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Diffstat (limited to 'include/linux/bit_spinlock.h')
-rw-r--r--include/linux/bit_spinlock.h24
1 files changed, 20 insertions, 4 deletions
diff --git a/include/linux/bit_spinlock.h b/include/linux/bit_spinlock.h
index c0989b5b0407..7869a6e59b6a 100644
--- a/include/linux/bit_spinlock.h
+++ b/include/linux/bit_spinlock.h
@@ -7,6 +7,18 @@
#include <linux/atomic.h>
#include <linux/bug.h>
+#include <asm/processor.h> /* for cpu_relax() */
+
+/*
+ * For static context analysis, we need a unique token for each possible bit
+ * that can be used as a bit_spinlock. The easiest way to do that is to create a
+ * fake context that we can cast to with the __bitlock(bitnum, addr) macro
+ * below, which will give us unique instances for each (bit, addr) pair that the
+ * static analysis can use.
+ */
+context_lock_struct(__context_bitlock) { };
+#define __bitlock(bitnum, addr) (struct __context_bitlock *)(bitnum + (addr))
+
/*
* bit-based spin_lock()
*
@@ -14,6 +26,7 @@
* are significantly faster.
*/
static __always_inline void bit_spin_lock(int bitnum, unsigned long *addr)
+ __acquires(__bitlock(bitnum, addr))
{
/*
* Assuming the lock is uncontended, this never enters
@@ -32,13 +45,14 @@ static __always_inline void bit_spin_lock(int bitnum, unsigned long *addr)
preempt_disable();
}
#endif
- __acquire(bitlock);
+ __acquire(__bitlock(bitnum, addr));
}
/*
* Return true if it was acquired
*/
static __always_inline int bit_spin_trylock(int bitnum, unsigned long *addr)
+ __cond_acquires(true, __bitlock(bitnum, addr))
{
preempt_disable();
#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
@@ -47,7 +61,7 @@ static __always_inline int bit_spin_trylock(int bitnum, unsigned long *addr)
return 0;
}
#endif
- __acquire(bitlock);
+ __acquire(__bitlock(bitnum, addr));
return 1;
}
@@ -55,6 +69,7 @@ static __always_inline int bit_spin_trylock(int bitnum, unsigned long *addr)
* bit-based spin_unlock()
*/
static __always_inline void bit_spin_unlock(int bitnum, unsigned long *addr)
+ __releases(__bitlock(bitnum, addr))
{
#ifdef CONFIG_DEBUG_SPINLOCK
BUG_ON(!test_bit(bitnum, addr));
@@ -63,7 +78,7 @@ static __always_inline void bit_spin_unlock(int bitnum, unsigned long *addr)
clear_bit_unlock(bitnum, addr);
#endif
preempt_enable();
- __release(bitlock);
+ __release(__bitlock(bitnum, addr));
}
/*
@@ -72,6 +87,7 @@ static __always_inline void bit_spin_unlock(int bitnum, unsigned long *addr)
* protecting the rest of the flags in the word.
*/
static __always_inline void __bit_spin_unlock(int bitnum, unsigned long *addr)
+ __releases(__bitlock(bitnum, addr))
{
#ifdef CONFIG_DEBUG_SPINLOCK
BUG_ON(!test_bit(bitnum, addr));
@@ -80,7 +96,7 @@ static __always_inline void __bit_spin_unlock(int bitnum, unsigned long *addr)
__clear_bit_unlock(bitnum, addr);
#endif
preempt_enable();
- __release(bitlock);
+ __release(__bitlock(bitnum, addr));
}
/*