From: Binoy Jayan <binoy.jayan@linaro.org>
To: Doug Ledford <dledford@redhat.com>,
Sean Hefty <sean.hefty@intel.com>,
Hal Rosenstock <hal.rosenstock@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>,
linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org,
Binoy Jayan <binoy.jayan@linaro.org>
Subject: [PATCH v4 02/10] IB/core: Replace semaphore sm_sem with an atomic wait
Date: Thu, 27 Oct 2016 12:29:06 +0530 [thread overview]
Message-ID: <1477551554-30349-3-git-send-email-binoy.jayan@linaro.org> (raw)
In-Reply-To: <1477551554-30349-1-git-send-email-binoy.jayan@linaro.org>
The semaphore 'sm_sem' is used for an exclusive ownership of the device
so model the same as an atomic variable with an associated wait_event.
Semaphores are going away in the future.
Signed-off-by: Binoy Jayan <binoy.jayan@linaro.org>
---
drivers/infiniband/core/user_mad.c | 20 ++++++++++++++------
1 file changed, 14 insertions(+), 6 deletions(-)
diff --git a/drivers/infiniband/core/user_mad.c b/drivers/infiniband/core/user_mad.c
index 415a318..6101c0a 100644
--- a/drivers/infiniband/core/user_mad.c
+++ b/drivers/infiniband/core/user_mad.c
@@ -67,6 +67,8 @@ enum {
IB_UMAD_MINOR_BASE = 0
};
+#define UMAD_F_CLAIM 0x01
+
/*
* Our lifetime rules for these structs are the following:
* device special file is opened, we take a reference on the
@@ -87,7 +89,8 @@ struct ib_umad_port {
struct cdev sm_cdev;
struct device *sm_dev;
- struct semaphore sm_sem;
+ wait_queue_head_t wq;
+ unsigned long flags;
struct mutex file_mutex;
struct list_head file_list;
@@ -1030,12 +1033,14 @@ static int ib_umad_sm_open(struct inode *inode, struct file *filp)
port = container_of(inode->i_cdev, struct ib_umad_port, sm_cdev);
if (filp->f_flags & O_NONBLOCK) {
- if (down_trylock(&port->sm_sem)) {
+ if (test_and_set_bit(UMAD_F_CLAIM, &port->flags)) {
ret = -EAGAIN;
goto fail;
}
} else {
- if (down_interruptible(&port->sm_sem)) {
+ if (wait_event_interruptible(port->wq,
+ !test_and_set_bit(UMAD_F_CLAIM,
+ &port->flags))) {
ret = -ERESTARTSYS;
goto fail;
}
@@ -1060,7 +1065,8 @@ static int ib_umad_sm_open(struct inode *inode, struct file *filp)
ib_modify_port(port->ib_dev, port->port_num, 0, &props);
err_up_sem:
- up(&port->sm_sem);
+ clear_bit(UMAD_F_CLAIM, &port->flags);
+ wake_up(&port->wq);
fail:
return ret;
@@ -1079,7 +1085,8 @@ static int ib_umad_sm_close(struct inode *inode, struct file *filp)
ret = ib_modify_port(port->ib_dev, port->port_num, 0, &props);
mutex_unlock(&port->file_mutex);
- up(&port->sm_sem);
+ clear_bit(UMAD_F_CLAIM, &port->flags);
+ wake_up(&port->wq);
kobject_put(&port->umad_dev->kobj);
@@ -1177,7 +1184,8 @@ static int ib_umad_init_port(struct ib_device *device, int port_num,
port->ib_dev = device;
port->port_num = port_num;
- sema_init(&port->sm_sem, 1);
+ init_waitqueue_head(&port->wq);
+ __clear_bit(UMAD_F_CLAIM, &port->flags);
mutex_init(&port->file_mutex);
INIT_LIST_HEAD(&port->file_list);
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project
next prev parent reply other threads:[~2016-10-27 6:59 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-27 6:59 [PATCH v4 00/10] infiniband: Remove semaphores Binoy Jayan
2016-10-27 6:59 ` [PATCH v4 01/10] IB/core: iwpm_nlmsg_request: Replace semaphore with completion Binoy Jayan
2016-10-27 6:59 ` Binoy Jayan [this message]
2016-10-27 6:59 ` [PATCH v4 03/10] IB/hns: Replace semaphore poll_sem with mutex Binoy Jayan
2016-10-27 6:59 ` [PATCH v4 04/10] IB/mthca: " Binoy Jayan
2016-10-27 6:59 ` [PATCH v4 05/10] IB/isert: Replace semaphore sem with completion Binoy Jayan
2016-10-30 21:12 ` Sagi Grimberg
2016-11-18 6:57 ` Binoy Jayan
2016-11-18 8:58 ` Arnd Bergmann
2016-11-18 9:10 ` Binoy Jayan
2016-10-27 6:59 ` [PATCH v4 06/10] IB/hns: Replace counting semaphore event_sem with wait_event Binoy Jayan
2016-10-27 6:59 ` [PATCH v4 07/10] IB/mthca: " Binoy Jayan
2016-10-27 6:59 ` [PATCH v4 08/10] IB/mlx5: Add helper mlx5_ib_post_send_wait Binoy Jayan
2016-10-27 6:59 ` [PATCH v4 09/10] IB/mlx5: Replace semaphore umr_common:sem with wait_event Binoy Jayan
2016-10-27 6:59 ` [PATCH v4 10/10] IB/mlx5: Simplify completion into a wait_event Binoy Jayan
2016-10-30 21:17 ` Sagi Grimberg
2016-11-02 15:59 ` Leon Romanovsky
2016-11-03 6:03 ` Binoy Jayan
2016-11-03 15:37 ` Linus Torvalds
2016-11-07 5:51 ` Binoy Jayan
2016-10-27 7:13 ` [PATCH v4 00/10] infiniband: Remove semaphores Leon Romanovsky
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