233 lines
6.2 KiB
C
233 lines
6.2 KiB
C
/***********************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__ */
|