[PATCH 02/11][v3] async_tx: add support for asynchronous GF multiplication
Yuri Tikhonov
yur at emcraft.com
Tue Jan 13 11:43:06 EST 2009
This adds support for doing asynchronous GF multiplication by adding
four additional functions to async_tx API:
async_pq() does simultaneous XOR of sources and XOR of sources
GF-multiplied by given coefficients.
async_pq_zero_sum() checks if results of calculations match given
ones.
async_gen_syndrome() does sumultaneous XOR and R/S syndrome of sources.
async_syndrome_zerosum() checks if results of XOR/syndrome calculation
matches given ones.
Latter two functions just use async_pq() with the approprite coefficients
in asynchronous case but have significant optimizations if synchronous
case.
To support this API dmaengine driver should set DMA_PQ and
DMA_PQ_ZERO_SUM capabilities and provide device_prep_dma_pq and
device_prep_dma_pqzero_sum methods in dma_device structure.
Signed-off-by: Yuri Tikhonov <yur at emcraft.com>
Signed-off-by: Ilya Yanok <yanok at emcraft.com>
---
crypto/async_tx/Kconfig | 4 +
crypto/async_tx/Makefile | 1 +
crypto/async_tx/async_pq.c | 615 +++++++++++++++++++++++++++++++++++++++++++
crypto/async_tx/async_xor.c | 2 +-
include/linux/async_tx.h | 46 +++-
include/linux/dmaengine.h | 30 ++-
6 files changed, 693 insertions(+), 5 deletions(-)
create mode 100644 crypto/async_tx/async_pq.c
diff --git a/crypto/async_tx/Kconfig b/crypto/async_tx/Kconfig
index d8fb391..cb6d731 100644
--- a/crypto/async_tx/Kconfig
+++ b/crypto/async_tx/Kconfig
@@ -14,3 +14,7 @@ config ASYNC_MEMSET
tristate
select ASYNC_CORE
+config ASYNC_PQ
+ tristate
+ select ASYNC_CORE
+
diff --git a/crypto/async_tx/Makefile b/crypto/async_tx/Makefile
index 27baa7d..1b99265 100644
--- a/crypto/async_tx/Makefile
+++ b/crypto/async_tx/Makefile
@@ -2,3 +2,4 @@ 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
diff --git a/crypto/async_tx/async_pq.c b/crypto/async_tx/async_pq.c
new file mode 100644
index 0000000..5871651
--- /dev/null
+++ b/crypto/async_tx/async_pq.c
@@ -0,0 +1,615 @@
+/*
+ * Copyright(c) 2007 Yuri Tikhonov <yur at emcraft.com>
+ *
+ * Developed for DENX Software Engineering GmbH
+ *
+ * Asynchronous GF-XOR calculations ASYNC_TX API.
+ *
+ * based on async_xor.c code written by:
+ * Dan Williams <dan.j.williams at intel.com>
+ *
+ * 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/xor.h>
+#include <linux/async_tx.h>
+
+#include "../drivers/md/raid6.h"
+
+/**
+ * The following static variables are used in cases of synchronous
+ * zero sum to save the values to check. Two pages used for zero sum and
+ * the third one is for dumb P destination when calling gen_syndrome()
+ */
+static spinlock_t spare_lock;
+static struct page *spare_pages[3];
+
+/**
+ * do_async_pq - asynchronously calculate P and/or Q
+ */
+static struct dma_async_tx_descriptor *
+do_async_pq(struct dma_chan *chan, struct page **blocks, unsigned char *scfs,
+ 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_device *dma = chan->device;
+ dma_addr_t dma_dest[2], dma_src[src_cnt];
+ struct dma_async_tx_descriptor *tx = NULL;
+ dma_async_tx_callback _cb_fn;
+ void *_cb_param;
+ unsigned char *scf = NULL;
+ int i, src_off = 0;
