1 files changed, 606 insertions, 0 deletions

diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h
new file mode 100644
index 000000000000..e895f3eaf53a
--- /dev/null
+++ b/include/linux/spinlock.h
@@ -0,0 +1,606 @@
+#ifndef __LINUX_SPINLOCK_H
+#define __LINUX_SPINLOCK_H
+
+/*
+ * include/linux/spinlock.h - generic locking declarations
+ */
+
+#include <linux/config.h>
+#include <linux/preempt.h>
+#include <linux/linkage.h>
+#include <linux/compiler.h>
+#include <linux/thread_info.h>
+#include <linux/kernel.h>
+#include <linux/stringify.h>
+
+#include <asm/processor.h>      /* for cpu relax */
+#include <asm/system.h>
+
+/*
+ * Must define these before including other files, inline functions need them
+ */
+#define LOCK_SECTION_NAME                       \
+        ".text.lock." __stringify(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")))
+
+/*
+ * If CONFIG_SMP is set, pull in the _raw_* definitions
+ */
+#ifdef CONFIG_SMP
+
+#define assert_spin_locked(x)   BUG_ON(!spin_is_locked(x))
+#include <asm/spinlock.h>
+
+int __lockfunc _spin_trylock(spinlock_t *lock);
+int __lockfunc _read_trylock(rwlock_t *lock);
+int __lockfunc _write_trylock(rwlock_t *lock);
+
+void __lockfunc _spin_lock(spinlock_t *lock)    __acquires(spinlock_t);
+void __lockfunc _read_lock(rwlock_t *lock)      __acquires(rwlock_t);
+void __lockfunc _write_lock(rwlock_t *lock)     __acquires(rwlock_t);
+
+void __lockfunc _spin_unlock(spinlock_t *lock)  __releases(spinlock_t);
+void __lockfunc _read_unlock(rwlock_t *lock)    __releases(rwlock_t);
+void __lockfunc _write_unlock(rwlock_t *lock)   __releases(rwlock_t);
+
+unsigned long __lockfunc _spin_lock_irqsave(spinlock_t *lock)   __acquires(spinlock_t);
+unsigned long __lockfunc _read_lock_irqsave(rwlock_t *lock)     __acquires(rwlock_t);
+unsigned long __lockfunc _write_lock_irqsave(rwlock_t *lock)    __acquires(rwlock_t);
+
+void __lockfunc _spin_lock_irq(spinlock_t *lock)        __acquires(spinlock_t);
+void __lockfunc _spin_lock_bh(spinlock_t *lock)         __acquires(spinlock_t);
+void __lockfunc _read_lock_irq(rwlock_t *lock)          __acquires(rwlock_t);
+void __lockfunc _read_lock_bh(rwlock_t *lock)           __acquires(rwlock_t);
+void __lockfunc _write_lock_irq(rwlock_t *lock)         __acquires(rwlock_t);
+void __lockfunc _write_lock_bh(rwlock_t *lock)          __acquires(rwlock_t);
+
+void __lockfunc _spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags)  __releases(spinlock_t);
+void __lockfunc _spin_unlock_irq(spinlock_t *lock)                              __releases(spinlock_t);
+void __lockfunc _spin_unlock_bh(spinlock_t *lock)                               __releases(spinlock_t);
+void __lockfunc _read_unlock_irqrestore(rwlock_t *lock, unsigned long flags)    __releases(rwlock_t);
+void __lockfunc _read_unlock_irq(rwlock_t *lock)                                __releases(rwlock_t);
+void __lockfunc _read_unlock_bh(rwlock_t *lock)                                 __releases(rwlock_t);
+void __lockfunc _write_unlock_irqrestore(rwlock_t *lock, unsigned long flags)   __releases(rwlock_t);
+void __lockfunc _write_unlock_irq(rwlock_t *lock)                               __releases(rwlock_t);
+void __lockfunc _write_unlock_bh(rwlock_t *lock)                                __releases(rwlock_t);
+
+int __lockfunc _spin_trylock_bh(spinlock_t *lock);
+int __lockfunc generic_raw_read_trylock(rwlock_t *lock);
+int in_lock_functions(unsigned long addr);
+
+#else
+
+#define in_lock_functions(ADDR) 0
+
+#if !defined(CONFIG_PREEMPT) && !defined(CONFIG_DEBUG_SPINLOCK)
+# define _atomic_dec_and_lock(atomic,lock) atomic_dec_and_test(atomic)
+# define ATOMIC_DEC_AND_LOCK
+#endif
+
+#ifdef CONFIG_DEBUG_SPINLOCK
+ 
+#define SPINLOCK_MAGIC  0x1D244B3C
+typedef struct {
+        unsigned long magic;
+        volatile unsigned long lock;
