cvmx-spinlock.h

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/***********************license start***************
 * Author: Cavium Networks
 *
 * Contact: [email protected]
 * 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**************************************/

#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 */

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}

static inline void cvmx_spinlock_init(cvmx_spinlock_t *lock)
{
    lock->value = CVMX_SPINLOCK_UNLOCKED_VAL;
}

static inline int cvmx_spinlock_locked(cvmx_spinlock_t *lock)
{
    return lock->value != CVMX_SPINLOCK_UNLOCKED_VAL;
}

static inline void cvmx_spinlock_unlock(cvmx_spinlock_t *lock)
{
    CVMX_SYNCWS;
    lock->value = 0;
    CVMX_SYNCWS;
}

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 */
}

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");

}

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");

}

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 */
}

static inline void cvmx_spinlock_bit_unlock(uint32_t *word)
{
    CVMX_SYNCWS;
    *word &= ~(1UL << 31);
    CVMX_SYNCWS;
}

#endif /* __CVMX_SPINLOCK_H__ */