diff options
Diffstat (limited to 'drivers/staging/rdma/hfi1/iowait.h')
| -rw-r--r-- | drivers/staging/rdma/hfi1/iowait.h | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/drivers/staging/rdma/hfi1/iowait.h b/drivers/staging/rdma/hfi1/iowait.h new file mode 100644 index 000000000000..fa361b405851 --- /dev/null +++ b/drivers/staging/rdma/hfi1/iowait.h @@ -0,0 +1,186 @@ +#ifndef _HFI1_IOWAIT_H +#define _HFI1_IOWAIT_H +/* + * + * This file is provided under a dual BSD/GPLv2 license. When using or + * redistributing this file, you may do so under either license. + * + * GPL LICENSE SUMMARY + * + * Copyright(c) 2015 Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of version 2 of the GNU General Public License as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that 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. + * + * BSD LICENSE + * + * Copyright(c) 2015 Intel Corporation. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * - Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * - Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * - Neither the name of Intel Corporation nor the names of its + * contributors may be used to endorse or promote products derived + * from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + */ + +#include <linux/list.h> +#include <linux/workqueue.h> +#include <linux/sched.h> + +/* + * typedef (*restart_t)() - restart callback + * @work: pointer to work structure + */ +typedef void (*restart_t)(struct work_struct *work); + +struct sdma_txreq; +struct sdma_engine; +/** + * struct iowait - linkage for delayed progress/waiting + * @list: used to add/insert into QP/PQ wait lists + * @tx_head: overflow list of sdma_txreq's + * @sleep: no space callback + * @wakeup: space callback + * @iowork: workqueue overhead + * @wait_dma: wait for sdma_busy == 0 + * @sdma_busy: # of packets in flight + * @count: total number of descriptors in tx_head'ed list + * @tx_limit: limit for overflow queuing + * @tx_count: number of tx entry's in tx_head'ed list + * + * This is to be embedded in user's state structure + * (QP or PQ). + * + * The sleep and wakeup members are a + * bit misnamed. They do not strictly + * speaking sleep or wake up, but they + * are callbacks for the ULP to implement + * what ever queuing/dequeuing of + * the embedded iowait and its containing struct + * when a resource shortage like SDMA ring space is seen. + * + * Both potentially have locks help + * so sleeping is not allowed. + * + * The wait_dma member along with the iow + */ + +struct iowait { + struct list_head list; + struct list_head tx_head; + int (*sleep)( + struct sdma_engine *sde, + struct iowait *wait, + struct sdma_txreq *tx, + unsigned seq); + void (*wakeup)(struct iowait *wait, int reason); + struct work_struct iowork; + wait_queue_head_t wait_dma; + atomic_t sdma_busy; + u32 count; + u32 tx_limit; + u32 tx_count; +}; + +#define SDMA_AVAIL_REASON 0 + +/** + * iowait_init() - initialize wait structure + * @wait: wait struct to initialize + * @tx_limit: limit for overflow queuing + * @func: restart function for workqueue + * @sleep: sleep function for no space + * @wakeup: wakeup function for no space + * + * This function initializes the iowait + * structure embedded in the QP or PQ. + * + */ + +static inline void iowait_init( + struct iowait *wait, + u32 tx_limit, + void (*func)(struct work_struct *work), + int (*sleep)( + struct sdma_engine *sde, + struct iowait *wait, + struct sdma_txreq *tx, + unsigned seq), + void (*wakeup)(struct iowait *wait, int reason)) +{ + wait->count = 0; + INIT_LIST_HEAD(&wait->list); + INIT_LIST_HEAD(&wait->tx_head); + INIT_WORK(&wait->iowork, func); + init_waitqueue_head(&wait->wait_dma); + atomic_set(&wait->sdma_busy, 0); + wait->tx_limit = tx_limit; + wait->sleep = sleep; + wait->wakeup = wakeup; +} + +/** + * iowait_schedule() - initialize wait structure + * @wait: wait struct to schedule + * @wq: workqueue for schedule + */ +static inline void iowait_schedule( + struct iowait *wait, + struct workqueue_struct *wq) +{ + queue_work(wq, &wait->iowork); +} + +/** + * iowait_sdma_drain() - wait for DMAs to drain + * + * @wait: iowait structure + * + * This will delay until the iowait sdmas have + * completed. + */ +static inline void iowait_sdma_drain(struct iowait *wait) +{ + wait_event(wait->wait_dma, !atomic_read(&wait->sdma_busy)); +} + +/** + * iowait_drain_wakeup() - trigger iowait_drain() waiter + * + * @wait: iowait structure + * + * This will trigger any waiters. + */ +static inline void iowait_drain_wakeup(struct iowait *wait) +{ + wake_up(&wait->wait_dma); +} + +#endif |