+        volatile unsigned int babble;
+        const char *module;
+        char *owner;
+        int oline;
+} spinlock_t;
+#define SPIN_LOCK_UNLOCKED (spinlock_t) { SPINLOCK_MAGIC, 0, 10, __FILE__ , NULL, 0}
+
+#define spin_lock_init(x) \
+        do { \
+                (x)->magic = SPINLOCK_MAGIC; \
+                (x)->lock = 0; \
+                (x)->babble = 5; \
+                (x)->module = __FILE__; \
+                (x)->owner = NULL; \
+                (x)->oline = 0; \
+        } while (0)
+
+#define CHECK_LOCK(x) \
+        do { \
+                if ((x)->magic != SPINLOCK_MAGIC) { \
+                        printk(KERN_ERR "%s:%d: spin_is_locked on uninitialized spinlock %p.\n", \
+                                        __FILE__, __LINE__, (x)); \
+                } \
+        } while(0)
+
+#define _raw_spin_lock(x)               \
+        do { \
+                CHECK_LOCK(x); \
+                if ((x)->lock&&(x)->babble) { \
+                        (x)->babble--; \
+                        printk("%s:%d: spin_lock(%s:%p) already locked by %s/%d\n", \
+                                        __FILE__,__LINE__, (x)->module, \
+                                        (x), (x)->owner, (x)->oline); \
+                } \
+                (x)->lock = 1; \
+                (x)->owner = __FILE__; \
+                (x)->oline = __LINE__; \
+        } while (0)
+
+/* without debugging, spin_is_locked on UP always says
+ * FALSE. --> printk if already locked. */
+#define spin_is_locked(x) \
+        ({ \
+                CHECK_LOCK(x); \
+                if ((x)->lock&&(x)->babble) { \
+                        (x)->babble--; \
+                        printk("%s:%d: spin_is_locked(%s:%p) already locked by %s/%d\n", \
+                                        __FILE__,__LINE__, (x)->module, \
+                                        (x), (x)->owner, (x)->oline); \
+                } \
+                0; \
+        })
+
+/* with debugging, assert_spin_locked() on UP does check
+ * the lock value properly */
+#define assert_spin_locked(x) \
+        ({ \
+                CHECK_LOCK(x); \
+                BUG_ON(!(x)->lock); \
+        })
+
+/* without debugging, spin_trylock on UP always says
+ * TRUE. --> printk if already locked. */
+#define _raw_spin_trylock(x) \
+        ({ \
+                CHECK_LOCK(x); \
+                if ((x)->lock&&(x)->babble) { \
+                        (x)->babble--; \
+                        printk("%s:%d: spin_trylock(%s:%p) already locked by %s/%d\n", \
+                                        __FILE__,__LINE__, (x)->module, \
+                                        (x), (x)->owner, (x)->oline); \
+                } \
+                (x)->lock = 1; \
+                (x)->owner = __FILE__; \
+                (x)->oline = __LINE__; \
+                1; \
+        })
+
+#define spin_unlock_wait(x)     \
+        do { \
+                CHECK_LOCK(x); \
+                if ((x)->lock&&(x)->babble) { \
+                        (x)->babble--; \
+                        printk("%s:%d: spin_unlock_wait(%s:%p) owned by %s/%d\n", \
+                                        __FILE__,__LINE__, (x)->module, (x), \
+                                        (x)->owner, (x)->oline); \
+                }\
+        } while (0)
+
+#define _raw_spin_unlock(x) \
+        do { \
+                CHECK_LOCK(x); \
+                if (!(x)->lock&&(x)->babble) { \
+                        (x)->babble--; \
+                        printk("%s:%d: spin_unlock(%s:%p) not locked\n", \
+                                        __FILE__,__LINE__, (x)->module, (x));\
+                } \
+                (x)->lock = 0; \
+        } while (0)
+#else
+/*
+ * gcc versions before ~2.95 have a nasty bug with empty initializers.
