[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.
 * 	This routine is marked __always_inline so it can be compiled away
 * 	when CONFIG_DMA_ENGINE=n
 */
static __always_inline 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");
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
1367a3d3 DW	33	/* do_async_xor - dma map the pages and perform the xor with an engine.
	34	* This routine is marked __always_inline so it can be compiled away
	35	* when CONFIG_DMA_ENGINE=n
	36	*/
	37	static __always_inline void
9bc89cd8 DW	38	do_async_xor(struct dma_async_tx_descriptor tx, struct dma_device device,
	39	struct dma_chan chan, struct page dest, struct page **src_list,
	40	unsigned int offset, unsigned int src_cnt, size_t len,
	41	enum async_tx_flags flags, struct dma_async_tx_descriptor *depend_tx,
	42	dma_async_tx_callback cb_fn, void *cb_param)
	43	{
	44	dma_addr_t dma_addr;
	45	enum dma_data_direction dir;
	46	int i;
	47
	48	pr_debug("%s: len: %zu\n", __FUNCTION__, len);
	49
	50	dir = (flags & ASYNC_TX_ASSUME_COHERENT) ?
	51	DMA_NONE : DMA_FROM_DEVICE;
	52
	53	dma_addr = dma_map_page(device->dev, dest, offset, len, dir);
	54	tx->tx_set_dest(dma_addr, tx, 0);
	55
	56	dir = (flags & ASYNC_TX_ASSUME_COHERENT) ?
	57	DMA_NONE : DMA_TO_DEVICE;
	58
	59	for (i = 0; i < src_cnt; i++) {
	60	dma_addr = dma_map_page(device->dev, src_list[i],
	61	offset, len, dir);
	62	tx->tx_set_src(dma_addr, tx, i);
	63	}
	64
	65	async_tx_submit(chan, tx, flags, depend_tx, cb_fn, cb_param);
	66	}
	67
	68	static void
	69	do_sync_xor(struct page dest, struct page *src_list, unsigned int offset,
	70	unsigned int src_cnt, size_t len, enum async_tx_flags flags,
	71	struct dma_async_tx_descriptor *depend_tx,
	72	dma_async_tx_callback cb_fn, void *cb_param)
	73	{
	74	void *_dest;
	75	int i;
	76
	77	pr_debug("%s: len: %zu\n", __FUNCTION__, len);
	78
	79	/* reuse the 'src_list' array to convert to buffer pointers */
	80	for (i = 0; i < src_cnt; i++)
	81	src_list[i] = (struct page *)
	82	(page_address(src_list[i]) + offset);
	83
	84	/* set destination address */
	85	_dest = page_address(dest) + offset;
	86
	87	if (flags & ASYNC_TX_XOR_ZERO_DST)
	88	memset(_dest, 0, len);
	89
	90	xor_blocks(src_cnt, len, _dest,
	91	(void **) src_list);
	92
	93	async_tx_sync_epilog(flags, depend_tx, cb_fn, cb_param);
	94	}
	95
	96	/**
	97	* async_xor - attempt to xor a set of blocks with a dma engine.
	98	* xor_blocks always uses the dest as a source so the ASYNC_TX_XOR_ZERO_DST
	99	* flag must be set to not include dest data in the calculation. The
	100	* assumption with dma eninges is that they only use the destination
	101	* buffer as a source when it is explicity specified in the source list.
102	* @dest: destination page
103	* @src_list: array of source pages (if the dest is also a source it must be
104	* at index zero). The contents of this array may be overwritten.
105	* @offset: offset in pages to start transaction
106	* @src_cnt: number of source pages
107	* @len: length in bytes
108	* @flags: ASYNC_TX_XOR_ZERO_DST, ASYNC_TX_XOR_DROP_DEST,
109	* ASYNC_TX_ASSUME_COHERENT, ASYNC_TX_ACK, ASYNC_TX_DEP_ACK
110	* @depend_tx: xor depends on the result of this transaction.
