PCI: ibmphp: Turn semaphores into completions or mutexes

The sem_exit variable is conceptually a completion, so it should be called
that.

Similarly, the semOperations semaphore is a simple mutex, and can be
changed into that, respectively.

With both converted, the ibmphp_hpc_initvars() function is no longer used
and can be removed.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

1 files changed, 14 insertions, 33 deletions

diff --git a/drivers/pci/hotplug/ibmphp_hpc.c b/drivers/pci/hotplug/ibmphp_hpc.c
index 752c384cbd4c..508a62a6b5f9 100644
--- a/drivers/pci/hotplug/ibmphp_hpc.c
+++ b/drivers/pci/hotplug/ibmphp_hpc.c
@@ -15,13 +15,13 @@
 
 #include <linux/wait.h>
 #include <linux/time.h>
+#include <linux/completion.h>
 #include <linux/delay.h>
 #include <linux/module.h>
 #include <linux/pci.h>
 #include <linux/init.h>
 #include <linux/mutex.h>
 #include <linux/sched.h>
-#include <linux/semaphore.h>
 #include <linux/kthread.h>
 #include "ibmphp.h"
 
@@ -88,10 +88,10 @@ static int to_debug = 0;
 //----------------------------------------------------------------------------
 // global variables
 //----------------------------------------------------------------------------
-static struct mutex sem_hpcaccess;      // lock access to HPC
-static struct semaphore semOperations;  // lock all operations and
+static DEFINE_MUTEX(sem_hpcaccess);     // lock access to HPC
+static DEFINE_MUTEX(operations_mutex);  // lock all operations and
                                         // access to data structures
-static struct semaphore sem_exit;       // make sure polling thread goes away
+static DECLARE_COMPLETION(exit_complete); // make sure polling thread goes away
 static struct task_struct *ibmphp_poll_thread;
 //----------------------------------------------------------------------------
 // local function prototypes
@@ -110,23 +110,6 @@ static int hpc_wait_ctlr_notworking(int, struct controller *, void __iomem *, u8
 
 
 /*----------------------------------------------------------------------
-* Name:    ibmphp_hpc_initvars
-*
-* Action:  initialize semaphores and variables
-*---------------------------------------------------------------------*/
-void __init ibmphp_hpc_initvars(void)
-{
-        debug("%s - Entry\n", __func__);
-
-        mutex_init(&sem_hpcaccess);
-        sema_init(&semOperations, 1);
-        sema_init(&sem_exit, 0);
-        to_debug = 0;
-
-        debug("%s - Exit\n", __func__);
-}
-
-/*----------------------------------------------------------------------
 * Name:    i2c_ctrl_read
 *
 * Action:  read from HPC over I2C
@@ -780,7 +763,7 @@ void free_hpc_access(void)
 *---------------------------------------------------------------------*/
 void ibmphp_lock_operations(void)
 {
-        down(&semOperations);
+        mutex_lock(&operations_mutex);
         to_debug = 1;
 }
 
@@ -790,7 +773,7 @@ void ibmphp_lock_operations(void)
 void ibmphp_unlock_operations(void)
 {
         debug("%s - Entry\n", __func__);
-        up(&semOperations);
+        mutex_unlock(&operations_mutex);
         to_debug = 0;
         debug("%s - Exit\n", __func__);
 }
@@ -816,7 +799,7 @@ static int poll_hpc(void *data)
 
         while (!kthread_should_stop()) {
                 /* try to get the lock to do some kind of hardware access */
-                down(&semOperations);
+                mutex_lock(&operations_mutex);
 
                 switch (poll_state) {
                 case POLL_LATCH_REGISTER:
@@ -871,13 +854,13 @@ static int poll_hpc(void *data)
                         break;
                 case POLL_SLEEP:
                         /* don't sleep with a lock on the hardware */
-                        up(&semOperations);
+                        mutex_unlock(&operations_mutex);
                         msleep(POLL_INTERVAL_SEC * 1000);
 
                         if (kthread_should_stop())
                                 goto out_sleep;
 
-                        down(&semOperations);
+                        mutex_lock(&operations_mutex);
 
                         if (poll_count >= POLL_LATCH_CNT) {
                                 poll_count = 0;
@@ -887,12 +870,12 @@ static int poll_hpc(void *data)
                         break;
                 }
                 /* give up the hardware semaphore */
-                up(&semOperations);
+                mutex_unlock(&operations_mutex);
                 /* sleep for a short time just for good measure */
 out_sleep:
                 msleep(100);
         }
-        up(&sem_exit);
+        complete(&exit_complete);
         debug("%s - Exit\n", __func__);
         return 0;
 }
@@ -1060,9 +1043,9 @@ void __exit ibmphp_hpc_stop_poll_thread(void)
         debug("after locking operations\n");
 
         // wait for poll thread to exit
-        debug("before sem_exit down\n");
-        down(&sem_exit);
-        debug("after sem_exit down\n");
+        debug("before exit_complete down\n");
+        wait_for_completion(&exit_complete);
+        debug("after exit_completion down\n");
 
         // cleanup
         debug("before free_hpc_access\n");
@@ -1070,8 +1053,6 @@ void __exit ibmphp_hpc_stop_poll_thread(void)
         debug("after free_hpc_access\n");
         ibmphp_unlock_operations();
         debug("after unlock operations\n");
-        up(&sem_exit);
-        debug("after sem exit up\n");
 
         debug("%s - Exit\n", __func__);
 }