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-rw-r--r--crypto/async_tx/async_pq.c75
1 files changed, 48 insertions, 27 deletions
diff --git a/crypto/async_tx/async_pq.c b/crypto/async_tx/async_pq.c
index b88db6d..fdd8257 100644
--- a/crypto/async_tx/async_pq.c
+++ b/crypto/async_tx/async_pq.c
@@ -24,16 +24,13 @@
#include <linux/dma-mapping.h>
#include <linux/raid/pq.h>
#include <linux/async_tx.h>
+#include <linux/gfp.h>
/**
- * scribble - space to hold throwaway P buffer for synchronous gen_syndrome
+ * pq_scribble_page - space to hold throwaway P or Q buffer for
+ * synchronous gen_syndrome
*/
-static struct page *scribble;
-
-static bool is_raid6_zero_block(struct page *p)
-{
- return p == (void *) raid6_empty_zero_page;
-}
+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
@@ -83,7 +80,7 @@ do_async_gen_syndrome(struct dma_chan *chan, struct page **blocks,
* sources and update the coefficients accordingly
*/
for (i = 0, idx = 0; i < src_cnt; i++) {
- if (is_raid6_zero_block(blocks[i]))
+ if (blocks[i] == NULL)
continue;
dma_src[idx] = dma_map_page(dma->dev, blocks[i], offset, len,
DMA_TO_DEVICE);
@@ -160,9 +157,9 @@ do_sync_gen_syndrome(struct page **blocks, unsigned int offset, int disks,
srcs = (void **) blocks;
for (i = 0; i < disks; i++) {
- if (is_raid6_zero_block(blocks[i])) {
+ if (blocks[i] == NULL) {
BUG_ON(i > disks - 3); /* P or Q can't be zero */
- srcs[i] = blocks[i];
+ srcs[i] = (void*)raid6_empty_zero_page;
} else
srcs[i] = page_address(blocks[i]) + offset;
}
@@ -186,10 +183,14 @@ do_sync_gen_syndrome(struct page **blocks, unsigned int offset, int disks,
* 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.
+ * 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 overridden
+ * '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,
@@ -227,11 +228,11 @@ async_gen_syndrome(struct page **blocks, unsigned int offset, int disks,
async_tx_quiesce(&submit->depend_tx);
if (!P(blocks, disks)) {
- P(blocks, disks) = scribble;
+ P(blocks, disks) = pq_scribble_page;
BUG_ON(len + offset > PAGE_SIZE);
}
if (!Q(blocks, disks)) {
- Q(blocks, disks) = scribble;
+ Q(blocks, disks) = pq_scribble_page;
BUG_ON(len + offset > PAGE_SIZE);
}
do_sync_gen_syndrome(blocks, offset, disks, len, submit);
@@ -240,6 +241,16 @@ async_gen_syndrome(struct page **blocks, unsigned int offset, int disks,
}
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
@@ -260,13 +271,13 @@ 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_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);
@@ -285,22 +296,32 @@ async_syndrome_val(struct page **blocks, unsigned int offset, int disks,
__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; i++)
+ for (i = 0; i < disks-2; 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);
+ 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,
- disks - 2,
- raid6_gfexp,
+ src_cnt,
+ coefs,
len, pqres,
dma_flags);
if (likely(tx))
@@ -373,9 +394,9 @@ EXPORT_SYMBOL_GPL(async_syndrome_val);
static int __init async_pq_init(void)
{
- scribble = alloc_page(GFP_KERNEL);
+ pq_scribble_page = alloc_page(GFP_KERNEL);
- if (scribble)
+ if (pq_scribble_page)
return 0;
pr_err("%s: failed to allocate required spare page\n", __func__);
@@ -385,7 +406,7 @@ static int __init async_pq_init(void)
static void __exit async_pq_exit(void)
{
- put_page(scribble);
+ put_page(pq_scribble_page);
}
module_init(async_pq_init);
generated by cgit v1.1 at 2024-12-24 01:10:41 +0000