[PATCH 2/8] IB/core: Replace semaphore sm_sem with completion

From: Binoy Jayan
Date: Mon Oct 17 2016 - 12:32:11 EST


The semaphore 'sm_sem' is used as completion, so convert it to
struct completion. Semaphores are going away in the future. The initial
status of the completion variable is marked as completed by a call to
the function 'complete' immediately following the initialization.

Signed-off-by: Binoy Jayan <binoy.jayan@xxxxxxxxxx>
---
drivers/infiniband/core/user_mad.c | 14 ++++++++------
1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/infiniband/core/user_mad.c b/drivers/infiniband/core/user_mad.c
index 415a318..df070cc 100644
--- a/drivers/infiniband/core/user_mad.c
+++ b/drivers/infiniband/core/user_mad.c
@@ -47,6 +47,7 @@
#include <linux/kref.h>
#include <linux/compat.h>
#include <linux/sched.h>
+#include <linux/completion.h>
#include <linux/semaphore.h>
#include <linux/slab.h>

@@ -87,7 +88,7 @@ struct ib_umad_port {

struct cdev sm_cdev;
struct device *sm_dev;
- struct semaphore sm_sem;
+ struct completion sm_comp;

struct mutex file_mutex;
struct list_head file_list;
@@ -1030,12 +1031,12 @@ 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 (!try_wait_for_completion(&port->sm_comp)) {
ret = -EAGAIN;
goto fail;
}
} else {
- if (down_interruptible(&port->sm_sem)) {
+ if (wait_for_completion_interruptible(&port->sm_comp)) {
ret = -ERESTARTSYS;
goto fail;
}
@@ -1060,7 +1061,7 @@ 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);
+ complete(&port->sm_comp);

fail:
return ret;
@@ -1079,7 +1080,7 @@ 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);
+ complete(&port->sm_comp);

kobject_put(&port->umad_dev->kobj);

@@ -1177,7 +1178,8 @@ 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_completion(&port->sm_comp);
+ complete(&port->sm_comp);
mutex_init(&port->file_mutex);
INIT_LIST_HEAD(&port->file_list);

--
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