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;
}
/**
* async_raid6_datap_recov - asynchronously calculate a data and the 'p' block
* @disks: number of disks in the RAID-6 array
* @bytes: block size
* @faila: 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_datap_recov(int disks, size_t bytes, int faila,
struct page **blocks, struct async_submit_ctl *submit)
{
struct dma_async_tx_descriptor *tx = NULL;
struct page *p, *q, *dq;
u8 coef;
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;
struct page *srcs[2];
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 (!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_datap_recov(disks, bytes, faila, ptrs);
async_tx_sync_epilog(submit);
return NULL;
}
good_srcs = 0;
good = -1;
for (i = 0; i < disks-2; i++) {
if (i == faila)
continue;
if (blocks[i]) {
good = i;
good_srcs++;
if (good_srcs > 1)
break;
}
}
BUG_ON(good_srcs == 0);
p = blocks[disks-2];
q = blocks[disks-1];
/* Compute syndrome with zero for the missing data page
* Use the dead data page as temporary storage for delta q
*/
dq = blocks[faila];
blocks[faila] = NULL;
blocks[disks-1] = dq;
/* in the 4-disk case we only need to perform a single source
* multiplication with the one good data block.
*/
if (good_srcs == 1) {
struct page *g = blocks[good];
init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL,
scribble);
tx = async_memcpy(p, 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);
} else {
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] = dq;
blocks[disks-1] = q;
/* calculate g^{-faila} */
coef = raid6_gfinv[raid6_gfexp[faila]];
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);
init_async_submit(submit, ASYNC_TX_FENCE, tx, NULL, NULL, scribble);
tx = async_mult(dq, dq, coef, bytes, submit);
srcs[0] = p;
srcs[1] = dq;
init_async_submit(submit, flags | ASYNC_TX_XOR_DROP_DST, tx, cb_fn,
cb_param, scribble);
tx = async_xor(p, 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;
}
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;
}
/* Recover two failed blocks. */
static void raid6_dual_recov(int disks, size_t bytes, int faila, int failb, struct page **ptrs)
{
struct async_submit_ctl submit;
struct completion cmp;
struct dma_async_tx_descriptor *tx = NULL;
enum sum_check_flags result = ~0;
if (faila > failb)
swap(faila, failb);
if (failb == disks-1) {
if (faila == disks-2) {
/* P+Q failure. Just rebuild the syndrome. */
init_async_submit(&submit, 0, NULL, NULL, NULL, addr_conv);
tx = async_gen_syndrome(ptrs, 0, disks, bytes, &submit);
} else {
struct page *blocks[disks];
struct page *dest;
int count = 0;
int i;
/* data+Q failure. Reconstruct data from P,
* then rebuild syndrome
*/
for (i = disks; i-- ; ) {
if (i == faila || i == failb)
continue;
blocks[count++] = ptrs[i];
}
dest = ptrs[faila];
init_async_submit(&submit, ASYNC_TX_XOR_ZERO_DST, NULL,
NULL, NULL, addr_conv);
tx = async_xor(dest, blocks, 0, count, bytes, &submit);
init_async_submit(&submit, 0, tx, NULL, NULL, addr_conv);
tx = async_gen_syndrome(ptrs, 0, disks, bytes, &submit);
}
} else {
if (failb == disks-2) {
/* data+P failure. */
init_async_submit(&submit, 0, NULL, NULL, NULL, addr_conv);
tx = async_raid6_datap_recov(disks, bytes, faila, ptrs, &submit);
} else {
/* data+data failure. */
init_async_submit(&submit, 0, NULL, NULL, NULL, addr_conv);
tx = async_raid6_2data_recov(disks, bytes, faila, failb, ptrs, &submit);
}
}
init_completion(&cmp);
init_async_submit(&submit, ASYNC_TX_ACK, tx, callback, &cmp, addr_conv);
tx = async_syndrome_val(ptrs, 0, disks, bytes, &result, spare, &submit);
async_tx_issue_pending(tx);
if (wait_for_completion_timeout(&cmp, msecs_to_jiffies(3000)) == 0)
pr("%s: timeout! (faila: %d failb: %d disks: %d)\n",
__func__, faila, failb, disks);
if (result != 0)
