arch/mips/include/asm/octeon/cvmx-spinlock.h - maze/linux - Git at Google

 /***********************license start***************
  * Author: Cavium Networks
  *
  * Contact: support@caviumnetworks.com
  * This file is part of the OCTEON SDK
  *
  * Copyright (c) 2003-2008 Cavium Networks
  *
  * This file 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 file is distributed in the hope that it will be useful, but
  * AS-IS and WITHOUT ANY WARRANTY; without even the implied warranty
  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, TITLE, or
  * NONINFRINGEMENT.  See the GNU General Public License for more
  * details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this file; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  * or visit http://www.gnu.org/licenses/.
  *
  * This file may also be available under a different license from Cavium.
  * Contact Cavium Networks for more information
  ***********************license end**************************************/

 /**
  * Implementation of spinlocks for Octeon CVMX.	 Although similar in
  * function to Linux kernel spinlocks, they are not compatible.
  * Octeon CVMX spinlocks are only used to synchronize with the boot
  * monitor and other non-Linux programs running in the system.
  */

 #ifndef __CVMX_SPINLOCK_H__
 #define __CVMX_SPINLOCK_H__

 #include <asm/octeon/cvmx-asm.h>

 /* Spinlocks for Octeon */

 /* define these to enable recursive spinlock debugging */
 /*#define CVMX_SPINLOCK_DEBUG */

 /**
  * Spinlocks for Octeon CVMX
  */
 typedef struct {
 	volatile uint32_t value;
 } cvmx_spinlock_t;

 /* note - macros not expanded in inline ASM, so values hardcoded */
 #define	 CVMX_SPINLOCK_UNLOCKED_VAL  0
 #define	 CVMX_SPINLOCK_LOCKED_VAL    1

 #define CVMX_SPINLOCK_UNLOCKED_INITIALIZER  {CVMX_SPINLOCK_UNLOCKED_VAL}

 /**
  * Initialize a spinlock
  *
  * @lock:   Lock to initialize
  */
 static inline void cvmx_spinlock_init(cvmx_spinlock_t *lock)
 {
 	lock->value = CVMX_SPINLOCK_UNLOCKED_VAL;
 }

 /**
  * Return non-zero if the spinlock is currently locked
  *
  * @lock:   Lock to check
  * Returns Non-zero if locked
  */
 static inline int cvmx_spinlock_locked(cvmx_spinlock_t *lock)
 {
 	return lock->value != CVMX_SPINLOCK_UNLOCKED_VAL;
 }

 /**
  * Releases lock
  *
  * @lock:   pointer to lock structure
  */
 static inline void cvmx_spinlock_unlock(cvmx_spinlock_t *lock)
 {
 	CVMX_SYNCWS;
 	lock->value = 0;
 	CVMX_SYNCWS;
 }

 /**
  * Attempts to take the lock, but does not spin if lock is not available.
  * May take some time to acquire the lock even if it is available
  * due to the ll/sc not succeeding.
  *
  * @lock:   pointer to lock structure
  *
  * Returns 0: lock successfully taken
  *	   1: lock not taken, held by someone else
  * These return values match the Linux semantics.
  */

 static inline unsigned int cvmx_spinlock_trylock(cvmx_spinlock_t *lock)
 {
 	unsigned int tmp;

 	__asm__ __volatile__(".set noreorder	     \n"
 			     "1: ll   %[tmp], %[val] \n"
 			/* if lock held, fail immediately */
 			     "	 bnez %[tmp], 2f     \n"
 			     "	 li   %[tmp], 1	     \n"
 			     "	 sc   %[tmp], %[val] \n"
 			     "	 beqz %[tmp], 1b     \n"
 			     "	 li   %[tmp], 0	     \n"
 			     "2:		     \n"
 			     ".set reorder	     \n" :
 			[val] "+m"(lock->value), [tmp] "=&r"(tmp)
 			     : : "memory");

 	return tmp != 0;		/* normalize to 0 or 1 */
 }

 /**
  * Gets lock, spins until lock is taken
  *
  * @lock:   pointer to lock structure
  */
 static inline void cvmx_spinlock_lock(cvmx_spinlock_t *lock)
 {
 	unsigned int tmp;

 	__asm__ __volatile__(".set noreorder	     \n"
 			     "1: ll   %[tmp], %[val]  \n"
 			     "	 bnez %[tmp], 1b     \n"
 			     "	 li   %[tmp], 1	     \n"
 			     "	 sc   %[tmp], %[val] \n"
 			     "	 beqz %[tmp], 1b     \n"
 			     "	 nop		    \n"
 			     ".set reorder	     \n" :
 			[val] "+m"(lock->value), [tmp] "=&r"(tmp)
 			: : "memory");

 }

 /** ********************************************************************
  * Bit spinlocks
  * These spinlocks use a single bit (bit 31) of a 32 bit word for locking.
  * The rest of the bits in the word are left undisturbed.  This enables more
  * compact data structures as only 1 bit is consumed for the lock.
  *
  */

