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spinlock: Introduce SP_WFE() and SP_SEV()

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Summary:
- This commit introduces SP_WFE() and SP_SEV() to be used for spinlock
- Also, use wfe/sev instructions for ARMV7-A to reduce power consumption

Impact:
- ARMV7-a SMP only

Testing:
- sabre-6quad:smp (QEMU, dev board)
- maix-bit:smp, esp32-devkitc:smp, spresense:smp sim:smp (compile only)

Signed-off-by: Masayuki Ishikawa <Masayuki.Ishikawa@jp.sony.com>
This commit is contained in:
Masayuki Ishikawa 2020-12-07 21:04:16 +09:00 committed by Xiang Xiao
parent 21cb7935c5
commit 6158b6b77b
4 changed files with 24 additions and 0 deletions
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7
arch/arm/Kconfig
View File

@ -590,6 +590,7 @@ config ARCH_CORTEXM7
config ARCH_ARMV7A
bool
default n
select ARM_HAVE_WFE_SEV
config ARCH_CORTEXA5
bool
@ -789,6 +790,12 @@ config ARM_THUMB
default n
depends on ARCH_ARMV7A
config ARM_HAVE_WFE_SEV
bool
default n
---help---
Use WFE and SEV instructions for spinlock to reduce power consumption
config ARM_HAVE_MPU_UNIFIED
bool
default n

5
arch/arm/include/spinlock.h
View File

@ -95,6 +95,11 @@
#define SP_DSB(n) __asm__ __volatile__ ("dsb sy" : : : "memory")
#define SP_DMB(n) __asm__ __volatile__ ("dmb st" : : : "memory")
#ifdef CONFIG_ARM_HAVE_WFE_SEV
#define SP_WFE() __asm__ __volatile__ ("wfe" : : : "memory")
#define SP_SEV() __asm__ __volatile__ ("sev" : : : "memory")
#endif
/****************************************************************************
* Public Types
****************************************************************************/

8
include/nuttx/spinlock.h
View File

@ -80,6 +80,14 @@
# define SP_DSB()
#endif
#if !defined(SP_WFE)
# define SP_WFE()
#endif
#if !defined(SP_SEV)
# define SP_SEV()
#endif
#if defined(CONFIG_SCHED_INSTRUMENTATION_SPINLOCKS) && !defined(__SP_UNLOCK_FUNCTION)
# define __SP_UNLOCK_FUNCTION 1
#endif

4
sched/semaphore/spinlock.c
View File

@ -89,6 +89,7 @@ void spin_lock(FAR volatile spinlock_t *lock)
while (up_testset(lock) == SP_LOCKED)
{
SP_DSB();
SP_WFE();
}
#ifdef CONFIG_SCHED_INSTRUMENTATION_SPINLOCKS
@ -126,6 +127,7 @@ void spin_lock_wo_note(FAR volatile spinlock_t *lock)
while (up_testset(lock) == SP_LOCKED)
{
SP_DSB();
SP_WFE();
}
SP_DMB();
@ -241,6 +243,7 @@ void spin_unlock(FAR volatile spinlock_t *lock)
SP_DMB();
*lock = SP_UNLOCKED;
SP_DSB();
SP_SEV();
}
#endif
@ -269,6 +272,7 @@ void spin_unlock_wo_note(FAR volatile spinlock_t *lock)
SP_DMB();
*lock = SP_UNLOCKED;
SP_DSB();
SP_SEV();
}
/****************************************************************************