06878b3a80
Currently, the Driver Synchronization Core (DSC) blocks transitions up-tree and down-tree from a node currently undergoing a transition, but only rejects operations down-tree from the current node. Instead, reject new operations both up-tree and down-tree from the current node under transition. This provides more forgiving safety guarantees to operation implementations at the cost of a reduced amount of parallelism that can be achieved. Change-Id: I09e1c48f7030a2252380d172c1c00ee22eac39c5 CRs-Fixed: 2421786
56 lines
2.4 KiB
C
56 lines
2.4 KiB
C
/*
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* Copyright (c) 2018-2019 The Linux Foundation. All rights reserved.
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*
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* Permission to use, copy, modify, and/or distribute this software for
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* any purpose with or without fee is hereby granted, provided that the
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* above copyright notice and this permission notice appear in all
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* copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
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* WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
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* WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
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* AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
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* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
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* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
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* TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
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* PERFORMANCE OF THIS SOFTWARE.
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*/
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/**
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* DOC: Driver Synchronization Core (DSC) APIs for use by the driver
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* orchestration layer.
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*
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* This infrastructure accomplishes two high level goals:
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* 1) Replace ad-hoc locking/flags (hdd_init_deinit_lock,
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* iface_change_lock, con_mode_flag, etc., etc., etc.)
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* 2) Make cds_ssr_protect() and driver state checking atomic
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*
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* These two goals are commplished in DSC via two corollary concepts:
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* 1) Transitions (as in driver state machine transitions)
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* These are mutually exclusive, and replace ad-hoc locking
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* 2) Operations (as in operations the driver is currently servicing)
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* These execute concurrently with other operations, and replace
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* cds_ssr_protect(). Any active transition causes new operations to be
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* rejected, in the same way as cds_ssr_protect/hdd_validate_context would.
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*
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* Transitions and operations are split into 3 distinct levels: driver, psoc,
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* and vdev. These levels are arranged into a tree, with a single driver at
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* the root, zero or more psocs per driver, and zero or more vdevs per psoc.
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*
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* High level transitions block transitions and operations at the same level,
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* down-tree, and up-tree. So a driver transition effectively prevents any new
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* activity in the system, while a vdev transition prevents transtitions and
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* operations on the same vdev, its parent psoc, and the driver. This also means
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* that sibling nodes can transition at the same time, e.g. one vdev going up at
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* the same time another is going down.
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*/
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#ifndef __WLAN_DSC_H
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#define __WLAN_DSC_H
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#include "wlan_dsc_driver.h"
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#include "wlan_dsc_psoc.h"
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#include "wlan_dsc_vdev.h"
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#endif /* __WLAN_DSC_H */
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