Commit 66bcfcdf authored by Ahmed S. Darwish's avatar Ahmed S. Darwish Committed by Peter Zijlstra
Browse files

seqlock: Prefix internal seqcount_t-only macros with a "do_" 



When the seqcount_LOCKNAME_t group of data types were introduced, two
classes of seqlock.h sequence counter macros were added:

  - An external public API which can either take a plain seqcount_t or
    any of the seqcount_LOCKNAME_t variants.

  - An internal API which takes only a plain seqcount_t.

To distinguish between the two groups, the "*_seqcount_t_*" pattern was
used for the latter. This confused a number of mm/ call-site developers,
and Linus also commented that it was not a standard practice for marking
seqlock.h internal APIs.

Distinguish the latter group of macros by prefixing a "do_".

Signed-off-by: default avatarAhmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/CAHk-=wikhGExmprXgaW+MVXG1zsGpztBbVwOb23vetk41EtTBQ@mail.gmail.com
parent cf486472

include/linux/seqlock.h

+33 −33
Original line number Diff line number Diff line
@@ -425,9 +425,9 @@ SEQCOUNT_LOCKNAME(ww_mutex, struct ww_mutex, true, &s->lock->base, ww_mu 
 * Return: true if a read section retry is required, else false

 */

#define __read_seqcount_retry(s, start)					\

	__read_seqcount_t_retry(seqprop_ptr(s), start)

	do___read_seqcount_retry(seqprop_ptr(s), start)



static inline int __read_seqcount_t_retry(const seqcount_t *s, unsigned start)

static inline int do___read_seqcount_retry(const seqcount_t *s, unsigned start)

{

	kcsan_atomic_next(0);

	return unlikely(READ_ONCE(s->sequence) != start);
@@ -445,12 +445,12 @@ static inline int __read_seqcount_t_retry(const seqcount_t *s, unsigned start) 
 * Return: true if a read section retry is required, else false

 */

#define read_seqcount_retry(s, start)					\

	read_seqcount_t_retry(seqprop_ptr(s), start)

	do_read_seqcount_retry(seqprop_ptr(s), start)



static inline int read_seqcount_t_retry(const seqcount_t *s, unsigned start)

static inline int do_read_seqcount_retry(const seqcount_t *s, unsigned start)

{

	smp_rmb();

	return __read_seqcount_t_retry(s, start);

	return do___read_seqcount_retry(s, start);

}



/**
@@ -462,10 +462,10 @@ do { \ 
	if (seqprop_preemptible(s))					\

		preempt_disable();					\

									\

	raw_write_seqcount_t_begin(seqprop_ptr(s));			\

	do_raw_write_seqcount_begin(seqprop_ptr(s));			\

} while (0)



static inline void raw_write_seqcount_t_begin(seqcount_t *s)

static inline void do_raw_write_seqcount_begin(seqcount_t *s)

{

	kcsan_nestable_atomic_begin();

	s->sequence++;
@@ -478,13 +478,13 @@ static inline void raw_write_seqcount_t_begin(seqcount_t *s) 
 */

#define raw_write_seqcount_end(s)					\

do {									\

	raw_write_seqcount_t_end(seqprop_ptr(s));			\

	do_raw_write_seqcount_end(seqprop_ptr(s));			\

									\

	if (seqprop_preemptible(s))					\

		preempt_enable();					\

} while (0)



static inline void raw_write_seqcount_t_end(seqcount_t *s)

static inline void do_raw_write_seqcount_end(seqcount_t *s)

{

	smp_wmb();

	s->sequence++;
@@ -506,12 +506,12 @@ do { \ 
	if (seqprop_preemptible(s))					\

		preempt_disable();					\

									\

	write_seqcount_t_begin_nested(seqprop_ptr(s), subclass);	\

	do_write_seqcount_begin_nested(seqprop_ptr(s), subclass);	\

} while (0)



static inline void write_seqcount_t_begin_nested(seqcount_t *s, int subclass)

static inline void do_write_seqcount_begin_nested(seqcount_t *s, int subclass)

{

	raw_write_seqcount_t_begin(s);

	do_raw_write_seqcount_begin(s);

	seqcount_acquire(&s->dep_map, subclass, 0, _RET_IP_);

}
@@ -533,12 +533,12 @@ do { \ 
	if (seqprop_preemptible(s))					\

		preempt_disable();					\

									\

	write_seqcount_t_begin(seqprop_ptr(s));				\

	do_write_seqcount_begin(seqprop_ptr(s));			\

} while (0)



static inline void write_seqcount_t_begin(seqcount_t *s)

static inline void do_write_seqcount_begin(seqcount_t *s)

{

	write_seqcount_t_begin_nested(s, 0);

	do_write_seqcount_begin_nested(s, 0);

}



/**
@@ -549,16 +549,16 @@ static inline void write_seqcount_t_begin(seqcount_t *s) 
 */

