fedora core 6 1.2949 + vserver 2.2.0

[linux-2.6.git] / include / linux / hardirq.h

diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h
index 7e1aad3..612472a 100644 (file)
--- a/include/linux/hardirq.h
+++ b/include/linux/hardirq.h
@@ -1,20 +1,65 @@
 #ifndef LINUX_HARDIRQ_H
 #define LINUX_HARDIRQ_H
 
-#include <linux/config.h>
+#include <linux/preempt.h>
 #include <linux/smp_lock.h>
+#include <linux/lockdep.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
+
+#ifndef MAX_HARDIRQS_PER_CPU
+#define MAX_HARDIRQS_PER_CPU NR_IRQS
+#endif
+
+/*
+ * 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) < MAX_HARDIRQS_PER_CPU
+# 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 HARDIRQ_MASK   (__IRQ_MASK(HARDIRQ_BITS) << HARDIRQ_SHIFT)
 
 #define PREEMPT_OFFSET (1UL << PREEMPT_SHIFT)
 #define SOFTIRQ_OFFSET (1UL << SOFTIRQ_SHIFT)
 #define HARDIRQ_OFFSET (1UL << HARDIRQ_SHIFT)
 
+#if PREEMPT_ACTIVE < (1 << (HARDIRQ_SHIFT + HARDIRQ_BITS))
+#error PREEMPT_ACTIVE is too low!
+#endif
+
 #define hardirq_count()        (preempt_count() & HARDIRQ_MASK)
 #define softirq_count()        (preempt_count() & SOFTIRQ_MASK)
 #define irq_count()    (preempt_count() & (HARDIRQ_MASK | SOFTIRQ_MASK))
@@ -27,12 +72,16 @@
 #define in_softirq()           (softirq_count())
 #define in_interrupt()         (irq_count())
 
-#ifdef CONFIG_PREEMPT
+#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 in_atomic()   (preempt_count() != 0)
 # define preemptible() 0
 # define IRQ_EXIT_OFFSET HARDIRQ_OFFSET
 #endif
@@ -43,4 +92,43 @@ extern void synchronize_irq(unsigned int irq);
 # define synchronize_irq(irq)  barrier()
 #endif
 
+struct task_struct;
+
+#ifndef CONFIG_VIRT_CPU_ACCOUNTING
+static inline void account_system_vtime(struct task_struct *tsk)
+{
+}
+#endif
+
+/*
+ * It is safe to do non-atomic ops on ->hardirq_context,
+ * because NMI handlers may not preempt and the ops are
+ * always balanced, so the interrupted value of ->hardirq_context
+ * will always be restored.
+ */
+#define irq_enter()                                    \
+       do {                                            \
+               account_system_vtime(current);          \
+               add_preempt_count(HARDIRQ_OFFSET);      \
+               trace_hardirq_enter();                  \
+       } while (0)
+
+/*
+ * Exit irq context without processing softirqs:
+ */
+#define __irq_exit()                                   \
+       do {                                            \
+               trace_hardirq_exit();                   \
+               account_system_vtime(current);          \
+               sub_preempt_count(HARDIRQ_OFFSET);      \
+       } while (0)
+
+/*
+ * Exit irq context and process softirqs if needed:
+ */
+extern void irq_exit(void);
+
+#define nmi_enter()            do { lockdep_off(); irq_enter(); } while (0)
+#define nmi_exit()             do { __irq_exit(); lockdep_on(); } while (0)
+
 #endif /* LINUX_HARDIRQ_H */