From 88ba2aa586c874681c072101287e15d40de7e6e2 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Thu, 9 Apr 2009 16:16:18 -0700 Subject: async_tx: kill ASYNC_TX_DEP_ACK flag In support of inter-channel chaining async_tx utilizes an ack flag to gate whether a dependent operation can be chained to another. While the flag is not set the chain can be considered open for appending. Setting the ack flag closes the chain and flags the descriptor for garbage collection. The ASYNC_TX_DEP_ACK flag essentially means "close the chain after adding this dependency". Since each operation can only have one child the api now implicitly sets the ack flag at dependency submission time. This removes an unnecessary management burden from clients of the api. [ Impact: clean up and enforce one dependency per operation ] Reviewed-by: Andre Noll Acked-by: Maciej Sosnowski Signed-off-by: Dan Williams --- crypto/async_tx/async_tx.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'crypto/async_tx/async_tx.c') diff --git a/crypto/async_tx/async_tx.c b/crypto/async_tx/async_tx.c index 06eb6cc09fef..3766bc3d7d89 100644 --- a/crypto/async_tx/async_tx.c +++ b/crypto/async_tx/async_tx.c @@ -223,7 +223,7 @@ async_tx_submit(struct dma_chan *chan, struct dma_async_tx_descriptor *tx, if (flags & ASYNC_TX_ACK) async_tx_ack(tx); - if (depend_tx && (flags & ASYNC_TX_DEP_ACK)) + if (depend_tx) async_tx_ack(depend_tx); } EXPORT_SYMBOL_GPL(async_tx_submit); @@ -231,7 +231,7 @@ EXPORT_SYMBOL_GPL(async_tx_submit); /** * async_trigger_callback - schedules the callback function to be run after * any dependent operations have been completed. - * @flags: ASYNC_TX_ACK, ASYNC_TX_DEP_ACK + * @flags: ASYNC_TX_ACK * @depend_tx: 'callback' requires the completion of this transaction * @cb_fn: function to call after depend_tx completes * @cb_param: parameter to pass to the callback routine -- cgit v1.2.2 From a08abd8ca890a377521d65d493d174bebcaf694b Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Wed, 3 Jun 2009 11:43:59 -0700 Subject: async_tx: structify submission arguments, add scribble Prepare the api for the arrival of a new parameter, 'scribble'. This will allow callers to identify scratchpad memory for dma address or page address conversions. As this adds yet another parameter, take this opportunity to convert the common submission parameters (flags, dependency, callback, and callback argument) into an object that is passed by reference. Also, take this opportunity to fix up the kerneldoc and add notes about the relevant ASYNC_TX_* flags for each routine. [ Impact: moves api pass-by-value parameters to a pass-by-reference struct ] Signed-off-by: Andre Noll Acked-by: Maciej Sosnowski Signed-off-by: Dan Williams --- crypto/async_tx/async_tx.c | 51 ++++++++++++++++++++++++---------------------- 1 file changed, 27 insertions(+), 24 deletions(-) (limited to 'crypto/async_tx/async_tx.c') diff --git a/crypto/async_tx/async_tx.c b/crypto/async_tx/async_tx.c index 3766bc3d7d89..802a5ce437d9 100644 --- a/crypto/async_tx/async_tx.c +++ b/crypto/async_tx/async_tx.c @@ -45,13 +45,15 @@ static void __exit async_tx_exit(void) /** * __async_tx_find_channel - find a channel to carry out the operation or let * the transaction execute synchronously - * @depend_tx: transaction dependency + * @submit: transaction dependency and submission modifiers * @tx_type: transaction type */ struct dma_chan * -__async_tx_find_channel(struct dma_async_tx_descriptor *depend_tx, - enum dma_transaction_type tx_type) +__async_tx_find_channel(struct async_submit_ctl *submit, + enum dma_transaction_type tx_type) { + struct dma_async_tx_descriptor *depend_tx = submit->depend_tx; + /* see if we can keep the chain on one channel */ if (depend_tx && dma_has_cap(tx_type, depend_tx->chan->device->cap_mask)) @@ -144,13 +146,14 @@ async_tx_channel_switch(struct dma_async_tx_descriptor *depend_tx, /** - * submit_disposition - while holding depend_tx->lock we must avoid submitting - * new operations to prevent a circular locking dependency with - * drivers that already hold a channel lock when calling - * async_tx_run_dependencies. + * submit_disposition - flags for routing an incoming operation * @ASYNC_TX_SUBMITTED: we were able to append the new operation under the lock * @ASYNC_TX_CHANNEL_SWITCH: when the lock is dropped schedule a channel switch * @ASYNC_TX_DIRECT_SUBMIT: when the lock is dropped submit directly + * + * while holding depend_tx->lock we must avoid submitting new operations + * to prevent a circular locking dependency with drivers that already + * hold a channel lock when calling async_tx_run_dependencies. */ enum submit_disposition { ASYNC_TX_SUBMITTED, @@ -160,11 +163,12 @@ enum submit_disposition { void async_tx_submit(struct dma_chan *chan, struct dma_async_tx_descriptor *tx, - enum async_tx_flags flags, struct dma_async_tx_descriptor *depend_tx, - dma_async_tx_callback cb_fn, void *cb_param) + struct async_submit_ctl *submit) { - tx->callback = cb_fn; - tx->callback_param = cb_param; + struct dma_async_tx_descriptor *depend_tx = submit->depend_tx; + + tx->callback = submit->cb_fn; + tx->callback_param = submit->cb_param; if (depend_tx) { enum submit_disposition s; @@ -220,7 +224,7 @@ async_tx_submit(struct dma_chan *chan, struct dma_async_tx_descriptor *tx, tx->tx_submit(tx); } - if (flags & ASYNC_TX_ACK) + if (submit->flags & ASYNC_TX_ACK) async_tx_ack(tx); if (depend_tx) @@ -229,21 +233,20 @@ async_tx_submit(struct dma_chan *chan, struct dma_async_tx_descriptor *tx, EXPORT_SYMBOL_GPL(async_tx_submit); /** - * async_trigger_callback - schedules the callback function to be run after - * any dependent operations have been completed. - * @flags: ASYNC_TX_ACK - * @depend_tx: 'callback' requires the completion of this transaction - * @cb_fn: function to call after depend_tx completes - * @cb_param: parameter to pass to the callback routine + * async_trigger_callback - schedules the callback function to be run + * @submit: submission and completion parameters + * + * honored flags: ASYNC_TX_ACK + * + * The callback is run after any dependent operations have completed. */ struct dma_async_tx_descriptor * -async_trigger_callback(enum async_tx_flags flags, - struct dma_async_tx_descriptor *depend_tx, - dma_async_tx_callback cb_fn, void *cb_param) +async_trigger_callback(struct async_submit_ctl *submit) { struct dma_chan *chan; struct dma_device *device; struct dma_async_tx_descriptor *tx; + struct dma_async_tx_descriptor *depend_tx = submit->depend_tx; if (depend_tx) { chan = depend_tx->chan; @@ -262,14 +265,14 @@ async_trigger_callback(enum async_tx_flags flags, if (tx) { pr_debug("%s: (async)\n", __func__); - async_tx_submit(chan, tx, flags, depend_tx, cb_fn, cb_param); + async_tx_submit(chan, tx, submit); } else { pr_debug("%s: (sync)\n", __func__); /* wait for any prerequisite operations */ - async_tx_quiesce(&depend_tx); + async_tx_quiesce(&submit->depend_tx); - async_tx_sync_epilog(cb_fn, cb_param); + async_tx_sync_epilog(submit); } return tx; -- cgit v1.2.2 From af1f951eb6ef27b01cbfb3f6c21b770af4368a6d Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Sat, 29 Aug 2009 19:09:26 -0700 Subject: async_tx: kill needless module_{init|exit} If module_init and module_exit are nops then neither need to be defined. [ Impact: pure cleanup ] Reviewed-by: Andre Noll Acked-by: Maciej Sosnowski Signed-off-by: Dan Williams --- crypto/async_tx/async_tx.c | 17 +++-------------- 1 file changed, 3 insertions(+), 14 deletions(-) (limited to 'crypto/async_tx/async_tx.c') diff --git a/crypto/async_tx/async_tx.c b/crypto/async_tx/async_tx.c index 802a5ce437d9..6e37ad3f4417 100644 --- a/crypto/async_tx/async_tx.c +++ b/crypto/async_tx/async_tx.c @@ -42,6 +42,9 @@ static void __exit async_tx_exit(void) async_dmaengine_put(); } +module_init(async_tx_init); +module_exit(async_tx_exit); + /** * __async_tx_find_channel - find a channel to carry out the operation or let * the transaction execute synchronously @@ -61,17 +64,6 @@ __async_tx_find_channel(struct async_submit_ctl *submit, return async_dma_find_channel(tx_type); } EXPORT_SYMBOL_GPL(__async_tx_find_channel); -#else -static int __init async_tx_init(void) -{ - printk(KERN_INFO "async_tx: api initialized (sync-only)\n"); - return 0; -} - -static void __exit async_tx_exit(void) -{ - do { } while (0); -} #endif @@ -298,9 +290,6 @@ void async_tx_quiesce(struct dma_async_tx_descriptor **tx) } EXPORT_SYMBOL_GPL(async_tx_quiesce); -module_init(async_tx_init); -module_exit(async_tx_exit); - MODULE_AUTHOR("Intel