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@@ -0,0 +1,98 @@
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+#ifndef __ASM_PREEMPT_H
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+#define __ASM_PREEMPT_H
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+
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+#include <asm/rmwcc.h>
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+#include <asm/percpu.h>
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+#include <linux/thread_info.h>
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+
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+DECLARE_PER_CPU(int, __preempt_count);
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+
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+/*
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+ * We mask the PREEMPT_NEED_RESCHED bit so as not to confuse all current users
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+ * that think a non-zero value indicates we cannot preempt.
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+ */
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+static __always_inline int preempt_count(void)
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+{
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+ return __this_cpu_read_4(__preempt_count) & ~PREEMPT_NEED_RESCHED;
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+}
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+
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+static __always_inline void preempt_count_set(int pc)
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+{
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+ __this_cpu_write_4(__preempt_count, pc);
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+}
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+
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+/*
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+ * must be macros to avoid header recursion hell
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+ */
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+#define task_preempt_count(p) \
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+ (task_thread_info(p)->saved_preempt_count & ~PREEMPT_NEED_RESCHED)
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+
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+#define init_task_preempt_count(p) do { \
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+ task_thread_info(p)->saved_preempt_count = PREEMPT_DISABLED; \
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+} while (0)
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+
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+#define init_idle_preempt_count(p, cpu) do { \
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+ task_thread_info(p)->saved_preempt_count = PREEMPT_ENABLED; \
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+ per_cpu(__preempt_count, (cpu)) = PREEMPT_ENABLED; \
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+} while (0)
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+
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+/*
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+ * We fold the NEED_RESCHED bit into the preempt count such that
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+ * preempt_enable() can decrement and test for needing to reschedule with a
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+ * single instruction.
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+ *
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+ * We invert the actual bit, so that when the decrement hits 0 we know we both
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+ * need to resched (the bit is cleared) and can resched (no preempt count).
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+ */
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+
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+static __always_inline void set_preempt_need_resched(void)
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+{
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+ __this_cpu_and_4(__preempt_count, ~PREEMPT_NEED_RESCHED);
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+}
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+
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+static __always_inline void clear_preempt_need_resched(void)
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+{
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+ __this_cpu_or_4(__preempt_count, PREEMPT_NEED_RESCHED);
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+}
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+
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+static __always_inline bool test_preempt_need_resched(void)
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+{
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+ return !(__this_cpu_read_4(__preempt_count) & PREEMPT_NEED_RESCHED);
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+}
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+
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+/*
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+ * The various preempt_count add/sub methods
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+ */
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+
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+static __always_inline void __preempt_count_add(int val)
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+{
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+ __this_cpu_add_4(__preempt_count, val);
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+}
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+
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+static __always_inline void __preempt_count_sub(int val)
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+{
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+ __this_cpu_add_4(__preempt_count, -val);
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+}
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+
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+static __always_inline bool __preempt_count_dec_and_test(void)
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+{
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+ GEN_UNARY_RMWcc("decl", __preempt_count, __percpu_arg(0), "e");
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+}
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+
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+/*
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+ * Returns true when we need to resched -- even if we can not.
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+ */
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+static __always_inline bool need_resched(void)
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+{
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+ return unlikely(test_preempt_need_resched());
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+}
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+
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+/*
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+ * Returns true when we need to resched and can (barring IRQ state).
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+ */
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+static __always_inline bool should_resched(void)
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+{
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+ return unlikely(!__this_cpu_read_4(__preempt_count));
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+}
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+
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+#endif /* __ASM_PREEMPT_H */
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