Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / include / linux / proportions.h

diff --git a/kernel/include/linux/proportions.h b/kernel/include/linux/proportions.h
new file mode 100644 (file)
index 0000000..00e8e8f
--- /dev/null
+++ b/kernel/include/linux/proportions.h
@@ -0,0 +1,137 @@
+/*
+ * FLoating proportions
+ *
+ *  Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
+ *
+ * This file contains the public data structure and API definitions.
+ */
+
+#ifndef _LINUX_PROPORTIONS_H
+#define _LINUX_PROPORTIONS_H
+
+#include <linux/percpu_counter.h>
+#include <linux/spinlock.h>
+#include <linux/mutex.h>
+#include <linux/gfp.h>
+
+struct prop_global {
+       /*
+        * The period over which we differentiate
+        *
+        *   period = 2^shift
+        */
+       int shift;
+       /*
+        * The total event counter aka 'time'.
+        *
+        * Treated as an unsigned long; the lower 'shift - 1' bits are the
+        * counter bits, the remaining upper bits the period counter.
+        */
+       struct percpu_counter events;
+};
+
+/*
+ * global proportion descriptor
+ *
+ * this is needed to consitently flip prop_global structures.
+ */
+struct prop_descriptor {
+       int index;
+       struct prop_global pg[2];
+       struct mutex mutex;             /* serialize the prop_global switch */
+};
+
+int prop_descriptor_init(struct prop_descriptor *pd, int shift, gfp_t gfp);
+void prop_change_shift(struct prop_descriptor *pd, int new_shift);
+
+/*
+ * ----- PERCPU ------
+ */
+
+struct prop_local_percpu {
+       /*
+        * the local events counter
+        */
+       struct percpu_counter events;
+
+       /*
+        * snapshot of the last seen global state
+        */
+       int shift;
+       unsigned long period;
+       raw_spinlock_t lock;            /* protect the snapshot state */
+};
+
+int prop_local_init_percpu(struct prop_local_percpu *pl, gfp_t gfp);
+void prop_local_destroy_percpu(struct prop_local_percpu *pl);
+void __prop_inc_percpu(struct prop_descriptor *pd, struct prop_local_percpu *pl);
+void prop_fraction_percpu(struct prop_descriptor *pd, struct prop_local_percpu *pl,
+               long *numerator, long *denominator);
+
+static inline
+void prop_inc_percpu(struct prop_descriptor *pd, struct prop_local_percpu *pl)
+{
+       unsigned long flags;
+
+       local_irq_save(flags);
+       __prop_inc_percpu(pd, pl);
+       local_irq_restore(flags);
+}
+
+/*
+ * Limit the time part in order to ensure there are some bits left for the
+ * cycle counter and fraction multiply.
+ */
+#if BITS_PER_LONG == 32
+#define PROP_MAX_SHIFT (3*BITS_PER_LONG/4)
+#else
+#define PROP_MAX_SHIFT (BITS_PER_LONG/2)
+#endif
+
+#define PROP_FRAC_SHIFT                (BITS_PER_LONG - PROP_MAX_SHIFT - 1)
+#define PROP_FRAC_BASE         (1UL << PROP_FRAC_SHIFT)
+
+void __prop_inc_percpu_max(struct prop_descriptor *pd,
+                          struct prop_local_percpu *pl, long frac);
+
+
+/*
+ * ----- SINGLE ------
+ */
+
+struct prop_local_single {
+       /*
+        * the local events counter
+        */
+       unsigned long events;
+
+       /*
+        * snapshot of the last seen global state
+        * and a lock protecting this state
+        */
+       unsigned long period;
+       int shift;
+       raw_spinlock_t lock;            /* protect the snapshot state */
+};
+
+#define INIT_PROP_LOCAL_SINGLE(name)                   \
+{      .lock = __RAW_SPIN_LOCK_UNLOCKED(name.lock),    \
+}
+
+int prop_local_init_single(struct prop_local_single *pl);
+void prop_local_destroy_single(struct prop_local_single *pl);
+void __prop_inc_single(struct prop_descriptor *pd, struct prop_local_single *pl);
+void prop_fraction_single(struct prop_descriptor *pd, struct prop_local_single *pl,
+               long *numerator, long *denominator);
+
+static inline
+void prop_inc_single(struct prop_descriptor *pd, struct prop_local_single *pl)
+{
+       unsigned long flags;
+
+       local_irq_save(flags);
+       __prop_inc_single(pd, pl);
+       local_irq_restore(flags);
+}
+
+#endif /* _LINUX_PROPORTIONS_H */