+ unsigned short pq_src_cnt;
+ enum async_tx_flags async_flags;
+ enum dma_ctrl_flags dma_flags = 0;
+
+ /* If we won't handle src_cnt in one shot, then the following
+ * flag(s) will be set only on the first pass of prep_dma
+ */
+ if (flags & ASYNC_TX_PQ_ZERO_P)
+ dma_flags |= DMA_PREP_ZERO_P;
+ if (flags & ASYNC_TX_PQ_ZERO_Q)
+ dma_flags |= DMA_PREP_ZERO_Q;
+
+ /* DMAs use destinations as sources, so use BIDIRECTIONAL mapping */
+ if (blocks[src_cnt]) {
+ dma_dest[0] = dma_map_page(dma->dev, blocks[src_cnt],
+ offset, len, DMA_BIDIRECTIONAL);
+ dma_flags |= DMA_PREP_HAVE_P;
+ }
+ if (blocks[src_cnt+1]) {
+ dma_dest[1] = dma_map_page(dma->dev, blocks[src_cnt+1],
+ offset, len, DMA_BIDIRECTIONAL);
+ dma_flags |= DMA_PREP_HAVE_Q;
+ }
+
+ for (i = 0; i < src_cnt; i++)
+ dma_src[i] = dma_map_page(dma->dev, blocks[i],
+ offset, len, DMA_TO_DEVICE);
+
+ while (src_cnt) {
+ async_flags = flags;
+ pq_src_cnt = min(src_cnt, (int)dma->max_pq);
+ /* 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) {
+ async_flags &= ~ASYNC_TX_ACK;
+ dma_flags |= DMA_COMPL_SKIP_DEST_UNMAP;
+ _cb_fn = NULL;
+ _cb_param = NULL;
+ } else {
+ _cb_fn = cb_fn;
+ _cb_param = cb_param;
+ }
+ if (_cb_fn)
+ dma_flags |= DMA_PREP_INTERRUPT;
+ if (scfs)
+ scf = &scfs[src_off];
+
+ /* 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_pq(chan, dma_dest,
+ &dma_src[src_off], pq_src_cnt,
+ scf, len, dma_flags);
+ if (unlikely(!tx))
+ async_tx_quiesce(&depend_tx);
+
+ /* spin wait for the preceeding transactions to complete */
+ while (unlikely(!tx)) {
+ dma_async_issue_pending(chan);
+ tx = dma->device_prep_dma_pq(chan, dma_dest,
+ &dma_src[src_off], pq_src_cnt,
+ scf, len, dma_flags);
+ }
+
+ async_tx_submit(chan, tx, async_flags, depend_tx,
+ _cb_fn, _cb_param);
+
+ depend_tx = tx;
+ flags |= ASYNC_TX_DEP_ACK;
+
+ if (src_cnt > pq_src_cnt) {
+ /* drop completed sources */
+ src_cnt -= pq_src_cnt;
+ src_off += pq_src_cnt;
+
+ /* use the intermediate result as a source; we
+ * clear DMA_PREP_ZERO, so prep_dma_pq will
+ * include destination(s) into calculations. Thus
+ * keep DMA_PREP_HAVE_x in dma_flags only
+ */
+ dma_flags &= (DMA_PREP_HAVE_P | DMA_PREP_HAVE_Q);
+ } else
+ break;
+ }
+
+ return tx;
+}
+
+/**
+ * do_sync_pq - synchronously calculate P and Q
+ */
+static void
+do_sync_pq(struct page **blocks, unsigned char *scfs, 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)
+{
+ int i, pos;
+ uint8_t *p = NULL, *q = NULL, *src;
+
+ /* set destination addresses */
+ if (blocks[src_cnt])
+ p = (uint8_t *)(page_address(blocks[src_cnt]) + offset);
+ if (blocks[src_cnt+1])
+ q = (uint8_t *)(page_address(blocks[src_cnt+1]) + offset);
+
+ if (flags & ASYNC_TX_PQ_ZERO_P) {
+ BUG_ON(!p);
+ memset(p, 0, len);
+ }
+
+ if (flags & ASYNC_TX_PQ_ZERO_Q) {
+ BUG_ON(!q);
+ memset(q, 0, len);
+ }
+
+ for (i = 0; i < src_cnt; i++) {
+ src = (uint8_t *)(page_address(blocks[i]) + offset);
+ for (pos = 0; pos < len; pos++) {
+ if (p)
+ p[pos] ^= src[pos];
+ if (q)
+ q[pos] ^= raid6_gfmul[scfs[i]][src[pos]];
+ }
+ }
+ async_tx_sync_epilog(cb_fn, cb_param);
+}
+
+/**
+ * async_pq - attempt to do XOR and Galois calculations in parallel using
+ * a dma engine.
