Merge git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

11 files changed, 1445 insertions, 247 deletions

diff --git a/crypto/aead.c b/crypto/aead.c
index d9aa733db16..0a55da70845 100644
--- a/crypto/aead.c
+++ b/crypto/aead.c
@@ -18,6 +18,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/rtnetlink.h>
+#include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/seq_file.h>
 
diff --git a/crypto/async_tx/Kconfig b/crypto/async_tx/Kconfig
index d8fb3914598..e28e276ac61 100644
--- a/crypto/async_tx/Kconfig
+++ b/crypto/async_tx/Kconfig
@@ -14,3 +14,17 @@ config ASYNC_MEMSET
 	tristate
 	select ASYNC_CORE
 
+config ASYNC_PQ
+	tristate
+	select ASYNC_CORE
+
+config ASYNC_RAID6_RECOV
+	tristate
+	select ASYNC_CORE
+	select ASYNC_PQ
+
+config ASYNC_TX_DISABLE_PQ_VAL_DMA
+	bool
+
+config ASYNC_TX_DISABLE_XOR_VAL_DMA
+	bool
diff --git a/crypto/async_tx/Makefile b/crypto/async_tx/Makefile
index 27baa7d52fb..d1e0e6f72bc 100644
--- a/crypto/async_tx/Makefile
+++ b/crypto/async_tx/Makefile
@@ -2,3 +2,6 @@ obj-$(CONFIG_ASYNC_CORE) += async_tx.o
 obj-$(CONFIG_ASYNC_MEMCPY) += async_memcpy.o
 obj-$(CONFIG_ASYNC_MEMSET) += async_memset.o
 obj-$(CONFIG_ASYNC_XOR) += async_xor.o
+obj-$(CONFIG_ASYNC_PQ) += async_pq.o
+obj-$(CONFIG_ASYNC_RAID6_RECOV) += async_raid6_recov.o
+obj-$(CONFIG_ASYNC_RAID6_TEST) += raid6test.o
diff --git a/crypto/async_tx/async_memcpy.c b/crypto/async_tx/async_memcpy.c
index ddccfb01c41..0ec1fb69d4e 100644
--- a/crypto/async_tx/async_memcpy.c
+++ b/crypto/async_tx/async_memcpy.c
@@ -33,28 +33,31 @@
  * async_memcpy - attempt to copy memory with a dma engine.
  * @dest: destination page
  * @src: src page
- * @offset: offset in pages to start transaction
+ * @dest_offset: offset into 'dest' to start transaction
+ * @src_offset: offset into 'src' to start transaction
  * @len: length in bytes
- * @flags: ASYNC_TX_ACK, ASYNC_TX_DEP_ACK,
- * @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
+ * @submit: submission / completion modifiers
+ *
+ * honored flags: ASYNC_TX_ACK
  */
 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)
+	     unsigned int src_offset, size_t len,
+	     struct async_submit_ctl *submit)
 {
-	struct dma_chan *chan = async_tx_find_channel(depend_tx, DMA_MEMCPY,
+	struct dma_chan *chan = async_tx_find_channel(submit, DMA_MEMCPY,
 						      &dest, 1, &src, 1, len);
 	struct dma_device *device = chan ? chan->device : NULL;
 	struct dma_async_tx_descriptor *tx = NULL;
 
-	if (device) {
+	if (device && is_dma_copy_aligned(device, src_offset, dest_offset, len)) {
 		dma_addr_t dma_dest, dma_src;
-		unsigned long dma_prep_flags = cb_fn ? DMA_PREP_INTERRUPT : 0;
+		unsigned long dma_prep_flags = 0;
 
+		if (submit->cb_fn)
+			dma_prep_flags |= DMA_PREP_INTERRUPT;
+		if (submit->flags & ASYNC_TX_FENCE)
+			dma_prep_flags |= DMA_PREP_FENCE;
 		dma_dest = dma_map_page(device->dev, dest, dest_offset, len,
 					DMA_FROM_DEVICE);
 
@@ -67,13 +70,13 @@ async_memcpy(struct page *dest, struct page *src, unsigned int dest_offset,
 
 	if (tx) {
 		pr_debug("%s: (async) len: %zu\n", __func__, len);
-		async_tx_submit(chan, tx, flags, depend_tx, cb_fn, cb_param);
+		async_tx_submit(chan, tx, submit);
 	} else {
 		void *dest_buf, *src_buf;
 		pr_debug("%s: (sync) len: %zu\n", __func__, len);
 
 		/* wait for any prerequisite operations */
-		async_tx_quiesce(&depend_tx);
+		async_tx_quiesce(&submit->depend_tx);
 
 		dest_buf = kmap_atomic(dest, KM_USER0) + dest_offset;
 		src_buf = kmap_atomic(src, KM_USER1) + src_offset;
@@ -83,26 +86,13 @@ async_memcpy(struct page *dest, struct page *src, unsigned int dest_offset,
 		kunmap_atomic(dest_buf, KM_USER0);
 		kunmap_atomic(src_buf, KM_USER1);
 
