dma-buf: nuke seqno-fence

Entirely unused.
Signed-off-by: NChristian König <christian.koenig@amd.com>
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210729070330.41443-1-christian.koenig@amd.com

drivers/dma-buf/Makefile

 # SPDX-License-Identifier: GPL-2.0-only
 obj-y := dma-buf.o dma-fence.o dma-fence-array.o dma-fence-chain.o \
-	 dma-resv.o seqno-fence.o
+	 dma-resv.o
 obj-$(CONFIG_DMABUF_HEAPS)	+= dma-heap.o
 obj-$(CONFIG_DMABUF_HEAPS)	+= heaps/
 obj-$(CONFIG_SYNC_FILE)		+= sync_file.o

drivers/dma-buf/seqno-fence.c

-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * seqno-fence, using a dma-buf to synchronize fencing
- *
- * Copyright (C) 2012 Texas Instruments
- * Copyright (C) 2012-2014 Canonical Ltd
- * Authors:
- *   Rob Clark <robdclark@gmail.com>
- *   Maarten Lankhorst <maarten.lankhorst@canonical.com>
- */
-
-#include <linux/slab.h>
-#include <linux/export.h>
-#include <linux/seqno-fence.h>
-
-static const char *seqno_fence_get_driver_name(struct dma_fence *fence)
-{
-	struct seqno_fence *seqno_fence = to_seqno_fence(fence);
-
-	return seqno_fence->ops->get_driver_name(fence);
-}
-
-static const char *seqno_fence_get_timeline_name(struct dma_fence *fence)
-{
-	struct seqno_fence *seqno_fence = to_seqno_fence(fence);
-
-	return seqno_fence->ops->get_timeline_name(fence);
-}
-
-static bool seqno_enable_signaling(struct dma_fence *fence)
-{
-	struct seqno_fence *seqno_fence = to_seqno_fence(fence);
-
-	return seqno_fence->ops->enable_signaling(fence);
-}
-
-static bool seqno_signaled(struct dma_fence *fence)
-{
-	struct seqno_fence *seqno_fence = to_seqno_fence(fence);
-
-	return seqno_fence->ops->signaled && seqno_fence->ops->signaled(fence);
-}
-
-static void seqno_release(struct dma_fence *fence)
-{
-	struct seqno_fence *f = to_seqno_fence(fence);
-
-	dma_buf_put(f->sync_buf);
-	if (f->ops->release)
-		f->ops->release(fence);
-	else
-		dma_fence_free(&f->base);
-}
-
-static signed long seqno_wait(struct dma_fence *fence, bool intr,
-			      signed long timeout)
-{
-	struct seqno_fence *f = to_seqno_fence(fence);
-
-	return f->ops->wait(fence, intr, timeout);
-}
-
-const struct dma_fence_ops seqno_fence_ops = {
-	.get_driver_name = seqno_fence_get_driver_name,
-	.get_timeline_name = seqno_fence_get_timeline_name,
-	.enable_signaling = seqno_enable_signaling,
-	.signaled = seqno_signaled,
-	.wait = seqno_wait,
-	.release = seqno_release,
-};
-EXPORT_SYMBOL(seqno_fence_ops);

include/linux/seqno-fence.h

-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * seqno-fence, using a dma-buf to synchronize fencing
- *
- * Copyright (C) 2012 Texas Instruments
- * Copyright (C) 2012 Canonical Ltd
- * Authors:
- *   Rob Clark <robdclark@gmail.com>
- *   Maarten Lankhorst <maarten.lankhorst@canonical.com>
- */
-
-#ifndef __LINUX_SEQNO_FENCE_H
-#define __LINUX_SEQNO_FENCE_H
-
-#include <linux/dma-fence.h>
-#include <linux/dma-buf.h>
-
-enum seqno_fence_condition {
-	SEQNO_FENCE_WAIT_GEQUAL,
-	SEQNO_FENCE_WAIT_NONZERO
-};
-
-struct seqno_fence {
-	struct dma_fence base;
-
-	const struct dma_fence_ops *ops;
-	struct dma_buf *sync_buf;
-	uint32_t seqno_ofs;
-	enum seqno_fence_condition condition;
-};
-
-extern const struct dma_fence_ops seqno_fence_ops;
-
-/**
- * to_seqno_fence - cast a fence to a seqno_fence
- * @fence: fence to cast to a seqno_fence
- *
- * Returns NULL if the fence is not a seqno_fence,
- * or the seqno_fence otherwise.
- */
-static inline struct seqno_fence *
-to_seqno_fence(struct dma_fence *fence)
-{
-	if (fence->ops != &seqno_fence_ops)
-		return NULL;
-	return container_of(fence, struct seqno_fence, base);
-}
-
-/**
- * seqno_fence_init - initialize a seqno fence
- * @fence: seqno_fence to initialize
- * @lock: pointer to spinlock to use for fence
- * @sync_buf: buffer containing the memory location to signal on
- * @context: the execution context this fence is a part of
- * @seqno_ofs: the offset within @sync_buf
- * @seqno: the sequence # to signal on
- * @cond: fence wait condition
- * @ops: the fence_ops for operations on this seqno fence
- *
- * This function initializes a struct seqno_fence with passed parameters,
- * and takes a reference on sync_buf which is released on fence destruction.
- *
- * A seqno_fence is a dma_fence which can complete in software when
- * enable_signaling is called, but it also completes when
- * (s32)((sync_buf)[seqno_ofs] - seqno) >= 0 is true
- *
- * The seqno_fence will take a refcount on the sync_buf until it's
- * destroyed, but actual lifetime of sync_buf may be longer if one of the
- * callers take a reference to it.
- *
- * Certain hardware have instructions to insert this type of wait condition
- * in the command stream, so no intervention from software would be needed.
- * This type of fence can be destroyed before completed, however a reference
- * on the sync_buf dma-buf can be taken. It is encouraged to re-use the same
- * dma-buf for sync_buf, since mapping or unmapping the sync_buf to the
- * device's vm can be expensive.
- *
- * It is recommended for creators of seqno_fence to call dma_fence_signal()
- * before destruction. This will prevent possible issues from wraparound at
- * time of issue vs time of check, since users can check dma_fence_is_signaled()
- * before submitting instructions for the hardware to wait on the fence.
- * However, when ops.enable_signaling is not called, it doesn't have to be
- * done as soon as possible, just before there's any real danger of seqno
- * wraparound.
- */
-static inline void
-seqno_fence_init(struct seqno_fence *fence, spinlock_t *lock,
-		 struct dma_buf *sync_buf,  uint32_t context,
-		 uint32_t seqno_ofs, uint32_t seqno,
-		 enum seqno_fence_condition cond,
-		 const struct dma_fence_ops *ops)
-{
-	BUG_ON(!fence || !sync_buf || !ops);
-	BUG_ON(!ops->wait || !ops->enable_signaling ||
-	       !ops->get_driver_name || !ops->get_timeline_name);
-
-	/*
-	 * ops is used in dma_fence_init for get_driver_name, so needs to be
-	 * initialized first
-	 */
-	fence->ops = ops;
-	dma_fence_init(&fence->base, &seqno_fence_ops, lock, context, seqno);
-	get_dma_buf(sync_buf);
-	fence->sync_buf = sync_buf;
-	fence->seqno_ofs = seqno_ofs;
-	fence->condition = cond;
-}
-
-#endif /* __LINUX_SEQNO_FENCE_H */