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Diffstat (limited to 'Documentation/crypto/async-tx-api.txt')
| -rw-r--r-- | Documentation/crypto/async-tx-api.txt | 75 |
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 |