From bfbd1bb744b0f1091f0cd14467ec7d8b51560bee Mon Sep 17 00:00:00 2001 From: Oleksandr Tymoshenko Date: Sat, 8 Oct 2016 17:58:26 +0000 Subject: [PATCH] Allow using of driver's mutex instead internal one for evdev locking. 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 --- sys/dev/evdev/evdev.c | 38 +++++++++++++++++++++++++++++------ sys/dev/evdev/evdev.h | 1 + sys/dev/evdev/evdev_mt.c | 16 +++++++++++---- sys/dev/evdev/evdev_private.h | 14 ++++++++++--- 4 files changed, 56 insertions(+), 13 deletions(-) diff --git a/sys/dev/evdev/evdev.c b/sys/dev/evdev/evdev.c index 4ad1db20cef0..7da8eb14182c 100644 --- a/sys/dev/evdev/evdev.c +++ b/sys/dev/evdev/evdev.c @@ -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); } diff --git a/sys/dev/evdev/evdev.h b/sys/dev/evdev/evdev.h index 7cfd21d6b63b..2c4aeee1abcf 100644 --- a/sys/dev/evdev/evdev.h +++ b/sys/dev/evdev/evdev.h @@ -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 *); diff --git a/sys/dev/evdev/evdev_mt.c b/sys/dev/evdev/evdev_mt.c index 1ff332cbaf30..ef36006ddaf6 100644 --- a/sys/dev/evdev/evdev_mt.c +++ b/sys/dev/evdev/evdev_mt.c @@ -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); } diff --git a/sys/dev/evdev/evdev_private.h b/sys/dev/evdev/evdev_private.h index e8bfda49cd52..4305c5959587 100644 --- a/sys/dev/evdev/evdev_private.h +++ b/sys/dev/evdev/evdev_private.h @@ -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 {