--- /dev/null
+#ifndef _LWK_SPINLOCK_H
+#define _LWK_SPINLOCK_H
+
+/*
+ * include/lwk/spinlock.h - generic spinlock/rwlock declarations
+ *
+ * here's the role of the various spinlock/rwlock related include files:
+ *
+ * arch/spinlock_types.h: contains the raw_spinlock_t/raw_rwlock_t and the
+ * initializers
+ *
+ * lwk/spinlock_types.h:
+ * defines the generic type and initializers
+ *
+ * arch/spinlock.h: contains the __raw_spin_*()/etc. lowlevel
+ * implementations, mostly inline assembly code
+ *
+ * lwk/spinlock_api_smp.h:
+ * contains the prototypes for the _spin_*() APIs.
+ *
+ * lwk/spinlock.h: builds the final spin_*() APIs.
+ *
+ * lwk/spinlock.h: builds the final spin_*() APIs.
+ */
+
+#include <lwk/kernel.h>
+#include <lwk/linkage.h>
+#include <lwk/compiler.h>
+#include <lwk/stringify.h>
+#include <arch/system.h>
+
+/*
+ * Must define these before including other files, inline functions need them
+ */
+#define LOCK_SECTION_NAME ".text.lock."KBUILD_BASENAME
+
+#define LOCK_SECTION_START(extra) \
+ ".subsection 1\n\t" \
+ extra \
+ ".ifndef " LOCK_SECTION_NAME "\n\t" \
+ LOCK_SECTION_NAME ":\n\t" \
+ ".endif\n"
+
+#define LOCK_SECTION_END \
+ ".previous\n\t"
+
+#define __lockfunc fastcall __attribute__((section(".spinlock.text")))
+
+/*
+ * Pull the raw_spinlock_t and raw_rwlock_t definitions:
+ */
+#include <lwk/spinlock_types.h>
+
+extern int __lockfunc generic__raw_read_trylock(raw_rwlock_t *lock);
+
+/*
+ * Pull the __raw*() functions/declarations:
+ */
+# include <arch/spinlock.h>
+
+#define spin_lock_init(lock) do { *(lock) = (spinlock_t)SPIN_LOCK_UNLOCKED; } while (0)
+#define rwlock_init(lock) do { *(lock) = (rwlock_t)RW_LOCK_UNLOCKED; } while (0)
+
+#define spin_is_locked(lock) __raw_spin_is_locked(&(lock)->raw_lock)
+
+/**
+ * spin_unlock_wait - wait until the spinlock gets unlocked
+ * @lock: the spinlock in question.
+ */
+#define spin_unlock_wait(lock) __raw_spin_unlock_wait(&(lock)->raw_lock)
+
+/*
+ * Pull the _spin_*()/_read_*()/_write_*() functions/declarations:
+ */
+#include <lwk/spinlock_api_smp.h>
+
+#ifdef CONFIG_DEBUG_SPINLOCK
+ extern void _raw_spin_lock(spinlock_t *lock);
+#define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock)
+ extern int _raw_spin_trylock(spinlock_t *lock);
+ extern void _raw_spin_unlock(spinlock_t *lock);
+
+ extern void _raw_read_lock(rwlock_t *lock);
+ extern int _raw_read_trylock(rwlock_t *lock);
+ extern void _raw_read_unlock(rwlock_t *lock);
+ extern void _raw_write_lock(rwlock_t *lock);
+ extern int _raw_write_trylock(rwlock_t *lock);
+ extern void _raw_write_unlock(rwlock_t *lock);
+#else
+# define _raw_spin_unlock(lock) __raw_spin_unlock(&(lock)->raw_lock)
+# define _raw_spin_trylock(lock) __raw_spin_trylock(&(lock)->raw_lock)
+# define _raw_spin_lock(lock) __raw_spin_lock(&(lock)->raw_lock)
+# define _raw_spin_lock_flags(lock, flags) \
+ __raw_spin_lock_flags(&(lock)->raw_lock, *(flags))
+# define _raw_read_lock(rwlock) __raw_read_lock(&(rwlock)->raw_lock)
+# define _raw_write_lock(rwlock) __raw_write_lock(&(rwlock)->raw_lock)
+# define _raw_read_unlock(rwlock) __raw_read_unlock(&(rwlock)->raw_lock)
+# define _raw_write_unlock(rwlock) __raw_write_unlock(&(rwlock)->raw_lock)
+# define _raw_read_trylock(rwlock) __raw_read_trylock(&(rwlock)->raw_lock)
+# define _raw_write_trylock(rwlock) __raw_write_trylock(&(rwlock)->raw_lock)
+#endif
+
+#define read_can_lock(rwlock) __raw_read_can_lock(&(rwlock)->raw_lock)
+#define write_can_lock(rwlock) __raw_write_can_lock(&(rwlock)->raw_lock)
+
+/*
+ * Define the various spin_lock and rw_lock methods.