Corporation"); MODULE_DESCRIPTION("Asynchronous Bulk Memory Transactions API"); MODULE_LICENSE("GPL"); -- cgit v1.2.2 From 95475e57113c66aac7583925736ed2e2d58c990d Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Tue, 14 Jul 2009 12:19:02 -0700 Subject: async_tx: remove walk of tx->parent chain in dma_wait_for_async_tx We currently walk the parent chain when waiting for a given tx to complete however this walk may race with the driver cleanup routine. The routines in async_raid6_recov.c may fall back to the synchronous path at any point so we need to be prepared to call async_tx_quiesce() (which calls dma_wait_for_async_tx). To remove the ->parent walk we guarantee that every time a dependency is attached ->issue_pending() is invoked, then we can simply poll the initial descriptor until completion. This also allows for a lighter weight 'issue pending' implementation as there is no longer a requirement to iterate through all the channels' ->issue_pending() routines as long as operations have been submitted in an ordered chain. async_tx_issue_pending() is added for this case. Signed-off-by: Dan Williams --- crypto/async_tx/async_tx.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'crypto/async_tx/async_tx.c') diff --git a/crypto/async_tx/async_tx.c b/crypto/async_tx/async_tx.c index 6e37ad3f4417..60615fedcf5e 100644 --- a/crypto/async_tx/async_tx.c +++ b/crypto/async_tx/async_tx.c @@ -77,8 +77,8 @@ static void async_tx_channel_switch(struct dma_async_tx_descriptor *depend_tx, struct dma_async_tx_descriptor *tx) { - struct dma_chan *chan; - struct dma_device *device; + struct dma_chan *chan = depend_tx->chan; + struct dma_device *device = chan->device; struct dma_async_tx_descriptor *intr_tx = (void *) ~0; /* first check to see if we can still append to depend_tx */ @@ -90,11 +90,11 @@ async_tx_channel_switch(struct dma_async_tx_descriptor *depend_tx, } spin_unlock_bh(&depend_tx->lock); - if (!intr_tx) + /* attached dependency, flush the parent channel */ + if (!intr_tx) { + device->device_issue_pending(chan); return; - - chan = depend_tx->chan; - device = chan->device; + } /* see if we can schedule an interrupt * otherwise poll for completion @@ -128,6 +128,7 @@ async_tx_channel_switch(struct dma_async_tx_descriptor *depend_tx, intr_tx->tx_submit(intr_tx); async_tx_ack(intr_tx); } + device->device_issue_pending(chan); } else { if (dma_wait_for_async_tx(depend_tx) == DMA_ERROR) panic("%s: DMA_ERROR waiting for depend_tx\n", -- cgit v1.2.2 From 138f4c359d23d2ec38d18bd70dd9613ae515fe93 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Tue, 8 Sep 2009 17:42:51 -0700 Subject: dmaengine, async_tx: add a "no channel switch" allocator Channel switching is problematic for some dmaengine drivers as the architecture precludes separating the ->prep from ->submit. In these cases the driver can select ASYNC_TX_DISABLE_CHANNEL_SWITCH to modify the async_tx allocator to only return channels that support all of the required asynchronous operations. For example MD_RAID456=y selects support for asynchronous xor, xor validate, pq, pq validate, and memcpy. When ASYNC_TX_DISABLE_CHANNEL_SWITCH=y any channel with all these capabilities is marked DMA_ASYNC_TX allowing async_tx_find_channel() to quickly locate compatible channels with the guarantee that dependency chains will remain on one channel. When ASYNC_TX_DISABLE_CHANNEL_SWITCH=n async_tx_find_channel() may select channels that lead to operation chains that need to cross channel boundaries using the async_tx channel switch capability. Signed-off-by: Dan Williams --- crypto/async_tx/async_tx.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'crypto/async_tx/async_tx.c') diff --git a/crypto/async_tx/async_tx.c b/crypto/async_tx/async_tx.c index 60615fedcf5e..f9cdf04fe7c0 100644 --- a/crypto/async_tx/async_tx.c +++ b/crypto/async_tx/async_tx.c @@ -81,6 +81,10 @@ async_tx_channel_switch(struct dma_async_tx_descriptor *depend_tx, struct dma_device *device = chan->device; struct dma_async_tx_descriptor *intr_tx = (void *) ~0; + #ifdef CONFIG_ASYNC_TX_DISABLE_CHANNEL_SWITCH + BUG(); + #endif + /* first check to see if we can still append to depend_tx */ spin_lock_bh(&depend_tx->lock); if (depend_tx->parent && depend_tx->chan == tx->chan) { -- cgit v1.2.2