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Diffstat (limited to 'include/linux/seqno-fence.h')
| -rw-r--r-- | include/linux/seqno-fence.h | 109 |
1 files changed, 0 insertions, 109 deletions
diff --git a/include/linux/seqno-fence.h b/include/linux/seqno-fence.h deleted file mode 100644 index 3cca2b8fac43..000000000000 --- a/include/linux/seqno-fence.h +++ /dev/null @@ -1,109 +0,0 @@ -/* 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 */ |