#define write_seqcount_end(s)						\

do {									\

	write_seqcount_t_end(seqprop_ptr(s));				\

	do_write_seqcount_end(seqprop_ptr(s));				\

									\

	if (seqprop_preemptible(s))					\

		preempt_enable();					\

} while (0)



static inline void write_seqcount_t_end(seqcount_t *s)

static inline void do_write_seqcount_end(seqcount_t *s)

{

	seqcount_release(&s->dep_map, _RET_IP_);

	raw_write_seqcount_t_end(s);

	do_raw_write_seqcount_end(s);

}



/**
@@ -603,9 +603,9 @@ static inline void write_seqcount_t_end(seqcount_t *s) 
 *      }

 */

#define raw_write_seqcount_barrier(s)					\

	raw_write_seqcount_t_barrier(seqprop_ptr(s))

	do_raw_write_seqcount_barrier(seqprop_ptr(s))



static inline void raw_write_seqcount_t_barrier(seqcount_t *s)

static inline void do_raw_write_seqcount_barrier(seqcount_t *s)

{

	kcsan_nestable_atomic_begin();

	s->sequence++;
@@ -623,9 +623,9 @@ static inline void raw_write_seqcount_t_barrier(seqcount_t *s) 
 * will complete successfully and see data older than this.

 */

#define write_seqcount_invalidate(s)					\

	write_seqcount_t_invalidate(seqprop_ptr(s))

	do_write_seqcount_invalidate(seqprop_ptr(s))



static inline void write_seqcount_t_invalidate(seqcount_t *s)

static inline void do_write_seqcount_invalidate(seqcount_t *s)

{

	smp_wmb();

	kcsan_nestable_atomic_begin();
@@ -865,9 +865,9 @@ static inline unsigned read_seqretry(const seqlock_t *sl, unsigned start) 
}



/*

 * For all seqlock_t write side functions, use write_seqcount_*t*_begin()

 * instead of the generic write_seqcount_begin(). This way, no redundant

 * lockdep_assert_held() checks are added.

 * For all seqlock_t write side functions, use the the internal

 * do_write_seqcount_begin() instead of generic write_seqcount_begin().

 * This way, no redundant lockdep_assert_held() checks are added.

 */



/**
@@ -886,7 +886,7 @@ static inline unsigned read_seqretry(const seqlock_t *sl, unsigned start) 
static inline void write_seqlock(seqlock_t *sl)

{

	spin_lock(&sl->lock);

	write_seqcount_t_begin(&sl->seqcount.seqcount);

	do_write_seqcount_begin(&sl->seqcount.seqcount);

}



/**
@@ -898,7 +898,7 @@ static inline void write_seqlock(seqlock_t *sl) 
 */

static inline void write_sequnlock(seqlock_t *sl)

{

	write_seqcount_t_end(&sl->seqcount.seqcount);

	do_write_seqcount_end(&sl->seqcount.seqcount);

	spin_unlock(&sl->lock);

}
@@ -912,7 +912,7 @@ static inline void write_sequnlock(seqlock_t *sl) 
static inline void write_seqlock_bh(seqlock_t *sl)

{

	spin_lock_bh(&sl->lock);

	write_seqcount_t_begin(&sl->seqcount.seqcount);

	do_write_seqcount_begin(&sl->seqcount.seqcount);

}



/**
@@ -925,7 +925,7 @@ static inline void write_seqlock_bh(seqlock_t *sl) 
 */

static inline void write_sequnlock_bh(seqlock_t *sl)

{

	write_seqcount_t_end(&sl->seqcount.seqcount);

	do_write_seqcount_end(&sl->seqcount.seqcount);

	spin_unlock_bh(&sl->lock);

}
@@ -939,7 +939,7 @@ static inline void write_sequnlock_bh(seqlock_t *sl) 
static inline void write_seqlock_irq(seqlock_t *sl)

{

	spin_lock_irq(&sl->lock);

	write_seqcount_t_begin(&sl->seqcount.seqcount);

	do_write_seqcount_begin(&sl->seqcount.seqcount);

}



/**
@@ -951,7 +951,7 @@ static inline void write_seqlock_irq(seqlock_t *sl) 
 */

static inline void write_sequnlock_irq(seqlock_t *sl)

{

	write_seqcount_t_end(&sl->seqcount.seqcount);

	do_write_seqcount_end(&sl->seqcount.seqcount);

	spin_unlock_irq(&sl->lock);

}
@@ -960,7 +960,7 @@ static inline unsigned long __write_seqlock_irqsave(seqlock_t *sl) 
	unsigned long flags;



	spin_lock_irqsave(&sl->lock, flags);

	write_seqcount_t_begin(&sl->seqcount.seqcount);

	do_write_seqcount_begin(&sl->seqcount.seqcount);

	return flags;

}
@@ -989,7 +989,7 @@ static inline unsigned long __write_seqlock_irqsave(seqlock_t *sl) 
static inline void

write_sequnlock_irqrestore(seqlock_t *sl, unsigned long flags)

{

	write_seqcount_t_end(&sl->seqcount.seqcount);

	do_write_seqcount_end(&sl->seqcount.seqcount);

	spin_unlock_irqrestore(&sl->lock, flags);

}

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