+ */
+#if (__GNUC__ > 2)
+  typedef struct { } spinlock_t;
+  #define SPIN_LOCK_UNLOCKED (spinlock_t) { }
+#else
+  typedef struct { int gcc_is_buggy; } spinlock_t;
+  #define SPIN_LOCK_UNLOCKED (spinlock_t) { 0 }
+#endif
+
+/*
+ * If CONFIG_SMP is unset, declare the _raw_* definitions as nops
+ */
+#define spin_lock_init(lock)    do { (void)(lock); } while(0)
+#define _raw_spin_lock(lock)    do { (void)(lock); } while(0)
+#define spin_is_locked(lock)    ((void)(lock), 0)
+#define assert_spin_locked(lock)        do { (void)(lock); } while(0)
+#define _raw_spin_trylock(lock) (((void)(lock), 1))
+#define spin_unlock_wait(lock)  (void)(lock)
+#define _raw_spin_unlock(lock) do { (void)(lock); } while(0)
+#endif /* CONFIG_DEBUG_SPINLOCK */
+
+/* RW spinlocks: No debug version */
+
+#if (__GNUC__ > 2)
+  typedef struct { } rwlock_t;
+  #define RW_LOCK_UNLOCKED (rwlock_t) { }
+#else
+  typedef struct { int gcc_is_buggy; } rwlock_t;
+  #define RW_LOCK_UNLOCKED (rwlock_t) { 0 }
+#endif
+
+#define rwlock_init(lock)       do { (void)(lock); } while(0)
+#define _raw_read_lock(lock)    do { (void)(lock); } while(0)
+#define _raw_read_unlock(lock)  do { (void)(lock); } while(0)
+#define _raw_write_lock(lock)   do { (void)(lock); } while(0)
+#define _raw_write_unlock(lock) do { (void)(lock); } while(0)
+#define read_can_lock(lock)     (((void)(lock), 1))
+#define write_can_lock(lock)    (((void)(lock), 1))
+#define _raw_read_trylock(lock) ({ (void)(lock); (1); })
+#define _raw_write_trylock(lock) ({ (void)(lock); (1); })
+
+#define _spin_trylock(lock)     ({preempt_disable(); _raw_spin_trylock(lock) ? \
+                                1 : ({preempt_enable(); 0;});})
+
+#define _read_trylock(lock)     ({preempt_disable();_raw_read_trylock(lock) ? \
+                                1 : ({preempt_enable(); 0;});})
+
+#define _write_trylock(lock)    ({preempt_disable(); _raw_write_trylock(lock) ? \
+                                1 : ({preempt_enable(); 0;});})
+
+#define _spin_trylock_bh(lock)  ({preempt_disable(); local_bh_disable(); \
+                                _raw_spin_trylock(lock) ? \
+                                1 : ({preempt_enable(); local_bh_enable(); 0;});})
+
+#define _spin_lock(lock)        \
+do { \
+        preempt_disable(); \
+        _raw_spin_lock(lock); \
+        __acquire(lock); \
+} while(0)
+
+#define _write_lock(lock) \
+do { \
+        preempt_disable(); \
+        _raw_write_lock(lock); \
+        __acquire(lock); \
+} while(0)
+ 
+#define _read_lock(lock)        \
+do { \
+        preempt_disable(); \
+        _raw_read_lock(lock); \
+        __acquire(lock); \
+} while(0)
+
+#define _spin_unlock(lock) \
+do { \
+        _raw_spin_unlock(lock); \
+        preempt_enable(); \
+        __release(lock); \
+} while (0)
+
+#define _write_unlock(lock) \
+do { \
+        _raw_write_unlock(lock); \
+        preempt_enable(); \
+        __release(lock); \
+} while(0)
+
+#define _read_unlock(lock) \
+do { \
+        _raw_read_unlock(lock); \
+        preempt_enable(); \
+        __release(lock); \
+} while(0)
+
+#define _spin_lock_irqsave(lock, flags) \
+do {    \
+        local_irq_save(flags); \
