Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

include/linux/hardirq.h

@@ -0,0 +1,106 @@
+#ifndef LINUX_HARDIRQ_H
+#define LINUX_HARDIRQ_H
+
+#include <linux/config.h>
+#include <linux/smp_lock.h>
+#include <asm/hardirq.h>
+#include <asm/system.h>
+
+/*
+ * We put the hardirq and softirq counter into the preemption
+ * counter. The bitmask has the following meaning:
+ *
+ * - bits 0-7 are the preemption count (max preemption depth: 256)
+ * - bits 8-15 are the softirq count (max # of softirqs: 256)
+ *
+ * The hardirq count can be overridden per architecture, the default is:
+ *
+ * - bits 16-27 are the hardirq count (max # of hardirqs: 4096)
+ * - ( bit 28 is the PREEMPT_ACTIVE flag. )
+ *
+ * PREEMPT_MASK: 0x000000ff
+ * SOFTIRQ_MASK: 0x0000ff00
+ * HARDIRQ_MASK: 0x0fff0000
+ */
+#define PREEMPT_BITS	8
+#define SOFTIRQ_BITS	8
+
+#ifndef HARDIRQ_BITS
+#define HARDIRQ_BITS	12
+/*
+ * The hardirq mask has to be large enough to have space for potentially
+ * all IRQ sources in the system nesting on a single CPU.
+ */
+#if (1 << HARDIRQ_BITS) < NR_IRQS
+# error HARDIRQ_BITS is too low!
+#endif
+#endif
+
+#define PREEMPT_SHIFT	0
+#define SOFTIRQ_SHIFT	(PREEMPT_SHIFT + PREEMPT_BITS)
+#define HARDIRQ_SHIFT	(SOFTIRQ_SHIFT + SOFTIRQ_BITS)
+
+#define __IRQ_MASK(x)	((1UL << (x))-1)
+
+#define PREEMPT_MASK	(__IRQ_MASK(PREEMPT_BITS) << PREEMPT_SHIFT)
+#define HARDIRQ_MASK	(__IRQ_MASK(HARDIRQ_BITS) << HARDIRQ_SHIFT)
+#define SOFTIRQ_MASK	(__IRQ_MASK(SOFTIRQ_BITS) << SOFTIRQ_SHIFT)
+
+#define PREEMPT_OFFSET	(1UL << PREEMPT_SHIFT)
+#define SOFTIRQ_OFFSET	(1UL << SOFTIRQ_SHIFT)
+#define HARDIRQ_OFFSET	(1UL << HARDIRQ_SHIFT)
+
+#define hardirq_count()	(preempt_count() & HARDIRQ_MASK)
+#define softirq_count()	(preempt_count() & SOFTIRQ_MASK)
+#define irq_count()	(preempt_count() & (HARDIRQ_MASK | SOFTIRQ_MASK))
+
+/*
+ * Are we doing bottom half or hardware interrupt processing?
+ * Are we in a softirq context? Interrupt context?
+ */
+#define in_irq()		(hardirq_count())
+#define in_softirq()		(softirq_count())
+#define in_interrupt()		(irq_count())
+
+#if defined(CONFIG_PREEMPT) && !defined(CONFIG_PREEMPT_BKL)
+# define in_atomic()	((preempt_count() & ~PREEMPT_ACTIVE) != kernel_locked())
+#else
+# define in_atomic()	((preempt_count() & ~PREEMPT_ACTIVE) != 0)
+#endif
+
+#ifdef CONFIG_PREEMPT
+# define preemptible()	(preempt_count() == 0 && !irqs_disabled())
+# define IRQ_EXIT_OFFSET (HARDIRQ_OFFSET-1)
+#else
+# define preemptible()	0
+# define IRQ_EXIT_OFFSET HARDIRQ_OFFSET
+#endif
+
+#ifdef CONFIG_SMP
+extern void synchronize_irq(unsigned int irq);
+#else
+# define synchronize_irq(irq)	barrier()
+#endif
+
+#define nmi_enter()		irq_enter()
+#define nmi_exit()		sub_preempt_count(HARDIRQ_OFFSET)
+
+#ifndef CONFIG_VIRT_CPU_ACCOUNTING
+static inline void account_user_vtime(struct task_struct *tsk)
+{
+}
+
+static inline void account_system_vtime(struct task_struct *tsk)
+{
+}
+#endif
+
+#define irq_enter()					\
+	do {						\
+		account_system_vtime(current);		\
+		add_preempt_count(HARDIRQ_OFFSET);	\
+	} while (0)
+
+extern void irq_exit(void);
+
+#endif /* LINUX_HARDIRQ_H */