+ * @blocks: source block array from 0 to (src_cnt-1) with the p destination
+ * at blocks[src_cnt] and q at blocks[src_cnt + 1]. Only one of two
+ * destinations may be present (another then has to be set to NULL).
+ * By default, the result of calculations is XOR-ed with the initial
+ * content of the destinationa buffers. Use ASYNC_TX_PQ_ZERO_x flags
+ * to avoid this.
+ * NOTE: client code must assume the contents of this array are destroyed
+ * @scfs: array of source coefficients used in GF-multiplication
+ * @offset: offset in pages to start transaction
+ * @src_cnt: number of source pages
+ * @len: length in bytes
+ * @flags: ASYNC_TX_PQ_ZERO_P, ASYNC_TX_PQ_ZERO_Q, ASYNC_TX_ASSUME_COHERENT,
+ * ASYNC_TX_ACK, ASYNC_TX_DEP_ACK, ASYNC_TX_ASYNC_ONLY
+ * @depend_tx: depends on the result of this transaction.
+ * @cb_fn: function to call when the operation completes
+ * @cb_param: parameter to pass to the callback routine
+ */
+struct dma_async_tx_descriptor *
+async_pq(struct page **blocks, unsigned char *scfs, 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_PQ,
+ &blocks[src_cnt], 2,
+ blocks, src_cnt, len);
+ struct dma_device *device = chan ? chan->device : NULL;
+ struct dma_async_tx_descriptor *tx = NULL;
+
+ if (!device && (flags & ASYNC_TX_ASYNC_ONLY))
+ return NULL;
+
+ if (device) {
+ /* run pq asynchronously */
+ tx = do_async_pq(chan, blocks, scfs, offset, src_cnt,
+ len, flags, depend_tx, cb_fn,cb_param);
+ } else {
+ /* run pq synchronously */
+ if (!blocks[src_cnt+1]) {
+ struct page *pdst = blocks[src_cnt];
+ int i;
+
+ /* Calculate P-parity only.
+ * As opposite to async_xor(), async_pq() assumes
+ * that destinations are included into calculations,
+ * so we should re-arrange the xor src list to
+ * achieve the similar behavior.
+ */
+ if (!(flags & ASYNC_TX_PQ_ZERO_P)) {
+ /* If async_pq() user doesn't set ZERO flag,
+ * it's assumed that destination has some
+ * reasonable data to include in calculations.
+ * The destination must be at position 0, so
+ * shift the sources and put pdst at the
+ * beginning of the list.
+ */
+ for (i = src_cnt - 1; i >= 0; i--)
+ blocks[i+1] = blocks[i];
+ blocks[0] = pdst;
+ src_cnt++;
+ flags |= ASYNC_TX_XOR_DROP_DST;
+ } else {
+ /* If async_pq() user want to clear P, then
+ * this will be done automatically in async
+ * case, and with the help of ZERO_DST in
+ * the sync one.
+ */
+ flags &= ~ASYNC_TX_PQ_ZERO_P;
+ flags |= ASYNC_TX_XOR_ZERO_DST;
+ }
+
+ return async_xor(pdst, blocks, offset,
+ src_cnt, len, flags, depend_tx,
+ cb_fn, cb_param);
+ }
+
+ /* wait for any prerequisite operations */
+ async_tx_quiesce(&depend_tx);
+
+ do_sync_pq(blocks, scfs, offset, src_cnt, len, flags,
+ depend_tx, cb_fn, cb_param);
+ }
+
+ return tx;
+}
+EXPORT_SYMBOL_GPL(async_pq);
+
+/**
+ * do_sync_gen_syndrome - synchronously calculate P (xor) and Q (Reed-Solomon
+ * code)
+ */
+static void
+do_sync_gen_syndrome(struct page **blocks, 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)
+{
+ int i;
+ void *tsrc[src_cnt+2];
+
+ for (i = 0; i < src_cnt + 2; i++)
+ tsrc[i] = page_address(blocks[i]) + offset;
+
+ raid6_call.gen_syndrome(i, len, tsrc);
+
+ async_tx_sync_epilog(cb_fn, cb_param);
+}
+
+/**
+ * async_gen_syndrome - attempt to generate P (xor) and Q (Reed-Solomon code)
+ * with a dma engine for a given set of blocks. This routine assumes a
+ * field of GF(2^8) with a primitive polynomial of 0x11d and a generator
+ * of {02}.
