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libc/atomic: decoupling atomic and spinlock to avoid recursion
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1. use irq save in AMP mode
2. use critical section in SMP mode

Signed-off-by: chao an <anchao@lixiang.com>
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@anchao
anchao committed Oct 12, 2024
1 parent 1bba720 commit f9cbaf5
Showing 1 changed file with 63 additions and 37 deletions.
100 changes: 63 additions & 37 deletions libs/libc/machine/arch_atomic.c
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Original file line number Diff line number Diff line change
Expand Up @@ -28,7 +28,33 @@

#include <stdbool.h>
#include <stdint.h>
#include <nuttx/spinlock.h>
#include <nuttx/irq.h>

/****************************************************************************
* Private Data
****************************************************************************/

#ifdef CONFIG_SMP
static inline_function irqstate_t atomic_lock(void)
{
return enter_critical_section();
}

static inline_function void atomic_unlock(irqstate_t flags)
{
leave_critical_section(flags);
}
#else
static inline_function irqstate_t atomic_lock(void)
{
return up_irq_save();
}

static inline_function void atomic_unlock(irqstate_t flags)
{
up_irq_restore(flags);
}
#endif

/****************************************************************************
* Pre-processor Definitions
Expand All @@ -39,23 +65,23 @@
void weak_function __atomic_store_##n (FAR volatile void *ptr, \
type value, int memorder) \
{ \
irqstate_t irqstate = spin_lock_irqsave(NULL); \
irqstate_t irqstate = atomic_lock(); \
\
*(FAR type *)ptr = value; \
\
spin_unlock_irqrestore(NULL, irqstate); \
atomic_unlock(irqstate); \
}

#define LOAD(n, type) \
\
type weak_function __atomic_load_##n (FAR const volatile void *ptr, \
int memorder) \
{ \
irqstate_t irqstate = spin_lock_irqsave(NULL); \
irqstate_t irqstate = atomic_lock(); \
\
type ret = *(FAR type *)ptr; \
\
spin_unlock_irqrestore(NULL, irqstate); \
atomic_unlock(irqstate); \
return ret; \
}

Expand All @@ -64,13 +90,13 @@
type weak_function __atomic_exchange_##n (FAR volatile void *ptr, \
type value, int memorder) \
{ \
irqstate_t irqstate = spin_lock_irqsave(NULL); \
irqstate_t irqstate = atomic_lock(); \
FAR type *tmp = (FAR type *)ptr; \
\
type ret = *tmp; \
*tmp = value; \
\
spin_unlock_irqrestore(NULL, irqstate); \
atomic_unlock(irqstate); \
return ret; \
}

Expand All @@ -82,7 +108,7 @@
int success, int failure) \
{ \
bool ret = false; \
irqstate_t irqstate = spin_lock_irqsave(NULL); \
irqstate_t irqstate = atomic_lock(); \
FAR type *tmpmem = (FAR type *)mem; \
FAR type *tmpexp = (FAR type *)expect; \
\
Expand All @@ -96,7 +122,7 @@
*tmpexp = *tmpmem; \
} \
\
spin_unlock_irqrestore(NULL, irqstate); \
atomic_unlock(irqstate); \
return ret; \
}

Expand All @@ -105,13 +131,13 @@
type weak_function __atomic_flags_test_and_set##n (FAR volatile void *ptr, \
int memorder) \
{ \
irqstate_t irqstate = spin_lock_irqsave(NULL); \
irqstate_t irqstate = atomic_lock(); \
FAR type *tmp = (FAR type *)ptr; \
type ret = *tmp; \
\
*(FAR type *)ptr = 1; \
\
spin_unlock_irqrestore(NULL, irqstate); \
atomic_unlock(irqstate); \
return ret; \
}

Expand All @@ -120,13 +146,13 @@
type weak_function __atomic_fetch_add_##n (FAR volatile void *ptr, \
type value, int memorder) \
{ \
irqstate_t irqstate = spin_lock_irqsave(NULL); \
irqstate_t irqstate = atomic_lock(); \
FAR type *tmp = (FAR type *)ptr; \
type ret = *tmp; \
\
*tmp = *tmp + value; \
\
spin_unlock_irqrestore(NULL, irqstate); \
atomic_unlock(irqstate); \
return ret; \
}

Expand All @@ -135,13 +161,13 @@
type weak_function __atomic_fetch_sub_##n (FAR volatile void *ptr, \
type value, int memorder) \
{ \
irqstate_t irqstate = spin_lock_irqsave(NULL); \
irqstate_t irqstate = atomic_lock(); \
FAR type *tmp = (FAR type *)ptr; \
type ret = *tmp; \
\
*tmp = *tmp - value; \
\
spin_unlock_irqrestore(NULL, irqstate); \
atomic_unlock(irqstate); \
return ret; \
}

Expand All @@ -150,13 +176,13 @@
type weak_function __atomic_fetch_and_##n (FAR volatile void *ptr, \
type value, int memorder) \
{ \
irqstate_t irqstate = spin_lock_irqsave(NULL); \
irqstate_t irqstate = atomic_lock(); \
FAR type *tmp = (FAR type *)ptr; \
type ret = *tmp; \
\
*tmp = *tmp & value; \
\
spin_unlock_irqrestore(NULL, irqstate); \
atomic_unlock(irqstate); \
return ret; \
}

