drivers/gpu/drm/msm/msm_fence.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2013-2016 Red Hat
   4  * Author: Rob Clark <robdclark@gmail.com>
   5  */
   6
   7 #include <linux/dma-fence.h>
   8
   9 #include "msm_drv.h"
  10 #include "msm_fence.h"
  11
  12
  13 struct msm_fence_context *
  14 msm_fence_context_alloc(struct drm_device *dev, volatile uint32_t *fenceptr,
  15                 const char *name)
  16 {
  17         struct msm_fence_context *fctx;
  18         static int index = 0;
  19
  20         fctx = kzalloc(sizeof(*fctx), GFP_KERNEL);
  21         if (!fctx)
  22                 return ERR_PTR(-ENOMEM);
  23
  24         fctx->dev = dev;
  25         strncpy(fctx->name, name, sizeof(fctx->name));
  26         fctx->context = dma_fence_context_alloc(1);
  27         fctx->index = index++;
  28         fctx->fenceptr = fenceptr;
  29         spin_lock_init(&fctx->spinlock);
  30
  31         return fctx;
  32 }
  33
  34 void msm_fence_context_free(struct msm_fence_context *fctx)
  35 {
  36         kfree(fctx);
  37 }
  38
  39 bool msm_fence_completed(struct msm_fence_context *fctx, uint32_t fence)
  40 {
  41         /*
  42          * Note: Check completed_fence first, as fenceptr is in a write-combine
  43          * mapping, so it will be more expensive to read.
  44          */
  45         return (int32_t)(fctx->completed_fence - fence) >= 0 ||
  46                 (int32_t)(*fctx->fenceptr - fence) >= 0;
  47 }
  48
  49 /* called from irq handler and workqueue (in recover path) */
  50 void msm_update_fence(struct msm_fence_context *fctx, uint32_t fence)
  51 {
  52         unsigned long flags;
  53
  54         spin_lock_irqsave(&fctx->spinlock, flags);
  55         fctx->completed_fence = max(fence, fctx->completed_fence);
  56         spin_unlock_irqrestore(&fctx->spinlock, flags);
  57 }
  58
  59 struct msm_fence {
  60         struct dma_fence base;
  61         struct msm_fence_context *fctx;
  62 };
  63
  64 static inline struct msm_fence *to_msm_fence(struct dma_fence *fence)
  65 {
  66         return container_of(fence, struct msm_fence, base);
  67 }
  68
  69 static const char *msm_fence_get_driver_name(struct dma_fence *fence)
  70 {
  71         return "msm";
  72 }
  73
  74 static const char *msm_fence_get_timeline_name(struct dma_fence *fence)
  75 {
  76         struct msm_fence *f = to_msm_fence(fence);
  77         return f->fctx->name;
  78 }
  79
  80 static bool msm_fence_signaled(struct dma_fence *fence)
  81 {
  82         struct msm_fence *f = to_msm_fence(fence);
  83         return msm_fence_completed(f->fctx, f->base.seqno);
  84 }
  85
  86 static const struct dma_fence_ops msm_fence_ops = {
  87         .get_driver_name = msm_fence_get_driver_name,
  88         .get_timeline_name = msm_fence_get_timeline_name,
  89         .signaled = msm_fence_signaled,
  90 };
  91
  92 struct dma_fence *
  93 msm_fence_alloc(struct msm_fence_context *fctx)
  94 {
  95         struct msm_fence *f;
  96
  97         f = kzalloc(sizeof(*f), GFP_KERNEL);
  98         if (!f)
  99                 return ERR_PTR(-ENOMEM);
 100
 101         f->fctx = fctx;
 102
 103         dma_fence_init(&f->base, &msm_fence_ops, &fctx->spinlock,
 104                        fctx->context, ++fctx->last_fence);
 105
 106         return &f->base;
 107 }