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Diffstat (limited to 'include/linux/seqlock.h')
-rw-r--r--include/linux/seqlock.h54
1 files changed, 32 insertions, 22 deletions
diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h
index 987a59d977c5..e92f9d5577ba 100644
--- a/include/linux/seqlock.h
+++ b/include/linux/seqlock.h
@@ -191,11 +191,9 @@ static inline void seqcount_lockdep_reader_access(const seqcount_t *s)
* @lockname: "LOCKNAME" part of seqcount_LOCKNAME_t
* @locktype: LOCKNAME canonical C data type
* @preemptible: preemptibility of above locktype
- * @lockmember: argument for lockdep_assert_held()
- * @lockbase: associated lock release function (prefix only)
- * @lock_acquire: associated lock acquisition function (full call)
+ * @lockbase: prefix for associated lock/unlock
*/
-#define SEQCOUNT_LOCKNAME(lockname, locktype, preemptible, lockmember, lockbase, lock_acquire) \
+#define SEQCOUNT_LOCKNAME(lockname, locktype, preemptible, lockbase) \
typedef struct seqcount_##lockname { \
seqcount_t seqcount; \
__SEQ_LOCK(locktype *lock); \
@@ -207,6 +205,12 @@ __seqprop_##lockname##_ptr(seqcount_##lockname##_t *s) \
return &s->seqcount; \
} \
\
+static __always_inline const seqcount_t * \
+__seqprop_##lockname##_const_ptr(const seqcount_##lockname##_t *s) \
+{ \
+ return &s->seqcount; \
+} \
+ \
static __always_inline unsigned \
__seqprop_##lockname##_sequence(const seqcount_##lockname##_t *s) \
{ \
@@ -216,7 +220,7 @@ __seqprop_##lockname##_sequence(const seqcount_##lockname##_t *s) \
return seq; \
\
if (preemptible && unlikely(seq & 1)) { \
- __SEQ_LOCK(lock_acquire); \
+ __SEQ_LOCK(lockbase##_lock(s->lock)); \
__SEQ_LOCK(lockbase##_unlock(s->lock)); \
\
/* \
@@ -242,7 +246,7 @@ __seqprop_##lockname##_preemptible(const seqcount_##lockname##_t *s) \
static __always_inline void \
__seqprop_##lockname##_assert(const seqcount_##lockname##_t *s) \
{ \
- __SEQ_LOCK(lockdep_assert_held(lockmember)); \
+ __SEQ_LOCK(lockdep_assert_held(s->lock)); \
}
/*
@@ -254,6 +258,11 @@ static inline seqcount_t *__seqprop_ptr(seqcount_t *s)
return s;
}
+static inline const seqcount_t *__seqprop_const_ptr(const seqcount_t *s)
+{
+ return s;
+}
+
static inline unsigned __seqprop_sequence(const seqcount_t *s)
{
return READ_ONCE(s->sequence);
@@ -271,10 +280,10 @@ static inline void __seqprop_assert(const seqcount_t *s)
#define __SEQ_RT IS_ENABLED(CONFIG_PREEMPT_RT)
-SEQCOUNT_LOCKNAME(raw_spinlock, raw_spinlock_t, false, s->lock, raw_spin, raw_spin_lock(s->lock))
-SEQCOUNT_LOCKNAME(spinlock, spinlock_t, __SEQ_RT, s->lock, spin, spin_lock(s->lock))
-SEQCOUNT_LOCKNAME(rwlock, rwlock_t, __SEQ_RT, s->lock, read, read_lock(s->lock))
-SEQCOUNT_LOCKNAME(mutex, struct mutex, true, s->lock, mutex, mutex_lock(s->lock))
+SEQCOUNT_LOCKNAME(raw_spinlock, raw_spinlock_t, false, raw_spin)
+SEQCOUNT_LOCKNAME(spinlock, spinlock_t, __SEQ_RT, spin)
+SEQCOUNT_LOCKNAME(rwlock, rwlock_t, __SEQ_RT, read)
+SEQCOUNT_LOCKNAME(mutex, struct mutex, true, mutex)
/*
* SEQCNT_LOCKNAME_ZERO - static initializer for seqcount_LOCKNAME_t
@@ -294,19 +303,20 @@ SEQCOUNT_LOCKNAME(mutex, struct mutex, true, s->lock, mutex
#define SEQCNT_WW_MUTEX_ZERO(name, lock) SEQCOUNT_LOCKNAME_ZERO(name, lock)
