mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-11-25 16:40:52 +07:00
1f58d9465c
The seqno_fence_init() function's cond argument isn't described in the kerneldoc comment. Fix that to silence a warning when building DocBook documentation. Signed-off-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
118 lines
3.9 KiB
C
118 lines
3.9 KiB
C
/*
|
|
* 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>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* under the terms of the GNU General Public License version 2 as published by
|
|
* the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope that it will be useful, but WITHOUT
|
|
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
|
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
|
|
* more details.
|
|
*/
|
|
|
|
#ifndef __LINUX_SEQNO_FENCE_H
|
|
#define __LINUX_SEQNO_FENCE_H
|
|
|
|
#include <linux/fence.h>
|
|
#include <linux/dma-buf.h>
|
|
|
|
enum seqno_fence_condition {
|
|
SEQNO_FENCE_WAIT_GEQUAL,
|
|
SEQNO_FENCE_WAIT_NONZERO
|
|
};
|
|
|
|
struct seqno_fence {
|
|
struct fence base;
|
|
|
|
const struct fence_ops *ops;
|
|
struct dma_buf *sync_buf;
|
|
uint32_t seqno_ofs;
|
|
enum seqno_fence_condition condition;
|
|
};
|
|
|
|
extern const struct 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 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 fence_signal
|
|
* before destruction. This will prevent possible issues from wraparound at
|
|
* time of issue vs time of check, since users can check 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 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 fence_init for get_driver_name, so needs to be
|
|
* initialized first
|
|
*/
|
|
fence->ops = ops;
|
|
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 */
|