-		async_tx_sync_epilog(cb_fn, cb_param);
+		async_tx_sync_epilog(submit);
 	}
 
 	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");
diff --git a/crypto/async_tx/async_memset.c b/crypto/async_tx/async_memset.c
index 5b5eb99bb24..58e4a8752ae 100644
--- a/crypto/async_tx/async_memset.c
+++ b/crypto/async_tx/async_memset.c
@@ -35,26 +35,26 @@
  * @val: fill value
  * @offset: offset in pages to start transaction
  * @len: length in bytes
- * @flags: ASYNC_TX_ACK, ASYNC_TX_DEP_ACK
- * @depend_tx: memset 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
+ *
+ * honored flags: ASYNC_TX_ACK
  */
 struct dma_async_tx_descriptor *
-async_memset(struct page *dest, int val, unsigned int 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)
+async_memset(struct page *dest, int val, unsigned int offset, size_t len,
+	     struct async_submit_ctl *submit)
 {
-	struct dma_chan *chan = async_tx_find_channel(depend_tx, DMA_MEMSET,
+	struct dma_chan *chan = async_tx_find_channel(submit, DMA_MEMSET,
 						      &dest, 1, NULL, 0, len);
 	struct dma_device *device = chan ? chan->device : NULL;
 	struct dma_async_tx_descriptor *tx = NULL;
 
-	if (device) {
+	if (device && is_dma_fill_aligned(device, offset, 0, len)) {
 		dma_addr_t dma_dest;
-		unsigned long dma_prep_flags = cb_fn ? DMA_PREP_INTERRUPT : 0;
+		unsigned long dma_prep_flags = 0;
 
+		if (submit->cb_fn)
+			dma_prep_flags |= DMA_PREP_INTERRUPT;
+		if (submit->flags & ASYNC_TX_FENCE)
+			dma_prep_flags |= DMA_PREP_FENCE;
 		dma_dest = dma_map_page(device->dev, dest, offset, len,
 					DMA_FROM_DEVICE);
 
@@ -64,38 +64,25 @@ async_memset(struct page *dest, int val, unsigned int offset,
 
 	if (tx) {
 		pr_debug("%s: (async) len: %zu\n", __func__, len);
-		async_tx_submit(chan, tx, flags, depend_tx, cb_fn, cb_param);
+		async_tx_submit(chan, tx, submit);
 	} else { /* run the memset synchronously */
 		void *dest_buf;
 		pr_debug("%s: (sync) len: %zu\n", __func__, len);
 
-		dest_buf = (void *) (((char *) page_address(dest)) + offset);
+		dest_buf = page_address(dest) + offset;
 
 		/* wait for any prerequisite operations */
-		async_tx_quiesce(&depend_tx);
+		async_tx_quiesce(&submit->depend_tx);
 
 		memset(dest_buf, val, len);
 
-		async_tx_sync_epilog(cb_fn, cb_param);
+		async_tx_sync_epilog(submit);
 	}
 
 	return tx;
 }
 EXPORT_SYMBOL_GPL(async_memset);
 