+ * @blocks: source block array ordered from 0..src_cnt-1 with the P destination
+ * at blocks[src_cnt] and Q at blocks[src_cnt + 1]. Only one of two
+ * destinations may be present (another then has to be set to NULL).
+ * NOTE: client code must assume the contents of this array are destroyed
+ * @offset: offset in pages to start transaction
+ * @src_cnt: number of source pages: 2 < src_cnt <= 255
+ * @len: length of blocks in bytes
+ * @flags: ASYNC_TX_ACK, ASYNC_TX_DEP_ACK, ASYNC_TX_ASYNC_ONLY
+ * @depend_tx: P+Q operation depends on the result of this transaction.
+ * @cb_fn: function to call when P+Q generation completes
+ * @cb_param: parameter to pass to the callback routine
+ */
+struct dma_async_tx_descriptor *
+async_gen_syndrome(struct page **blocks, 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_PQ,
+ &blocks[src_cnt], 2,
+ blocks, src_cnt, len);
+ struct dma_device *device = chan ? chan->device : NULL;
+ struct dma_async_tx_descriptor *tx = NULL;
+
+ BUG_ON(src_cnt > 255 || (!blocks[src_cnt] && !blocks[src_cnt+1]));
+
+ if (!device && (flags & ASYNC_TX_ASYNC_ONLY))
+ return NULL;
+
+ /* Synchronous gen_syndrome() doesn't take care of destinations,
+ * but asynchronous implies them as sources; so, when generating
+ * syndromes - command to clear destinations up explicitly
+ */
+ if (blocks[src_cnt])
+ flags |= ASYNC_TX_PQ_ZERO_P;
+ if (blocks[src_cnt+1])
+ flags |= ASYNC_TX_PQ_ZERO_Q;
+
+ if (device) {
+ /* run the xor asynchronously */
+ tx = do_async_pq(chan, blocks, (uint8_t *)raid6_gfexp,
+ offset, src_cnt, len, flags, depend_tx,
+ cb_fn, cb_param);
+ } else {
+ /* run the pq synchronously */
+ /* wait for any prerequisite operations */
+ async_tx_quiesce(&depend_tx);
+
+ if (!blocks[src_cnt])
+ blocks[src_cnt] = spare_pages[2];
+ if (!blocks[src_cnt+1])
+ blocks[src_cnt+1] = spare_pages[2];
+ do_sync_gen_syndrome(blocks, offset, src_cnt, len, flags,
+ depend_tx, cb_fn, cb_param);
+ }
+
+ return tx;
+}
+EXPORT_SYMBOL_GPL(async_gen_syndrome);
+
+/**
+ * async_pq_zero_sum - attempt a PQ parities check with a dma engine.
+ * @blocks: array of source pages. The 0..src_cnt-1 are the sources, the
+ * src_cnt and src_cnt+1 are the P and Q destinations to check, resp.
+ * Only one of two destinations may be present.
+ * NOTE: client code must assume the contents of this array are destroyed
+ * @scfs: coefficients to use in GF-multiplications
+ * @offset: offset in pages to start transaction
+ * @src_cnt: number of source pages
+ * @len: length in bytes
+ * @presult: where to store the result of P-ckeck, which is 0 if P-parity
+ * OK, and non-zero otherwise.
+ * @qresult: where to store the result of Q-ckeck, which is 0 if Q-parity
+ * OK, and non-zero otherwise.
