble region
 * is not specified.
 */
struct dma_async_tx_descriptor *
async_xor_val(struct page *dest, struct page **src_list, unsigned int offset,
	      int src_cnt, size_t len, enum sum_check_flags *result,
	      struct async_submit_ctl *submit)
{
	struct dma_chan *chan = async_tx_find_channel(submit, DMA_XOR_VAL,
						      &dest, 1, src_list,
						      src_cnt, len);
	struct dma_device *device = chan ? chan->device : NULL;
	struct dma_async_tx_descriptor *tx = NULL;
	dma_addr_t *dma_src = NULL;

	BUG_ON(src_cnt <= 1);

	if (submit->scribble)
		dma_src = submit->scribble;
	else if (sizeof(dma_addr_t) <= sizeof(struct page *))
		dma_src = (dma_addr_t *) src_list;

	if (dma_src && device && src_cnt <= device->max_xor) {
		unsigned long dma_prep_flags;
		int i;

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

		dma_prep_flags = submit->cb_fn ? DMA_PREP_INTERRUPT : 0;
		for (i = 0; i < src_cnt; i++)
			dma_src[i] = dma_map_page(device->dev, src_list[i],
						  offset, len, DMA_TO_DEVICE);

		tx = device->device_prep_dma_xor_val(chan, dma_src, src_cnt,
						     len, result,
						     dma_prep_flags);
		if (unlikely(!tx)) {
			async_tx_quiesce(&submit->depend_tx);

			while (!tx) {
				dma_async_issue_pending(chan);
				tx = device->device_prep_dma_xor_val(chan,
					dma_src, src_cnt, len, result,
					dma_prep_flags);
			}
		}

		async_tx_submit(chan, tx, submit);
	} else {
		enum async_tx_flags flags_orig = submit->flags;

		pr_debug("%s: (sync) len: %zu\n", __func__, len);
		WARN_ONCE(device && src_cnt <= device->max_xor,
			  "%s: no space for dma address conversion\n",
			  __func__);

		submit->flags |= ASYNC_TX_XOR_DROP_DST;
		submit->flags &= ~ASYNC_TX_ACK;

		tx = async_xor(dest, src_list, offset, src_cnt, len, submit);

		async_tx_quiesce(&tx);

		*result = !page_is_zero(dest, offset, len) << SUM_CHECK_P;

		async_tx_sync_epilog(submit);
		submit->flags = flags_orig;
	}

	return tx;
}
EXPORT_SYMBOL_GPL(async_xor_val);