-static int __init async_memset_init(void)
-{
-	return 0;
-}
-
-static void __exit async_memset_exit(void)
-{
-	do { } while (0);
-}
-
-module_init(async_memset_init);
-module_exit(async_memset_exit);
-
 MODULE_AUTHOR("Intel Corporation");
 MODULE_DESCRIPTION("asynchronous memset api");
 MODULE_LICENSE("GPL");
diff --git a/crypto/async_tx/async_pq.c b/crypto/async_tx/async_pq.c
new file mode 100644
index 00000000000..ec87f53d505
--- /dev/null
+++ b/crypto/async_tx/async_pq.c
@@ -0,0 +1,415 @@
+/*
+ * Copyright(c) 2007 Yuri Tikhonov <yur@emcraft.com>
+ * Copyright(c) 2009 Intel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that 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., 59
+ * Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ *
+ * The full GNU General Public License is included in this distribution in the
+ * file called COPYING.
+ */
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/dma-mapping.h>
+#include <linux/raid/pq.h>
+#include <linux/async_tx.h>
+
+/**
+ * pq_scribble_page - space to hold throwaway P or Q buffer for
+ * synchronous gen_syndrome
+ */
+static struct page *pq_scribble_page;
+
+/* the struct page *blocks[] parameter passed to async_gen_syndrome()
+ * and async_syndrome_val() contains the 'P' destination address at
+ * blocks[disks-2] and the 'Q' destination address at blocks[disks-1]
+ *
+ * note: these are macros as they are used as lvalues
+ */
+#define P(b, d) (b[d-2])
+#define Q(b, d) (b[d-1])
+
+/**
+ * do_async_gen_syndrome - asynchronously calculate P and/or Q
+ */
+static __async_inline struct dma_async_tx_descriptor *
+do_async_gen_syndrome(struct dma_chan *chan, struct page **blocks,
+		      const unsigned char *scfs, unsigned int offset, int disks,
+		      size_t len, dma_addr_t *dma_src,
+		      struct async_submit_ctl *submit)
+{
+	struct dma_async_tx_descriptor *tx = NULL;
+	struct dma_device *dma = chan->device;
+	enum dma_ctrl_flags dma_flags = 0;
+	enum async_tx_flags flags_orig = submit->flags;
+	dma_async_tx_callback cb_fn_orig = submit->cb_fn;
+	dma_async_tx_callback cb_param_orig = submit->cb_param;
+	int src_cnt = disks - 2;
+	unsigned char coefs[src_cnt];
+	unsigned short pq_src_cnt;
+	dma_addr_t dma_dest[2];
+	int src_off = 0;
+	int idx;
+	int i;
+
+	/* DMAs use destinations as sources, so use BIDIRECTIONAL mapping */
+	if (P(blocks, disks))
+		dma_dest[0] = dma_map_page(dma->dev, P(blocks, disks), offset,
+					   len, DMA_BIDIRECTIONAL);
+	else
+		dma_flags |= DMA_PREP_PQ_DISABLE_P;
+	if (Q(blocks, disks))
+		dma_dest[1] = dma_map_page(dma->dev, Q(blocks, disks), offset,
+					   len, DMA_BIDIRECTIONAL);
+	else
+		dma_flags |= DMA_PREP_PQ_DISABLE_Q;
+
+	/* convert source addresses being careful to collapse 'empty'
+	 * sources and update the coefficients accordingly
+	 */
+	for (i = 0, idx = 0; i < src_cnt; i++) {
+		if (blocks[i] == NULL)
+			continue;
+		dma_src[idx] = dma_map_page(dma->dev, blocks[i], offset, len,
+					    DMA_TO_DEVICE);
+		coefs[idx] = scfs[i];
+		idx++;
+	}
+	src_cnt = idx;
+
+	while (src_cnt > 0) {
+		submit->flags = flags_orig;
+		pq_src_cnt = min(src_cnt, dma_maxpq(dma, dma_flags));
+		/* if we are submitting additional pqs, leave the chain open,
+		 * clear the callback parameters, and leave the destination
+		 * buffers mapped
+		 */
+		if (src_cnt > pq_src_cnt) {
+			submit->flags &= ~ASYNC_TX_ACK;
+			submit->flags |= ASYNC_TX_FENCE;
+			dma_flags |= DMA_COMPL_SKIP_DEST_UNMAP;
+			submit->cb_fn = NULL;
+			submit->cb_param = NULL;
+		} else {
+			dma_flags &= ~DMA_COMPL_SKIP_DEST_UNMAP;
+			submit->cb_fn = cb_fn_orig;
+			submit->cb_param = cb_param_orig;
+			if (cb_fn_orig)
+				dma_flags |= DMA_PREP_INTERRUPT;
+		}
+		if (submit->flags & ASYNC_TX_FENCE)
+			dma_flags |= DMA_PREP_FENCE;
+
+		/* 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
+		 */
+		for (;;) {