#define __seqprop_case(s, lockname, prop) \
- seqcount_##lockname##_t: __seqprop_##lockname##_##prop((void *)(s))
+ seqcount_##lockname##_t: __seqprop_##lockname##_##prop
#define __seqprop(s, prop) _Generic(*(s), \
- seqcount_t: __seqprop_##prop((void *)(s)), \
+ seqcount_t: __seqprop_##prop, \
__seqprop_case((s), raw_spinlock, prop), \
__seqprop_case((s), spinlock, prop), \
__seqprop_case((s), rwlock, prop), \
__seqprop_case((s), mutex, prop))
-#define seqprop_ptr(s) __seqprop(s, ptr)
-#define seqprop_sequence(s) __seqprop(s, sequence)
-#define seqprop_preemptible(s) __seqprop(s, preemptible)
-#define seqprop_assert(s) __seqprop(s, assert)
+#define seqprop_ptr(s) __seqprop(s, ptr)(s)
+#define seqprop_const_ptr(s) __seqprop(s, const_ptr)(s)
+#define seqprop_sequence(s) __seqprop(s, sequence)(s)
+#define seqprop_preemptible(s) __seqprop(s, preemptible)(s)
+#define seqprop_assert(s) __seqprop(s, assert)(s)
/**
* __read_seqcount_begin() - begin a seqcount_t read section w/o barrier
@@ -355,7 +365,7 @@ SEQCOUNT_LOCKNAME(mutex, struct mutex, true, s->lock, mutex
*/
#define read_seqcount_begin(s) \
({ \
- seqcount_lockdep_reader_access(seqprop_ptr(s)); \
+ seqcount_lockdep_reader_access(seqprop_const_ptr(s)); \
raw_read_seqcount_begin(s); \
})
@@ -421,7 +431,7 @@ SEQCOUNT_LOCKNAME(mutex, struct mutex, true, s->lock, mutex
* Return: true if a read section retry is required, else false
*/
#define __read_seqcount_retry(s, start) \
- do___read_seqcount_retry(seqprop_ptr(s), start)
+ do___read_seqcount_retry(seqprop_const_ptr(s), start)
static inline int do___read_seqcount_retry(const seqcount_t *s, unsigned start)
{
@@ -441,7 +451,7 @@ static inline int do___read_seqcount_retry(const seqcount_t *s, unsigned start)
* Return: true if a read section retry is required, else false
*/
#define read_seqcount_retry(s, start) \
- do_read_seqcount_retry(seqprop_ptr(s), start)
+ do_read_seqcount_retry(seqprop_const_ptr(s), start)
static inline int do_read_seqcount_retry(const seqcount_t *s, unsigned start)
{
@@ -512,8 +522,8 @@ do { \
static inline void do_write_seqcount_begin_nested(seqcount_t *s, int subclass)
{
- do_raw_write_seqcount_begin(s);
seqcount_acquire(&s->dep_map, subclass, 0, _RET_IP_);
+ do_raw_write_seqcount_begin(s);
}
/**
@@ -574,7 +584,7 @@ static inline void do_write_seqcount_end(seqcount_t *s)
* via WRITE_ONCE): a) to ensure the writes become visible to other threads
* atomically, avoiding compiler optimizations; b) to document which writes are
* meant to propagate to the reader critical section. This is necessary because
- * neither writes before and after the barrier are enclosed in a seq-writer
+ * neither writes before nor after the barrier are enclosed in a seq-writer
* critical section that would ensure readers are aware of ongoing writes::
*
* seqcount_t seq;
@@ -864,7 +874,7 @@ static inline unsigned read_seqretry(const seqlock_t *sl, unsigned start)
}
/*
- * For all seqlock_t write side functions, use the the internal
+ * For all seqlock_t write side functions, use the internal
* do_write_seqcount_begin() instead of generic write_seqcount_begin().
* This way, no redundant lockdep_assert_held() checks are added.
*/