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authorSrikant Patnaik2015-01-11 12:28:04 +0530
committerSrikant Patnaik2015-01-11 12:28:04 +0530
commit871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch)
tree8718f573808810c2a1e8cb8fb6ac469093ca2784 /include/linux/hardirq.h
parent9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff)
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Moved, renamed, and deleted files
The original directory structure was scattered and unorganized. Changes are basically to make it look like kernel structure.
Diffstat (limited to 'include/linux/hardirq.h')
-rw-r--r--include/linux/hardirq.h210
1 files changed, 210 insertions, 0 deletions
diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h
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--- /dev/null
+++ b/include/linux/hardirq.h
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+#ifndef LINUX_HARDIRQ_H
+#define LINUX_HARDIRQ_H
+
+#include <linux/preempt.h>
+#include <linux/lockdep.h>
+#include <linux/ftrace_irq.h>
+#include <asm/hardirq.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 in theory reach the same as NR_IRQS.
+ * In reality, the number of nested IRQS is limited to the stack
+ * size as well. For archs with over 1000 IRQS it is not practical
+ * to expect that they will all nest. We give a max of 10 bits for
+ * hardirq nesting. An arch may choose to give less than 10 bits.
+ * m68k expects it to be 8.
+ *
+ * - bits 16-25 are the hardirq count (max # of nested hardirqs: 1024)
+ * - bit 26 is the NMI_MASK
+ * - bit 28 is the PREEMPT_ACTIVE flag
+ *
+ * PREEMPT_MASK: 0x000000ff
+ * SOFTIRQ_MASK: 0x0000ff00
+ * HARDIRQ_MASK: 0x03ff0000
+ * NMI_MASK: 0x04000000
+ */
+#define PREEMPT_BITS 8
+#define SOFTIRQ_BITS 8
+#define NMI_BITS 1
+
+#define MAX_HARDIRQ_BITS 10
+
+#ifndef HARDIRQ_BITS
+# define HARDIRQ_BITS MAX_HARDIRQ_BITS
+#endif
+
+#if HARDIRQ_BITS > MAX_HARDIRQ_BITS
+#error HARDIRQ_BITS too high!
+#endif
+
+#define PREEMPT_SHIFT 0
+#define SOFTIRQ_SHIFT (PREEMPT_SHIFT + PREEMPT_BITS)
+#define HARDIRQ_SHIFT (SOFTIRQ_SHIFT + SOFTIRQ_BITS)
+#define NMI_SHIFT (HARDIRQ_SHIFT + HARDIRQ_BITS)
+
+#define __IRQ_MASK(x) ((1UL << (x))-1)
+
+#define PREEMPT_MASK (__IRQ_MASK(PREEMPT_BITS) << PREEMPT_SHIFT)
+#define SOFTIRQ_MASK (__IRQ_MASK(SOFTIRQ_BITS) << SOFTIRQ_SHIFT)
+#define HARDIRQ_MASK (__IRQ_MASK(HARDIRQ_BITS) << HARDIRQ_SHIFT)
+#define NMI_MASK (__IRQ_MASK(NMI_BITS) << NMI_SHIFT)
+
+#define PREEMPT_OFFSET (1UL << PREEMPT_SHIFT)
+#define SOFTIRQ_OFFSET (1UL << SOFTIRQ_SHIFT)
+#define HARDIRQ_OFFSET (1UL << HARDIRQ_SHIFT)
+#define NMI_OFFSET (1UL << NMI_SHIFT)
+
+#define SOFTIRQ_DISABLE_OFFSET (2 * SOFTIRQ_OFFSET)
+
+#ifndef PREEMPT_ACTIVE
+#define PREEMPT_ACTIVE_BITS 1
+#define PREEMPT_ACTIVE_SHIFT (NMI_SHIFT + NMI_BITS)
+#define PREEMPT_ACTIVE (__IRQ_MASK(PREEMPT_ACTIVE_BITS) << PREEMPT_ACTIVE_SHIFT)
+#endif
+
+#if PREEMPT_ACTIVE < (1 << (NMI_SHIFT + NMI_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 \
+ | NMI_MASK))
+
+/*
+ * Are we doing bottom half or hardware interrupt processing?
+ * Are we in a softirq context? Interrupt context?
+ * in_softirq - Are we currently processing softirq or have bh disabled?
+ * in_serving_softirq - Are we currently processing softirq?
+ */
+#define in_irq() (hardirq_count())
+#define in_softirq() (softirq_count())
+#define in_interrupt() (irq_count())
+#define in_serving_softirq() (softirq_count() & SOFTIRQ_OFFSET)
+
+/*
+ * Are we in NMI context?
+ */
+#define in_nmi() (preempt_count() & NMI_MASK)
+
+#if defined(CONFIG_PREEMPT_COUNT)
+# define PREEMPT_CHECK_OFFSET 1
+#else
+# define PREEMPT_CHECK_OFFSET 0
+#endif
+
+/*
+ * Are we running in atomic context? WARNING: this macro cannot
+ * always detect atomic context; in particular, it cannot know about
+ * held spinlocks in non-preemptible kernels. Thus it should not be
+ * used in the general case to determine whether sleeping is possible.
+ * Do not use in_atomic() in driver code.
+ */
+#define in_atomic() ((preempt_count() & ~PREEMPT_ACTIVE) != 0)
+
+/*
+ * Check whether we were atomic before we did preempt_disable():
+ * (used by the scheduler, *after* releasing the kernel lock)
+ */
+#define in_atomic_preempt_off() \
+ ((preempt_count() & ~PREEMPT_ACTIVE) != PREEMPT_CHECK_OFFSET)
+
+#ifdef CONFIG_PREEMPT_COUNT
+# 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
+
+#if defined(CONFIG_SMP) || defined(CONFIG_GENERIC_HARDIRQS)
+extern void synchronize_irq(unsigned int irq);
+#else
+# define synchronize_irq(irq) barrier()
+#endif
+
+struct task_struct;
+
+#if !defined(CONFIG_VIRT_CPU_ACCOUNTING) && !defined(CONFIG_IRQ_TIME_ACCOUNTING)
+static inline void account_system_vtime(struct task_struct *tsk)
+{
+}
+#else
+extern void account_system_vtime(struct task_struct *tsk);
+#endif
+
+#if defined(CONFIG_TINY_RCU) || defined(CONFIG_TINY_PREEMPT_RCU)
+
+static inline void rcu_nmi_enter(void)
+{
+}
+
+static inline void rcu_nmi_exit(void)
+{
+}
+
+#else
+extern void rcu_nmi_enter(void);
+extern void rcu_nmi_exit(void);
+#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)
+
+/*
+ * Enter irq context (on NO_HZ, update jiffies):
+ */
+extern void irq_enter(void);
+
+/*
+ * 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 { \
+ ftrace_nmi_enter(); \
+ BUG_ON(in_nmi()); \
+ add_preempt_count(NMI_OFFSET + HARDIRQ_OFFSET); \
+ lockdep_off(); \
+ rcu_nmi_enter(); \
+ trace_hardirq_enter(); \
+ } while (0)
+
+#define nmi_exit() \
+ do { \
+ trace_hardirq_exit(); \
+ rcu_nmi_exit(); \
+ lockdep_on(); \
+ BUG_ON(!in_nmi()); \
+ sub_preempt_count(NMI_OFFSET + HARDIRQ_OFFSET); \
+ ftrace_nmi_exit(); \
+ } while (0)
+
+#endif /* LINUX_HARDIRQ_H */