X-Git-Url: https://git.proxmox.com/?a=blobdiff_plain;f=arch%2Farm%2Finclude%2Fasm%2Fspinlock.h;h=f8b8965666e9b14842786742f48ccdef49000802;hb=15e7e5c1ebf556cd620c9b091e121091ac760f6d;hp=6220e9fdf4c7d0917fe50dc54b23f70502ea43a5;hpb=1aa2b3b7a6c4f3dbd3671171113a20e6a6190e3b;p=mirror_ubuntu-bionic-kernel.git

diff --git a/arch/arm/include/asm/spinlock.h b/arch/arm/include/asm/spinlock.h
index 6220e9fdf4c7..f8b8965666e9 100644
--- a/arch/arm/include/asm/spinlock.h
+++ b/arch/arm/include/asm/spinlock.h
@@ -97,19 +97,22 @@ static inline void arch_spin_lock(arch_spinlock_t *lock)
 
 static inline int arch_spin_trylock(arch_spinlock_t *lock)
 {
-	unsigned long tmp;
+	unsigned long contended, res;
 	u32 slock;
 
-	__asm__ __volatile__(
-"	ldrex	%0, [%2]\n"
-"	subs	%1, %0, %0, ror #16\n"
-"	addeq	%0, %0, %3\n"
-"	strexeq	%1, %0, [%2]"
-	: "=&r" (slock), "=&r" (tmp)
-	: "r" (&lock->slock), "I" (1 << TICKET_SHIFT)
-	: "cc");
-
-	if (tmp == 0) {
+	do {
+		__asm__ __volatile__(
+		"	ldrex	%0, [%3]\n"
+		"	mov	%2, #0\n"
+		"	subs	%1, %0, %0, ror #16\n"
+		"	addeq	%0, %0, %4\n"
+		"	strexeq	%2, %0, [%3]"
+		: "=&r" (slock), "=&r" (contended), "=r" (res)
+		: "r" (&lock->slock), "I" (1 << TICKET_SHIFT)
+		: "cc");
+	} while (res);
+
+	if (!contended) {
 		smp_mb();
 		return 1;
 	} else {