+			tx = dma->device_prep_dma_pq(chan, dma_dest,
+						     &dma_src[src_off],
+						     pq_src_cnt,
+						     &coefs[src_off], len,
+						     dma_flags);
+			if (likely(tx))
+				break;
+			async_tx_quiesce(&submit->depend_tx);
+			dma_async_issue_pending(chan);
+		}
+
+		async_tx_submit(chan, tx, submit);
+		submit->depend_tx = tx;
+
+		/* drop completed sources */
+		src_cnt -= pq_src_cnt;
+		src_off += pq_src_cnt;
+
+		dma_flags |= DMA_PREP_CONTINUE;
+	}
+
+	return tx;
+}
+
+/**
+ * do_sync_gen_syndrome - synchronously calculate a raid6 syndrome
+ */
+static void
+do_sync_gen_syndrome(struct page **blocks, unsigned int offset, int disks,
+		     size_t len, struct async_submit_ctl *submit)
+{
+	void **srcs;
+	int i;
+
+	if (submit->scribble)
+		srcs = submit->scribble;
+	else
+		srcs = (void **) blocks;
+
+	for (i = 0; i < disks; i++) {
+		if (blocks[i] == NULL) {
+			BUG_ON(i > disks - 3); /* P or Q can't be zero */
+			srcs[i] = (void*)raid6_empty_zero_page;
+		} else
+			srcs[i] = page_address(blocks[i]) + offset;
+	}
+	raid6_call.gen_syndrome(disks, len, srcs);
+	async_tx_sync_epilog(submit);
+}
+
+/**
+ * async_gen_syndrome - asynchronously calculate a raid6 syndrome
+ * @blocks: source blocks from idx 0..disks-3, P @ disks-2 and Q @ disks-1
+ * @offset: common offset into each block (src and dest) to start transaction
+ * @disks: number of blocks (including missing P or Q, see below)
+ * @len: length of operation in bytes
+ * @submit: submission/completion modifiers
+ *
+ * General note: This routine assumes a field of GF(2^8) with a
+ * primitive polynomial of 0x11d and a generator of {02}.
+ *
+ * 'disks' note: callers can optionally omit either P or Q (but not
+ * both) from the calculation by setting blocks[disks-2] or
+ * blocks[disks-1] to NULL.  When P or Q is omitted 'len' must be <=
+ * PAGE_SIZE as a temporary buffer of this size is used in the
+ * synchronous path.  'disks' always accounts for both destination
+ * buffers.  If any source buffers (blocks[i] where i < disks - 2) are
+ * set to NULL those buffers will be replaced with the raid6_zero_page
+ * in the synchronous path and omitted in the hardware-asynchronous
+ * path.
+ *
+ * 'blocks' note: if submit->scribble is NULL then the contents of
+ * 'blocks' may be overwritten to perform address conversions
+ * (dma_map_page() or page_address()).
+ */
+struct dma_async_tx_descriptor *
+async_gen_syndrome(struct page **blocks, unsigned int offset, int disks,
+		   size_t len, struct async_submit_ctl *submit)
+{
+	int src_cnt = disks - 2;
+	struct dma_chan *chan = async_tx_find_channel(submit, DMA_PQ,
+						      &P(blocks, disks), 2,
+						      blocks, src_cnt, len);
+	struct dma_device *device = chan ? chan->device : NULL;
+	dma_addr_t *dma_src = NULL;
+
+	BUG_ON(disks > 255 || !(P(blocks, disks) || Q(blocks, disks)));
+
+	if (submit->scribble)
+		dma_src = submit->scribble;
+	else if (sizeof(dma_addr_t) <= sizeof(struct page *))
+		dma_src = (dma_addr_t *) blocks;
+
+	if (dma_src && device &&
+	    (src_cnt <= dma_maxpq(device, 0) ||
+	     dma_maxpq(device, DMA_PREP_CONTINUE) > 0) &&
+	    is_dma_pq_aligned(device, offset, 0, len)) {
+		/* run the p+q asynchronously */
+		pr_debug("%s: (async) disks: %d len: %zu\n",
+			 __func__, disks, len);
+		return do_async_gen_syndrome(chan, blocks, raid6_gfexp, offset,
+					     disks, len, dma_src, submit);
+	}
+
+	/* run the pq synchronously */
+	pr_debug("%s: (sync) disks: %d len: %zu\n", __func__, disks, len);
+
+	/* wait for any prerequisite operations */
+	async_tx_quiesce(&submit->depend_tx);
+
+	if (!P(blocks, disks)) {
+		P(blocks, disks) = pq_scribble_page;
+		BUG_ON(len + offset > PAGE_SIZE);
+	}
+	if (!Q(blocks, disks)) {
+		Q(blocks, disks) = pq_scribble_page;
+		BUG_ON(len + offset > PAGE_SIZE);
+	}
+	do_sync_gen_syndrome(blocks, offset, disks, len, submit);
