nuttx/arch/xtensa/include/spinlock.h
hujun5 4cb419866f arch: inline up_testset in arm arm64 riscv xtensa
test:
Configuring NuttX and compile:
$ ./tools/configure.sh -l qemu-armv8a:nsh_smp
$ make
Running with qemu
$ qemu-system-aarch64 -cpu cortex-a53 -smp 4 -nographic \
   -machine virt,virtualization=on,gic-version=3 \
   -net none -chardev stdio,id=con,mux=on -serial chardev:con \
   -mon chardev=con,mode=readline -kernel ./nuttx

Signed-off-by: hujun5 <hujun5@xiaomi.com>
2024-08-21 01:45:10 +08:00

105 lines
3.9 KiB
C

/****************************************************************************
* arch/xtensa/include/spinlock.h
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
#ifndef __ARCH_XTENSA_INCLUDE_SPINLOCK_H
#define __ARCH_XTENSA_INCLUDE_SPINLOCK_H
/****************************************************************************
* Included Files
****************************************************************************/
#ifndef __ASSEMBLY__
# include <stdint.h>
#endif /* __ASSEMBLY__ */
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
#define SP_UNLOCKED 0 /* The Un-locked state */
#define SP_LOCKED 1 /* The Locked state */
/****************************************************************************
* Public Types
****************************************************************************/
#ifndef __ASSEMBLY__
/* The Type of a spinlock.
*
* This must be a uint32_ because it will be set using S32C1I instruction.
* That instruction atomically stores to a memory location only if its
* current value is the expected one. The state register (SCOMPARE1) is
* used to provide the additional comparison operand. Some implementations
* also have a state register (ATOMCTL) for further control of the atomic
* operation in cache and on the PIF bus.
*/
typedef uint32_t spinlock_t;
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
/****************************************************************************
* Name: up_testset
*
* Description:
* Perform an atomic test and set operation on the provided spinlock.
*
* This function must be provided via the architecture-specific logic.
*
* Input Parameters:
* lock - The address of spinlock object.
*
* Returned Value:
* The spinlock is always locked upon return. The value of previous value
* of the spinlock variable is returned, either SP_LOCKED if the spinlock
* as previously locked (meaning that the test-and-set operation failed to
* obtain the lock) or SP_UNLOCKED if the spinlock was previously unlocked
* (meaning that we successfully obtained the lock)
*
****************************************************************************/
#if defined(CONFIG_SPINLOCK)
static inline_function spinlock_t up_testset(volatile spinlock_t *lock)
{
/* Perform the 32-bit compare and set operation */
spinlock_t ret;
__asm__ __volatile__
(
"WSR %2, SCOMPARE1\n" /* Initialize SCOMPARE1 */
"S32C1I %0, %1, 0\n" /* Store the compare value into the lock,
* if the lock is the same as compare1.
* Otherwise, no write-access */
: "=r"(ret) : "r"(lock), "r"(SP_UNLOCKED), "0"(SP_LOCKED)
);
return ret;
}
#endif
/* See prototype in nuttx/include/nuttx/spinlock.h */
#endif /* __ASSEMBLY__ */
#endif /* __ARCH_XTENSA_INCLUDE_SPINLOCK_H */