Merge with Linux 2.4.0-test9. Please check DECstation, I had a number

of rejects to fixup while integrating Linus patches.  I also found
that this kernel will only boot SMP on Origin; the UP kernel freeze
soon after bootup with SCSI timeout messages.  I commit this anyway
since I found that the last CVS versions had the same problem.

1 files changed, 41 insertions, 35 deletions

diff --git a/include/asm-sparc/hardirq.h b/include/asm-sparc/hardirq.h
index cfee071dc..00205d6ef 100644
--- a/include/asm-sparc/hardirq.h
+++ b/include/asm-sparc/hardirq.h
@@ -1,7 +1,7 @@
 /* hardirq.h: 32-bit Sparc hard IRQ support.
  *
  * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
- * Copyright (C) 1998-99 Anton Blanchard (anton@progsoc.uts.edu.au)
+ * Copyright (C) 1998-2000 Anton Blanchard (anton@linuxcare.com)
  */
 
 #ifndef __SPARC_HARDIRQ_H
@@ -9,77 +9,83 @@
 
 #include <linux/config.h>
 #include <linux/threads.h>
+#include <linux/brlock.h>
+#include <linux/spinlock.h>
 
 /* entry.S is sensitive to the offsets of these fields */
 typedef struct {
 	unsigned int __softirq_active;
 	unsigned int __softirq_mask;
+#ifndef CONFIG_SMP
 	unsigned int __local_irq_count;
+#else
+	unsigned int __unused_on_SMP;	/* DaveM says use brlock for SMP irq. KAO */
+#endif
 	unsigned int __local_bh_count;
 	unsigned int __syscall_count;
 } ____cacheline_aligned irq_cpustat_t;
 
 #include <linux/irq_cpustat.h>	/* Standard mappings for irq_cpustat_t above */
+/* Note that local_irq_count() is replaced by sparc64 specific version for SMP */
+
+#ifndef CONFIG_SMP
+#define irq_enter(cpu, irq)	((void)(irq), local_irq_count(cpu)++)
+#define irq_exit(cpu, irq)	((void)(irq), local_irq_count(cpu)--)
+#else
+#undef local_irq_count
+#define local_irq_count(cpu)	(__brlock_array[cpu][BR_GLOBALIRQ_LOCK])
+#define irq_enter(cpu, irq)	br_read_lock(BR_GLOBALIRQ_LOCK)
+#define irq_exit(cpu, irq)	br_read_unlock(BR_GLOBALIRQ_LOCK)
+#endif
 
 /*
  * Are we in an interrupt context? Either doing bottom half
  * or hardware interrupt processing?
  */
-#define in_interrupt() ({ int __cpu = smp_processor_id(); \
-	(local_irq_count(__cpu) + local_bh_count(__cpu) != 0); })
+#define in_interrupt() ((local_irq_count(smp_processor_id()) + \
+		         local_bh_count(smp_processor_id())) != 0)
 
-#define in_irq() ({ int __cpu = smp_processor_id(); \
-	(local_irq_count(__cpu) != 0); })
+/* This tests only the local processors hw IRQ context disposition.  */
+#define in_irq() (local_irq_count(smp_processor_id()) != 0)
 
 #ifndef CONFIG_SMP
 
-#define hardirq_trylock(cpu)	(local_irq_count(cpu) == 0)
-#define hardirq_endlock(cpu)	do { (void)(cpu); } while (0)
-
-#define hardirq_enter(cpu)	(++local_irq_count(cpu))
-#define hardirq_exit(cpu)	(--local_irq_count(cpu))
+#define hardirq_trylock(cpu)	((void)(cpu), local_irq_count(smp_processor_id()) == 0)
+#define hardirq_endlock(cpu)	do { (void)(cpu); } while(0)
 
 #define synchronize_irq()	barrier()
 
-#else
+#else /* (CONFIG_SMP) */
 
-#include <asm/atomic.h>
-#include <linux/spinlock.h>
-#include <asm/system.h>
-#include <asm/smp.h>
+static __inline__ int irqs_running(void)
+{
+	int i;
+
+	for (i = 0; i < smp_num_cpus; i++)
+		if (local_irq_count(cpu_logical_map(i)))
+			return 1;
+	return 0;
+}
 
 extern unsigned char global_irq_holder;
-extern spinlock_t global_irq_lock;
-extern atomic_t global_irq_count;
 
 static inline void release_irqlock(int cpu)
 {
-	/* if we didn't own the irq lock, just ignore.. */
-	if (global_irq_holder == (unsigned char) cpu) {
+	/* if we didn't own the irq lock, just ignore... */
+	if(global_irq_holder == (unsigned char) cpu) {
 		global_irq_holder = NO_PROC_ID;
-		spin_unlock(&global_irq_lock);
+		br_write_unlock(BR_GLOBALIRQ_LOCK);
 	}
 }
 
-static inline void hardirq_enter(int cpu)
-{
-	++local_irq_count(cpu);
-	atomic_inc(&global_irq_count);
-}
-
-static inline void hardirq_exit(int cpu)
-{
-	atomic_dec(&global_irq_count);
-	--local_irq_count(cpu);
-}
-
 static inline int hardirq_trylock(int cpu)
 {
-	return (! atomic_read(&global_irq_count) &&
-		! spin_is_locked (&global_irq_lock));
+	spinlock_t *lock = &__br_write_locks[BR_GLOBALIRQ_LOCK].lock;
+
+	return (!local_irq_count(cpu) && !spin_is_locked(lock));
 }
 
-#define hardirq_endlock(cpu)	do { } while (0)
+#define hardirq_endlock(cpu)	do { (void)(cpu); } while (0)
 
 extern void synchronize_irq(void);