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(async_gen_syndrome);
+
+static inline struct dma_chan *
+pq_val_chan(struct async_submit_ctl *submit, struct page **blocks, int disks, size_t len)
+{
+	#ifdef CONFIG_ASYNC_TX_DISABLE_PQ_VAL_DMA
+	return NULL;
+	#endif
+	return async_tx_find_channel(submit, DMA_PQ_VAL, NULL, 0,  blocks,
+				     disks, len);
+}
+
+/**
+ * async_syndrome_val - asynchronously validate a raid6 syndrome
+ * @blocks: source blocks from idx 0..disks-3, P @ disks-2 and Q @ disks-1
+ * @offset: common offset into each block (src and dest) to start transaction
+ * @disks: number of blocks (including missing P or Q, see below)
+ * @len: length of operation in bytes
+ * @pqres: on val failure SUM_CHECK_P_RESULT and/or SUM_CHECK_Q_RESULT are set
+ * @spare: temporary result buffer for the synchronous case
+ * @submit: submission / completion modifiers
+ *
+ * The same notes from async_gen_syndrome apply to the 'blocks',
+ * and 'disks' parameters of this routine.  The synchronous path
+ * requires a temporary result buffer and submit->scribble to be
+ * specified.
+ */
+struct dma_async_tx_descriptor *
+async_syndrome_val(struct page **blocks, unsigned int offset, int disks,
+		   size_t len, enum sum_check_flags *pqres, struct page *spare,
+		   struct async_submit_ctl *submit)
+{
+	struct dma_chan *chan = pq_val_chan(submit, blocks, disks, len);
+	struct dma_device *device = chan ? chan->device : NULL;
+	struct dma_async_tx_descriptor *tx;
+	unsigned char coefs[disks-2];
+	enum dma_ctrl_flags dma_flags = submit->cb_fn ? DMA_PREP_INTERRUPT : 0;
+	dma_addr_t *dma_src = NULL;
+	int src_cnt = 0;
+
+	BUG_ON(disks < 4);
+
+	if (submit->scribble)
+		dma_src = submit->scribble;
+	else if (sizeof(dma_addr_t) <= sizeof(struct page *))
+		dma_src = (dma_addr_t *) blocks;
+
+	if (dma_src && device && disks <= dma_maxpq(device, 0) &&
+	    is_dma_pq_aligned(device, offset, 0, len)) {
+		struct device *dev = device->dev;
+		dma_addr_t *pq = &dma_src[disks-2];
+		int i;
+
+		pr_debug("%s: (async) disks: %d len: %zu\n",
+			 __func__, disks, len);
+		if (!P(blocks, disks))
+			dma_flags |= DMA_PREP_PQ_DISABLE_P;
+		else
+			pq[0] = dma_map_page(dev, P(blocks, disks),
+					     offset, len,
+					     DMA_TO_DEVICE);
+		if (!Q(blocks, disks))
+			dma_flags |= DMA_PREP_PQ_DISABLE_Q;
+		else
+			pq[1] = dma_map_page(dev, Q(blocks, disks),
+					     offset, len,
+					     DMA_TO_DEVICE);
+
+		if (submit->flags & ASYNC_TX_FENCE)
+			dma_flags |= DMA_PREP_FENCE;
+		for (i = 0; i < disks-2; i++)
+			if (likely(blocks[i])) {
+				dma_src[src_cnt] = dma_map_page(dev, blocks[i],
+								offset, len,
+								DMA_TO_DEVICE);
+				coefs[src_cnt] = raid6_gfexp[i];
+				src_cnt++;
+			}
+
+		for (;;) {
+			tx = device->device_prep_dma_pq_val(chan, pq, dma_src,
+							    src_cnt,
+							    coefs,
+							    len, pqres,
+							    dma_flags);
+			if (likely(tx))
+				break;
+			async_tx_quiesce(&submit->depend_tx);
+			dma_async_issue_pending(chan);
+		}
+		async_tx_submit(chan, tx, submit);
+
+		return tx;
+	} else {
+		struct page *p_src = P(blocks, disks);
+		struct page *q_src = Q(blocks, disks);
+		enum async_tx_flags flags_orig = submit->flags;
+		dma_async_tx_callback cb_fn_orig = submit->cb_fn;
+		void *scribble = submit->scribble;
+		void *cb_param_orig = submit->cb_param;
+		void *p, *q, *s;
+
+		pr_debug("%s: (sync) disks: %d len: %zu\n",
+			 __func__, disks, len);
+
+		/* caller must provide a temporary result buffer and
+		 * allow the input parameters to be preserved
+		 */
+		BUG_ON(!spare || !scribble);
+
+		/* wait for any prerequisite operations */
+		async_tx_quiesce(&submit->depend_tx);
+
+		/* recompute p and/or q into the temporary buffer and then
+		 * check to see the result matches the current value
+		 */
+		tx = NULL;
+		*pqres = 0;
+		if (p_src) {
