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authorLinus Torvalds <torvalds@linux-foundation.org>2018-06-11 12:09:19 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-06-11 12:09:19 -0700
commit6f75edeadd0dd3d58017bc3bcdc2b80879a7cfd3 (patch)
treee75729deec3343feec7a19820fba633df4aea9b0 /include
parentd2b2250c3e565038a746b5db1de2af20a6468f02 (diff)
parente759176c7f6b6d84a31276e11d687f232f6e4ecf (diff)
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
Diffstat (limited to 'include')
-rw-r--r--include/linux/hwspinlock.h68
1 files changed, 59 insertions, 9 deletions
diff --git a/include/linux/hwspinlock.h b/include/linux/hwspinlock.h
index 859d673d98c8..57537e67b468 100644
--- a/include/linux/hwspinlock.h
+++ b/include/linux/hwspinlock.h
@@ -1,18 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0 */
/*
* Hardware spinlock public 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 __LINUX_HWSPINLOCK_H
@@ -24,6 +16,7 @@
/* hwspinlock mode argument */
#define HWLOCK_IRQSTATE 0x01 /* Disable interrupts, save state */
#define HWLOCK_IRQ 0x02 /* Disable interrupts, don't save state */
+#define HWLOCK_RAW 0x03
struct device;
struct device_node;
@@ -176,6 +169,25 @@ static inline int hwspin_trylock_irq(struct hwspinlock *hwlock)
}
/**
+ * hwspin_trylock_raw() - attempt to lock a specific hwspinlock
+ * @hwlock: an hwspinlock which we want to trylock
+ *
+ * This function attempts to lock an hwspinlock, and will immediately fail
+ * if the hwspinlock is already taken.
+ *
+ * Caution: User must protect the routine of getting hardware lock with mutex
+ * or spinlock to avoid dead-lock, that will let user can do some time-consuming
+ * or sleepable operations under the hardware lock.
+ *
+ * Returns 0 if we successfully locked the hwspinlock, -EBUSY if
+ * the hwspinlock was already taken, and -EINVAL if @hwlock is invalid.
+ */
+static inline int hwspin_trylock_raw(struct hwspinlock *hwlock)
+{
+ return __hwspin_trylock(hwlock, HWLOCK_RAW, NULL);
+}
+
+/**
* hwspin_trylock() - attempt to lock a specific hwspinlock
* @hwlock: an hwspinlock which we want to trylock
*
@@ -243,6 +255,29 @@ int hwspin_lock_timeout_irq(struct hwspinlock *hwlock, unsigned int to)
}
/**
+ * hwspin_lock_timeout_raw() - lock an hwspinlock with timeout limit
+ * @hwlock: the hwspinlock to be locked
+ * @to: timeout value in msecs
+ *
+ * This function locks the underlying @hwlock. If the @hwlock
+ * is already taken, the function will busy loop waiting for it to
+ * be released, but give up when @timeout msecs have elapsed.
+ *
+ * Caution: User must protect the routine of getting hardware lock with mutex
+ * or spinlock to avoid dead-lock, that will let user can do some time-consuming
+ * or sleepable operations under the hardware lock.
+ *
+ * Returns 0 when the @hwlock was successfully taken, and an appropriate
+ * error code otherwise (most notably an -ETIMEDOUT if the @hwlock is still
+ * busy after @timeout msecs). The function will never sleep.
+ */
+static inline
+int hwspin_lock_timeout_raw(struct hwspinlock *hwlock, unsigned int to)
+{
+ return __hwspin_lock_timeout(hwlock, to, HWLOCK_RAW, NULL);
+}
+
+/**
* hwspin_lock_timeout() - lock an hwspinlock with timeout limit
* @hwlock: the hwspinlock to be locked
* @to: timeout value in msecs
@@ -302,6 +337,21 @@ static inline void hwspin_unlock_irq(struct hwspinlock *hwlock)
}
/**
+ * hwspin_unlock_raw() - unlock hwspinlock
+ * @hwlock: a previously-acquired hwspinlock which we want to unlock
+ *
+ * This function will unlock a specific hwspinlock.
+ *
+ * @hwlock must be already locked (e.g. by hwspin_trylock()) before calling
+ * this function: it is a bug to call unlock on a @hwlock that is already
+ * unlocked.
+ */
+static inline void hwspin_unlock_raw(struct hwspinlock *hwlock)
+{
+ __hwspin_unlock(hwlock, HWLOCK_RAW, NULL);
+}
+
+/**
* hwspin_unlock() - unlock hwspinlock
* @hwlock: a previously-acquired hwspinlock which we want to unlock
*