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
 13struct msm_fence_context *
 14msm_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	/*
 32	 * Start out close to the 32b fence rollover point, so we can
 33	 * catch bugs with fence comparisons.
 34	 */
 35	fctx->last_fence = 0xffffff00;
 36	fctx->completed_fence = fctx->last_fence;
 37	*fctx->fenceptr = fctx->last_fence;
 38
 39	return fctx;
 40}
 41
 42void msm_fence_context_free(struct msm_fence_context *fctx)
 43{
 44	kfree(fctx);
 45}
 46
 47bool msm_fence_completed(struct msm_fence_context *fctx, uint32_t fence)
 48{
 49	/*
 50	 * Note: Check completed_fence first, as fenceptr is in a write-combine
 51	 * mapping, so it will be more expensive to read.
 52	 */
 53	return (int32_t)(fctx->completed_fence - fence) >= 0 ||
 54		(int32_t)(*fctx->fenceptr - fence) >= 0;
 55}
 56
 57/* called from irq handler and workqueue (in recover path) */
 58void msm_update_fence(struct msm_fence_context *fctx, uint32_t fence)
 59{
 60	unsigned long flags;
 61
 62	spin_lock_irqsave(&fctx->spinlock, flags);
 63	if (fence_after(fence, fctx->completed_fence))
 64		fctx->completed_fence = fence;
 65	spin_unlock_irqrestore(&fctx->spinlock, flags);
 66}
 67
 68struct msm_fence {
 69	struct dma_fence base;
 70	struct msm_fence_context *fctx;
 71};
 72
 73static inline struct msm_fence *to_msm_fence(struct dma_fence *fence)
 74{
 75	return container_of(fence, struct msm_fence, base);
 76}
 77
 78static const char *msm_fence_get_driver_name(struct dma_fence *fence)
 79{
 80	return "msm";
 81}
 82
 83static const char *msm_fence_get_timeline_name(struct dma_fence *fence)
 84{
 85	struct msm_fence *f = to_msm_fence(fence);
 86	return f->fctx->name;
 87}
 88
 89static bool msm_fence_signaled(struct dma_fence *fence)
 90{
 91	struct msm_fence *f = to_msm_fence(fence);
 92	return msm_fence_completed(f->fctx, f->base.seqno);
 93}
 94
 95static const struct dma_fence_ops msm_fence_ops = {
 96	.get_driver_name = msm_fence_get_driver_name,
 97	.get_timeline_name = msm_fence_get_timeline_name,
 98	.signaled = msm_fence_signaled,
 99};
100
101struct dma_fence *
102msm_fence_alloc(struct msm_fence_context *fctx)
103{
104	struct msm_fence *f;
105
106	f = kzalloc(sizeof(*f), GFP_KERNEL);
107	if (!f)
108		return ERR_PTR(-ENOMEM);
109
110	f->fctx = fctx;
111
112	dma_fence_init(&f->base, &msm_fence_ops, &fctx->spinlock,
113		       fctx->context, ++fctx->last_fence);
114
115	return &f->base;
116}