msm_fence.c

   1 /*
   2  * Copyright (C) 2013-2016 Red Hat
   3  * Author: Rob Clark <robdclark@gmail.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 as published by
   7  * the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include <linux/fence.h>
  19
  20 #include "msm_drv.h"
  21 #include "msm_fence.h"
  22
  23
  24 struct msm_fence_context *
  25 msm_fence_context_alloc(struct drm_device *dev, const char *name)
  26 {
  27         struct msm_fence_context *fctx;
  28
  29         fctx = kzalloc(sizeof(*fctx), GFP_KERNEL);
  30         if (!fctx)
  31                 return ERR_PTR(-ENOMEM);
  32
  33         fctx->dev = dev;
  34         fctx->name = name;
  35         fctx->context = fence_context_alloc(1);
  36         init_waitqueue_head(&fctx->event);
  37         spin_lock_init(&fctx->spinlock);
  38
  39         return fctx;
  40 }
  41
  42 void msm_fence_context_free(struct msm_fence_context *fctx)
  43 {
  44         kfree(fctx);
  45 }
  46
  47 static inline bool fence_completed(struct msm_fence_context *fctx, uint32_t fence)
  48 {
  49         return (int32_t)(fctx->completed_fence - fence) >= 0;
  50 }
  51
  52 /* legacy path for WAIT_FENCE ioctl: */
  53 int msm_wait_fence(struct msm_fence_context *fctx, uint32_t fence,
  54                 ktime_t *timeout, bool interruptible)
  55 {
  56         int ret;
  57
  58         if (fence > fctx->last_fence) {
  59                 DRM_ERROR_RATELIMITED("%s: waiting on invalid fence: %u (of %u)\n",
  60                                 fctx->name, fence, fctx->last_fence);
  61                 return -EINVAL;
  62         }
  63
  64         if (!timeout) {
  65                 /* no-wait: */
  66                 ret = fence_completed(fctx, fence) ? 0 : -EBUSY;
  67         } else {
  68                 unsigned long remaining_jiffies = timeout_to_jiffies(timeout);
  69
  70                 if (interruptible)
  71                         ret = wait_event_interruptible_timeout(fctx->event,
  72                                 fence_completed(fctx, fence),
  73                                 remaining_jiffies);
  74                 else
  75                         ret = wait_event_timeout(fctx->event,
  76                                 fence_completed(fctx, fence),
  77                                 remaining_jiffies);
  78
  79                 if (ret == 0) {
  80                         DBG("timeout waiting for fence: %u (completed: %u)",
  81                                         fence, fctx->completed_fence);
  82                         ret = -ETIMEDOUT;
  83                 } else if (ret != -ERESTARTSYS) {
  84                         ret = 0;
  85                 }
  86         }
  87
  88         return ret;
  89 }
  90
  91 /* called from workqueue */
  92 void msm_update_fence(struct msm_fence_context *fctx, uint32_t fence)
  93 {
  94         spin_lock(&fctx->spinlock);
  95         fctx->completed_fence = max(fence, fctx->completed_fence);
  96         spin_unlock(&fctx->spinlock);
  97
  98         wake_up_all(&fctx->event);
  99 }
 100
 101 struct msm_fence {
 102         struct msm_fence_context *fctx;
 103         struct fence base;
 104 };
 105
 106 static inline struct msm_fence *to_msm_fence(struct fence *fence)
 107 {
 108         return container_of(fence, struct msm_fence, base);
 109 }
 110
 111 static const char *msm_fence_get_driver_name(struct fence *fence)
 112 {
 113         return "msm";
 114 }
 115
 116 static const char *msm_fence_get_timeline_name(struct fence *fence)
 117 {
 118         struct msm_fence *f = to_msm_fence(fence);
 119         return f->fctx->name;
 120 }
 121
 122 static bool msm_fence_enable_signaling(struct fence *fence)
 123 {
 124         return true;
 125 }
 126
 127 static bool msm_fence_signaled(struct fence *fence)
 128 {
 129         struct msm_fence *f = to_msm_fence(fence);
 130         return fence_completed(f->fctx, f->base.seqno);
 131 }
 132
 133 static void msm_fence_release(struct fence *fence)
 134 {
 135         struct msm_fence *f = to_msm_fence(fence);
 136         kfree_rcu(f, base.rcu);
 137 }
 138
 139 static const struct fence_ops msm_fence_ops = {
 140         .get_driver_name = msm_fence_get_driver_name,
 141         .get_timeline_name = msm_fence_get_timeline_name,
 142         .enable_signaling = msm_fence_enable_signaling,
 143         .signaled = msm_fence_signaled,
 144         .wait = fence_default_wait,
 145         .release = msm_fence_release,
 146 };
 147
 148 struct fence *
 149 msm_fence_alloc(struct msm_fence_context *fctx)
 150 {
 151         struct msm_fence *f;
 152
 153         f = kzalloc(sizeof(*f), GFP_KERNEL);
 154         if (!f)
 155                 return ERR_PTR(-ENOMEM);
 156
 157         f->fctx = fctx;
 158
 159         fence_init(&f->base, &msm_fence_ops, &fctx->spinlock,
 160                         fctx->context, ++fctx->last_fence);
 161
 162         return &f->base;
 163 }