+ * @flags: ASYNC_TX_ASSUME_COHERENT, ASYNC_TX_ACK, ASYNC_TX_DEP_ACK
+ * @depend_tx: 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_pq_zero_sum(struct page **blocks, unsigned char *scfs,
+ unsigned int offset, int src_cnt, size_t len, u32 *pqres,
+ 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_PQ_ZERO_SUM,
+ &blocks[src_cnt], 2,
+ blocks, src_cnt, len);
+ struct dma_device *device = chan ? chan->device : NULL;
+ struct dma_async_tx_descriptor *tx = NULL;
+ enum dma_ctrl_flags dma_flags = cb_fn ? DMA_PREP_INTERRUPT : 0;
+
+ BUG_ON(src_cnt < 2);
+
+ if (blocks[src_cnt])
+ dma_flags |= DMA_PREP_HAVE_P;
+ if (blocks[src_cnt+1])
+ dma_flags |= DMA_PREP_HAVE_Q;
+
+ if (device && src_cnt <= (int)device->max_pq) {
+ dma_addr_t dma_src[src_cnt + 2];
+ int i;
+
+ for (i = 0; i < src_cnt + 2; i++) {
+ if (likely(blocks[i])) {
+ dma_src[i] = dma_map_page(device->dev,
+ blocks[i], offset,
+ len, DMA_TO_DEVICE);
+ }
+ }
+
+ tx = device->device_prep_dma_pqzero_sum(chan, dma_src, src_cnt,
+ scfs, len, pqres,
+ dma_flags);
+
+ if (unlikely(!tx)) {
+ async_tx_quiesce(&depend_tx);
+
+ while (unlikely(!tx)) {
+ dma_async_issue_pending(chan);
+ tx = device->device_prep_dma_pqzero_sum(chan,
+ dma_src, src_cnt, scfs, len,
+ pqres, dma_flags);
+ }
+ }
+
+ async_tx_submit(chan, tx, flags, depend_tx, cb_fn, cb_param);
+ } else {
+ struct page *pdest = blocks[src_cnt];
+ struct page *qdest = blocks[src_cnt + 1];
+ enum async_tx_flags lflags = flags;
+
+ lflags &= ~ASYNC_TX_ACK;
+ lflags |= ASYNC_TX_PQ_ZERO_P | ASYNC_TX_PQ_ZERO_Q;
+
+ spin_lock(&spare_lock);
+ blocks[src_cnt] = spare_pages[0];
+ blocks[src_cnt + 1] = spare_pages[1];
+ tx = async_pq(blocks, scfs, offset, src_cnt, len, lflags,
+ depend_tx, NULL, NULL);
+ async_tx_quiesce(&tx);
+
+ if (dma_flags & DMA_PREP_HAVE_P) {
+ if (memcmp(page_address(pdest) + offset,
+ page_address(spare_pages[0]) + offset,
+ len) == 0)
+ *pqres &= ~DMA_PCHECK_FAILED;
+ else
+ *pqres |= DMA_PCHECK_FAILED;
+ }
+ if (dma_flags & DMA_PREP_HAVE_Q) {
+ if (memcmp(page_address(qdest) + offset,
+ page_address(spare_pages[1]) + offset,
+ len) == 0)
+ *pqres &= ~DMA_QCHECK_FAILED;
+ else
+ *pqres |= DMA_QCHECK_FAILED;
+ }
+ spin_unlock(&spare_lock);
+ }
+
+ return tx;
+}
+EXPORT_SYMBOL_GPL(async_pq_zero_sum);
+
+/**
+ * async_syndrome_zero_sum - attempt a P (xor) and Q (Reed-Solomon code)
+ * parities check with a dma engine. This routine assumes a field of
+ * GF(2^8) with a primitive polynomial of 0x11d and a generator of {02}.
+ * @blocks: array of source pages. The 0..src_cnt-1 are the sources, the
+ * src_cnt and src_cnt+1 are the P and Q destinations to check, resp.
+ * Only one of two destinations may be present.
+ * NOTE: client code must assume the contents of this array are destroyed
+ * @offset: offset in pages to start transaction
+ * @src_cnt: number of source pages
+ * @len: length in bytes
+ * @pqres: the pointer, where to flag about the result of the check: the
+ * result of P-check is stored at bit0, the result of Q-check is stored
+ * at bit1. If the bit is cleared, then the corresponding parity is OK.
+ * If the bit is set, then the corresponding parity is bad.
