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LinuxKPI: linux/seqlock.h: Fix write_seqcount_(begin|end)

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in seqcount_mutex_t case with removal of extraneous mutex lock/unlock
calls and addition of missing critical section.
While here strip one inline wrap layer to reduce code size.

Fixes startup lockup of i915kms after update to drm-kmod v5.12

Reviewed by:	hselasky, bz
MFC after:	1week
Differential Revision:	https://reviews.freebsd.org/D37699
This commit is contained in:
Vladimir Kondratyev 2022-12-24 12:01:20 +03:00
parent 0661cf74e6
commit 68f08e26e2
1 changed files with 13 additions and 81 deletions
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94
sys/compat/linuxkpi/common/include/linux/seqlock.h
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@ -36,8 +36,6 @@
#include <sys/rwlock.h>
#include <sys/seqc.h>
#include <linux/mutex.h>
struct lock_class_key;
struct seqcount {
@ -52,8 +50,7 @@ struct seqlock {
typedef struct seqlock seqlock_t;
struct seqcount_mutex {
struct mutex *seqm_lock;
struct seqcount seqm_count;
seqc_t seqc;
};
typedef struct seqcount_mutex seqcount_mutex_t;
@ -66,98 +63,33 @@ __seqcount_init(struct seqcount *seqcount, const char *name __unused,
#define seqcount_init(seqcount) __seqcount_init(seqcount, NULL, NULL)
static inline void
seqcount_mutex_init(struct seqcount_mutex *seqcount, struct mutex *mutex)
seqcount_mutex_init(struct seqcount_mutex *seqcount, void *mutex __unused)
{
seqcount->seqm_lock = mutex;
seqcount_init(&seqcount->seqm_count);
seqcount->seqc = 0;
}
#define write_seqcount_begin(s) \
_Generic(*(s), \
struct seqcount: lkpi_write_seqcount_begin, \
struct seqcount_mutex: lkpi_write_seqcount_mutex_begin \
)(s)
static inline void
lkpi_write_seqcount_begin(struct seqcount *seqcount)
{
seqc_sleepable_write_begin(&seqcount->seqc);
}
static inline void
lkpi_write_seqcount_mutex_begin(struct seqcount_mutex *seqcount)
{
mutex_lock(seqcount->seqm_lock);
lkpi_write_seqcount_begin(&seqcount->seqm_count);
}
struct seqcount: seqc_sleepable_write_begin, \
struct seqcount_mutex: seqc_write_begin \
)(&(s)->seqc)
#define write_seqcount_end(s) \
_Generic(*(s), \
struct seqcount: lkpi_write_seqcount_end, \
struct seqcount_mutex: lkpi_write_seqcount_mutex_end \
)(s)
struct seqcount: seqc_sleepable_write_end, \
struct seqcount_mutex: seqc_write_end \
)(&(s)->seqc)
static inline void
lkpi_write_seqcount_end(struct seqcount *seqcount)
{
seqc_sleepable_write_end(&seqcount->seqc);
}
static inline void
lkpi_write_seqcount_mutex_end(struct seqcount_mutex *seqcount)
{
lkpi_write_seqcount_end(&seqcount->seqm_count);
mutex_unlock(seqcount->seqm_lock);
}
#define read_seqcount_begin(s) \
_Generic(*(s), \
struct seqcount: lkpi_read_seqcount_begin, \
struct seqcount_mutex: lkpi_read_seqcount_mutex_begin \
)(s)
static inline unsigned
lkpi_read_seqcount_begin(const struct seqcount *seqcount)
{
return (seqc_read(&seqcount->seqc));
}
static inline unsigned
lkpi_read_seqcount_mutex_begin(const struct seqcount_mutex *seqcount)
{
return (lkpi_read_seqcount_begin(&seqcount->seqm_count));
}
static inline unsigned
raw_read_seqcount(const struct seqcount *seqcount)
{
return (seqc_read_any(&seqcount->seqc));
}
#define read_seqcount_begin(s) seqc_read(&(s)->seqc)
#define raw_read_seqcount(s) seqc_read_any(&(s)->seqc)
/*
* XXX: Are predicts from inline functions still not honored by clang?
*/
#define __read_seqcount_retry(seqcount, gen) \
(!seqc_consistent_no_fence(&(seqcount)->seqc, gen))
#define read_seqcount_retry(s, old) \
_Generic(*(s), \
struct seqcount: lkpi_read_seqcount_retry, \
struct seqcount_mutex: lkpi_read_seqcount_mutex_retry \
)(s, old)
static inline int
lkpi_read_seqcount_retry(
const struct seqcount *seqcount, unsigned int old)
{
return (!seqc_consistent(&seqcount->seqc, old));
}
static inline int
lkpi_read_seqcount_mutex_retry(
const struct seqcount_mutex *seqcount, unsigned int old)
{
return (!seqc_consistent(&seqcount->seqm_count.seqc, old));
}
#define read_seqcount_retry(seqcount, gen) \
(!seqc_consistent(&(seqcount)->seqc, gen))
static inline void
seqlock_init(struct seqlock *seqlock)