1 /* drm_lists.h -- Buffer list handling routines -*- linux-c -*-
2 * Created: Mon Apr 19 20:54:22 1999 by faith@valinux.com
3 *
4 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
5 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
6 * All Rights Reserved.
7 *
8 * Permission is hereby granted, free of charge, to any person obtaining a
9 * copy of this software and associated documentation files (the "Software"),
10 * to deal in the Software without restriction, including without limitation
11 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
12 * and/or sell copies of the Software, and to permit persons to whom the
13 * Software is furnished to do so, subject to the following conditions:
14 *
15 * The above copyright notice and this permission notice (including the next
16 * paragraph) shall be included in all copies or substantial portions of the
17 * Software.
18 *
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
22 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
23 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
24 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
25 * OTHER DEALINGS IN THE SOFTWARE.
26 *
27 * Authors:
28 * Rickard E. (Rik) Faith <faith@valinux.com>
29 * Gareth Hughes <gareth@valinux.com>
30 */
31
32 #include "drmP.h"
33
34 #if __HAVE_DMA_WAITLIST
35
DRM(waitlist_create)36 int DRM(waitlist_create)(drm_waitlist_t *bl, int count)
37 {
38 if (bl->count) return -EINVAL;
39
40 bl->bufs = DRM(alloc)((bl->count + 2) * sizeof(*bl->bufs),
41 DRM_MEM_BUFLISTS);
42
43 if(!bl->bufs) return -ENOMEM;
44 memset(bl->bufs, 0, sizeof(*bl->bufs));
45 bl->count = count;
46 bl->rp = bl->bufs;
47 bl->wp = bl->bufs;
48 bl->end = &bl->bufs[bl->count+1];
49 bl->write_lock = SPIN_LOCK_UNLOCKED;
50 bl->read_lock = SPIN_LOCK_UNLOCKED;
51 return 0;
52 }
53
DRM(waitlist_destroy)54 int DRM(waitlist_destroy)(drm_waitlist_t *bl)
55 {
56 if (bl->rp != bl->wp) return -EINVAL;
57 if (bl->bufs) DRM(free)(bl->bufs,
58 (bl->count + 2) * sizeof(*bl->bufs),
59 DRM_MEM_BUFLISTS);
60 bl->count = 0;
61 bl->bufs = NULL;
62 bl->rp = NULL;
63 bl->wp = NULL;
64 bl->end = NULL;
65 return 0;
66 }
67
DRM(waitlist_put)68 int DRM(waitlist_put)(drm_waitlist_t *bl, drm_buf_t *buf)
69 {
70 int left;
71 unsigned long flags;
72
73 left = DRM_LEFTCOUNT(bl);
74 if (!left) {
75 DRM_ERROR("Overflow while adding buffer %d from pid %d\n",
76 buf->idx, buf->pid);
77 return -EINVAL;
78 }
79 #if __HAVE_DMA_HISTOGRAM
80 buf->time_queued = get_cycles();
81 #endif
82 buf->list = DRM_LIST_WAIT;
83
84 spin_lock_irqsave(&bl->write_lock, flags);
85 *bl->wp = buf;
86 if (++bl->wp >= bl->end) bl->wp = bl->bufs;
87 spin_unlock_irqrestore(&bl->write_lock, flags);
88
89 return 0;
90 }
91
DRM(waitlist_get)92 drm_buf_t *DRM(waitlist_get)(drm_waitlist_t *bl)
93 {
94 drm_buf_t *buf;
95 unsigned long flags;
96
97 spin_lock_irqsave(&bl->read_lock, flags);
98 buf = *bl->rp;
99 if (bl->rp == bl->wp) {
100 spin_unlock_irqrestore(&bl->read_lock, flags);
101 return NULL;
102 }
103 if (++bl->rp >= bl->end) bl->rp = bl->bufs;
104 spin_unlock_irqrestore(&bl->read_lock, flags);
105
