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 <[email protected]>
   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
  19         fctx = kzalloc(sizeof(*fctx), GFP_KERNEL);
  20         if (!fctx)
  21                 return ERR_PTR(-ENOMEM);
  22
  23         fctx->dev = dev;
  24         strncpy(fctx->name, name, sizeof(fctx->name));
  25         fctx->context = dma_fence_context_alloc(1);
  26         fctx->fenceptr = fenceptr;
  27         spin_lock_init(&fctx->spinlock);
  28
  29         return fctx;
  30 }
  31
  32 void msm_fence_context_free(struct msm_fence_context *fctx)
  33 {
  34         kfree(fctx);
  35 }
  36
  37 static inline bool fence_completed(struct msm_fence_context *fctx, uint32_t fence)
  38 {
  39         /*
  40          * Note: Check completed_fence first, as fenceptr is in a write-combine
  41          * mapping, so it will be more expensive to read.
  42          */
  43         return (int32_t)(fctx->completed_fence - fence) >= 0 ||
  44                 (int32_t)(*fctx->fenceptr - fence) >= 0;
  45 }
  46
  47 /* called from workqueue */
  48 void msm_update_fence(struct msm_fence_context *fctx, uint32_t fence)
  49 {
  50         spin_lock(&fctx->spinlock);
  51         fctx->completed_fence = max(fence, fctx->completed_fence);
  52         spin_unlock(&fctx->spinlock);
  53 }
  54
  55 struct msm_fence {
  56         struct dma_fence base;
  57         struct msm_fence_context *fctx;
  58 };
  59
  60 static inline struct msm_fence *to_msm_fence(struct dma_fence *fence)
  61 {
  62         return container_of(fence, struct msm_fence, base);
  63 }
  64
  65 static const char *msm_fence_get_driver_name(struct dma_fence *fence)
  66 {
  67         return "msm";
  68 }
  69
  70 static const char *msm_fence_get_timeline_name(struct dma_fence *fence)
  71 {
  72         struct msm_fence *f = to_msm_fence(fence);
  73         return f->fctx->name;
  74 }
  75
  76 static bool msm_fence_signaled(struct dma_fence *fence)
  77 {
  78         struct msm_fence *f = to_msm_fence(fence);
  79         return fence_completed(f->fctx, f->base.seqno);
  80 }
  81
  82 static const struct dma_fence_ops msm_fence_ops = {
  83         .get_driver_name = msm_fence_get_driver_name,
  84         .get_timeline_name = msm_fence_get_timeline_name,
  85         .signaled = msm_fence_signaled,
  86 };
  87
  88 struct dma_fence *
  89 msm_fence_alloc(struct msm_fence_context *fctx)
  90 {
  91         struct msm_fence *f;
  92
  93         f = kzalloc(sizeof(*f), GFP_KERNEL);
  94         if (!f)
  95                 return ERR_PTR(-ENOMEM);
  96
  97         f->fctx = fctx;
  98
  99         dma_fence_init(&f->base, &msm_fence_ops, &fctx->spinlock,
 100                        fctx->context, ++fctx->last_fence);
 101
 102         return &f->base;
 103 }