+ * @flags: ASYNC_TX_ASSUME_COHERENT, ASYNC_TX_ACK, ASYNC_TX_DEP_ACK
+ * @depend_tx: 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_syndrome_zero_sum(struct page **blocks, unsigned int offset,
+ int src_cnt, size_t len, u32 *pqres, 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_PQ_ZERO_SUM,
+ &blocks[src_cnt], 2,
+ blocks, src_cnt, len);
+ struct dma_device *device = chan ? chan->device : NULL;
+ struct dma_async_tx_descriptor *tx = NULL;
+ enum dma_ctrl_flags dma_flags = cb_fn ? DMA_PREP_INTERRUPT : 0;
+
+ BUG_ON(src_cnt < 2);
+
+ if (blocks[src_cnt])
+ dma_flags |= DMA_PREP_HAVE_P;
+ if (blocks[src_cnt+1])
+ dma_flags |= DMA_PREP_HAVE_Q;
+
+ if (device && src_cnt <= (int)device->max_pq) {
+ dma_addr_t dma_src[src_cnt + 2];
+ int i;
+
+
+ for (i = 0; i < src_cnt + 2; i++) {
+ if (likely(blocks[i])) {
+ dma_src[i] = dma_map_page(device->dev,
+ blocks[i], offset,
+ len, DMA_TO_DEVICE);
+ }
+ }
+
+ tx = device->device_prep_dma_pqzero_sum(chan, dma_src, src_cnt,
+ (uint8_t *)raid6_gfexp,
+ len, pqres, dma_flags);
+
+ if (unlikely(!tx)) {
+ async_tx_quiesce(&depend_tx);
+ while (unlikely(!tx)) {
+ dma_async_issue_pending(chan);
+ tx = device->device_prep_dma_pqzero_sum(chan,
+ dma_src, src_cnt,
+ (uint8_t *)raid6_gfexp, len,
+ pqres, dma_flags);
+ }
+ }
+
+ async_tx_submit(chan, tx, flags, depend_tx, cb_fn, cb_param);
+ } else {
+ struct page *pdest = blocks[src_cnt];
+ struct page *qdest = blocks[src_cnt + 1];
+ enum async_tx_flags lflags = flags;
+
+ lflags &= ~ASYNC_TX_ACK;
+
+ spin_lock(&spare_lock);
+ blocks[src_cnt] = spare_pages[0];
+ blocks[src_cnt + 1] = spare_pages[1];
+ tx = async_gen_syndrome(blocks, offset,
+ src_cnt, len, lflags,
+ depend_tx, NULL, NULL);
+ async_tx_quiesce(&tx);
+
+ if (dma_flags & DMA_PREP_HAVE_P) {
+ if (memcmp(page_address(pdest) + offset,
+ page_address(spare_pages[0]) + offset,
+ len) == 0)
+ *pqres &= ~DMA_PCHECK_FAILED;
+ else
+ *pqres |= DMA_PCHECK_FAILED;
+ }
+ if (dma_flags & DMA_PREP_HAVE_Q) {
+ if (memcmp(page_address(qdest) + offset,
+ page_address(spare_pages[1]) + offset,
+ len) == 0)
+ *pqres &= ~DMA_QCHECK_FAILED;
+ else
+ *pqres |= DMA_QCHECK_FAILED;
+ }
+ spin_unlock(&spare_lock);
+ }
+
+ return tx;
+}
+EXPORT_SYMBOL_GPL(async_syndrome_zero_sum);
+
+static int __init async_pq_init(void)
+{
+ spin_lock_init(&spare_lock);
+
+ spare_pages[0] = alloc_page(GFP_KERNEL);
+ if (!spare_pages[0])
+ goto abort;
+ spare_pages[1] = alloc_page(GFP_KERNEL);
+ if (!spare_pages[1])
+ goto abort;
+ spare_pages[2] = alloc_page(GFP_KERNEL);
+ if (!spare_pages[2])
+ goto abort;
+ return 0;
+abort:
+ safe_put_page(spare_pages[2]);
+ safe_put_page(spare_pages[1]);
+ safe_put_page(spare_pages[0]);
+ printk(KERN_ERR "%s: cannot allocate spare!\n", __func__);
+ return -ENOMEM;
+}
+
+static void __exit async_pq_exit(void)
+{
+ safe_put_page(spare_pages[2]);
+ safe_put_page(spare_pages[1]);
+ safe_put_page(spare_pages[0]);
+}
+
+module_init(async_pq_init);
+module_exit(async_pq_exit);
+
+MODULE_AUTHOR("Yuri Tikhonov <yur at emcraft.com>");
+MODULE_DESCRIPTION("asynchronous pq/pq-zero-sum api");
+MODULE_LICENSE("GPL");
diff --git a/crypto/async_tx/async_xor.c b/crypto/async_tx/async_xor.c
index e1f1f28..c2bc0ea 100644
--- a/crypto/async_tx/async_xor.c
+++ b/crypto/async_tx/async_xor.c
@@ -68,7 +68,7 @@ do_async_xor(struct dma_chan *chan, struct page *dest, struct page **src_list,
while (src_cnt) {
async_flags = flags;
dma_flags = 0;
- xor_src_cnt = min(src_cnt, dma->max_xor);
+ 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
diff --git a/include/linux/async_tx.h b/include/linux/async_tx.h
index 45f6297..2f92d87 100644
--- a/include/linux/async_tx.h
+++ b/include/linux/async_tx.h
@@ -47,15 +47,26 @@ struct dma_chan_ref {
* address is an implied source, whereas the asynchronous case it must be listed
* as a source. The destination address must be the first address in the source
* array.