MODULE_AUTHOR("Intel Corporation");
MODULE_DESCRIPTION("asynchronous xor/xor-zero-sum api");
MODULE_LICENSE("GPL");
Commit	Line	Data
9bc89cd8 DW	1	/*
	2	* xor offload engine api
	3	*
	4	* Copyright © 2006, Intel Corporation.
	5	*
	6	* Dan Williams <dan.j.williams@intel.com>
	7	*
	8	* with architecture considerations by:
	9	* Neil Brown <neilb@suse.de>
	10	* Jeff Garzik <jeff@garzik.org>
	11	*
	12	* This program is free software; you can redistribute it and/or modify it
	13	* under the terms and conditions of the GNU General Public License,
	14	* version 2, as published by the Free Software Foundation.
	15	*
	16	* This program is distributed in the hope it will be useful, but WITHOUT
	17	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	18	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	19	* more details.
	20	*
	21	* You should have received a copy of the GNU General Public License along with
	22	* this program; if not, write to the Free Software Foundation, Inc.,
	23	* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
	24	*
	25	*/
	26	#include <linux/kernel.h>
	27	#include <linux/interrupt.h>
	28	#include <linux/mm.h>
	29	#include <linux/dma-mapping.h>
	30	#include <linux/raid/xor.h>
	31	#include <linux/async_tx.h>
	32
06164f31 DW	33	/* do_async_xor - dma map the pages and perform the xor with an engine */
06164f31 DW	34	static __async_inline struct dma_async_tx_descriptor *
1e55db2d	35	do_async_xor(struct dma_chan chan, struct page dest, struct page **src_list,
04ce9ab3	36	unsigned int offset, int src_cnt, size_t len, dma_addr_t *dma_src,
a08abd8c	37	struct async_submit_ctl *submit)
9bc89cd8	38	{
1e55db2d	39	struct dma_device *dma = chan->device;
1e55db2d DW	40	struct dma_async_tx_descriptor *tx = NULL;
1e55db2d DW	41	int src_off = 0;
9bc89cd8	42	int i;
a08abd8c DW	43	dma_async_tx_callback cb_fn_orig = submit->cb_fn;
	44	void *cb_param_orig = submit->cb_param;
	45	enum async_tx_flags flags_orig = submit->flags;
1e55db2d DW	46	enum dma_ctrl_flags dma_flags;
	47	int xor_src_cnt;
	48	dma_addr_t dma_dest;
9bc89cd8	49
a06d568f DW	50	/* map the dest bidrectional in case it is re-used as a source */
	51	dma_dest = dma_map_page(dma->dev, dest, offset, len, DMA_BIDIRECTIONAL);
	52	for (i = 0; i < src_cnt; i++) {
	53	/* only map the dest once */
	54	if (unlikely(src_list[i] == dest)) {
	55	dma_src[i] = dma_dest;
	56	continue;
	57	}
1e55db2d	58	dma_src[i] = dma_map_page(dma->dev, src_list[i], offset,
0036731c	59	len, DMA_TO_DEVICE);
a06d568f	60	}
0036731c	61
1e55db2d	62	while (src_cnt) {
a08abd8c	63	submit->flags = flags_orig;
1e55db2d	64	dma_flags = 0;
b2f46fd8	65	xor_src_cnt = min(src_cnt, (int)dma->max_xor);
1e55db2d DW	66	/* if we are submitting additional xors, leave the chain open,
	67	* clear the callback parameters, and leave the destination
	68	* buffer mapped
	69	*/
	70	if (src_cnt > xor_src_cnt) {
a08abd8c	71	submit->flags &= ~ASYNC_TX_ACK;
1e55db2d	72	dma_flags = DMA_COMPL_SKIP_DEST_UNMAP;
a08abd8c DW	73	submit->cb_fn = NULL;
a08abd8c DW	74	submit->cb_param = NULL;
1e55db2d	75	} else {
a08abd8c DW	76	submit->cb_fn = cb_fn_orig;
a08abd8c DW	77	submit->cb_param = cb_param_orig;
1e55db2d	78	}
a08abd8c	79	if (submit->cb_fn)
1e55db2d DW	80	dma_flags \|= DMA_PREP_INTERRUPT;
	81
	82	/* Since we have clobbered the src_list we are committed
	83	* to doing this asynchronously. Drivers force forward progress
	84	* in case they can not provide a descriptor
	85	*/
	86	tx = dma->device_prep_dma_xor(chan, dma_dest, &dma_src[src_off],
	87	xor_src_cnt, len, dma_flags);
	88
669ab0b2	89	if (unlikely(!tx))
a08abd8c	90	async_tx_quiesce(&submit->depend_tx);
0036731c	91
1e55db2d	92	/* spin wait for the preceeding transactions to complete */
669ab0b2 DW	93	while (unlikely(!tx)) {
669ab0b2 DW	94	dma_async_issue_pending(chan);
1e55db2d DW	95	tx = dma->device_prep_dma_xor(chan, dma_dest,
	96	&dma_src[src_off],
	97	xor_src_cnt, len,
	98	dma_flags);
669ab0b2	99	}
9bc89cd8	100
