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authorLinus Torvalds <torvalds@linux-foundation.org>2009-09-24 07:55:29 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-09-24 07:55:29 -0700
commita487b6705a811087c182c8cab7e3b5845dfa6ccb (patch)
treec9c1e41b7105b5ac9de7a74416d15f12433ed6ff /Documentation
parent9f6ac7850a9c6363f4117fd2248e232a2d534627 (diff)
parent4b3df5668c8ebaebd8d66a5a94374be3e3b2ef0c (diff)
downloadvexpress-lsk-a487b6705a811087c182c8cab7e3b5845dfa6ccb.tar.gz
Merge branch 'for-linus' of git://neil.brown.name/md
* 'for-linus' of git://neil.brown.name/md: (97 commits) md: raid-1/10: fix RW bits manipulation md: remove unnecessary memset from multipath. md: report device as congested when suspended md: Improve name of threads created by md_register_thread md: remove sparse warnings about lock context. md: remove sparse waring "symbol xxx shadows an earlier one" async_tx/raid6: add missing dma_unmap calls to the async fail case ioat3: fix uninitialized var warnings drivers/dma/ioat/dma_v2.c: fix warnings raid6test: fix stack overflow ioat2: clarify ring size limits md/raid6: cleanup ops_run_compute6_2 md/raid6: eliminate BUG_ON with side effect dca: module load should not be an error message ioat: driver version 4.0 dca: registering requesters in multiple dca domains async_tx: remove HIGHMEM64G restriction dmaengine: sh: Add Support SuperH DMA Engine driver dmaengine: Move all map_sg/unmap_sg for slave channel to its client fsldma: Add DMA_SLAVE support ...
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/crypto/async-tx-api.txt75
1 files changed, 45 insertions, 30 deletions
diff --git a/Documentation/crypto/async-tx-api.txt b/Documentation/crypto/async-tx-api.txt
index 9f59fcbf5d8..ba046b8fa92 100644
--- a/Documentation/crypto/async-tx-api.txt
+++ b/Documentation/crypto/async-tx-api.txt
@@ -54,20 +54,23 @@ features surfaced as a result:
3.1 General format of the API:
struct dma_async_tx_descriptor *
-async_<operation>(<op specific parameters>,
- enum async_tx_flags flags,
- struct dma_async_tx_descriptor *dependency,
- dma_async_tx_callback callback_routine,
- void *callback_parameter);
+async_<operation>(<op specific parameters>, struct async_submit ctl *submit)
3.2 Supported operations:
-memcpy - memory copy between a source and a destination buffer
-memset - fill a destination buffer with a byte value
-xor - xor a series of source buffers and write the result to a
- destination buffer
-xor_zero_sum - xor a series of source buffers and set a flag if the
- result is zero. The implementation attempts to prevent
- writes to memory
+memcpy - memory copy between a source and a destination buffer
+memset - fill a destination buffer with a byte value
+xor - xor a series of source buffers and write the result to a
+ destination buffer
+xor_val - xor a series of source buffers and set a flag if the
+ result is zero. The implementation attempts to prevent
+ writes to memory
+pq - generate the p+q (raid6 syndrome) from a series of source buffers
+pq_val - validate that a p and or q buffer are in sync with a given series of
+ sources
+datap - (raid6_datap_recov) recover a raid6 data block and the p block
+ from the given sources
+2data - (raid6_2data_recov) recover 2 raid6 data blocks from the given
+ sources
3.3 Descriptor management:
The return value is non-NULL and points to a 'descriptor' when the operation
@@ -80,8 +83,8 @@ acknowledged by the application before the offload engine driver is allowed to
recycle (or free) the descriptor. A descriptor can be acked by one of the
following methods:
1/ setting the ASYNC_TX_ACK flag if no child operations are to be submitted
-2/ setting the ASYNC_TX_DEP_ACK flag to acknowledge the parent
- descriptor of a new operation.
+2/ submitting an unacknowledged descriptor as a dependency to another
+ async_tx call will implicitly set the acknowledged state.
3/ calling async_tx_ack() on the descriptor.
3.4 When does the operation execute?
@@ -119,30 +122,42 @@ of an operation.
Perform a xor->copy->xor operation where each operation depends on the
result from the previous operation:
-void complete_xor_copy_xor(void *param)
+void callback(void *param)
{
- printk("complete\n");
+ struct completion *cmp = param;
+
+ complete(cmp);
}
-int run_xor_copy_xor(struct page **xor_srcs,
- int xor_src_cnt,
- struct page *xor_dest,
- size_t xor_len,
- struct page *copy_src,
- struct page *copy_dest,
- size_t copy_len)
+void run_xor_copy_xor(struct page **xor_srcs,
+ int xor_src_cnt,
+ struct page *xor_dest,
+ size_t xor_len,
+ struct page *copy_src,
+ struct page *copy_dest,
+ size_t copy_len)
{
struct dma_async_tx_descriptor *tx;
+ addr_conv_t addr_conv[xor_src_cnt];
+ struct async_submit_ctl submit;
+ addr_conv_t addr_conv[NDISKS];
+ struct completion cmp;
+
+ init_async_submit(&submit, ASYNC_TX_XOR_DROP_DST, NULL, NULL, NULL,
+ addr_conv);
+ tx = async_xor(xor_dest, xor_srcs, 0, xor_src_cnt, xor_len, &submit)
- tx = async_xor(xor_dest, xor_srcs, 0, xor_src_cnt, xor_len,
- ASYNC_TX_XOR_DROP_DST, NULL, NULL, NULL);
- tx = async_memcpy(copy_dest, copy_src, 0, 0, copy_len,
- ASYNC_TX_DEP_ACK, tx, NULL, NULL);
- tx = async_xor(xor_dest, xor_srcs, 0, xor_src_cnt, xor_len,
- ASYNC_TX_XOR_DROP_DST | ASYNC_TX_DEP_ACK | ASYNC_TX_ACK,
- tx, complete_xor_copy_xor, NULL);
+ submit->depend_tx = tx;
+ tx = async_memcpy(copy_dest, copy_src, 0, 0, copy_len, &submit);
+
+ init_completion(&cmp);
+ init_async_submit(&submit, ASYNC_TX_XOR_DROP_DST | ASYNC_TX_ACK, tx,
+ callback, &cmp, addr_conv);
+ tx = async_xor(xor_dest, xor_srcs, 0, xor_src_cnt, xor_len, &submit);
async_tx_issue_pending_all();
+
+ wait_for_completion(&cmp);
}
See include/linux/async_tx.h for more information on the flags. See the