diff options
Diffstat (limited to 'crypto/async_tx/async_tx.c')
-rw-r--r-- | crypto/async_tx/async_tx.c | 350 |
1 files changed, 5 insertions, 345 deletions
diff --git a/crypto/async_tx/async_tx.c b/crypto/async_tx/async_tx.c index dcbf1be149f..f21147f3626 100644 --- a/crypto/async_tx/async_tx.c +++ b/crypto/async_tx/async_tx.c @@ -28,351 +28,18 @@ #include <linux/async_tx.h> #ifdef CONFIG_DMA_ENGINE -static enum dma_state_client -dma_channel_add_remove(struct dma_client *client, - struct dma_chan *chan, enum dma_state state); - -static struct dma_client async_tx_dma = { - .event_callback = dma_channel_add_remove, - /* .cap_mask == 0 defaults to all channels */ -}; - -/** - * dma_cap_mask_all - enable iteration over all operation types - */ -static dma_cap_mask_t dma_cap_mask_all; - -/** - * chan_ref_percpu - tracks channel allocations per core/opertion - */ -struct chan_ref_percpu { - struct dma_chan_ref *ref; -}; - -static int channel_table_initialized; -static struct chan_ref_percpu *channel_table[DMA_TX_TYPE_END]; - -/** - * async_tx_lock - protect modification of async_tx_master_list and serialize - * rebalance operations - */ -static spinlock_t async_tx_lock; - -static LIST_HEAD(async_tx_master_list); - -/* async_tx_issue_pending_all - start all transactions on all channels */ -void async_tx_issue_pending_all(void) -{ - struct dma_chan_ref *ref; - - rcu_read_lock(); - list_for_each_entry_rcu(ref, &async_tx_master_list, node) - ref->chan->device->device_issue_pending(ref->chan); - rcu_read_unlock(); -} -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) -{ - struct dma_chan_ref *ref; - ref = container_of(rcu, struct dma_chan_ref, rcu); - kfree(ref); -} - -static void -init_dma_chan_ref(struct dma_chan_ref *ref, struct dma_chan *chan) -{ - INIT_LIST_HEAD(&ref->node); - INIT_RCU_HEAD(&ref->rcu); - ref->chan = chan; - atomic_set(&ref->count, 0); -} - -/** - * get_chan_ref_by_cap - returns the nth channel of the given capability - * defaults to returning the channel with the desired capability and the - * lowest reference count if the index can not be satisfied - * @cap: capability to match - * @index: nth channel desired, passing -1 has the effect of forcing the - * default return value - */ -static struct dma_chan_ref * -get_chan_ref_by_cap(enum dma_transaction_type cap, int index) -{ - struct dma_chan_ref *ret_ref = NULL, *min_ref = NULL, *ref; - - rcu_read_lock(); - list_for_each_entry_rcu(ref, &async_tx_master_list, node) - if (dma_has_cap(cap, ref->chan->device->cap_mask)) { - if (!min_ref) - min_ref = ref; - else if (atomic_read(&ref->count) < - atomic_read(&min_ref->count)) - min_ref = ref; - - if (index-- == 0) { - ret_ref = ref; - break; - } - } - rcu_read_unlock(); - - if (!ret_ref) - ret_ref = min_ref; - - if (ret_ref) - atomic_inc(&ret_ref->count); - - return ret_ref; -} - -/** - * async_tx_rebalance - redistribute the available channels, optimize - * for cpu isolation in the SMP case, and opertaion isolation in the - * uniprocessor case - */ -static void async_tx_rebalance(void) -{ - int cpu, cap, cpu_idx = 0; - unsigned long flags; - - if (!channel_table_initialized) - return; - - spin_lock_irqsave(&async_tx_lock, flags); - - /* undo the last distribution */ - for_each_dma_cap_mask(cap, dma_cap_mask_all) - for_each_possible_cpu(cpu) { - struct dma_chan_ref *ref = - per_cpu_ptr(channel_table[cap], cpu)->ref; - if (ref) { - atomic_set(&ref->count, 0); - per_cpu_ptr(channel_table[cap], cpu)->ref = - NULL; - } - } - - for_each_dma_cap_mask(cap, dma_cap_mask_all) - for_each_online_cpu(cpu) { - struct dma_chan_ref *new; - if (NR_CPUS > 1) - new = get_chan_ref_by_cap(cap, cpu_idx++); - else - new = get_chan_ref_by_cap(cap, -1); - - per_cpu_ptr(channel_table[cap], cpu)->ref = new; - } - - spin_unlock_irqrestore(&async_tx_lock, flags); -} - -static enum dma_state_client -dma_channel_add_remove(struct dma_client *client, - struct dma_chan *chan, enum dma_state state) -{ - unsigned long found, flags; - struct dma_chan_ref *master_ref, *ref; - enum dma_state_client ack = DMA_DUP; /* default: take no action */ - - switch (state) { - case DMA_RESOURCE_AVAILABLE: - found = 0; - rcu_read_lock(); - list_for_each_entry_rcu(ref, &async_tx_master_list, node) - if (ref->chan == chan) { - found = 1; - break; - } - rcu_read_unlock(); - - pr_debug("async_tx: dma resource available [%s]\n", - found ? "old" : "new"); - - if (!found) - ack = DMA_ACK; - else - break; - - /* add the channel to the generic management list */ - master_ref = kmalloc(sizeof(*master_ref), GFP_KERNEL); - if (master_ref) { - /* keep a reference until async_tx is unloaded */ - dma_chan_get(chan); - init_dma_chan_ref(master_ref, chan); - spin_lock_irqsave(&async_tx_lock, flags); - list_add_tail_rcu(&master_ref->node, - &async_tx_master_list); - spin_unlock_irqrestore(&async_tx_lock, - flags); - } else { - printk(KERN_WARNING "async_tx: unable to create" - " new master entry in response to" - " a DMA_RESOURCE_ADDED event" - " (-ENOMEM)\n"); - return 0; - } - - async_tx_rebalance(); - break; - case DMA_RESOURCE_REMOVED: - found = 0; - spin_lock_irqsave(&async_tx_lock, flags); - list_for_each_entry(ref, &async_tx_master_list, node) - if (ref->chan == chan) { - /* permit backing devices to go away */ - dma_chan_put(ref->chan); - list_del_rcu(&ref->node); - call_rcu(&ref->rcu, free_dma_chan_ref); - found = 1; - break; - } - spin_unlock_irqrestore(&async_tx_lock, flags); - - pr_debug("async_tx: dma resource removed [%s]\n", - found ? "ours" : "not ours"); - - if (found) - ack = DMA_ACK; - else - break; - - async_tx_rebalance(); - break; - case DMA_RESOURCE_SUSPEND: - case DMA_RESOURCE_RESUME: - printk(KERN_WARNING "async_tx: does not support dma channel" - " suspend/resume\n"); - break; - default: - BUG(); - } - - return ack; -} - -static int __init -async_tx_init(void) +static int __init async_tx_init(void) { - enum dma_transaction_type cap; - - spin_lock_init(&async_tx_lock); - bitmap_fill(dma_cap_mask_all.bits, DMA_TX_TYPE_END); - - /* an interrupt will never be an explicit operation type. - * clearing this bit prevents allocation to a slot in 'channel_table' - */ - clear_bit(DMA_INTERRUPT, dma_cap_mask_all.bits); - - for_each_dma_cap_mask(cap, dma_cap_mask_all) { - channel_table[cap] = alloc_percpu(struct chan_ref_percpu); - if (!channel_table[cap]) - goto err; - } - - channel_table_initialized = 1; - dma_async_client_register(&async_tx_dma); - dma_async_client_chan_request(&async_tx_dma); + dmaengine_get(); printk(KERN_INFO "async_tx: api initialized (async)\n"); return 0; -err: - printk(KERN_ERR "async_tx: initialization failure\n"); - - while (--cap >= 0) - free_percpu(channel_table[cap]); - - return 1; } static void __exit async_tx_exit(void) { - enum dma_transaction_type cap; - - channel_table_initialized = 0; - - for_each_dma_cap_mask(cap, dma_cap_mask_all) - if (channel_table[cap]) - free_percpu(channel_table[cap]); - - dma_async_client_unregister(&async_tx_dma); + dmaengine_put(); } /** @@ -387,16 +54,9 @@ __async_tx_find_channel(struct dma_async_tx_descriptor *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)) + dma_has_cap(tx_type, depend_tx->chan->device->cap_mask)) return depend_tx->chan; - else if (likely(channel_table_initialized)) { - struct dma_chan_ref *ref; - int cpu = get_cpu(); - ref = per_cpu_ptr(channel_table[tx_type], cpu)->ref; - put_cpu(); - return ref ? ref->chan : NULL; - } else - return NULL; + return dma_find_channel(tx_type); } EXPORT_SYMBOL_GPL(__async_tx_find_channel); #else |