commit c4c4018b04f9b7993e3800dc1f391ac8947764a5
author Ralf Baechle <ralf@linux-mips.org> Fri Feb 23 13:40:45 2007 +0000
committer Ralf Baechle <ralf@linux-mips.org> Mon Feb 26 23:06:06 2007 +0000
tree 346c9a4aa9c46eee6df883f89553e43b9d7033fc
parent cbc841356702ccf4f16e760c84006ed3ddd4b1fd

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

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

arch/mips/kernel/vpe.c

diff --git a/arch/mips/kernel/vpe.c b/arch/mips/kernel/vpe.c
index 9aca871..c9ee9d2 100644
--- a/arch/mips/kernel/vpe.c
+++ b/arch/mips/kernel/vpe.c
@@ -1079,6 +1079,7 @@
 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 @@
 		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 @@
 		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;