+			init_async_submit(submit, ASYNC_TX_XOR_ZERO_DST, NULL,
+					  NULL, NULL, scribble);
+			tx = async_xor(spare, blocks, offset, disks-2, len, submit);
+			async_tx_quiesce(&tx);
+			p = page_address(p_src) + offset;
+			s = page_address(spare) + offset;
+			*pqres |= !!memcmp(p, s, len) << SUM_CHECK_P;
+		}
+
+		if (q_src) {
+			P(blocks, disks) = NULL;
+			Q(blocks, disks) = spare;
+			init_async_submit(submit, 0, NULL, NULL, NULL, scribble);
+			tx = async_gen_syndrome(blocks, offset, disks, len, submit);
+			async_tx_quiesce(&tx);
+			q = page_address(q_src) + offset;
+			s = page_address(spare) + offset;
+			*pqres |= !!memcmp(q, s, len) << SUM_CHECK_Q;
+		}
+
+		/* restore P, Q and submit */
+		P(blocks, disks) = p_src;
+		Q(blocks, disks) = q_src;
+
+		submit->cb_fn = cb_fn_orig;
+		submit->cb_param = cb_param_orig;
+		submit->flags = flags_orig;
+		async_tx_sync_epilog(submit);
+
+		return NULL;
+	}
+}
+EXPORT_SYMBOL_GPL(async_syndrome_val);
+
+static int __init async_pq_init(void)
+{
+	pq_scribble_page = alloc_page(GFP_KERNEL);
+
+	if (pq_scribble_page)
+		return 0;
+
+	pr_err("%s: failed to allocate required spare page\n", __func__);
+
+	return -ENOMEM;
+}
+
+static void __exit async_pq_exit(void)
+{
+	put_page(pq_scribble_page);
+}
+
+module_init(async_pq_init);
+module_exit(async_pq_exit);
+
+MODULE_DESCRIPTION("asynchronous raid6 syndrome generation/validation");
+MODULE_LICENSE("GPL");
diff --git a/crypto/async_tx/async_raid6_recov.c b/crypto/async_tx/async_raid6_recov.c
new file mode 100644
index 00000000000..943f2abac9b
--- /dev/null
+++ b/crypto/async_tx/async_raid6_recov.c
@@ -0,0 +1,500 @@
+/*
+ * Asynchronous RAID-6 recovery calculations ASYNC_TX API.
+ * Copyright(c) 2009 Intel Corporation
+ *
+ * based on raid6recov.c:
+ *   Copyright 2002 H. Peter Anvin
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that 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/dma-mapping.h>
+#include <linux/raid/pq.h>
+#include <linux/async_tx.h>
+
+static struct dma_async_tx_descriptor *
+async_sum_product(struct page *dest, struct page **srcs, unsigned char *coef,
+		  size_t len, struct async_submit_ctl *submit)
+{
+	struct dma_chan *chan = async_tx_find_channel(submit, DMA_PQ,
+						      &dest, 1, srcs, 2, len);
+	struct dma_device *dma = chan ? chan->device : NULL;
+	const u8 *amul, *bmul;
+	u8 ax, bx;
+	u8 *a, *b, *c;
+
+	if (dma) {
+		dma_addr_t dma_dest[2];
+		dma_addr_t dma_src[2];
+		struct device *dev = dma->dev;
+		struct dma_async_tx_descriptor *tx;
+		enum dma_ctrl_flags dma_flags = DMA_PREP_PQ_DISABLE_P;
+
+		if (submit->flags & ASYNC_TX_FENCE)
+			dma_flags |= DMA_PREP_FENCE;
+		dma_dest[1] = dma_map_page(dev, dest, 0, len, DMA_BIDIRECTIONAL);
+		dma_src[0] = dma_map_page(dev, srcs[0], 0, len, DMA_TO_DEVICE);
+		dma_src[1] = dma_map_page(dev, srcs[1], 0, len, DMA_TO_DEVICE);
+		tx = dma->device_prep_dma_pq(chan, dma_dest, dma_src, 2, coef,
+					     len, dma_flags);
+		if (tx) {
+			async_tx_submit(chan, tx, submit);
+			return tx;
+		}
+
+		/* could not get a descriptor, unmap and fall through to
+		 * the synchronous path
+		 */
+		dma_unmap_page(dev, dma_dest[1], len, DMA_BIDIRECTIONAL);
+		dma_unmap_page(dev, dma_src[0], len, DMA_TO_DEVICE);
+		dma_unmap_page(dev, dma_src[1], len, DMA_TO_DEVICE);
+	}
+
+	/* run the operation synchronously */
+	async_tx_quiesce(&submit->depend_tx);
+	amul = raid6_gfmul[coef[0]];
+	bmul = raid6_gfmul[coef[1]];
+	a = page_address(srcs[0]);
+	b = page_address(srcs[1]);
+	c = page_address(dest);
+
+	while (len--) {
+		ax    = amul[*a++];
+		bx    = bmul[*b++];
+		*c++ = ax ^ bx;
+	}
+
+	return NULL;
+}
+
+static struct dma_async_tx_descriptor *
+async_mult(struct page *dest, struct page *src, u8 coef, size_t len,
+	   struct async_submit_ctl *submit)
+{
+	struct dma_chan *chan = async_tx_find_channel(submit, DMA_PQ,
