diff options
author | Dan Williams <dan.j.williams@intel.com> | 2009-01-05 17:14:31 -0700 |
---|---|---|
committer | Dan Williams <dan.j.williams@intel.com> | 2009-01-05 18:10:19 -0700 |
commit | 07f2211e4fbce6990722d78c4f04225da9c0e9cf (patch) | |
tree | 51934e20a334e93c8c399d2e6375f264551e9bc3 /crypto/async_tx | |
parent | 28405d8d9ce05f5bd869ef8b48da5086f9527d73 (diff) | |
download | lwn-07f2211e4fbce6990722d78c4f04225da9c0e9cf.tar.gz lwn-07f2211e4fbce6990722d78c4f04225da9c0e9cf.zip |
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')
-rw-r--r-- | crypto/async_tx/async_tx.c | 75 |
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) } EXPORT_SYMBOL_GPL(async_tx_issue_pending_all); -/* dma_wait_for_async_tx - spin wait for a transcation to complete - * @tx: transaction to wait on - */ -enum dma_status -dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx) -{ - enum dma_status status; - struct dma_async_tx_descriptor *iter; - struct dma_async_tx_descriptor *parent; - - if (!tx) - return DMA_SUCCESS; - - /* poll through the dependency chain, return when tx is complete */ - do { - iter = tx; - - /* find the root of the unsubmitted dependency chain */ - do { - parent = iter->parent; - if (!parent) - break; - else - iter = parent; - } while (parent); - - /* there is a small window for ->parent == NULL and - * ->cookie == -EBUSY - */ - while (iter->cookie == -EBUSY) - cpu_relax(); - - status = dma_sync_wait(iter->chan, iter->cookie); - } while (status == DMA_IN_PROGRESS || (iter != tx)); - - return status; -} -EXPORT_SYMBOL_GPL(dma_wait_for_async_tx); - -/* async_tx_run_dependencies - helper routine for dma drivers to process - * (start) dependent operations on their target channel - * @tx: transaction with dependencies - */ -void async_tx_run_dependencies(struct dma_async_tx_descriptor *tx) -{ - struct dma_async_tx_descriptor *dep = tx->next; - struct dma_async_tx_descriptor *dep_next; - struct dma_chan *chan; - - if (!dep) - return; - - chan = dep->chan; - - /* keep submitting up until a channel switch is detected - * in that case we will be called again as a result of - * processing the interrupt from async_tx_channel_switch - */ - for (; dep; dep = dep_next) { - spin_lock_bh(&dep->lock); - dep->parent = NULL; - dep_next = dep->next; - if (dep_next && dep_next->chan == chan) - dep->next = NULL; /* ->next will be submitted */ - else - dep_next = NULL; /* submit current dep and terminate */ - spin_unlock_bh(&dep->lock); - - dep->tx_submit(dep); - } - - chan->device->device_issue_pending(chan); -} -EXPORT_SYMBOL_GPL(async_tx_run_dependencies); - static void free_dma_chan_ref(struct rcu_head *rcu) { |