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-rw-r--r--kernel/include/asm-generic/preempt.h89
1 files changed, 89 insertions, 0 deletions
diff --git a/kernel/include/asm-generic/preempt.h b/kernel/include/asm-generic/preempt.h
new file mode 100644
index 000000000..eb6f9e6c3
--- /dev/null
+++ b/kernel/include/asm-generic/preempt.h
@@ -0,0 +1,89 @@
+#ifndef __ASM_PREEMPT_H
+#define __ASM_PREEMPT_H
+
+#include <linux/thread_info.h>
+
+#define PREEMPT_ENABLED (0)
+
+static __always_inline int preempt_count(void)
+{
+ return current_thread_info()->preempt_count;
+}
+
+static __always_inline int *preempt_count_ptr(void)
+{
+ return &current_thread_info()->preempt_count;
+}
+
+static __always_inline void preempt_count_set(int pc)
+{
+ *preempt_count_ptr() = pc;
+}
+
+/*
+ * must be macros to avoid header recursion hell
+ */
+#define init_task_preempt_count(p) do { \
+ task_thread_info(p)->preempt_count = PREEMPT_DISABLED; \
+} while (0)
+
+#define init_idle_preempt_count(p, cpu) do { \
+ task_thread_info(p)->preempt_count = PREEMPT_ENABLED; \
+} while (0)
+
+static __always_inline void set_preempt_need_resched(void)
+{
+}
+
+static __always_inline void clear_preempt_need_resched(void)
+{
+}
+
+static __always_inline bool test_preempt_need_resched(void)
+{
+ return false;
+}
+
+/*
+ * The various preempt_count add/sub methods
+ */
+
+static __always_inline void __preempt_count_add(int val)
+{
+ *preempt_count_ptr() += val;
+}
+
+static __always_inline void __preempt_count_sub(int val)
+{
+ *preempt_count_ptr() -= val;
+}
+
+static __always_inline bool __preempt_count_dec_and_test(void)
+{
+ /*
+ * Because of load-store architectures cannot do per-cpu atomic
+ * operations; we cannot use PREEMPT_NEED_RESCHED because it might get
+ * lost.
+ */
+ return !--*preempt_count_ptr() && tif_need_resched();
+}
+
+/*
+ * Returns true when we need to resched and can (barring IRQ state).
+ */
+static __always_inline bool should_resched(void)
+{
+ return unlikely(!preempt_count() && tif_need_resched());
+}
+
+#ifdef CONFIG_PREEMPT
+extern asmlinkage void preempt_schedule(void);
+#define __preempt_schedule() preempt_schedule()
+
+#ifdef CONFIG_CONTEXT_TRACKING
+extern asmlinkage void preempt_schedule_context(void);
+#define __preempt_schedule_context() preempt_schedule_context()
+#endif
+#endif /* CONFIG_PREEMPT */
+
+#endif /* __ASM_PREEMPT_H */