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	When a remoteproc crashes or goes down unexpectedly this can result in a state where locks held by the remoteproc will remain locked possibly resulting in deadlock. This new API hwspin_lock_bust() allows hwspinlock implementers to define a bust operation for freeing previously acquired hwspinlocks after verifying ownership of the acquired lock. Signed-off-by: Richard Maina <quic_rmaina@quicinc.com> Reviewed-by: Bjorn Andersson <andersson@kernel.org> Signed-off-by: Chris Lew <quic_clew@quicinc.com> Link: https://lore.kernel.org/r/20240529-hwspinlock-bust-v3-1-c8b924ffa5a2@quicinc.com Signed-off-by: Bjorn Andersson <andersson@kernel.org>
		
			
				
	
	
		
			72 lines
		
	
	
	
		
			2.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			72 lines
		
	
	
	
		
			2.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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 * Hardware spinlocks internal header
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 *
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 * Copyright (C) 2010 Texas Instruments Incorporated - http://www.ti.com
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 *
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 * Contact: Ohad Ben-Cohen <ohad@wizery.com>
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 */
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#ifndef __HWSPINLOCK_HWSPINLOCK_H
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#define __HWSPINLOCK_HWSPINLOCK_H
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#include <linux/spinlock.h>
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#include <linux/device.h>
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struct hwspinlock_device;
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/**
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 * struct hwspinlock_ops - platform-specific hwspinlock handlers
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 *
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 * @trylock: make a single attempt to take the lock. returns 0 on
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 *	     failure and true on success. may _not_ sleep.
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 * @unlock:  release the lock. always succeed. may _not_ sleep.
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 * @bust:    optional, platform-specific bust handler, called by hwspinlock
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 *	     core to bust a specific lock.
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 * @relax:   optional, platform-specific relax handler, called by hwspinlock
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 *	     core while spinning on a lock, between two successive
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 *	     invocations of @trylock. may _not_ sleep.
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 */
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struct hwspinlock_ops {
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	int (*trylock)(struct hwspinlock *lock);
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	void (*unlock)(struct hwspinlock *lock);
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	int (*bust)(struct hwspinlock *lock, unsigned int id);
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	void (*relax)(struct hwspinlock *lock);
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};
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/**
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 * struct hwspinlock - this struct represents a single hwspinlock instance
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 * @bank: the hwspinlock_device structure which owns this lock
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 * @lock: initialized and used by hwspinlock core
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 * @priv: private data, owned by the underlying platform-specific hwspinlock drv
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 */
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struct hwspinlock {
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	struct hwspinlock_device *bank;
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	spinlock_t lock;
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	void *priv;
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};
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/**
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 * struct hwspinlock_device - a device which usually spans numerous hwspinlocks
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 * @dev: underlying device, will be used to invoke runtime PM api
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 * @ops: platform-specific hwspinlock handlers
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 * @base_id: id index of the first lock in this device
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 * @num_locks: number of locks in this device
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 * @lock: dynamically allocated array of 'struct hwspinlock'
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 */
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struct hwspinlock_device {
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	struct device *dev;
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	const struct hwspinlock_ops *ops;
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	int base_id;
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	int num_locks;
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	struct hwspinlock lock[];
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};
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static inline int hwlock_to_id(struct hwspinlock *hwlock)
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{
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	int local_id = hwlock - &hwlock->bank->lock[0];
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	return hwlock->bank->base_id + local_id;
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}
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#endif /* __HWSPINLOCK_HWSPINLOCK_H */
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