Expand All @@ -165,13 +191,13 @@
type weak_function __atomic_fetch_or_##n (FAR volatile void *ptr, \
type value, int memorder) \
{ \
irqstate_t irqstate = spin_lock_irqsave(NULL); \
irqstate_t irqstate = atomic_lock(); \
FAR type *tmp = (FAR type *)ptr; \
type ret = *tmp; \
\
*tmp = *tmp | value; \
\
spin_unlock_irqrestore(NULL, irqstate); \
atomic_unlock(irqstate); \
return ret; \
}

Expand All @@ -180,13 +206,13 @@
type weak_function __atomic_fetch_xor_##n (FAR volatile void *ptr, \
type value, int memorder) \
{ \
irqstate_t irqstate = spin_lock_irqsave(NULL); \
irqstate_t irqstate = atomic_lock(); \
FAR type *tmp = (FAR type *)ptr; \
type ret = *tmp; \
\
*tmp = *tmp ^ value; \
\
spin_unlock_irqrestore(NULL, irqstate); \
atomic_unlock(irqstate); \
return ret; \
}

Expand All @@ -195,12 +221,12 @@
type weak_function __sync_add_and_fetch_##n (FAR volatile void *ptr, \
type value) \
{ \
irqstate_t irqstate = spin_lock_irqsave(NULL); \
irqstate_t irqstate = atomic_lock(); \
FAR type *tmp = (FAR type *)ptr; \
\
*tmp = *tmp + value; \
\
spin_unlock_irqrestore(NULL, irqstate); \
atomic_unlock(irqstate); \
return *tmp; \
}

Expand All @@ -209,12 +235,12 @@
type weak_function __sync_sub_and_fetch_##n (FAR volatile void *ptr, \
type value) \
{ \
irqstate_t irqstate = spin_lock_irqsave(NULL); \
irqstate_t irqstate = atomic_lock(); \
FAR type *tmp = (FAR type *)ptr; \
\
*tmp = *tmp - value; \
\
spin_unlock_irqrestore(NULL, irqstate); \
atomic_unlock(irqstate); \
return *tmp; \
}

Expand All @@ -223,12 +249,12 @@
type weak_function __sync_or_and_fetch_##n (FAR volatile void *ptr, \
type value) \
{ \
irqstate_t irqstate = spin_lock_irqsave(NULL); \
irqstate_t irqstate = atomic_lock(); \
FAR type *tmp = (FAR type *)ptr; \
\
*tmp = *tmp | value; \
\
spin_unlock_irqrestore(NULL, irqstate); \
atomic_unlock(irqstate); \
return *tmp; \
}

Expand All @@ -237,12 +263,12 @@
type weak_function __sync_and_and_fetch_##n (FAR volatile void *ptr, \
type value) \
{ \
irqstate_t irqstate = spin_lock_irqsave(NULL); \
irqstate_t irqstate = atomic_lock(); \
FAR type *tmp = (FAR type *)ptr; \
\
*tmp = *tmp & value; \
\
spin_unlock_irqrestore(NULL, irqstate); \
atomic_unlock(irqstate); \
return *tmp; \
}

Expand All @@ -251,12 +277,12 @@
type weak_function __sync_xor_and_fetch_##n (FAR volatile void *ptr, \
type value) \
{ \
irqstate_t irqstate = spin_lock_irqsave(NULL); \
irqstate_t irqstate = atomic_lock(); \
FAR type *tmp = (FAR type *)ptr; \
\
*tmp = *tmp ^ value; \
\
spin_unlock_irqrestore(NULL, irqstate); \
atomic_unlock(irqstate); \
return *tmp; \
}

Expand All @@ -265,12 +291,12 @@
type weak_function __sync_nand_and_fetch_##n (FAR volatile void *ptr, \
type value) \
{ \
irqstate_t irqstate = spin_lock_irqsave(NULL); \
irqstate_t irqstate = atomic_lock(); \
FAR type *tmp = (FAR type *)ptr; \
\
*tmp = ~(*tmp & value); \
\
spin_unlock_irqrestore(NULL, irqstate); \
atomic_unlock(irqstate); \
return *tmp; \
}

Expand All @@ -281,7 +307,7 @@
type newvalue) \
{ \
bool ret = false; \
irqstate_t irqstate = spin_lock_irqsave(NULL); \
irqstate_t irqstate = atomic_lock(); \
FAR type *tmp = (FAR type *)ptr; \
\
if (*tmp == oldvalue) \
Expand All @@ -290,7 +316,7 @@
*tmp = newvalue; \
} \
\
spin_unlock_irqrestore(NULL, irqstate); \
atomic_unlock(irqstate); \
return ret; \
}

Expand All @@ -300,7 +326,7 @@
type oldvalue, \
type newvalue) \
{ \
irqstate_t irqstate = spin_lock_irqsave(NULL); \
irqstate_t irqstate = atomic_lock(); \
FAR type *tmp = (FAR type *)ptr; \
type ret = *tmp; \
\
Expand All @@ -309,7 +335,7 @@
*tmp = newvalue; \
} \
\
spin_unlock_irqrestore(NULL, irqstate); \
atomic_unlock(irqstate); \
return ret; \
}

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