a08abd8c DW	101	async_tx_submit(chan, tx, submit);
a08abd8c DW	102	submit->depend_tx = tx;
1e55db2d DW	103
	104	if (src_cnt > xor_src_cnt) {
	105	/* drop completed sources */
	106	src_cnt -= xor_src_cnt;
	107	src_off += xor_src_cnt;
	108
	109	/* use the intermediate result a source */
	110	dma_src[--src_off] = dma_dest;
	111	src_cnt++;
	112	} else
	113	break;
	114	}
0036731c DW	115
0036731c DW	116	return tx;
9bc89cd8 DW	117	}
	118
	119	static void
	120	do_sync_xor(struct page dest, struct page *src_list, unsigned int offset,
a08abd8c	121	int src_cnt, size_t len, struct async_submit_ctl *submit)
9bc89cd8	122	{
9bc89cd8	123	int i;
1e55db2d DW	124	int xor_src_cnt;
	125	int src_off = 0;
	126	void *dest_buf;
04ce9ab3	127	void **srcs;
9bc89cd8	128
04ce9ab3 DW	129	if (submit->scribble)
	130	srcs = submit->scribble;
	131	else
	132	srcs = (void **) src_list;
	133
	134	/* convert to buffer pointers */
9bc89cd8	135	for (i = 0; i < src_cnt; i++)
1e55db2d	136	srcs[i] = page_address(src_list[i]) + offset;
9bc89cd8 DW	137
9bc89cd8 DW	138	/* set destination address */
1e55db2d	139	dest_buf = page_address(dest) + offset;
9bc89cd8	140
a08abd8c	141	if (submit->flags & ASYNC_TX_XOR_ZERO_DST)
1e55db2d	142	memset(dest_buf, 0, len);
9bc89cd8	143
1e55db2d DW	144	while (src_cnt > 0) {
	145	/* process up to 'MAX_XOR_BLOCKS' sources */
	146	xor_src_cnt = min(src_cnt, MAX_XOR_BLOCKS);
	147	xor_blocks(xor_src_cnt, len, dest_buf, &srcs[src_off]);
	148
	149	/* drop completed sources */
	150	src_cnt -= xor_src_cnt;
	151	src_off += xor_src_cnt;
	152	}
9bc89cd8	153
a08abd8c	154	async_tx_sync_epilog(submit);
9bc89cd8 DW	155	}
	156
	157	/**
	158	* async_xor - attempt to xor a set of blocks with a dma engine.
9bc89cd8	159	* @dest: destination page
a08abd8c DW	160	* @src_list: array of source pages
a08abd8c DW	161	* @offset: common src/dst offset to start transaction
9bc89cd8 DW	162	* @src_cnt: number of source pages
9bc89cd8 DW	163	* @len: length in bytes
a08abd8c DW	164	* @submit: submission / completion modifiers
	165	*
	166	* honored flags: ASYNC_TX_ACK, ASYNC_TX_XOR_ZERO_DST, ASYNC_TX_XOR_DROP_DST
	167	*
	168	* xor_blocks always uses the dest as a source so the
	169	* ASYNC_TX_XOR_ZERO_DST flag must be set to not include dest data in
	170	* the calculation. The assumption with dma eninges is that they only
	171	* use the destination buffer as a source when it is explicity specified
	172	* in the source list.
	173	*
	174	* src_list note: if the dest is also a source it must be at index zero.
	175	* The contents of this array will be overwritten if a scribble region
	176	* is not specified.
9bc89cd8 DW	177	*/
	178	struct dma_async_tx_descriptor *
	179	async_xor(struct page dest, struct page *src_list, unsigned int offset,
a08abd8c	180	int src_cnt, size_t len, struct async_submit_ctl *submit)
9bc89cd8	181	{
a08abd8c	182	struct dma_chan *chan = async_tx_find_channel(submit, DMA_XOR,
47437b2c DW	183	&dest, 1, src_list,
47437b2c DW	184	src_cnt, len);
04ce9ab3 DW	185	dma_addr_t *dma_src = NULL;
04ce9ab3 DW	186
9bc89cd8 DW	187	BUG_ON(src_cnt <= 1);
9bc89cd8 DW	188
04ce9ab3 DW	189	if (submit->scribble)
	190	dma_src = submit->scribble;
	191	else if (sizeof(dma_addr_t) <= sizeof(struct page *))
	192	dma_src = (dma_addr_t *) src_list;
	193
	194	if (dma_src && chan) {
1e55db2d DW	195	/* run the xor asynchronously */
1e55db2d DW	196	pr_debug("%s (async): len: %zu\n", __func__, len);
9bc89cd8	197
1e55db2d	198	return do_async_xor(chan, dest, src_list, offset, src_cnt, len,
04ce9ab3	199	dma_src, submit);
1e55db2d DW	200	} else {
	201	/* run the xor synchronously */
	202	pr_debug("%s (sync): len: %zu\n", __func__, len);
04ce9ab3 DW	203	WARN_ONCE(chan, "%s: no space for dma address conversion\n",
04ce9ab3 DW	204	__func__);
9bc89cd8	205
1e55db2d DW	206	/* in the sync case the dest is an implied source
1e55db2d DW	207	* (assumes the dest is the first source)
9bc89cd8	208	*/
a08abd8c	209	if (submit->flags & ASYNC_TX_XOR_DROP_DST) {
1e55db2d DW	210	src_cnt--;