+ */
+#define spin_trylock(lock) __cond_lock(_spin_trylock(lock))
+#define read_trylock(lock) __cond_lock(_read_trylock(lock))
+#define write_trylock(lock) __cond_lock(_write_trylock(lock))
+
+#define spin_lock(lock) _spin_lock(lock)
+#define write_lock(lock) _write_lock(lock)
+#define read_lock(lock) _read_lock(lock)
+
+#define spin_lock_irqsave(lock, flags) flags = _spin_lock_irqsave(lock)
+#define read_lock_irqsave(lock, flags) flags = _read_lock_irqsave(lock)
+#define write_lock_irqsave(lock, flags) flags = _write_lock_irqsave(lock)
+
+#define spin_lock_irq(lock) _spin_lock_irq(lock)
+#define spin_lock_bh(lock) _spin_lock_bh(lock)
+
+#define read_lock_irq(lock) _read_lock_irq(lock)
+#define read_lock_bh(lock) _read_lock_bh(lock)
+
+#define write_lock_irq(lock) _write_lock_irq(lock)
+#define write_lock_bh(lock) _write_lock_bh(lock)
+
+/*
+ * We inline the unlock functions in the nondebug case:
+ */
+#if defined(CONFIG_DEBUG_SPINLOCK)
+# define spin_unlock(lock) _spin_unlock(lock)
+# define read_unlock(lock) _read_unlock(lock)
+# define write_unlock(lock) _write_unlock(lock)
+#else
+# define spin_unlock(lock) __raw_spin_unlock(&(lock)->raw_lock)
+# define read_unlock(lock) __raw_read_unlock(&(lock)->raw_lock)
+# define write_unlock(lock) __raw_write_unlock(&(lock)->raw_lock)
+#endif
+
+#if defined(CONFIG_DEBUG_SPINLOCK)
+# define spin_unlock_irq(lock) _spin_unlock_irq(lock)
+# define read_unlock_irq(lock) _read_unlock_irq(lock)
+# define write_unlock_irq(lock) _write_unlock_irq(lock)
+#else
+# define spin_unlock_irq(lock) \
+ do { __raw_spin_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0)
+# define read_unlock_irq(lock) \
+ do { __raw_read_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0)
+# define write_unlock_irq(lock) \
+ do { __raw_write_unlock(&(lock)->raw_lock); local_irq_enable(); } while (0)
+#endif
+
+#define spin_unlock_irqrestore(lock, flags) \
+ _spin_unlock_irqrestore(lock, flags)
+#define spin_unlock_bh(lock) _spin_unlock_bh(lock)
+
+#define read_unlock_irqrestore(lock, flags) \
+ _read_unlock_irqrestore(lock, flags)
+#define read_unlock_bh(lock) _read_unlock_bh(lock)
+
+#define write_unlock_irqrestore(lock, flags) \
+ _write_unlock_irqrestore(lock, flags)
+#define write_unlock_bh(lock) _write_unlock_bh(lock)
+
+#define spin_trylock_bh(lock) __cond_lock(_spin_trylock_bh(lock))
+
+#define spin_trylock_irq(lock) \
+({ \
+ local_irq_disable(); \
+ _spin_trylock(lock) ? \
+ 1 : ({ local_irq_enable(); 0; }); \
+})
+
+#define spin_trylock_irqsave(lock, flags) \
+({ \
+ local_irq_save(flags); \
+ _spin_trylock(lock) ? \
+ 1 : ({ local_irq_restore(flags); 0; }); \
+})
+
+/*
+ * Pull the atomic_t declaration:
+ * (asm-mips/atomic.h needs above definitions)
+ */
+#include <arch/atomic.h>
+/**
+ * atomic_dec_and_lock - lock on reaching reference count zero
+ * @atomic: the atomic counter
+ * @lock: the spinlock in question
+ */
+extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock);
+#define atomic_dec_and_lock(atomic, lock) \
+ __cond_lock(_atomic_dec_and_lock(atomic, lock))
+
+/**
+ * spin_can_lock - would spin_trylock() succeed?
+ * @lock: the spinlock in question.
+ */
+#define spin_can_lock(lock) (!spin_is_locked(lock))
+
+#endif /* _LWK_SPINLOCK_H */