111	* @cb_fn: function to call when the xor completes
112	* @cb_param: parameter to pass to the callback routine
113	*/
114	struct dma_async_tx_descriptor *
115	async_xor(struct page dest, struct page *src_list, unsigned int offset,
116	int src_cnt, size_t len, enum async_tx_flags flags,
117	struct dma_async_tx_descriptor *depend_tx,
118	dma_async_tx_callback cb_fn, void *cb_param)
119	{
120	struct dma_chan *chan = async_tx_find_channel(depend_tx, DMA_XOR);
121	struct dma_device *device = chan ? chan->device : NULL;
122	struct dma_async_tx_descriptor *tx = NULL;
123	dma_async_tx_callback _cb_fn;
124	void *_cb_param;
125	unsigned long local_flags;
126	int xor_src_cnt;
127	int i = 0, src_off = 0, int_en;
128
129	BUG_ON(src_cnt <= 1);
130
131	while (src_cnt) {
132	local_flags = flags;
133	if (device) { /* run the xor asynchronously */
134	xor_src_cnt = min(src_cnt, device->max_xor);
135	/* if we are submitting additional xors
136	* only set the callback on the last transaction
137	*/
138	if (src_cnt > xor_src_cnt) {
139	local_flags &= ~ASYNC_TX_ACK;
140	_cb_fn = NULL;
141	_cb_param = NULL;
142	} else {
143	_cb_fn = cb_fn;
144	_cb_param = cb_param;
145	}
146
147	int_en = _cb_fn ? 1 : 0;
148
149	tx = device->device_prep_dma_xor(
150	chan, xor_src_cnt, len, int_en);
151
152	if (tx) {
153	do_async_xor(tx, device, chan, dest,
154	&src_list[src_off], offset, xor_src_cnt, len,
155	local_flags, depend_tx, _cb_fn,
156	_cb_param);
157	} else /* fall through */
158	goto xor_sync;
159	} else { /* run the xor synchronously */
160	xor_sync:
161	/* in the sync case the dest is an implied source
162	* (assumes the dest is at the src_off index)
163	*/
164	if (flags & ASYNC_TX_XOR_DROP_DST) {
165	src_cnt--;
166	src_off++;
167	}
168
169	/* process up to 'MAX_XOR_BLOCKS' sources */
170	xor_src_cnt = min(src_cnt, MAX_XOR_BLOCKS);
171
172	/* if we are submitting additional xors
173	* only set the callback on the last transaction
174	*/
175	if (src_cnt > xor_src_cnt) {
176	local_flags &= ~ASYNC_TX_ACK;
177	_cb_fn = NULL;
178	_cb_param = NULL;
179	} else {
180	_cb_fn = cb_fn;
181	_cb_param = cb_param;
182	}
183
184	/* wait for any prerequisite operations */
185	if (depend_tx) {
186	/* if ack is already set then we cannot be sure
187	* we are referring to the correct operation
188	*/
189	BUG_ON(depend_tx->ack);
190	if (dma_wait_for_async_tx(depend_tx) ==
191	DMA_ERROR)
192	panic("%s: DMA_ERROR waiting for "
193	"depend_tx\n",
194	__FUNCTION__);
195	}
196
197	do_sync_xor(dest, &src_list[src_off], offset,
198	xor_src_cnt, len, local_flags, depend_tx,
199	_cb_fn, _cb_param);
200	}
201
202	/* the previous tx is hidden from the client,
203	* so ack it
204	*/
205	if (i && depend_tx)
206	async_tx_ack(depend_tx);
207
208	depend_tx = tx;
209
210	if (src_cnt > xor_src_cnt) {
211	/* drop completed sources */
212	src_cnt -= xor_src_cnt;
213	src_off += xor_src_cnt;
214
215	/* unconditionally preserve the destination */
216	flags &= ~ASYNC_TX_XOR_ZERO_DST;
217
218	/* use the intermediate result a source, but remember
219	* it's dropped, because it's implied, in the sync case
220	*/
221	src_list[--src_off] = dest;
222	src_cnt++;
223	flags \|= ASYNC_TX_XOR_DROP_DST;
224	} else
225	src_cnt = 0;
226	i++;
227	}
228
229	return tx;
230	}
231	EXPORT_SYMBOL_GPL(async_xor);
232
233	static int page_is_zero(struct page *p, unsigned int offset, size_t len)
234	{
235	char *a = page_address(p) + offset;
236	return (((u32 ) a) == 0 &&
237	memcmp(a, a + 4, len - 4) == 0);
238	}
239
240	/**
241	* async_xor_zero_sum - attempt a xor parity check with a dma engine.