 /**
  * Gets lock, spins until lock is taken
  * Preserves the low 31 bits of the 32 bit
  * word used for the lock.
  *
  *
  * @word:  word to lock bit 31 of
  */
 static inline void cvmx_spinlock_bit_lock(uint32_t *word)
 {
 	unsigned int tmp;
 	unsigned int sav;

 	__asm__ __volatile__(".set noreorder	     \n"
 			     ".set noat		     \n"
 			     "1: ll    %[tmp], %[val]  \n"
 			     "	 bbit1 %[tmp], 31, 1b	 \n"
 			     "	 li    $at, 1	   \n"
 			     "	 ins   %[tmp], $at, 31, 1  \n"
 			     "	 sc    %[tmp], %[val] \n"
 			     "	 beqz  %[tmp], 1b     \n"
 			     "	 nop		    \n"
 			     ".set at		   \n"
 			     ".set reorder	     \n" :
 			[val] "+m"(*word), [tmp] "=&r"(tmp), [sav] "=&r"(sav)
 			     : : "memory");

 }

 /**
  * Attempts to get lock, returns immediately with success/failure
  * Preserves the low 31 bits of the 32 bit
  * word used for the lock.
  *
  *
  * @word:  word to lock bit 31 of
  * Returns 0: lock successfully taken
  *	   1: lock not taken, held by someone else
  * These return values match the Linux semantics.
  */
 static inline unsigned int cvmx_spinlock_bit_trylock(uint32_t *word)
 {
 	unsigned int tmp;

 	__asm__ __volatile__(".set noreorder\n\t"
 			     ".set noat\n"
 			     "1: ll    %[tmp], %[val] \n"
 			/* if lock held, fail immediately */
 			     "	 bbit1 %[tmp], 31, 2f	  \n"
 			     "	 li    $at, 1	   \n"
 			     "	 ins   %[tmp], $at, 31, 1  \n"
 			     "	 sc    %[tmp], %[val] \n"
 			     "	 beqz  %[tmp], 1b     \n"
 			     "	 li    %[tmp], 0      \n"
 			     "2:		     \n"
 			     ".set at		   \n"
 			     ".set reorder	     \n" :
 			[val] "+m"(*word), [tmp] "=&r"(tmp)
 			: : "memory");

 	return tmp != 0;		/* normalize to 0 or 1 */
 }

 /**
  * Releases bit lock
  *
  * Unconditionally clears bit 31 of the lock word.  Note that this is
  * done non-atomically, as this implementation assumes that the rest
  * of the bits in the word are protected by the lock.
  *
  * @word:  word to unlock bit 31 in
  */
 static inline void cvmx_spinlock_bit_unlock(uint32_t *word)
 {
 	CVMX_SYNCWS;
 	*word &= ~(1UL << 31);
 	CVMX_SYNCWS;
 }

 #endif /* __CVMX_SPINLOCK_H__ */
	/*********************license start*************
	* Author: Cavium Networks
	*
	* Contact: support@caviumnetworks.com
	* This file is part of the OCTEON SDK
	*
	* Copyright (c) 2003-2008 Cavium Networks
	*
	* This file 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 file is distributed in the hope that it will be useful, but
	* AS-IS and WITHOUT ANY WARRANTY; without even the implied warranty
	* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, TITLE, or
	* NONINFRINGEMENT. See the GNU General Public License for more
	* details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this file; if not, write to the Free Software
	* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	* or visit http://www.gnu.org/licenses/.
	*
	* This file may also be available under a different license from Cavium.
	* Contact Cavium Networks for more information
	*********************license end************************************/

	/**
	* Implementation of spinlocks for Octeon CVMX. Although similar in
	* function to Linux kernel spinlocks, they are not compatible.
	* Octeon CVMX spinlocks are only used to synchronize with the boot
	* monitor and other non-Linux programs running in the system.
	*/

	#ifndef __CVMX_SPINLOCK_H__
	#define __CVMX_SPINLOCK_H__

	#include <asm/octeon/cvmx-asm.h>

	/* Spinlocks for Octeon */

	/* define these to enable recursive spinlock debugging */
	/#define CVMX_SPINLOCK_DEBUG /

	/**
	* Spinlocks for Octeon CVMX
	*/
	typedef struct {
	volatile uint32_t value;
	} cvmx_spinlock_t;

	/* note - macros not expanded in inline ASM, so values hardcoded */
	#define CVMX_SPINLOCK_UNLOCKED_VAL 0
	#define CVMX_SPINLOCK_LOCKED_VAL 1

	#define CVMX_SPINLOCK_UNLOCKED_INITIALIZER {CVMX_SPINLOCK_UNLOCKED_VAL}

	/**
	* Initialize a spinlock
	*
	* @lock: Lock to initialize
	*/
	static inline void cvmx_spinlock_init(cvmx_spinlock_t *lock)
	{
	lock->value = CVMX_SPINLOCK_UNLOCKED_VAL;
	}

