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-rw-r--r--include/linux/preempt.h62
1 files changed, 62 insertions, 0 deletions
diff --git a/include/linux/preempt.h b/include/linux/preempt.h
new file mode 100644
index 0000000..dd98c54
--- /dev/null
+++ b/include/linux/preempt.h
@@ -0,0 +1,62 @@
+#ifndef __LINUX_PREEMPT_H
+#define __LINUX_PREEMPT_H
+
+/*
+ * include/linux/preempt.h - macros for accessing and manipulating
+ * preempt_count (used for kernel preemption, interrupt count, etc.)
+ */
+
+#include <linux/config.h>
+#include <linux/linkage.h>
+
+#ifdef CONFIG_DEBUG_PREEMPT
+ extern void fastcall add_preempt_count(int val);
+ extern void fastcall sub_preempt_count(int val);
+#else
+# define add_preempt_count(val) do { preempt_count() += (val); } while (0)
+# define sub_preempt_count(val) do { preempt_count() -= (val); } while (0)
+#endif
+
+#define inc_preempt_count() add_preempt_count(1)
+#define dec_preempt_count() sub_preempt_count(1)
+
+#define preempt_count() (current_thread_info()->preempt_count)
+
+#ifdef CONFIG_PREEMPT
+
+asmlinkage void preempt_schedule(void);
+
+#define preempt_disable() \
+do { \
+ inc_preempt_count(); \
+ barrier(); \
+} while (0)
+
+#define preempt_enable_no_resched() \
+do { \
+ barrier(); \
+ dec_preempt_count(); \
+} while (0)
+
+#define preempt_check_resched() \
+do { \
+ if (unlikely(test_thread_flag(TIF_NEED_RESCHED))) \
+ preempt_schedule(); \
+} while (0)
+
+#define preempt_enable() \
+do { \
+ preempt_enable_no_resched(); \
+ preempt_check_resched(); \
+} while (0)
+
+#else
+
+#define preempt_disable() do { } while (0)
+#define preempt_enable_no_resched() do { } while (0)
+#define preempt_enable() do { } while (0)
+#define preempt_check_resched() do { } while (0)
+
+#endif
+
+#endif /* __LINUX_PREEMPT_H */
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