	211	src_list++;
	212	}
9bc89cd8	213
1e55db2d	214	/* wait for any prerequisite operations */
a08abd8c	215	async_tx_quiesce(&submit->depend_tx);
9bc89cd8	216
a08abd8c	217	do_sync_xor(dest, src_list, offset, src_cnt, len, submit);
9bc89cd8	218
1e55db2d	219	return NULL;
9bc89cd8	220	}
9bc89cd8 DW	221	}
	222	EXPORT_SYMBOL_GPL(async_xor);
	223
	224	static int page_is_zero(struct page *p, unsigned int offset, size_t len)
	225	{
	226	char *a = page_address(p) + offset;
	227	return (((u32 ) a) == 0 &&
	228	memcmp(a, a + 4, len - 4) == 0);
	229	}
	230
	231	/**
099f53cb	232	* async_xor_val - attempt a xor parity check with a dma engine.
9bc89cd8	233	* @dest: destination page used if the xor is performed synchronously
a08abd8c	234	* @src_list: array of source pages
9bc89cd8 DW	235	* @offset: offset in pages to start transaction
	236	* @src_cnt: number of source pages
	237	* @len: length in bytes
	238	* @result: 0 if sum == 0 else non-zero
a08abd8c DW	239	* @submit: submission / completion modifiers
	240	*
	241	* honored flags: ASYNC_TX_ACK
	242	*
	243	* src_list note: if the dest is also a source it must be at index zero.
	244	* The contents of this array will be overwritten if a scribble region
	245	* is not specified.
9bc89cd8 DW	246	*/
9bc89cd8 DW	247	struct dma_async_tx_descriptor *
a08abd8c	248	async_xor_val(struct page dest, struct page *src_list, unsigned int offset,
ad283ea4	249	int src_cnt, size_t len, enum sum_check_flags *result,
a08abd8c	250	struct async_submit_ctl *submit)
9bc89cd8	251	{
a08abd8c	252	struct dma_chan *chan = async_tx_find_channel(submit, DMA_XOR_VAL,
47437b2c DW	253	&dest, 1, src_list,
47437b2c DW	254	src_cnt, len);
9bc89cd8	255	struct dma_device *device = chan ? chan->device : NULL;
0036731c	256	struct dma_async_tx_descriptor *tx = NULL;
04ce9ab3	257	dma_addr_t *dma_src = NULL;
9bc89cd8 DW	258
	259	BUG_ON(src_cnt <= 1);
	260
04ce9ab3 DW	261	if (submit->scribble)
	262	dma_src = submit->scribble;
	263	else if (sizeof(dma_addr_t) <= sizeof(struct page *))
	264	dma_src = (dma_addr_t *) src_list;
	265
	266	if (dma_src && device && src_cnt <= device->max_xor) {
a08abd8c	267	unsigned long dma_prep_flags;
0036731c	268	int i;
9bc89cd8	269
3280ab3e	270	pr_debug("%s: (async) len: %zu\n", __func__, len);
9bc89cd8	271
a08abd8c	272	dma_prep_flags = submit->cb_fn ? DMA_PREP_INTERRUPT : 0;
0036731c DW	273	for (i = 0; i < src_cnt; i++)
	274	dma_src[i] = dma_map_page(device->dev, src_list[i],
	275	offset, len, DMA_TO_DEVICE);
	276
099f53cb DW	277	tx = device->device_prep_dma_xor_val(chan, dma_src, src_cnt,
	278	len, result,
	279	dma_prep_flags);
669ab0b2	280	if (unlikely(!tx)) {
a08abd8c	281	async_tx_quiesce(&submit->depend_tx);
0036731c	282
e34a8ae7	283	while (!tx) {
669ab0b2	284	dma_async_issue_pending(chan);
099f53cb	285	tx = device->device_prep_dma_xor_val(chan,
0036731c	286	dma_src, src_cnt, len, result,
d4c56f97	287	dma_prep_flags);
e34a8ae7	288	}
9bc89cd8 DW	289	}
9bc89cd8 DW	290
a08abd8c	291	async_tx_submit(chan, tx, submit);
9bc89cd8	292	} else {
a08abd8c	293	enum async_tx_flags flags_orig = submit->flags;
9bc89cd8	294
3280ab3e	295	pr_debug("%s: (sync) len: %zu\n", __func__, len);
04ce9ab3 DW	296	WARN_ONCE(device && src_cnt <= device->max_xor,
	297	"%s: no space for dma address conversion\n",
	298	__func__);
9bc89cd8	299
a08abd8c DW	300	submit->flags \|= ASYNC_TX_XOR_DROP_DST;
a08abd8c DW	301	submit->flags &= ~ASYNC_TX_ACK;
9bc89cd8	302
a08abd8c	303	tx = async_xor(dest, src_list, offset, src_cnt, len, submit);
9bc89cd8	304
d2c52b79	305	async_tx_quiesce(&tx);
9bc89cd8	306
ad283ea4	307	*result = !page_is_zero(dest, offset, len) << SUM_CHECK_P;
9bc89cd8	308
a08abd8c DW	309	async_tx_sync_epilog(submit);
a08abd8c DW	310	submit->flags = flags_orig;
9bc89cd8 DW	311	}
	312
	313	return tx;
	314	}
099f53cb	315	EXPORT_SYMBOL_GPL(async_xor_val);
9bc89cd8	316
9bc89cd8 DW	317	MODULE_AUTHOR("Intel Corporation");
	318	MODULE_DESCRIPTION("asynchronous xor/xor-zero-sum api");
	319	MODULE_LICENSE("GPL");