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authorDan Williams <dan.j.williams@intel.com>2009-06-03 17:22:28 -0400
committerDan Williams <dan.j.williams@intel.com>2009-06-03 17:22:28 -0400
commit04ce9ab385dc97eb55299d533cd3af79b8fc7529 (patch)
tree9b8d0b9c1eba820a8a107d05abc2e2f8d4d20a59 /Documentation
parenta08abd8ca890a377521d65d493d174bebcaf694b (diff)
async_xor: permit callers to pass in a 'dma/page scribble' region
async_xor() needs space to perform dma and page address conversions. In most cases the code can simply reuse the struct page * array because the size of the native pointer matches the size of a dma/page address. In order to support archs where sizeof(dma_addr_t) is larger than sizeof(struct page *), or to preserve the input parameters, we utilize a memory region passed in by the caller. Since the code is now prepared to handle the case where it cannot perform address conversions on the stack, we no longer need the !HIGHMEM64G dependency in drivers/dma/Kconfig. [ Impact: don't clobber input buffers for address conversions ] Reviewed-by: Andre Noll <maan@systemlinux.org> Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/crypto/async-tx-api.txt43
1 files changed, 28 insertions, 15 deletions
diff --git a/Documentation/crypto/async-tx-api.txt b/Documentation/crypto/async-tx-api.txt
index dfe0475f7919..6b15e488c0e7 100644
--- a/Documentation/crypto/async-tx-api.txt
+++ b/Documentation/crypto/async-tx-api.txt
@@ -115,29 +115,42 @@ of an operation.
115Perform a xor->copy->xor operation where each operation depends on the 115Perform a xor->copy->xor operation where each operation depends on the
116result from the previous operation: 116result from the previous operation:
117 117
118void complete_xor_copy_xor(void *param) 118void callback(void *param)
119{ 119{
120 printk("complete\n"); 120 struct completion *cmp = param;
121
122 complete(cmp);
121} 123}
122 124
123int run_xor_copy_xor(struct page **xor_srcs, 125void run_xor_copy_xor(struct page **xor_srcs,
124 int xor_src_cnt, 126 int xor_src_cnt,
125 struct page *xor_dest, 127 struct page *xor_dest,
126 size_t xor_len, 128 size_t xor_len,
127 struct page *copy_src, 129 struct page *copy_src,
128 struct page *copy_dest, 130 struct page *copy_dest,
129 size_t copy_len) 131 size_t copy_len)
130{ 132{
131 struct dma_async_tx_descriptor *tx; 133 struct dma_async_tx_descriptor *tx;
134 addr_conv_t addr_conv[xor_src_cnt];
135 struct async_submit_ctl submit;
136 addr_conv_t addr_conv[NDISKS];
137 struct completion cmp;
138
139 init_async_submit(&submit, ASYNC_TX_XOR_DROP_DST, NULL, NULL, NULL,
140 addr_conv);
141 tx = async_xor(xor_dest, xor_srcs, 0, xor_src_cnt, xor_len, &submit)
132 142
133 tx = async_xor(xor_dest, xor_srcs, 0, xor_src_cnt, xor_len, 143 submit->depend_tx = tx;
134 ASYNC_TX_XOR_DROP_DST, NULL, NULL, NULL); 144 tx = async_memcpy(copy_dest, copy_src, 0, 0, copy_len, &submit);
135 tx = async_memcpy(copy_dest, copy_src, 0, 0, copy_len, tx, NULL, NULL); 145
136 tx = async_xor(xor_dest, xor_srcs, 0, xor_src_cnt, xor_len, 146 init_completion(&cmp);
137 ASYNC_TX_XOR_DROP_DST | ASYNC_TX_ACK, 147 init_async_submit(&submit, ASYNC_TX_XOR_DROP_DST | ASYNC_TX_ACK, tx,
138 tx, complete_xor_copy_xor, NULL); 148 callback, &cmp, addr_conv);
149 tx = async_xor(xor_dest, xor_srcs, 0, xor_src_cnt, xor_len, &submit);
139 150
140 async_tx_issue_pending_all(); 151 async_tx_issue_pending_all();
152
153 wait_for_completion(&cmp);
141} 154}
142 155
143See include/linux/async_tx.h for more information on the flags. See the 156See include/linux/async_tx.h for more information on the flags. See the