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1 | #ifndef _HFI1_IOWAIT_H |
2 | #define _HFI1_IOWAIT_H | |
3 | /* | |
4 | * | |
5 | * This file is provided under a dual BSD/GPLv2 license. When using or | |
6 | * redistributing this file, you may do so under either license. | |
7 | * | |
8 | * GPL LICENSE SUMMARY | |
9 | * | |
10 | * Copyright(c) 2015 Intel Corporation. | |
11 | * | |
12 | * This program is free software; you can redistribute it and/or modify | |
13 | * it under the terms of version 2 of the GNU General Public License as | |
14 | * published by the Free Software Foundation. | |
15 | * | |
16 | * This program is distributed in the hope that it will be useful, but | |
17 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
18 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
19 | * General Public License for more details. | |
20 | * | |
21 | * BSD LICENSE | |
22 | * | |
23 | * Copyright(c) 2015 Intel Corporation. | |
24 | * | |
25 | * Redistribution and use in source and binary forms, with or without | |
26 | * modification, are permitted provided that the following conditions | |
27 | * are met: | |
28 | * | |
29 | * - Redistributions of source code must retain the above copyright | |
30 | * notice, this list of conditions and the following disclaimer. | |
31 | * - Redistributions in binary form must reproduce the above copyright | |
32 | * notice, this list of conditions and the following disclaimer in | |
33 | * the documentation and/or other materials provided with the | |
34 | * distribution. | |
35 | * - Neither the name of Intel Corporation nor the names of its | |
36 | * contributors may be used to endorse or promote products derived | |
37 | * from this software without specific prior written permission. | |
38 | * | |
39 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | |
40 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | |
41 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR | |
42 | * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT | |
43 | * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | |
44 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT | |
45 | * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
46 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
47 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
48 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | |
49 | * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
50 | * | |
51 | */ | |
52 | ||
53 | #include <linux/list.h> | |
54 | #include <linux/workqueue.h> | |
55 | #include <linux/sched.h> | |
56 | ||
57 | /* | |
58 | * typedef (*restart_t)() - restart callback | |
59 | * @work: pointer to work structure | |
60 | */ | |
61 | typedef void (*restart_t)(struct work_struct *work); | |
62 | ||
63 | struct sdma_txreq; | |
64 | struct sdma_engine; | |
65 | /** | |
66 | * struct iowait - linkage for delayed progress/waiting | |
67 | * @list: used to add/insert into QP/PQ wait lists | |
68 | * @tx_head: overflow list of sdma_txreq's | |
69 | * @sleep: no space callback | |
70 | * @wakeup: space callback | |
71 | * @iowork: workqueue overhead | |
72 | * @wait_dma: wait for sdma_busy == 0 | |
73 | * @sdma_busy: # of packets in flight | |
74 | * @count: total number of descriptors in tx_head'ed list | |
75 | * @tx_limit: limit for overflow queuing | |
76 | * @tx_count: number of tx entry's in tx_head'ed list | |
77 | * | |
78 | * This is to be embedded in user's state structure | |
79 | * (QP or PQ). | |
80 | * | |
81 | * The sleep and wakeup members are a | |
82 | * bit misnamed. They do not strictly | |
83 | * speaking sleep or wake up, but they | |
84 | * are callbacks for the ULP to implement | |
85 | * what ever queuing/dequeuing of | |
86 | * the embedded iowait and its containing struct | |
87 | * when a resource shortage like SDMA ring space is seen. | |
88 | * | |
89 | * Both potentially have locks help | |
90 | * so sleeping is not allowed. | |
91 | * | |
92 | * The wait_dma member along with the iow | |
93 | */ | |
94 | ||
95 | struct iowait { | |
96 | struct list_head list; | |
97 | struct list_head tx_head; | |
98 | int (*sleep)( | |
99 | struct sdma_engine *sde, | |
100 | struct iowait *wait, | |
101 | struct sdma_txreq *tx, | |
102 | unsigned seq); | |
103 | void (*wakeup)(struct iowait *wait, int reason); | |
104 | struct work_struct iowork; | |
105 | wait_queue_head_t wait_dma; | |
106 | atomic_t sdma_busy; | |
107 | u32 count; | |
108 | u32 tx_limit; | |
109 | u32 tx_count; | |
110 | }; | |
111 | ||
112 | #define SDMA_AVAIL_REASON 0 | |
113 | ||
114 | /** | |
115 | * iowait_init() - initialize wait structure | |
116 | * @wait: wait struct to initialize | |
117 | * @tx_limit: limit for overflow queuing | |
118 | * @func: restart function for workqueue | |
119 | * @sleep: sleep function for no space | |
120 | * @wakeup: wakeup function for no space | |
121 | * | |
122 | * This function initializes the iowait | |
123 | * structure embedded in the QP or PQ. | |
124 | * | |
125 | */ | |
126 | ||
127 | static inline void iowait_init( | |
128 | struct iowait *wait, | |
129 | u32 tx_limit, | |
130 | void (*func)(struct work_struct *work), | |
131 | int (*sleep)( | |
132 | struct sdma_engine *sde, | |
133 | struct iowait *wait, | |
134 | struct sdma_txreq *tx, | |
135 | unsigned seq), | |
136 | void (*wakeup)(struct iowait *wait, int reason)) | |
137 | { | |
138 | wait->count = 0; | |
139 | INIT_LIST_HEAD(&wait->list); | |
140 | INIT_LIST_HEAD(&wait->tx_head); | |
141 | INIT_WORK(&wait->iowork, func); | |
142 | init_waitqueue_head(&wait->wait_dma); | |
143 | atomic_set(&wait->sdma_busy, 0); | |
144 | wait->tx_limit = tx_limit; | |
145 | wait->sleep = sleep; | |
146 | wait->wakeup = wakeup; | |
147 | } | |
148 | ||
149 | /** | |
150 | * iowait_schedule() - initialize wait structure | |
151 | * @wait: wait struct to schedule | |
152 | * @wq: workqueue for schedule | |
153 | */ | |
154 | static inline void iowait_schedule( | |
155 | struct iowait *wait, | |
156 | struct workqueue_struct *wq) | |
157 | { | |
158 | queue_work(wq, &wait->iowork); | |
159 | } | |
160 | ||
161 | /** | |
162 | * iowait_sdma_drain() - wait for DMAs to drain | |
163 | * | |
164 | * @wait: iowait structure | |
165 | * | |
166 | * This will delay until the iowait sdmas have | |
167 | * completed. | |
168 | */ | |
169 | static inline void iowait_sdma_drain(struct iowait *wait) | |
170 | { | |
171 | wait_event(wait->wait_dma, !atomic_read(&wait->sdma_busy)); | |
172 | } | |
173 | ||
174 | /** | |
175 | * iowait_drain_wakeup() - trigger iowait_drain() waiter | |
176 | * | |
177 | * @wait: iowait structure | |
178 | * | |
179 | * This will trigger any waiters. | |
180 | */ | |
181 | static inline void iowait_drain_wakeup(struct iowait *wait) | |
182 | { | |
183 | wake_up(&wait->wait_dma); | |
184 | } | |
185 | ||
186 | #endif |