+ * @ASYNC_TX_PQ_ZERO_P: this flag must be used for async_pq operations since the
+ * destination there is always the source (the result of P after async_pq is
+ * xor-ed with the previous content of P block if this flag isn't set).
+ * @ASYNC_TX_PQ_ZERO_Q: this flag must be used for async_pq operations since the
+ * destination there is always the source (the result of Q after async_pq is
+ * xor-ed with the previous content of Q block if this flag isn't set).
* @ASYNC_TX_ACK: immediately ack the descriptor, precludes setting up a
* dependency chain
* @ASYNC_TX_DEP_ACK: ack the dependency descriptor. Useful for chaining.
+ * @ASYNC_TX_ASYNC_ONLY: if set then try to perform operation requested only in
+ * the asynchronous mode. Useful for R6 recovery.
*/
enum async_tx_flags {
ASYNC_TX_XOR_ZERO_DST = (1 << 0),
ASYNC_TX_XOR_DROP_DST = (1 << 1),
- ASYNC_TX_ACK = (1 << 3),
- ASYNC_TX_DEP_ACK = (1 << 4),
+ ASYNC_TX_PQ_ZERO_P = (1 << 2),
+ ASYNC_TX_PQ_ZERO_Q = (1 << 3),
+ ASYNC_TX_ACK = (1 << 4),
+ ASYNC_TX_DEP_ACK = (1 << 5),
+ ASYNC_TX_ASYNC_ONLY = (1 << 6),
};
#ifdef CONFIG_DMA_ENGINE
@@ -131,5 +142,36 @@ async_trigger_callback(enum async_tx_flags flags,
struct dma_async_tx_descriptor *depend_tx,
dma_async_tx_callback cb_fn, void *cb_fn_param);
+struct dma_async_tx_descriptor *
+async_pq(struct page **blocks, unsigned char *scoef_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 callback, void *callback_param);
+
+struct dma_async_tx_descriptor *
+async_gen_syndrome(struct page **blocks, 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 callback, void *callback_param);
+
+struct dma_async_tx_descriptor *
+async_pq_zero_sum(struct page **blocks, unsigned char *scoef_list,
+ unsigned int offset, int src_cnt, size_t len,
+ u32 *pqres, enum async_tx_flags flags,
+ struct dma_async_tx_descriptor *depend_tx,
+ dma_async_tx_callback callback, void *callback_param);
+
+struct dma_async_tx_descriptor *
+async_syndrome_zero_sum(struct page **blocks, unsigned int offset,
+ int src_cnt, size_t len, u32 *pqres,
+ enum async_tx_flags flags, struct dma_async_tx_descriptor *depend_tx,
+ dma_async_tx_callback callback, void *callback_param);
+
+struct dma_async_tx_descriptor *
+async_syndrome_zero_sum(struct page **src_list, unsigned int offset,
+ int src_cnt, size_t len, u32 *pqres,
+ enum async_tx_flags flags, struct dma_async_tx_descriptor *depend_tx,
+ dma_async_tx_callback callback, void *callback_param);
+
void async_tx_quiesce(struct dma_async_tx_descriptor **tx);
#endif /* _ASYNC_TX_H_ */
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index 64dea2a..4a72082 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -55,7 +55,7 @@ enum dma_status {
enum dma_transaction_type {
DMA_MEMCPY,
DMA_XOR,
- DMA_PQ_XOR,
+ DMA_PQ,
DMA_DUAL_XOR,
DMA_PQ_UPDATE,
DMA_ZERO_SUM,
@@ -81,14 +81,28 @@ enum dma_transaction_type {
* dependency chains
* @DMA_COMPL_SKIP_SRC_UNMAP - set to disable dma-unmapping the source buffer(s)
* @DMA_COMPL_SKIP_DEST_UNMAP - set to disable dma-unmapping the destination(s)