106 return buf;
107 }
108
109 #endif /* __HAVE_DMA_WAITLIST */
110
111
112 #if __HAVE_DMA_FREELIST
113
DRM(freelist_create)114 int DRM(freelist_create)(drm_freelist_t *bl, int count)
115 {
116 atomic_set(&bl->count, 0);
117 bl->next = NULL;
118 init_waitqueue_head(&bl->waiting);
119 bl->low_mark = 0;
120 bl->high_mark = 0;
121 atomic_set(&bl->wfh, 0);
122 bl->lock = SPIN_LOCK_UNLOCKED;
123 ++bl->initialized;
124 return 0;
125 }
126
DRM(freelist_destroy)127 int DRM(freelist_destroy)(drm_freelist_t *bl)
128 {
129 atomic_set(&bl->count, 0);
130 bl->next = NULL;
131 return 0;
132 }
133
DRM(freelist_put)134 int DRM(freelist_put)(drm_device_t *dev, drm_freelist_t *bl, drm_buf_t *buf)
135 {
136 drm_device_dma_t *dma = dev->dma;
137
138 if (!dma) {
139 DRM_ERROR("No DMA support\n");
140 return 1;
141 }
142
143 if (buf->waiting || buf->pending || buf->list == DRM_LIST_FREE) {
144 DRM_ERROR("Freed buffer %d: w%d, p%d, l%d\n",
145 buf->idx, buf->waiting, buf->pending, buf->list);
146 }
147 if (!bl) return 1;
148 #if __HAVE_DMA_HISTOGRAM
149 buf->time_freed = get_cycles();
150 DRM(histogram_compute)(dev, buf);
151 #endif
152 buf->list = DRM_LIST_FREE;
153
154 spin_lock(&bl->lock);
155 buf->next = bl->next;
156 bl->next = buf;
157 spin_unlock(&bl->lock);
158
159 atomic_inc(&bl->count);
160 if (atomic_read(&bl->count) > dma->buf_count) {
161 DRM_ERROR("%d of %d buffers free after addition of %d\n",
162 atomic_read(&bl->count), dma->buf_count, buf->idx);
163 return 1;
164 }
165 /* Check for high water mark */
166 if (atomic_read(&bl->wfh) && atomic_read(&bl->count)>=bl->high_mark) {
167 atomic_set(&bl->wfh, 0);
168 wake_up_interruptible(&bl->waiting);
169 }
170 return 0;
171 }
172
DRM(freelist_try)173 static drm_buf_t *DRM(freelist_try)(drm_freelist_t *bl)
174 {
175 drm_buf_t *buf;
176
177 if (!bl) return NULL;
178
179 /* Get buffer */
180 spin_lock(&bl->lock);
181 if (!bl->next) {
182 spin_unlock(&bl->lock);
183 return NULL;
184 }
185 buf = bl->next;
186 bl->next = bl->next->next;
187 spin_unlock(&bl->lock);
188
189 atomic_dec(&bl->count);
190 buf->next = NULL;
191 buf->list = DRM_LIST_NONE;
192 if (buf->waiting || buf->pending) {
193 DRM_ERROR("Free buffer %d: w%d, p%d, l%d\n",
194 buf->idx, buf->waiting, buf->pending, buf->list);
195 }
196
197 return buf;
198 }
199
DRM(freelist_get)200 drm_buf_t *DRM(freelist_get)(drm_freelist_t *bl, int block)
201 {
202 drm_buf_t *buf = NULL;
203 DECLARE_WAITQUEUE(entry, current);
204
205 if (!bl || !bl->initialized) return NULL;
206
207 /* Check for low water mark */
208 if (atomic_read(&bl->count) <= bl->low_mark) /* Became low */
209 atomic_set(&bl->wfh, 1);
210 if (atomic_read(&bl->wfh)) {
211 if (block) {
212 add_wait_queue(&bl->waiting, &entry);
213 for (;;) {
214 current->state = TASK_INTERRUPTIBLE;
215 if (!atomic_read(&bl->wfh)
216 && (buf = DRM(freelist_try)(bl))) break;
217 schedule();
218 if (signal_pending(current)) break;
219 }
220 current->state = TASK_RUNNING;
221 remove_wait_queue(&bl->waiting, &entry);
222 }
223 return buf;
224 }
225
226 return DRM(freelist_try)(bl);
227 }
228
229 #endif /* __HAVE_DMA_FREELIST */
230