| #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 |