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
This commit is contained in:
Linus Torvalds
2018-06-11 12:09:19 -07:00
9 changed files with 118 additions and 81 deletions

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@@ -1,3 +1,4 @@
# SPDX-License-Identifier: GPL-2.0
#
# Generic HWSPINLOCK framework
#

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@@ -1,18 +1,10 @@
// 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);

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@@ -1,18 +1,10 @@
/* 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

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@@ -1,3 +1,4 @@
// 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>

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@@ -1,15 +1,7 @@
// 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>

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@@ -1,9 +1,8 @@
// SPDX-License-Identifier: GPL-2.0
/*
* SIRF hardware spinlock driver
*
* Copyright (c) 2015 Cambridge Silicon Radio Limited, a CSR plc group company.
*
* Licensed under GPLv2.
*/
#include <linux/kernel.h>

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@@ -1,15 +1,7 @@
// SPDX-License-Identifier: GPL-2.0
/*
* Spreadtrum hardware spinlock driver
* Copyright (C) 2017 Spreadtrum - http://www.spreadtrum.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/bitops.h>

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@@ -1,3 +1,4 @@
// SPDX-License-Identifier: GPL-2.0
/*
* u8500 HWSEM driver
*
@@ -10,15 +11,6 @@
* 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/module.h>