+						      &dest, 1, &src, 1, len);
+	struct dma_device *dma = chan ? chan->device : NULL;
+	const u8 *qmul; /* Q multiplier table */
+	u8 *d, *s;
+
+	if (dma) {
+		dma_addr_t dma_dest[2];
+		dma_addr_t dma_src[1];
+		struct device *dev = dma->dev;
+		struct dma_async_tx_descriptor *tx;
+		enum dma_ctrl_flags dma_flags = DMA_PREP_PQ_DISABLE_P;
+
+		if (submit->flags & ASYNC_TX_FENCE)
+			dma_flags |= DMA_PREP_FENCE;
+		dma_dest[1] = dma_map_page(dev, dest, 0, len, DMA_BIDIRECTIONAL);
+		dma_src[0] = dma_map_page(dev, src, 0, len, DMA_TO_DEVICE);
+		tx = dma->device_prep_dma_pq(chan, dma_dest, dma_src, 1, &coef,
+					     len, dma_flags);
+		if (tx) {
+			async_tx_submit(chan, tx, submit);
+			return tx;
+		}
+
+		/* could not get a descriptor, unmap and fall through to
+		 * the synchronous path
+		 */
+		dma_unmap_page(dev, dma_dest[1], len, DMA_BIDIRECTIONAL);
+		dma_unmap_page(dev, dma_src[0], len, DMA_TO_DEVICE);
+	}
+
+	/* no channel available, or failed to allocate a descriptor, so
+	 * perform the operation synchronously
+	 */
+	async_tx_quiesce(&submit->depend_tx);
+	qmul  = raid6_gfmul[coef];
+	d = page_address(dest);
+	s = page_address(src);
+
+	while (len--)
+		*d++ = qmul[*s++];
+
+	return NULL;
+}
+
+static struct dma_async_tx_descriptor *
+__2data_recov_4(int disks, size_t bytes, int faila, int failb,
+		struct page **blocks, struct async_submit_ctl *submit)
+{
+	struct dma_async_tx_descriptor *tx = NULL;
+	struct page *p, *q, *a, *b;
+	struct page *srcs[2];
+	unsigned char coef[2];
+	enum async_tx_flags flags = submit->flags;
+	dma_async_tx_callback cb_fn = submit->cb_fn;
+	void *cb_param = submit->cb_param;
+	void *scribble = submit->scribble;
+
+	p = blocks[disks-2];
+	q = blocks[disks-1];
+
+	a = blocks[faila];
+	b = blocks[failb];
+
+	/* in the 4 disk case P + Pxy == P and Q + Qxy == Q */
+	/* Dx = A*(P+Pxy) + B*(Q+Qxy) */
+	srcs[0] = p;
+	srcs[1] = q;
+	coef[0] = raid6_gfexi[failb-faila];
+	coef[1] = raid6_gfinv[raid6_gfexp[faila]^raid6_gfexp[failb]];
+	init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, scribble);
+	tx = async_sum_product(b, srcs, coef, bytes, submit);
+
+	/* Dy = P+Pxy+Dx */
+	srcs[0] = p;
+	srcs[1] = b;
+	init_async_submit(submit, flags | ASYNC_TX_XOR_ZERO_DST, tx, cb_fn,
+			  cb_param, scribble);
+	tx = async_xor(a, srcs, 0, 2, bytes, submit);
+
+	return tx;
+
+}
+
+static struct dma_async_tx_descriptor *
+__2data_recov_5(int disks, size_t bytes, int faila, int failb,
+		struct page **blocks, struct async_submit_ctl *submit)
+{
+	struct dma_async_tx_descriptor *tx = NULL;
+	struct page *p, *q, *g, *dp, *dq;
+	struct page *srcs[2];
+	unsigned char coef[2];
+	enum async_tx_flags flags = submit->flags;
+	dma_async_tx_callback cb_fn = submit->cb_fn;
+	void *cb_param = submit->cb_param;
+	void *scribble = submit->scribble;
+	int good_srcs, good, i;
+
+	good_srcs = 0;
+	good = -1;
+	for (i = 0; i < disks-2; i++) {
+		if (blocks[i] == NULL)
+			continue;
+		if (i == faila || i == failb)
+			continue;
+		good = i;
+		good_srcs++;
+	}
+	BUG_ON(good_srcs > 1);
+
+	p = blocks[disks-2];
+	q = blocks[disks-1];
+	g = blocks[good];
+
+	/* Compute syndrome with zero for the missing data pages
+	 * Use the dead data pages as temporary storage for delta p and
+	 * delta q
+	 */
+	dp = blocks[faila];
+	dq = blocks[failb];
+
+	init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, scribble);
+	tx = async_memcpy(dp, g, 0, 0, bytes, submit);
+	init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, scribble);
+	tx = async_mult(dq, g, raid6_gfexp[good], bytes, submit);
+
+	/* compute P + Pxy */
+	srcs[0] = dp;
+	srcs[1] = p;
+	init_async_submit(submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx,
+			  NULL, NULL, scribble);
+	tx = async_xor(dp, srcs, 0, 2, bytes, submit);
+
+	/* compute Q + Qxy */
+	srcs[0] = dq;
+	srcs[1] = q;