	/**
	* Return non-zero if the spinlock is currently locked
	*
	* @lock: Lock to check
	* Returns Non-zero if locked
	*/
	static inline int cvmx_spinlock_locked(cvmx_spinlock_t *lock)
	{
	return lock->value != CVMX_SPINLOCK_UNLOCKED_VAL;
	}

	/**
	* Releases lock
	*
	* @lock: pointer to lock structure
	*/
	static inline void cvmx_spinlock_unlock(cvmx_spinlock_t *lock)
	{
	CVMX_SYNCWS;
	lock->value = 0;
	CVMX_SYNCWS;
	}

	/**
	* Attempts to take the lock, but does not spin if lock is not available.
	* May take some time to acquire the lock even if it is available
	* due to the ll/sc not succeeding.
	*
	* @lock: pointer to lock structure
	*
	* Returns 0: lock successfully taken
	* 1: lock not taken, held by someone else
	* These return values match the Linux semantics.
	*/

	static inline unsigned int cvmx_spinlock_trylock(cvmx_spinlock_t *lock)
	{
	unsigned int tmp;

	__asm__ __volatile__(".set noreorder \n"
	"1: ll %[tmp], %[val] \n"
	/* if lock held, fail immediately */
	" bnez %[tmp], 2f \n"
	" li %[tmp], 1 \n"
	" sc %[tmp], %[val] \n"
	" beqz %[tmp], 1b \n"
	" li %[tmp], 0 \n"
	"2: \n"
	".set reorder \n" :
	[val] "+m"(lock->value), [tmp] "=&r"(tmp)
	: : "memory");

	return tmp != 0; /* normalize to 0 or 1 */
	}

	/**
	* Gets lock, spins until lock is taken
	*
	* @lock: pointer to lock structure
	*/
	static inline void cvmx_spinlock_lock(cvmx_spinlock_t *lock)
	{
	unsigned int tmp;

	__asm__ __volatile__(".set noreorder \n"
	"1: ll %[tmp], %[val] \n"
	" bnez %[tmp], 1b \n"
	" li %[tmp], 1 \n"
	" sc %[tmp], %[val] \n"
	" beqz %[tmp], 1b \n"
	" nop \n"
	".set reorder \n" :
	[val] "+m"(lock->value), [tmp] "=&r"(tmp)
	: : "memory");

	}

	/ ******************************************************************
	* Bit spinlocks
	* These spinlocks use a single bit (bit 31) of a 32 bit word for locking.
	* The rest of the bits in the word are left undisturbed. This enables more
	* compact data structures as only 1 bit is consumed for the lock.
	*
	*/

	/**
	* Gets lock, spins until lock is taken
	* Preserves the low 31 bits of the 32 bit
	* word used for the lock.
	*
	*
	* @word: word to lock bit 31 of
	*/
	static inline void cvmx_spinlock_bit_lock(uint32_t *word)
	{
	unsigned int tmp;
	unsigned int sav;

	__asm__ __volatile__(".set noreorder \n"
	".set noat \n"
	"1: ll %[tmp], %[val] \n"
	" bbit1 %[tmp], 31, 1b \n"
	" li $at, 1 \n"
	" ins %[tmp], $at, 31, 1 \n"
	" sc %[tmp], %[val] \n"
	" beqz %[tmp], 1b \n"
	" nop \n"
	".set at \n"
	".set reorder \n" :
	[val] "+m"(*word), [tmp] "=&r"(tmp), [sav] "=&r"(sav)
	: : "memory");

	}

	/**
	* Attempts to get lock, returns immediately with success/failure
	* Preserves the low 31 bits of the 32 bit
	* word used for the lock.
	*
	*
	* @word: word to lock bit 31 of
	* Returns 0: lock successfully taken
	* 1: lock not taken, held by someone else
	* These return values match the Linux semantics.
	*/
	static inline unsigned int cvmx_spinlock_bit_trylock(uint32_t *word)
	{
	unsigned int tmp;

	__asm__ __volatile__(".set noreorder\n\t"
	".set noat\n"
	"1: ll %[tmp], %[val] \n"
	/* if lock held, fail immediately */
	" bbit1 %[tmp], 31, 2f \n"
	" li $at, 1 \n"
	" ins %[tmp], $at, 31, 1 \n"
	" sc %[tmp], %[val] \n"
	" beqz %[tmp], 1b \n"
	" li %[tmp], 0 \n"
	"2: \n"
	".set at \n"
	".set reorder \n" :
	[val] "+m"(*word), [tmp] "=&r"(tmp)
	: : "memory");

	return tmp != 0; /* normalize to 0 or 1 */
	}

	/**
	* Releases bit lock
	*
	* Unconditionally clears bit 31 of the lock word. Note that this is
	* done non-atomically, as this implementation assumes that the rest
	* of the bits in the word are protected by the lock.
	*
	* @word: word to unlock bit 31 in
	*/
	static inline void cvmx_spinlock_bit_unlock(uint32_t *word)
	{
	CVMX_SYNCWS;
	*word &= ~(1UL << 31);
	CVMX_SYNCWS;
	}

	#endif /* __CVMX_SPINLOCK_H__ */