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authorDan Williams <dan.j.williams@intel.com>2009-01-05 19:14:31 -0500
committerDan Williams <dan.j.williams@intel.com>2009-01-05 20:10:19 -0500
commit07f2211e4fbce6990722d78c4f04225da9c0e9cf (patch)
tree51934e20a334e93c8c399d2e6375f264551e9bc3 /crypto/async_tx/async_tx.c
parent28405d8d9ce05f5bd869ef8b48da5086f9527d73 (diff)
dmaengine: remove dependency on async_tx
async_tx.ko is a consumer of dma channels. A circular dependency arises if modules in drivers/dma rely on common code in async_tx.ko. It prevents either module from being unloaded. Move dma_wait_for_async_tx and async_tx_run_dependencies to dmaeninge.o where they should have been from the beginning. Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'crypto/async_tx/async_tx.c')
-rw-r--r--crypto/async_tx/async_tx.c75
1 files changed, 0 insertions, 75 deletions
diff --git a/crypto/async_tx/async_tx.c b/crypto/async_tx/async_tx.c
index dcbf1be149f3..8cfac182165d 100644
--- a/crypto/async_tx/async_tx.c
+++ b/crypto/async_tx/async_tx.c
@@ -72,81 +72,6 @@ void async_tx_issue_pending_all(void)
72} 72}
73EXPORT_SYMBOL_GPL(async_tx_issue_pending_all); 73EXPORT_SYMBOL_GPL(async_tx_issue_pending_all);
74 74
75/* dma_wait_for_async_tx - spin wait for a transcation to complete
76 * @tx: transaction to wait on
77 */
78enum dma_status
79dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx)
80{
81 enum dma_status status;
82 struct dma_async_tx_descriptor *iter;
83 struct dma_async_tx_descriptor *parent;
84
85 if (!tx)
86 return DMA_SUCCESS;
87
88 /* poll through the dependency chain, return when tx is complete */
89 do {
90 iter = tx;
91
92 /* find the root of the unsubmitted dependency chain */
93 do {
94 parent = iter->parent;
95 if (!parent)
96 break;
97 else
98 iter = parent;
99 } while (parent);
100
101 /* there is a small window for ->parent == NULL and
102 * ->cookie == -EBUSY
103 */
104 while (iter->cookie == -EBUSY)
105 cpu_relax();
106
107 status = dma_sync_wait(iter->chan, iter->cookie);
108 } while (status == DMA_IN_PROGRESS || (iter != tx));
109
110 return status;
111}
112EXPORT_SYMBOL_GPL(dma_wait_for_async_tx);
113
114/* async_tx_run_dependencies - helper routine for dma drivers to process
115 * (start) dependent operations on their target channel
116 * @tx: transaction with dependencies
117 */
118void async_tx_run_dependencies(struct dma_async_tx_descriptor *tx)
119{
120 struct dma_async_tx_descriptor *dep = tx->next;
121 struct dma_async_tx_descriptor *dep_next;
122 struct dma_chan *chan;
123
124 if (!dep)
125 return;
126
127 chan = dep->chan;
128
129 /* keep submitting up until a channel switch is detected
130 * in that case we will be called again as a result of
131 * processing the interrupt from async_tx_channel_switch
132 */
133 for (; dep; dep = dep_next) {
134 spin_lock_bh(&dep->lock);
135 dep->parent = NULL;
136 dep_next = dep->next;
137 if (dep_next && dep_next->chan == chan)
138 dep->next = NULL; /* ->next will be submitted */
139 else
140 dep_next = NULL; /* submit current dep and terminate */
141 spin_unlock_bh(&dep->lock);
142
143 dep->tx_submit(dep);
144 }
145
146 chan->device->device_issue_pending(chan);
147}
148EXPORT_SYMBOL_GPL(async_tx_run_dependencies);
149
150static void 75static void
151free_dma_chan_ref(struct rcu_head *rcu) 76free_dma_chan_ref(struct rcu_head *rcu)
152{ 77{