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Commit 6f75edea authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'hwlock-v4.18' of git://github.com/andersson/remoteproc 

Pull hwspinlock updates from Bjorn Andersson:
 "In addition to migrating the files to use SPDX license headers this
  introduces the ability for clients to operate a hwlock without the
  framework taking any additional locks"

* tag 'hwlock-v4.18' of git://github.com/andersson/remoteproc:
  hwspinlock/u8500: Switch to SPDX license identifier
  hwspinlock: sprd: Switch to SPDX license identifier
  hwspinlock/sirf: Switch to SPDX license identifier
  hwspinlock: qcom: Switch to SPDX license identifier
  hwspinlock/omap: Switch to SPDX license identifier
  hwspinlock/core: Switch to SPDX license identifier
  hwspinlock: Introduce one new mode for hwspinlock
  hwspinlock: Convert to use 'switch' statement
parents d2b2250c e759176c

drivers/hwspinlock/Kconfig

+1 −0
Original line number Diff line number Diff line 
# SPDX-License-Identifier: GPL-2.0

#

# Generic HWSPINLOCK framework

#

drivers/hwspinlock/hwspinlock_core.c

+52 −25
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/*

 * Hardware spinlock framework

 *

 * Copyright (C) 2010 Texas Instruments Incorporated - http://www.ti.com

 *

 * Contact: Ohad Ben-Cohen <ohad@wizery.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.

 */



#define pr_fmt(fmt)    "%s: " fmt, __func__
@@ -71,10 +63,16 @@ static DEFINE_MUTEX(hwspinlock_tree_lock); 
 * This function attempts to lock an hwspinlock, and will immediately

 * fail if the hwspinlock is already taken.

 *

 * Upon a successful return from this function, preemption (and possibly

 * interrupts) is disabled, so the caller must not sleep, and is advised to

 * release the hwspinlock as soon as possible. This is required in order to

 * minimize remote cores polling on the hardware interconnect.

 * Caution: If the mode is HWLOCK_RAW, that means user must protect the routine

 * of getting hardware lock with mutex or spinlock. Since in some scenarios,

 * user need some time-consuming or sleepable operations under the hardware

 * lock, they need one sleepable lock (like mutex) to protect the operations.

 *

 * If the mode is not HWLOCK_RAW, upon a successful return from this function,

 * preemption (and possibly interrupts) is disabled, so the caller must not

 * sleep, and is advised to release the hwspinlock as soon as possible. This is

 * required in order to minimize remote cores polling on the hardware

 * interconnect.

 *

 * The user decides whether local interrupts are disabled or not, and if yes,

 * whether he wants their previous state to be saved. It is up to the user
@@ -106,12 +104,20 @@ int __hwspin_trylock(struct hwspinlock *hwlock, int mode, unsigned long *flags) 
	 *    problems with hwspinlock usage (e.g. scheduler checks like

	 *    'scheduling while atomic' etc.)

	 */

	if (mode == HWLOCK_IRQSTATE)

	switch (mode) {

	case HWLOCK_IRQSTATE:

		ret = spin_trylock_irqsave(&hwlock->lock, *flags);

	else if (mode == HWLOCK_IRQ)

		break;

	case HWLOCK_IRQ:

		ret = spin_trylock_irq(&hwlock->lock);

	else

		break;

	case HWLOCK_RAW:

		ret = 1;

		break;

	default:

		ret = spin_trylock(&hwlock->lock);

		break;

	}



	/* is lock already taken by another context on the local cpu ? */

	if (!ret)
@@ -122,12 +128,20 @@ int __hwspin_trylock(struct hwspinlock *hwlock, int mode, unsigned long *flags) 


	/* if hwlock is already taken, undo spin_trylock_* and exit */

	if (!ret) {

		if (mode == HWLOCK_IRQSTATE)

		switch (mode) {

		case HWLOCK_IRQSTATE:

			spin_unlock_irqrestore(&hwlock->lock, *flags);

		else if (mode == HWLOCK_IRQ)

			break;

		case HWLOCK_IRQ:

			spin_unlock_irq(&hwlock->lock);

		else

			break;

		case HWLOCK_RAW:

			/* Nothing to do */

			break;

		default:

			spin_unlock(&hwlock->lock);

			break;

		}



		return -EBUSY;

	}
@@ -160,9 +174,14 @@ EXPORT_SYMBOL_GPL(__hwspin_trylock); 
 * is already taken, the function will busy loop waiting for it to

 * be released, but give up after @timeout msecs have elapsed.

 *

 * Upon a successful return from this function, preemption is disabled

 * (and possibly local interrupts, too), so the caller must not sleep,

 * and is advised to release the hwspinlock as soon as possible.

 * Caution: If the mode is HWLOCK_RAW, that means user must protect the routine

 * of getting hardware lock with mutex or spinlock. Since in some scenarios,

 * user need some time-consuming or sleepable operations under the hardware

 * lock, they need one sleepable lock (like mutex) to protect the operations.

 *

 * If the mode is not HWLOCK_RAW, upon a successful return from this function,

 * preemption is disabled (and possibly local interrupts, too), so the caller

 * must not sleep, and is advised to release the hwspinlock as soon as possible.

 * This is required in order to minimize remote cores polling on the

 * hardware interconnect.

 *
@@ -249,12 +268,20 @@ void __hwspin_unlock(struct hwspinlock *hwlock, int mode, unsigned long *flags) 
	hwlock->bank->ops->unlock(hwlock);



	/* Undo the spin_trylock{_irq, _irqsave} called while locking */

	if (mode == HWLOCK_IRQSTATE)

	switch (mode) {

	case HWLOCK_IRQSTATE:

		spin_unlock_irqrestore(&hwlock->lock, *flags);

	else if (mode == HWLOCK_IRQ)

		break;

	case HWLOCK_IRQ:

		spin_unlock_irq(&hwlock->lock);

	else

		break;

	case HWLOCK_RAW:

		/* Nothing to do */

		break;

	default:

		spin_unlock(&hwlock->lock);

		break;

	}

}

EXPORT_SYMBOL_GPL(__hwspin_unlock);

drivers/hwspinlock/hwspinlock_internal.h

+1 −9
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 */

/*

 * Hardware spinlocks internal header

 *

 * Copyright (C) 2010 Texas Instruments Incorporated - http://www.ti.com

 *

 * Contact: Ohad Ben-Cohen <ohad@wizery.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 __HWSPINLOCK_HWSPINLOCK_H

drivers/hwspinlock/omap_hwspinlock.c

+1 −9
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/*

 * OMAP hardware spinlock driver

 *
@@ -6,15 +7,6 @@ 
 * Contact: Simon Que <sque@ti.com>

 *          Hari Kanigeri <h-kanigeri2@ti.com>

 *          Ohad Ben-Cohen <ohad@wizery.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.

 */



#include <linux/kernel.h>

drivers/hwspinlock/qcom_hwspinlock.c

+1 −9
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/*

 * Copyright (c) 2013, The Linux Foundation. All rights reserved.

 * Copyright (c) 2015, Sony Mobile Communications AB

 *

 * This software is licensed under the terms of the GNU General Public

 * License version 2, as published by the Free Software Foundation, and

 * may be copied, distributed, and modified under those terms.

 *

 * 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.

 */



#include <linux/hwspinlock.h>