[PATCH] ppc64: Use an atomic_t instead of a volatile unsigned long, from Stephen...

From: Anton Blanchard <anton@samba.org>

Use an atomic_t instead of a volatile unsigned long, from Stephen Rothwell

diff --git a/arch/ppc64/kernel/viopath.c b/arch/ppc64/kernel/viopath.c
index c7829012a706a169ad1621c31c626eeea39067c8..4448dc806fac623986b147317ba3d1eafa2df872 100644 (file)
--- a/arch/ppc64/kernel/viopath.c
+++ b/arch/ppc64/kernel/viopath.c
@@ -85,7 +85,7 @@ static void handleMonitorEvent(struct HvLpEvent *event);
 struct doneAllocParms_t {
        struct semaphore *sem;
        int number;
-       volatile unsigned long *wait_atomic;
+       atomic_t *wait_atomic;
        int used_wait_atomic;
 };
 
@@ -531,7 +531,7 @@ static void viopath_donealloc(void *parm, int number)
 
        parmsp->number = number;
        if (parmsp->used_wait_atomic)
-               *(parmsp->wait_atomic) = 0;
+               atomic_set(parmsp->wait_atomic, 0);
        else
                up(parmsp->sem);
 }
@@ -540,10 +540,11 @@ static int allocateEvents(HvLpIndex remoteLp, int numEvents)
 {
        struct doneAllocParms_t parms;
        DECLARE_MUTEX_LOCKED(Semaphore);
-       volatile unsigned long wait_atomic = 1;
+       atomic_t wait_atomic;
 
        if (in_atomic()) {
                parms.used_wait_atomic = 1;
+               atomic_set(&wait_atomic, 1);
                parms.wait_atomic = &wait_atomic;
        } else {
                parms.used_wait_atomic = 0;
@@ -552,7 +553,7 @@ static int allocateEvents(HvLpIndex remoteLp, int numEvents)
        mf_allocateLpEvents(remoteLp, HvLpEvent_Type_VirtualIo, 250,    /* It would be nice to put a real number here! */
                            numEvents, &viopath_donealloc, &parms);
        if (in_atomic()) {
-               while (wait_atomic)
+               while (atomic_read(&wait_atomic))
                        mb();
        } else
                down(&Semaphore);
@@ -656,6 +657,7 @@ int viopath_close(HvLpIndex remoteLp, int subtype, int numReq)
 
        spin_unlock_irqrestore(&statuslock, flags);
 
+       doneAllocParms.used_wait_atomic = 0;
        doneAllocParms.sem = &Semaphore;
        mf_deallocateLpEvents(remoteLp, HvLpEvent_Type_VirtualIo,
                              numReq, &viopath_donealloc, &doneAllocParms);