These changes are the raw update to linux-4.4.6-rt14. Kernel sources

[kvmfornfv.git] / kernel / include / asm-generic / qspinlock_types.h

diff --git a/kernel/include/asm-generic/qspinlock_types.h b/kernel/include/asm-generic/qspinlock_types.h
new file mode 100644 (file)
index 0000000..85f888e
--- /dev/null
+++ b/kernel/include/asm-generic/qspinlock_types.h
@@ -0,0 +1,79 @@
+/*
+ * Queued spinlock
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * (C) Copyright 2013-2015 Hewlett-Packard Development Company, L.P.
+ *
+ * Authors: Waiman Long <waiman.long@hp.com>
+ */
+#ifndef __ASM_GENERIC_QSPINLOCK_TYPES_H
+#define __ASM_GENERIC_QSPINLOCK_TYPES_H
+
+/*
+ * Including atomic.h with PARAVIRT on will cause compilation errors because
+ * of recursive header file incluson via paravirt_types.h. So don't include
+ * it if PARAVIRT is on.
+ */
+#ifndef CONFIG_PARAVIRT
+#include <linux/types.h>
+#include <linux/atomic.h>
+#endif
+
+typedef struct qspinlock {
+       atomic_t        val;
+} arch_spinlock_t;
+
+/*
+ * Bitfields in the atomic value:
+ *
+ * When NR_CPUS < 16K
+ *  0- 7: locked byte
+ *     8: pending
+ *  9-15: not used
+ * 16-17: tail index
+ * 18-31: tail cpu (+1)
+ *
+ * When NR_CPUS >= 16K
+ *  0- 7: locked byte
+ *     8: pending
+ *  9-10: tail index
+ * 11-31: tail cpu (+1)
+ */
+#define        _Q_SET_MASK(type)       (((1U << _Q_ ## type ## _BITS) - 1)\
+                                     << _Q_ ## type ## _OFFSET)
+#define _Q_LOCKED_OFFSET       0
+#define _Q_LOCKED_BITS         8
+#define _Q_LOCKED_MASK         _Q_SET_MASK(LOCKED)
+
+#define _Q_PENDING_OFFSET      (_Q_LOCKED_OFFSET + _Q_LOCKED_BITS)
+#if CONFIG_NR_CPUS < (1U << 14)
+#define _Q_PENDING_BITS                8
+#else
+#define _Q_PENDING_BITS                1
+#endif
+#define _Q_PENDING_MASK                _Q_SET_MASK(PENDING)
+
+#define _Q_TAIL_IDX_OFFSET     (_Q_PENDING_OFFSET + _Q_PENDING_BITS)
+#define _Q_TAIL_IDX_BITS       2
+#define _Q_TAIL_IDX_MASK       _Q_SET_MASK(TAIL_IDX)
+
+#define _Q_TAIL_CPU_OFFSET     (_Q_TAIL_IDX_OFFSET + _Q_TAIL_IDX_BITS)
+#define _Q_TAIL_CPU_BITS       (32 - _Q_TAIL_CPU_OFFSET)
+#define _Q_TAIL_CPU_MASK       _Q_SET_MASK(TAIL_CPU)
+
+#define _Q_TAIL_OFFSET         _Q_TAIL_IDX_OFFSET
+#define _Q_TAIL_MASK           (_Q_TAIL_IDX_MASK | _Q_TAIL_CPU_MASK)
+
+#define _Q_LOCKED_VAL          (1U << _Q_LOCKED_OFFSET)
+#define _Q_PENDING_VAL         (1U << _Q_PENDING_OFFSET)
+
+#endif /* __ASM_GENERIC_QSPINLOCK_TYPES_H */