patch-2.3.5 linux/include/asm-i386/softirq.h

• Lines: 84
• Date: Wed Jun 2 13:54:53 1999
• Orig file: v2.3.4/linux/include/asm-i386/softirq.h
• Orig date: Mon May 31 22:28:06 1999

diff -u --recursive --new-file v2.3.4/linux/include/asm-i386/softirq.h linux/include/asm-i386/softirq.h
@@ -6,6 +6,15 @@
 
 extern unsigned int local_bh_count[NR_CPUS];
 
+#define cpu_bh_disable(cpu)	do { local_bh_count[(cpu)]++; barrier(); } while (0)
+#define cpu_bh_enable(cpu)	do { barrier(); local_bh_count[(cpu)]--; } while (0)
+
+#define cpu_bh_trylock(cpu)	(local_bh_count[(cpu)] ? 0 : (local_bh_count[(cpu)] = 1))
+#define cpu_bh_endlock(cpu)	(local_bh_count[(cpu)] = 0)
+
+#define local_bh_disable()	cpu_bh_disable(smp_processor_id())
+#define local_bh_enable()	cpu_bh_enable(smp_processor_id())
+
 #define get_active_bhs()	(bh_mask & bh_active)
 #define clear_active_bhs(x)	atomic_clear_mask((x),&bh_active)
 
@@ -40,13 +49,6 @@
 
 extern void synchronize_bh(void);
 
-/*
- * This is suboptimal. We only need to disable bh's locally
- * on this CPU...
- */
-#define local_bh_disable()	atomic_inc(&global_bh_lock)
-#define local_bh_enable()	atomic_dec(&global_bh_lock)
-
 static inline void start_bh_atomic(void)
 {
 	atomic_inc(&global_bh_lock);
@@ -61,19 +63,20 @@
 /* These are for the IRQs testing the lock */
 static inline int softirq_trylock(int cpu)
 {
-	if (!test_and_set_bit(0,&global_bh_count)) {
-		if (atomic_read(&global_bh_lock) == 0) {
-			++local_bh_count[cpu];
-			return 1;
+	if (cpu_bh_trylock(cpu)) {
+		if (!test_and_set_bit(0,&global_bh_count)) {
+			if (atomic_read(&global_bh_lock) == 0)
+				return 1;
+			clear_bit(0,&global_bh_count);
 		}
-		clear_bit(0,&global_bh_count);
+		cpu_bh_endlock(cpu);
 	}
 	return 0;
 }
 
 static inline void softirq_endlock(int cpu)
 {
-	local_bh_count[cpu]--;
+	cpu_bh_enable(cpu);
 	clear_bit(0,&global_bh_count);
 }
 
@@ -81,22 +84,19 @@
 
 extern inline void start_bh_atomic(void)
 {
-	local_bh_count[smp_processor_id()]++;
+	local_bh_disable();
 	barrier();
 }
 
 extern inline void end_bh_atomic(void)
 {
 	barrier();
-	local_bh_count[smp_processor_id()]--;
+	local_bh_enable();
 }
 
-#define local_bh_disable()	(local_bh_count[smp_processor_id()]++)
-#define local_bh_enable()	(local_bh_count[smp_processor_id()]--)
-
 /* These are for the irq's testing the lock */
-#define softirq_trylock(cpu)	(local_bh_count[cpu] ? 0 : (local_bh_count[cpu]=1))
-#define softirq_endlock(cpu)	(local_bh_count[cpu] = 0)
+#define softirq_trylock(cpu)	(cpu_bh_trylock(cpu))
+#define softirq_endlock(cpu)	(cpu_bh_endlock(cpu))
 #define synchronize_bh()	barrier()
 
 #endif	/* SMP */