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Allow using of driver's mutex instead internal one for evdev locking.

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Add new API call: evdev_register_mtx which takes lock argument that
should be used instead of internal one for evdev locking. Useful for
cases if evdev_push_event() is always called with driver's lock taken
and reduces amount of lock aquisitions. This allows to avoid LOR
between ev_open/ev_close invocations and evdev_push_event() Such LOR
can happen when ev_open/ev_close methods acquire driver lock and
evdev_push_event() is called with this lock taken.

Submitted by:	Vladimir Kondratiev <wulf@cicgroup.ru>
This commit is contained in:
Oleksandr Tymoshenko 2016-10-08 17:58:26 +00:00
parent ccb890b548
commit bfbd1bb744
4 changed files with 56 additions and 13 deletions
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38
sys/dev/evdev/evdev.c
View File

@ -187,8 +187,8 @@ evdev_estimate_report_size(struct evdev_dev *evdev)
return (size);
}
int
evdev_register(struct evdev_dev *evdev)
static int
evdev_register_common(struct evdev_dev *evdev)
{
int ret;
@ -196,7 +196,6 @@ evdev_register(struct evdev_dev *evdev)
evdev->ev_shortname, evdev->ev_name, evdev->ev_serial);
/* Initialize internal structures */
mtx_init(&evdev->ev_mtx, "evmtx", NULL, MTX_DEF);
LIST_INIT(&evdev->ev_clients);
if (evdev_event_supported(evdev, EV_REP) &&
@ -228,12 +227,34 @@ evdev_register(struct evdev_dev *evdev)
/* Create char device node */
ret = evdev_cdev_create(evdev);
bail_out:
return (ret);
}
int
evdev_register(struct evdev_dev *evdev)
{
int ret;
evdev->ev_lock_type = EV_LOCK_INTERNAL;
evdev->ev_lock = &evdev->ev_mtx;
mtx_init(&evdev->ev_mtx, "evmtx", NULL, MTX_DEF);
ret = evdev_register_common(evdev);
if (ret != 0)
mtx_destroy(&evdev->ev_mtx);
return (ret);
}
int
evdev_register_mtx(struct evdev_dev *evdev, struct mtx *mtx)
{
evdev->ev_lock_type = EV_LOCK_MTX;
evdev->ev_lock = mtx;
return (evdev_register_common(evdev));
}
int
evdev_unregister(struct evdev_dev *evdev)
{
@ -257,7 +278,7 @@ evdev_unregister(struct evdev_dev *evdev)
/* destroy_dev can sleep so release lock */
ret = evdev_cdev_destroy(evdev);
evdev->ev_cdev = NULL;
if (ret == 0)
if (ret == 0 && evdev->ev_lock_type == EV_LOCK_INTERNAL)
mtx_destroy(&evdev->ev_mtx);
evdev_free_absinfo(evdev->ev_absinfo);
@ -735,16 +756,21 @@ evdev_push_event(struct evdev_dev *evdev, uint16_t type, uint16_t code,
int32_t value)
{
if (evdev->ev_lock_type != EV_LOCK_INTERNAL)
EVDEV_LOCK_ASSERT(evdev);
if (evdev_check_event(evdev, type, code, value) != 0)
return (EINVAL);
EVDEV_LOCK(evdev);
if (evdev->ev_lock_type == EV_LOCK_INTERNAL)
EVDEV_LOCK(evdev);
evdev_modify_event(evdev, type, code, &value);
if (type == EV_SYN && code == SYN_REPORT && evdev->ev_report_opened &&
bit_test(evdev->ev_flags, EVDEV_FLAG_MT_STCOMPAT))
evdev_send_mt_compat(evdev);
evdev_send_event(evdev, type, code, value);
EVDEV_UNLOCK(evdev);
if (evdev->ev_lock_type == EV_LOCK_INTERNAL)
EVDEV_UNLOCK(evdev);
return (0);
}

1
sys/dev/evdev/evdev.h
View File

@ -92,6 +92,7 @@ void evdev_set_serial(struct evdev_dev *, const char *);
void evdev_set_methods(struct evdev_dev *, void *,
const struct evdev_methods *);
int evdev_register(struct evdev_dev *);
int evdev_register_mtx(struct evdev_dev *, struct mtx *);
int evdev_unregister(struct evdev_dev *);
int evdev_push_event(struct evdev_dev *, uint16_t, uint16_t, int32_t);
int evdev_sync(struct evdev_dev *);

16
sys/dev/evdev/evdev_mt.c
View File

@ -227,9 +227,13 @@ void
evdev_push_nfingers(struct evdev_dev *evdev, int32_t nfingers)
{
EVDEV_LOCK(evdev);
if (evdev->ev_lock_type == EV_LOCK_INTERNAL)
EVDEV_LOCK(evdev);
else
EVDEV_LOCK_ASSERT(evdev);
evdev_send_nfingers(evdev, nfingers);
EVDEV_UNLOCK(evdev);
if (evdev->ev_lock_type == EV_LOCK_INTERNAL)
EVDEV_UNLOCK(evdev);
}
void
@ -263,7 +267,11 @@ void
evdev_push_mt_compat(struct evdev_dev *evdev)
{
EVDEV_LOCK(evdev);
if (evdev->ev_lock_type == EV_LOCK_INTERNAL)
EVDEV_LOCK(evdev);
else
EVDEV_LOCK_ASSERT(evdev);
evdev_send_mt_compat(evdev);
EVDEV_UNLOCK(evdev);
if (evdev->ev_lock_type == EV_LOCK_INTERNAL)
EVDEV_UNLOCK(evdev);
}

14
sys/dev/evdev/evdev_private.h
View File

@ -71,6 +71,12 @@ enum evdev_clock_id
EV_CLOCK_BOOTTIME /* monotonic, suspend-awared */
};
enum evdev_lock_type
{
EV_LOCK_INTERNAL = 0, /* Internal evdev mutex */
EV_LOCK_MTX, /* Driver`s mutex */
};
struct evdev_dev
{
char ev_name[NAMELEN];
@ -78,6 +84,8 @@ struct evdev_dev
char ev_serial[NAMELEN];
struct cdev * ev_cdev;
int ev_unit;
enum evdev_lock_type ev_lock_type;
struct mtx * ev_lock;
struct mtx ev_mtx;
struct input_id ev_id;
struct evdev_client * ev_grabber;
@ -123,9 +131,9 @@ struct evdev_dev
LIST_HEAD(, evdev_client) ev_clients;
};
#define EVDEV_LOCK(evdev) mtx_lock(&(evdev)->ev_mtx)
#define EVDEV_UNLOCK(evdev) mtx_unlock(&(evdev)->ev_mtx)
#define EVDEV_LOCK_ASSERT(evdev) mtx_assert(&(evdev)->ev_mtx, MA_OWNED)
#define EVDEV_LOCK(evdev) mtx_lock((evdev)->ev_lock)
#define EVDEV_UNLOCK(evdev) mtx_unlock((evdev)->ev_lock)
#define EVDEV_LOCK_ASSERT(evdev) mtx_assert((evdev)->ev_lock, MA_OWNED)
struct evdev_client
{