[MIPS] RTLX, VPE: Make open actually atomic.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 3 insertions, 4 deletions

diff --git a/arch/mips/kernel/vpe.c b/arch/mips/kernel/vpe.c
index 9aca871a307f..c9ee9d2d5856 100644
--- a/arch/mips/kernel/vpe.c
+++ b/arch/mips/kernel/vpe.c
@@ -1079,6 +1079,7 @@ static int getcwd(char *buff, int size)
 static int vpe_open(struct inode *inode, struct file *filp)
 {
         int minor, ret;
+        enum vpe_state state;
         struct vpe *v;
         struct vpe_notifications *not;
 
@@ -1093,7 +1094,8 @@ static int vpe_open(struct inode *inode, struct file *filp)
                 return -ENODEV;
         }
 
-        if (v->state != VPE_STATE_UNUSED) {
+        state = xchg(&v->state, VPE_STATE_INUSE);
+        if (state != VPE_STATE_UNUSED) {
                 dvpe();
 
                 printk(KERN_DEBUG "VPE loader: tc in use dumping regs\n");
@@ -1108,9 +1110,6 @@ static int vpe_open(struct inode *inode, struct file *filp)
                 cleanup_tc(get_tc(minor));
         }
 
-        // allocate it so when we get write ops we know it's expected.
-        v->state = VPE_STATE_INUSE;
-
         /* this of-course trashes what was there before... */
         v->pbuffer = vmalloc(P_SIZE);
         v->plen = P_SIZE;