drivers/char/drm/gamma_lists.h

   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 #define __NO_VERSION__
  33 #include "drmP.h"
  34
  35
  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
  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
  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 filp %p\n",
  76                           buf->idx, buf->filp);
  77                 return -EINVAL;
  78         }
  79         buf->list        = DRM_LIST_WAIT;
  80
  81         spin_lock_irqsave(&bl->write_lock, flags);
  82         *bl->wp = buf;
  83         if (++bl->wp >= bl->end) bl->wp = bl->bufs;
  84         spin_unlock_irqrestore(&bl->write_lock, flags);
  85
  86         return 0;
  87 }
  88
  89 drm_buf_t *DRM(waitlist_get)(drm_waitlist_t *bl)
  90 {
  91         drm_buf_t     *buf;
  92         unsigned long flags;
  93
  94         spin_lock_irqsave(&bl->read_lock, flags);
  95         buf = *bl->rp;
  96         if (bl->rp == bl->wp) {
  97                 spin_unlock_irqrestore(&bl->read_lock, flags);
  98                 return NULL;
  99         }
 100         if (++bl->rp >= bl->end) bl->rp = bl->bufs;
 101         spin_unlock_irqrestore(&bl->read_lock, flags);
 102
 103         return buf;
 104 }
 105
 106 int DRM(freelist_create)(drm_freelist_t *bl, int count)
 107 {
 108         atomic_set(&bl->count, 0);
 109         bl->next      = NULL;
 110         init_waitqueue_head(&bl->waiting);
 111         bl->low_mark  = 0;
 112         bl->high_mark = 0;
 113         atomic_set(&bl->wfh,   0);
 114         bl->lock      = SPIN_LOCK_UNLOCKED;
 115         ++bl->initialized;
 116         return 0;
 117 }
 118
 119 int DRM(freelist_destroy)(drm_freelist_t *bl)
 120 {
 121         atomic_set(&bl->count, 0);
 122         bl->next = NULL;
 123         return 0;
 124 }
 125
 126 int DRM(freelist_put)(drm_device_t *dev, drm_freelist_t *bl, drm_buf_t *buf)
 127 {
 128         drm_device_dma_t *dma  = dev->dma;
 129
 130         if (!dma) {
 131                 DRM_ERROR("No DMA support\n");
 132                 return 1;
 133         }
 134
 135         if (buf->waiting || buf->pending || buf->list == DRM_LIST_FREE) {
 136                 DRM_ERROR("Freed buffer %d: w%d, p%d, l%d\n",
 137                           buf->idx, buf->waiting, buf->pending, buf->list);
 138         }
 139         if (!bl) return 1;
 140         buf->list       = DRM_LIST_FREE;
 141
 142         spin_lock(&bl->lock);
 143         buf->next       = bl->next;
 144         bl->next        = buf;
 145         spin_unlock(&bl->lock);
 146
 147         atomic_inc(&bl->count);
 148         if (atomic_read(&bl->count) > dma->buf_count) {
 149                 DRM_ERROR("%d of %d buffers free after addition of %d\n",
 150                           atomic_read(&bl->count), dma->buf_count, buf->idx);
 151                 return 1;
 152         }
 153                                 /* Check for high water mark */
 154         if (atomic_read(&bl->wfh) && atomic_read(&bl->count)>=bl->high_mark) {
 155                 atomic_set(&bl->wfh, 0);
 156                 wake_up_interruptible(&bl->waiting);
 157         }
 158         return 0;
 159 }
 160
 161 static drm_buf_t *DRM(freelist_try)(drm_freelist_t *bl)
 162 {
 163         drm_buf_t         *buf;
 164
 165         if (!bl) return NULL;
 166
 167                                 /* Get buffer */
 168         spin_lock(&bl->lock);
 169         if (!bl->next) {
 170                 spin_unlock(&bl->lock);
 171                 return NULL;
 172         }
 173         buf       = bl->next;
 174         bl->next  = bl->next->next;
 175         spin_unlock(&bl->lock);
 176
 177         atomic_dec(&bl->count);
 178         buf->next = NULL;
 179         buf->list = DRM_LIST_NONE;
 180         if (buf->waiting || buf->pending) {
 181                 DRM_ERROR("Free buffer %d: w%d, p%d, l%d\n",
 182                           buf->idx, buf->waiting, buf->pending, buf->list);
 183         }
 184
 185         return buf;
 186 }
 187
 188 drm_buf_t *DRM(freelist_get)(drm_freelist_t *bl, int block)
 189 {
 190         drm_buf_t         *buf  = NULL;
 191         DECLARE_WAITQUEUE(entry, current);
 192
 193         if (!bl || !bl->initialized) return NULL;
 194
 195                                 /* Check for low water mark */
 196         if (atomic_read(&bl->count) <= bl->low_mark) /* Became low */
 197                 atomic_set(&bl->wfh, 1);
 198         if (atomic_read(&bl->wfh)) {
 199                 if (block) {
 200                         add_wait_queue(&bl->waiting, &entry);
 201                         for (;;) {
 202                                 current->state = TASK_INTERRUPTIBLE;
 203                                 if (!atomic_read(&bl->wfh)
 204                                     && (buf = DRM(freelist_try)(bl))) break;
 205                                 schedule();
 206                                 if (signal_pending(current)) break;
 207                         }
 208                         current->state = TASK_RUNNING;
 209                         remove_wait_queue(&bl->waiting, &entry);
 210                 }
 211                 return buf;
 212         }
 213
 214         return DRM(freelist_try)(bl);
 215 }
 216