+ * @DMA_PREP_HAVE_P - set if the destination list includes the correct
+ * address of P (P-parity should be handled)
+ * @DMA_PREP_HAVE_Q - set if the destination list includes the correct
+ * address of Q (Q-parity should be handled)
+ * @DMA_PREP_ZERO_P - set if P has to be zeroed before proceeding
+ * @DMA_PREP_ZERO_Q - set if Q has to be zeroed before proceeding
*/
enum dma_ctrl_flags {
DMA_PREP_INTERRUPT = (1 << 0),
DMA_CTRL_ACK = (1 << 1),
DMA_COMPL_SKIP_SRC_UNMAP = (1 << 2),
DMA_COMPL_SKIP_DEST_UNMAP = (1 << 3),
+
+ DMA_PREP_HAVE_P = (1 << 4),
+ DMA_PREP_HAVE_Q = (1 << 5),
+ DMA_PREP_ZERO_P = (1 << 6),
+ DMA_PREP_ZERO_Q = (1 << 7),
};
+#define DMA_PCHECK_FAILED (1 << 0)
+#define DMA_QCHECK_FAILED (1 << 1)
+
/**
* dma_cap_mask_t - capabilities bitmap modeled after cpumask_t.
* See linux/cpumask.h
@@ -211,6 +225,7 @@ struct dma_async_tx_descriptor {
* @global_node: list_head for global dma_device_list
* @cap_mask: one or more dma_capability flags
* @max_xor: maximum number of xor sources, 0 if no capability
+ * @max_pq: maximum number of PQ sources, 0 if no capability
* @refcount: reference count
* @done: IO completion struct
* @dev_id: unique device ID
@@ -220,7 +235,9 @@ struct dma_async_tx_descriptor {
* @device_free_chan_resources: release DMA channel's resources
* @device_prep_dma_memcpy: prepares a memcpy operation
* @device_prep_dma_xor: prepares a xor operation
+ * @device_prep_dma_pq: prepares a pq operation
* @device_prep_dma_zero_sum: prepares a zero_sum operation
+ * @device_prep_dma_pqzero_sum: prepares a pqzero_sum operation
* @device_prep_dma_memset: prepares a memset operation
* @device_prep_dma_interrupt: prepares an end of chain interrupt operation
* @device_prep_slave_sg: prepares a slave dma operation
@@ -233,7 +250,8 @@ struct dma_device {
struct list_head channels;
struct list_head global_node;
dma_cap_mask_t cap_mask;
- int max_xor;
+ unsigned short max_xor;
+ unsigned short max_pq;
int dev_id;
struct device *dev;
@@ -247,9 +265,17 @@ struct dma_device {
struct dma_async_tx_descriptor *(*device_prep_dma_xor)(
struct dma_chan *chan, dma_addr_t dest, dma_addr_t *src,
unsigned int src_cnt, size_t len, unsigned long flags);
+ struct dma_async_tx_descriptor *(*device_prep_dma_pq)(
+ struct dma_chan *chan, dma_addr_t *dst, dma_addr_t *src,
+ unsigned int src_cnt, unsigned char *scf,
+ size_t len, unsigned long flags);
struct dma_async_tx_descriptor *(*device_prep_dma_zero_sum)(
struct dma_chan *chan, dma_addr_t *src, unsigned int src_cnt,
size_t len, u32 *result, unsigned long flags);
+ struct dma_async_tx_descriptor *(*device_prep_dma_pqzero_sum)(
+ struct dma_chan *chan, dma_addr_t *src, unsigned int src_cnt,
+ unsigned char *scf, size_t len, u32 *pqres,
+ unsigned long flags);
struct dma_async_tx_descriptor *(*device_prep_dma_memset)(
struct dma_chan *chan, dma_addr_t dest, int value, size_t len,
unsigned long flags);
--
1.6.0.6
More information about the Linuxppc-dev
mailing list