patch-2.1.34 linux/include/asm-sparc/hardirq.h

• Lines: 73
• Date: Mon Apr 14 09:31:09 1997
• Orig file: v2.1.33/linux/include/asm-sparc/hardirq.h
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.1.33/linux/include/asm-sparc/hardirq.h linux/include/asm-sparc/hardirq.h
@@ -0,0 +1,72 @@
+/* hardirq.h: 32-bit Sparc hard IRQ support.
+ *
+ * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
+ */
+
+#ifndef __SPARC_HARDIRQ_H
+#define __SPARC_HARDIRQ_H
+
+#include <linux/tasks.h>
+
+extern unsigned int local_irq_count[NR_CPUS];
+#define in_interrupt()	(local_irq_count[smp_processor_id()] != 0)
+#define hardirq_depth()	(local_irq_count[smp_processor_id()])
+
+#ifndef __SMP__
+
+#define hardirq_trylock(cpu)	(++local_irq_count[cpu], (cpu)==0)
+#define hardirq_endlock(cpu)	(--local_irq_count[cpu])
+
+#define hardirq_enter(cpu)	(local_irq_count[cpu]++)
+#define hardirq_exit(cpu)	(local_irq_count[cpu]--)
+
+#define synchronize_irq()	do { } while(0)
+
+#else /* __SMP__ */
+
+#include <asm/atomic.h>
+#include <asm/spinlock.h>
+#include <asm/system.h>
+#include <asm/smp.h>
+
+extern unsigned char global_irq_holder;
+extern spinlock_t global_irq_lock;
+extern atomic_t global_irq_count;
+
+#define release_irqlock(cpu)				\
+do {	if(global_irq_holder == (unsigned char) cpu) {	\
+		global_irq_holder = NO_PROC_ID;		\
+		spin_unlock(&global_irq_lock);		\
+	}						\
+} while(0)
+
+/* Ordering of the counter bumps is _deadly_ important. */
+#define hardirq_enter(cpu) \
+	do { ++local_irq_count[cpu]; atomic_inc(&global_irq_count); } while(0)
+
+#define hardirq_exit(cpu) \
+	do { atomic_dec(&global_irq_count); --local_irq_count[cpu]; } while(0)
+
+#define hardirq_trylock(cpu)					\
+({	unsigned long flags; int ret = 1;			\
+	__save_flags(flags);					\
+	__cli();						\
+	if(atomic_add_return(1, &global_irq_count) != 1 ||	\
+	   global_irq_lock) {					\
+		atomic_dec(&global_irq_count);			\
+		__restore_flags(flags);				\
+		ret = 0;					\
+	} else {						\
+		++local_irq_count[cpu];				\
+		__sti();					\
+	}							\
+	ret;							\
+})
+
+#define hardirq_endlock(cpu) do { __cli(); hardirq_exit(cpu); __sti(); } while(0)
+
+extern void synchronize_irq(void);
+
+#endif /* __SMP__ */
+
+#endif /* __SPARC_HARDIRQ_H */