cregit-Linux how code gets into the kernel

Release 4.14 arch/mips/include/asm/octeon/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; }

Contributors

PersonTokensPropCommitsCommitProp
David Daney17100.00%1100.00%
Total17100.00%1100.00%

/** * 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; }

Contributors

PersonTokensPropCommitsCommitProp
David Daney18100.00%1100.00%
Total18100.00%1100.00%

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

Contributors

PersonTokensPropCommitsCommitProp
David Daney21100.00%1100.00%
Total21100.00%1100.00%

/** * 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 */ }

Contributors

PersonTokensPropCommitsCommitProp
David Daney2592.59%150.00%
Ralf Bächle27.41%150.00%
Total27100.00%2100.00%

/** * 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"); }

Contributors

PersonTokensPropCommitsCommitProp
David Daney1794.44%150.00%
Ralf Bächle15.56%150.00%
Total18100.00%2100.00%

/** ******************************************************************** * 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"); }

Contributors

PersonTokensPropCommitsCommitProp
David Daney2195.45%150.00%
Ralf Bächle14.55%150.00%
Total22100.00%2100.00%

/** * 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 */ }

Contributors

PersonTokensPropCommitsCommitProp
David Daney2696.30%150.00%
Ralf Bächle13.70%150.00%
Total27100.00%2100.00%

/** * 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; }

Contributors

PersonTokensPropCommitsCommitProp
David Daney25100.00%1100.00%
Total25100.00%1100.00%

#endif /* __CVMX_SPINLOCK_H__ */

Overall Contributors

PersonTokensPropCommitsCommitProp
David Daney21696.00%133.33%
Ralf Bächle83.56%133.33%
David Howells10.44%133.33%
Total225100.00%3100.00%
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with cregit.