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author | 2015-08-04 12:17:53 -0700 | |
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committer | 2015-08-04 15:44:42 -0700 | |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/crypto/async_tx/async_tx.c | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/crypto/async_tx/async_tx.c')
-rw-r--r-- | kernel/crypto/async_tx/async_tx.c | 294 |
1 files changed, 294 insertions, 0 deletions
diff --git a/kernel/crypto/async_tx/async_tx.c b/kernel/crypto/async_tx/async_tx.c new file mode 100644 index 000000000..39ea4791a --- /dev/null +++ b/kernel/crypto/async_tx/async_tx.c @@ -0,0 +1,294 @@ +/* + * core routines for the asynchronous memory transfer/transform api + * + * Copyright © 2006, Intel Corporation. + * + * Dan Williams <dan.j.williams@intel.com> + * + * with architecture considerations by: + * Neil Brown <neilb@suse.de> + * Jeff Garzik <jeff@garzik.org> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. + * + */ +#include <linux/rculist.h> +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/async_tx.h> + +#ifdef CONFIG_DMA_ENGINE +static int __init async_tx_init(void) +{ + async_dmaengine_get(); + + printk(KERN_INFO "async_tx: api initialized (async)\n"); + + return 0; +} + +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 + * @submit: transaction dependency and submission modifiers + * @tx_type: transaction type + */ +struct dma_chan * +__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)) + return depend_tx->chan; + return async_dma_find_channel(tx_type); +} +EXPORT_SYMBOL_GPL(__async_tx_find_channel); +#endif + + +/** + * async_tx_channel_switch - queue an interrupt descriptor with a dependency + * pre-attached. + * @depend_tx: the operation that must finish before the new operation runs + * @tx: the new operation + */ +static void +async_tx_channel_switch(struct dma_async_tx_descriptor *depend_tx, + struct dma_async_tx_descriptor *tx) +{ + 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 */ + txd_lock(depend_tx); + if (txd_parent(depend_tx) && depend_tx->chan == tx->chan) { + txd_chain(depend_tx, tx); + intr_tx = NULL; + } + txd_unlock(depend_tx); + + /* attached dependency, flush the parent channel */ + if (!intr_tx) { + device->device_issue_pending(chan); + return; + } + + /* see if we can schedule an interrupt + * otherwise poll for completion + */ + if (dma_has_cap(DMA_INTERRUPT, device->cap_mask)) + intr_tx = device->device_prep_dma_interrupt(chan, 0); + else + intr_tx = NULL; + + if (intr_tx) { + intr_tx->callback = NULL; + intr_tx->callback_param = NULL; + /* safe to chain outside the lock since we know we are + * not submitted yet + */ + txd_chain(intr_tx, tx); + + /* check if we need to append */ + txd_lock(depend_tx); + if (txd_parent(depend_tx)) { + txd_chain(depend_tx, intr_tx); + async_tx_ack(intr_tx); + intr_tx = NULL; + } + txd_unlock(depend_tx); + + if (intr_tx) { + txd_clear_parent(intr_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_COMPLETE) + panic("%s: DMA error waiting for depend_tx\n", + __func__); + tx->tx_submit(tx); + } +} + + +/** + * 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, + ASYNC_TX_CHANNEL_SWITCH, + ASYNC_TX_DIRECT_SUBMIT, +}; + +void +async_tx_submit(struct dma_chan *chan, struct dma_async_tx_descriptor *tx, + struct async_submit_ctl *submit) +{ + 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; + + /* sanity check the dependency chain: + * 1/ if ack is already set then we cannot be sure + * we are referring to the correct operation + * 2/ dependencies are 1:1 i.e. two transactions can + * not depend on the same parent + */ + BUG_ON(async_tx_test_ack(depend_tx) || txd_next(depend_tx) || + txd_parent(tx)); + + /* the lock prevents async_tx_run_dependencies from missing + * the setting of ->next when ->parent != NULL + */ + txd_lock(depend_tx); + if (txd_parent(depend_tx)) { + /* we have a parent so we can not submit directly + * if we are staying on the same channel: append + * else: channel switch + */ + if (depend_tx->chan == chan) { + txd_chain(depend_tx, tx); + s = ASYNC_TX_SUBMITTED; + } else + s = ASYNC_TX_CHANNEL_SWITCH; + } else { + /* we do not have a parent so we may be able to submit + * directly if we are staying on the same channel + */ + if (depend_tx->chan == chan) + s = ASYNC_TX_DIRECT_SUBMIT; + else + s = ASYNC_TX_CHANNEL_SWITCH; + } + txd_unlock(depend_tx); + + switch (s) { + case ASYNC_TX_SUBMITTED: + break; + case ASYNC_TX_CHANNEL_SWITCH: + async_tx_channel_switch(depend_tx, tx); + break; + case ASYNC_TX_DIRECT_SUBMIT: + txd_clear_parent(tx); + tx->tx_submit(tx); + break; + } + } else { + txd_clear_parent(tx); + tx->tx_submit(tx); + } + + if (submit->flags & ASYNC_TX_ACK) + async_tx_ack(tx); + + if (depend_tx) + async_tx_ack(depend_tx); +} +EXPORT_SYMBOL_GPL(async_tx_submit); + +/** + * 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(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; + device = chan->device; + + /* see if we can schedule an interrupt + * otherwise poll for completion + */ + if (device && !dma_has_cap(DMA_INTERRUPT, device->cap_mask)) + device = NULL; + + tx = device ? device->device_prep_dma_interrupt(chan, 0) : NULL; + } else + tx = NULL; + + if (tx) { + pr_debug("%s: (async)\n", __func__); + + async_tx_submit(chan, tx, submit); + } else { + pr_debug("%s: (sync)\n", __func__); + + /* wait for any prerequisite operations */ + async_tx_quiesce(&submit->depend_tx); + + async_tx_sync_epilog(submit); + } + + return tx; +} +EXPORT_SYMBOL_GPL(async_trigger_callback); + +/** + * async_tx_quiesce - ensure tx is complete and freeable upon return + * @tx - transaction to quiesce + */ +void async_tx_quiesce(struct dma_async_tx_descriptor **tx) +{ + if (*tx) { + /* if ack is already set then we cannot be sure + * we are referring to the correct operation + */ + BUG_ON(async_tx_test_ack(*tx)); + if (dma_wait_for_async_tx(*tx) != DMA_COMPLETE) + panic("%s: DMA error waiting for transaction\n", + __func__); + async_tx_ack(*tx); + *tx = NULL; + } +} +EXPORT_SYMBOL_GPL(async_tx_quiesce); + +MODULE_AUTHOR("Intel Corporation"); +MODULE_DESCRIPTION("Asynchronous Bulk Memory Transactions API"); +MODULE_LICENSE("GPL"); |