+	init_async_submit(submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx,
+			  NULL, NULL, scribble);
+	tx = async_xor(dq, srcs, 0, 2, bytes, submit);
+
+	/* Dx = A*(P+Pxy) + B*(Q+Qxy) */
+	srcs[0] = dp;
+	srcs[1] = dq;
+	coef[0] = raid6_gfexi[failb-faila];
+	coef[1] = raid6_gfinv[raid6_gfexp[faila]^raid6_gfexp[failb]];
+	init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, scribble);
+	tx = async_sum_product(dq, srcs, coef, bytes, submit);
+
+	/* Dy = P+Pxy+Dx */
+	srcs[0] = dp;
+	srcs[1] = dq;
+	init_async_submit(submit, flags | ASYNC_TX_XOR_DROP_DST, tx, cb_fn,
+			  cb_param, scribble);
+	tx = async_xor(dp, srcs, 0, 2, bytes, submit);
+
+	return tx;
+}
+
+static struct dma_async_tx_descriptor *
+__2data_recov_n(int disks, size_t bytes, int faila, int failb,
+	      struct page **blocks, struct async_submit_ctl *submit)
+{
+	struct dma_async_tx_descriptor *tx = NULL;
+	struct page *p, *q, *dp, *dq;
+	struct page *srcs[2];
+	unsigned char coef[2];
+	enum async_tx_flags flags = submit->flags;
+	dma_async_tx_callback cb_fn = submit->cb_fn;
+	void *cb_param = submit->cb_param;
+	void *scribble = submit->scribble;
+
+	p = blocks[disks-2];
+	q = blocks[disks-1];
+
+	/* Compute syndrome with zero for the missing data pages
+	 * Use the dead data pages as temporary storage for
+	 * delta p and delta q
+	 */
+	dp = blocks[faila];
+	blocks[faila] = NULL;
+	blocks[disks-2] = dp;
+	dq = blocks[failb];
+	blocks[failb] = NULL;
+	blocks[disks-1] = dq;
+
+	init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, scribble);
+	tx = async_gen_syndrome(blocks, 0, disks, bytes, submit);
+
+	/* Restore pointer table */
+	blocks[faila]   = dp;
+	blocks[failb]   = dq;
+	blocks[disks-2] = p;
+	blocks[disks-1] = q;
+
+	/* compute P + Pxy */
+	srcs[0] = dp;
+	srcs[1] = p;
+	init_async_submit(submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx,
+			  NULL, NULL, scribble);
+	tx = async_xor(dp, srcs, 0, 2, bytes, submit);
+
+	/* compute Q + Qxy */
+	srcs[0] = dq;
+	srcs[1] = q;
+	init_async_submit(submit, ASYNC_TX_FENCE|ASYNC_TX_XOR_DROP_DST, tx,
+			  NULL, NULL, scribble);
+	tx = async_xor(dq, srcs, 0, 2, bytes, submit);
+
+	/* Dx = A*(P+Pxy) + B*(Q+Qxy) */
+	srcs[0] = dp;
+	srcs[1] = dq;
+	coef[0] = raid6_gfexi[failb-faila];
+	coef[1] = raid6_gfinv[raid6_gfexp[faila]^raid6_gfexp[failb]];
+	init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, scribble);
+	tx = async_sum_product(dq, srcs, coef, bytes, submit);
+
+	/* Dy = P+Pxy+Dx */
+	srcs[0] = dp;
+	srcs[1] = dq;
+	init_async_submit(submit, flags | ASYNC_TX_XOR_DROP_DST, tx, cb_fn,
+			  cb_param, scribble);
+	tx = async_xor(dp, srcs, 0, 2, bytes, submit);
+
+	return tx;
+}
+
+/**
+ * async_raid6_2data_recov - asynchronously calculate two missing data blocks
+ * @disks: number of disks in the RAID-6 array
+ * @bytes: block size
+ * @faila: first failed drive index
+ * @failb: second failed drive index
+ * @blocks: array of source pointers where the last two entries are p and q
+ * @submit: submission/completion modifiers
+ */
+struct dma_async_tx_descriptor *
+async_raid6_2data_recov(int disks, size_t bytes, int faila, int failb,
+			struct page **blocks, struct async_submit_ctl *submit)
+{
+	int non_zero_srcs, i;
+
+	BUG_ON(faila == failb);
+	if (failb < faila)
+		swap(faila, failb);
+
+	pr_debug("%s: disks: %d len: %zu\n", __func__, disks, bytes);
+
+	/* we need to preserve the contents of 'blocks' for the async
+	 * case, so punt to synchronous if a scribble buffer is not available
+	 */
+	if (!submit->scribble) {
+		void **ptrs = (void **) blocks;
+
+		async_tx_quiesce(&submit->depend_tx);
+		for (i = 0; i < disks; i++)
+			if (blocks[i] == NULL)
+				ptrs[i] = (void *) raid6_empty_zero_page;
+			else
+				ptrs[i] = page_address(blocks[i]);
+
+		raid6_2data_recov(disks, bytes, faila, failb, ptrs);
+
+		async_tx_sync_epilog(submit);
+
+		r