patch-2.4.21 linux-2.4.21/arch/parisc/lib/locks.c

• Lines: 69
• Date: 2003-06-13 07:51:31.000000000 -0700
• Orig file: linux-2.4.20/arch/parisc/lib/locks.c
• Orig date: 1969-12-31 16:00:00.000000000 -0800

diff -urN linux-2.4.20/arch/parisc/lib/locks.c linux-2.4.21/arch/parisc/lib/locks.c
@@ -0,0 +1,68 @@
+/*
+ * debugging spinlocks for parisc
+ * 
+ * Adapted from the ppc version
+ */
+
+
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/delay.h>
+#include <linux/spinlock.h>
+#include <asm/processor.h>
+#include <asm/system.h>
+#include <asm/io.h>
+
+#ifdef CONFIG_DEBUG_SPINLOCK
+
+#undef INIT_STUCK
+#define INIT_STUCK 200000000 /*0xffffffff*/
+
+#define __spin_trylock(x) (__ldcw(&(x)->lock) != 0)
+
+void spin_lock(spinlock_t *lock)
+{
+	int cpu = smp_processor_id();
+	unsigned int stuck = INIT_STUCK;
+	while (!__spin_trylock(lock)) {
+		while ((unsigned volatile long)lock->lock == 0) {
+			if (!--stuck) {
+				printk("spin_lock(%p) CPU#%d NIP %p"
+				       " holder: cpu %ld pc %08lX\n",
+				       lock, cpu, __builtin_return_address(0),
+				       lock->owner_cpu,lock->owner_pc);
+				stuck = INIT_STUCK;
+				/* steal the lock */
+				/*xchg_u32((void *)&lock->lock,0);*/
+			}
+		}
+	}
+	lock->owner_pc = (unsigned long)__builtin_return_address(0);
+	lock->owner_cpu = cpu;
+}
+
+int spin_trylock(spinlock_t *lock)
+{
+	if (!__spin_trylock(lock))
+		return 0;
+	lock->owner_cpu = smp_processor_id(); 
+	lock->owner_pc = (unsigned long)__builtin_return_address(0);
+	return 1;
+}
+
+void spin_unlock(spinlock_t *lp)
+{
+  	if ( lp->lock )
+		printk("spin_unlock(%p): no lock cpu %d curr PC %p %s/%d\n",
+		       lp, smp_processor_id(), __builtin_return_address(0),
+		       current->comm, current->pid);
+	if ( lp->owner_cpu != smp_processor_id() )
+		printk("spin_unlock(%p): cpu %d trying clear of cpu %d pc %lx val %x\n",
+		      lp, smp_processor_id(), (int)lp->owner_cpu,
+		      lp->owner_pc,lp->lock);
+	lp->owner_pc = lp->owner_cpu = 0;
+	wmb();
+	lp->lock = 1;
+}
+
+#endif