242	* @dest: destination page used if the xor is performed synchronously
243	* @src_list: array of source pages. The dest page must be listed as a source
244	* at index zero. The contents of this array may be overwritten.
245	* @offset: offset in pages to start transaction
246	* @src_cnt: number of source pages
247	* @len: length in bytes
248	* @result: 0 if sum == 0 else non-zero
249	* @flags: ASYNC_TX_ASSUME_COHERENT, ASYNC_TX_ACK, ASYNC_TX_DEP_ACK
250	* @depend_tx: xor depends on the result of this transaction.
251	* @cb_fn: function to call when the xor completes
252	* @cb_param: parameter to pass to the callback routine
253	*/
254	struct dma_async_tx_descriptor *
255	async_xor_zero_sum(struct page dest, struct page *src_list,
256	unsigned int offset, int src_cnt, size_t len,
257	u32 *result, enum async_tx_flags flags,
258	struct dma_async_tx_descriptor *depend_tx,
259	dma_async_tx_callback cb_fn, void *cb_param)
260	{
261	struct dma_chan *chan = async_tx_find_channel(depend_tx, DMA_ZERO_SUM);
262	struct dma_device *device = chan ? chan->device : NULL;
263	int int_en = cb_fn ? 1 : 0;
264	struct dma_async_tx_descriptor *tx = device ?
265	device->device_prep_dma_zero_sum(chan, src_cnt, len, result,
266	int_en) : NULL;
267	int i;
268
269	BUG_ON(src_cnt <= 1);
270
271	if (tx) {
272	dma_addr_t dma_addr;
273	enum dma_data_direction dir;
274
275	pr_debug("%s: (async) len: %zu\n", __FUNCTION__, len);
276
277	dir = (flags & ASYNC_TX_ASSUME_COHERENT) ?
278	DMA_NONE : DMA_TO_DEVICE;
279
280	for (i = 0; i < src_cnt; i++) {
281	dma_addr = dma_map_page(device->dev, src_list[i],
282	offset, len, dir);
283	tx->tx_set_src(dma_addr, tx, i);
284	}
285
286	async_tx_submit(chan, tx, flags, depend_tx, cb_fn, cb_param);
287	} else {
288	unsigned long xor_flags = flags;
289
290	pr_debug("%s: (sync) len: %zu\n", __FUNCTION__, len);
291
292	xor_flags \|= ASYNC_TX_XOR_DROP_DST;
293	xor_flags &= ~ASYNC_TX_ACK;
294
295	tx = async_xor(dest, src_list, offset, src_cnt, len, xor_flags,
296	depend_tx, NULL, NULL);
297
298	if (tx) {
299	if (dma_wait_for_async_tx(tx) == DMA_ERROR)
300	panic("%s: DMA_ERROR waiting for tx\n",
301	__FUNCTION__);
302	async_tx_ack(tx);
303	}
304
305	*result = page_is_zero(dest, offset, len) ? 0 : 1;
306
307	tx = NULL;
308
309	async_tx_sync_epilog(flags, depend_tx, cb_fn, cb_param);
310	}
311
312	return tx;
313	}
314	EXPORT_SYMBOL_GPL(async_xor_zero_sum);
315
316	static int __init async_xor_init(void)
317	{
318	return 0;
319	}
320
321	static void __exit async_xor_exit(void)
322	{
323	do { } while (0);
324	}
325
326	module_init(async_xor_init);
327	module_exit(async_xor_exit);
328
329	MODULE_AUTHOR("Intel Corporation");
330	MODULE_DESCRIPTION("asynchronous xor/xor-zero-sum api");
331	MODULE_LICENSE("GPL");