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-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 9f59fcbf5d82..ba046b8fa92f 100644
--- a/Documentation/crypto/async-tx-api.txt
+++ b/Documentation/crypto/async-tx-api.txt
@@ -54,20 +54,23 @@ features surfaced as a result:
54 54
553.1 General format of the API: 553.1 General format of the API:
56struct dma_async_tx_descriptor * 56struct dma_async_tx_descriptor *
57async_<operation>(<op specific parameters>, 57async_<operation>(<op specific parameters>, struct async_submit ctl *submit)
58 enum async_tx_flags flags,
59 struct dma_async_tx_descriptor *dependency,
60 dma_async_tx_callback callback_routine,
61 void *callback_parameter);
62 58
633.2 Supported operations: 593.2 Supported operations:
64memcpy - memory copy between a source and a destination buffer 60memcpy - memory copy between a source and a destination buffer
65memset - fill a destination buffer with a byte value 61memset - fill a destination buffer with a byte value
66xor - xor a series of source buffers and write the result to a 62xor - xor a series of source buffers and write the result to a
67 destination buffer 63 destination buffer
68xor_zero_sum - xor a series of source buffers and set a flag if the 64xor_val - xor a series of source buffers and set a flag if the
69 result is zero. The implementation attempts to prevent 65 result is zero. The implementation attempts to prevent
70 writes to memory 66 writes to memory
67pq - generate the p+q (raid6 syndrome) from a series of source buffers
68pq_val - validate that a p and or q buffer are in sync with a given series of
69 sources
70datap - (raid6_datap_recov) recover a raid6 data block and the p block
71 from the given sources
722data - (raid6_2data_recov) recover 2 raid6 data blocks from the given
73 sources
71 74
723.3 Descriptor management: 753.3 Descriptor management:
73The return value is non-NULL and points to a 'descriptor' when the operation 76The 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
80recycle (or free) the descriptor. A descriptor can be acked by one of the 83recycle (or free) the descriptor. A descriptor can be acked by one of the
81following methods: 84following methods:
821/ setting the ASYNC_TX_ACK flag if no child operations are to be submitted 851/ setting the ASYNC_TX_ACK flag if no child operations are to be submitted
832/ setting the ASYNC_TX_DEP_ACK flag to acknowledge the parent 862/ submitting an unacknowledged descriptor as a dependency to another
84 descriptor of a new operation. 87 async_tx call will implicitly set the acknowledged state.
853/ calling async_tx_ack() on the descriptor. 883/ calling async_tx_ack() on the descriptor.
86 89
873.4 When does the operation execute? 903.4 When does the operation execute?
@@ -119,30 +122,42 @@ of an operation.
119Perform a xor->copy->xor operation where each operation depends on the 122Perform a xor->copy->xor operation where each operation depends on the
120result from the previous operation: 123result from the previous operation:
121 124
122void complete_xor_copy_xor(void *param) 125void callback(void *param)
123{ 126{
124 printk("complete\n"); 127 struct completion *cmp = param;
128
129 complete(cmp);
125} 130}
126 131
127int run_xor_copy_xor(struct page **xor_srcs, 132void run_xor_copy_xor(struct page **xor_srcs,
128 int xor_src_cnt, 133 int xor_src_cnt,
129 struct page *xor_dest, 134 struct page *xor_dest,
130 size_t xor_len, 135 size_t xor_len,
131 struct page *copy_src, 136 struct page *copy_src,
132 struct page *copy_dest, 137 struct page *copy_dest,
133 size_t copy_len) 138 size_t copy_len)
134{ 139{
135 struct dma_async_tx_descriptor *tx; 140 struct dma_async_tx_descriptor *tx;
141 addr_conv_t addr_conv[xor_src_cnt];
142 struct async_submit_ctl submit;
143 addr_conv_t addr_conv[NDISKS];
144 struct completion cmp;
145
146 init_async_submit(&submit, ASYNC_TX_XOR_DROP_DST, NULL, NULL, NULL,
147 addr_conv);
148 tx = async_xor(xor_dest, xor_srcs, 0, xor_src_cnt, xor_len, &submit)
136 149
137 tx = async_xor(xor_dest, xor_srcs, 0, xor_src_cnt, xor_len, 150 submit->depend_tx = tx;
138 ASYNC_TX_XOR_DROP_DST, NULL, NULL, NULL); 151 tx = async_memcpy(copy_dest, copy_src, 0, 0, copy_len, &submit);
139 tx = async_memcpy(copy_dest, copy_src, 0, 0, copy_len, 152
140 ASYNC_TX_DEP_ACK, tx, NULL, NULL); 153 init_completion(&cmp);
141 tx = async_xor(xor_dest, xor_srcs, 0, xor_src_cnt, xor_len, 154 init_async_submit(&submit, ASYNC_TX_XOR_DROP_DST | ASYNC_TX_ACK, tx,
142 ASYNC_TX_XOR_DROP_DST | ASYNC_TX_DEP_ACK | ASYNC_TX_ACK, 155 callback, &cmp, addr_conv);
143 tx, complete_xor_copy_xor, NULL); 156 tx = async_xor(xor_dest, xor_srcs, 0, xor_src_cnt, xor_len, &submit);
144 157
145 async_tx_issue_pending_all(); 158 async_tx_issue_pending_all();
159
160 wait_for_completion(&cmp);
146} 161}
147 162
148See include/linux/async_tx.h for more information on the flags. See the 163See include/linux/async_tx.h for more information on the flags. See the