pr("%s: validation failure! faila: %d failb: %d sum_check_flags: %x\n",
__func__, faila, failb, result);
}
/**
* 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 = xor_val_chan(submit, dest, 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 &&
is_dma_xor_aligned(device, offset, 0, len)) {
unsigned long dma_prep_flags = 0;
int i;
pr_debug("%s: (async) len: %zu\n", __func__, len);
if (submit->cb_fn)
dma_prep_flags |= DMA_PREP_INTERRUPT;
if (submit->flags & ASYNC_TX_FENCE)
dma_prep_flags |= DMA_PREP_FENCE;
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;
}
/**
* 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_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,
&dest, 1, src_list,
src_cnt, len);
struct dma_device *device = chan ? chan->device : NULL;
struct dma_async_tx_descriptor *tx = NULL;
BUG_ON(src_cnt <= 1);
if (device && src_cnt <= device->max_xor) {
dma_addr_t *dma_src = (dma_addr_t *) src_list;
unsigned long dma_prep_flags = cb_fn ? DMA_PREP_INTERRUPT : 0;
int i;
pr_debug("%s: (async) len: %zu\n", __func__, len);
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_zero_sum(chan, dma_src, src_cnt,
len, result,
dma_prep_flags);
if (!tx) {
if (depend_tx)
dma_wait_for_async_tx(depend_tx);
while (!tx)
tx = device->device_prep_dma_zero_sum(chan,
dma_src, src_cnt, len, result,
dma_prep_flags);
}
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", __func__, 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",
__func__);
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;
}
/**
* 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;
struct dmaengine_unmap_data *unmap = NULL;
BUG_ON(disks < 4);
if (device)
unmap = dmaengine_get_unmap_data(device->dev, disks, GFP_NOWAIT);
if (unmap && disks <= dma_maxpq(device, 0) &&
is_dma_pq_aligned(device, offset, 0, len)) {
struct device *dev = device->dev;
dma_addr_t pq[2];
int i, j = 0, src_cnt = 0;
pr_debug("%s: (async) disks: %d len: %zu\n",
__func__, disks, len);
unmap->len = len;
for (i = 0; i < disks-2; i++)
if (likely(blocks[i])) {
unmap->addr[j] = dma_map_page(dev, blocks[i],
offset, len,
DMA_TO_DEVICE);
coefs[j] = raid6_gfexp[i];
unmap->to_cnt++;
src_cnt++;
j++;
}
if (!P(blocks, disks)) {
pq[0] = 0;
dma_flags |= DMA_PREP_PQ_DISABLE_P;
} else {
pq[0] = dma_map_page(dev, P(blocks, disks),
offset, len,
DMA_TO_DEVICE);
unmap->addr[j++] = pq[0];
unmap->to_cnt++;
}
if (!Q(blocks, disks)) {
pq[1] = 0;
dma_flags |= DMA_PREP_PQ_DISABLE_Q;
} else {
pq[1] = dma_map_page(dev, Q(blocks, disks),
offset, len,
DMA_TO_DEVICE);
unmap->addr[j++] = pq[1];
unmap->to_cnt++;
}
if (submit->flags & ASYNC_TX_FENCE)
dma_flags |= DMA_PREP_FENCE;
for (;;) {
tx = device->device_prep_dma_pq_val(chan, pq,
unmap->addr,
src_cnt,
coefs,
len, pqres,
dma_flags);
if (likely(tx))
break;
async_tx_quiesce(&submit->depend_tx);
dma_async_issue_pending(chan);
}
dma_set_unmap(tx, unmap);
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;
}
}
/**
* 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 = async_tx_find_channel(submit, DMA_PQ_VAL,
NULL, 0, blocks, disks,
len);
struct dma_device *device = chan ? chan->device : NULL;
struct dma_async_tx_descriptor *tx;
enum dma_ctrl_flags dma_flags = submit->cb_fn ? DMA_PREP_INTERRUPT : 0;
dma_addr_t *dma_src = NULL;
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;
if (!Q(blocks, disks))
dma_flags |= DMA_PREP_PQ_DISABLE_Q;
if (submit->flags & ASYNC_TX_FENCE)
dma_flags |= DMA_PREP_FENCE;
for (i = 0; i < disks; i++)
if (likely(blocks[i])) {
BUG_ON(is_raid6_zero_block(blocks[i]));
dma_src[i] = dma_map_page(dev, blocks[i],
offset, len,
DMA_TO_DEVICE);
}
for (;;) {
tx = device->device_prep_dma_pq_val(chan, pq, dma_src,
disks - 2,
raid6_gfexp,
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;
}
}