+        preempt_disable(); \
+        _raw_spin_lock(lock); \
+        __acquire(lock); \
+} while (0)
+
+#define _spin_lock_irq(lock) \
+do { \
+        local_irq_disable(); \
+        preempt_disable(); \
+        _raw_spin_lock(lock); \
+        __acquire(lock); \
+} while (0)
+
+#define _spin_lock_bh(lock) \
+do { \
+        local_bh_disable(); \
+        preempt_disable(); \
+        _raw_spin_lock(lock); \
+        __acquire(lock); \
+} while (0)
+
+#define _read_lock_irqsave(lock, flags) \
+do {    \
+        local_irq_save(flags); \
+        preempt_disable(); \
+        _raw_read_lock(lock); \
+        __acquire(lock); \
+} while (0)
+
+#define _read_lock_irq(lock) \
+do { \
+        local_irq_disable(); \
+        preempt_disable(); \
+        _raw_read_lock(lock); \
+        __acquire(lock); \
+} while (0)
+
+#define _read_lock_bh(lock) \
+do { \
+        local_bh_disable(); \
+        preempt_disable(); \
+        _raw_read_lock(lock); \
+        __acquire(lock); \
+} while (0)
+
+#define _write_lock_irqsave(lock, flags) \
+do {    \
+        local_irq_save(flags); \
+        preempt_disable(); \
+        _raw_write_lock(lock); \
+        __acquire(lock); \
+} while (0)
+
+#define _write_lock_irq(lock) \
+do { \
+        local_irq_disable(); \
+        preempt_disable(); \
+        _raw_write_lock(lock); \
+        __acquire(lock); \
+} while (0)
+
+#define _write_lock_bh(lock) \
+do { \
+        local_bh_disable(); \
+        preempt_disable(); \
+        _raw_write_lock(lock); \
+        __acquire(lock); \
+} while (0)
+
+#define _spin_unlock_irqrestore(lock, flags) \
+do { \
+        _raw_spin_unlock(lock); \
+        local_irq_restore(flags); \
+        preempt_enable(); \
+        __release(lock); \
+} while (0)
+
+#define _spin_unlock_irq(lock) \
+do { \
+        _raw_spin_unlock(lock); \
+        local_irq_enable(); \
+        preempt_enable(); \
+        __release(lock); \
+} while (0)
+
+#define _spin_unlock_bh(lock) \
+do { \
+        _raw_spin_unlock(lock); \
+        preempt_enable(); \
+        local_bh_enable(); \
+        __release(lock); \
+} while (0)
+
+#define _write_unlock_bh(lock) \
+do { \
+        _raw_write_unlock(lock); \
+        preempt_enable(); \
+        local_bh_enable(); \
+        __release(lock); \
+} while (0)
+
+#define _read_unlock_irqrestore(lock, flags) \
+do { \
+        _raw_read_unlock(lock); \
+        local_irq_restore(flags); \
+        preempt_enable(); \
+        __release(lock); \
+} while (0)
+
+#define _write_unlock_irqrestore(lock, flags) \
+do { \
+        _raw_write_unlock(lock); \
+        local_irq_restore(flags); \
+        preempt_enable(); \
+        __release(lock); \
+} while (0)
+
+#define _read_unlock_irq(lock)  \
+do { \
+        _raw_read_unlock(lock); \
+        local_irq_enable();     \
+        preempt_enable();       \
+        __release(lock); \
+} while (0)
+
+#define _read_unlock_bh(lock)   \
+do { \
+        _raw_read_unlock(lock); \
+        local_bh_enable();      \
+        preempt_enable();       \
+        __release(lock); \
+} while (0)
+
+#define _write_unlock_irq(lock) \
+do { \
+        _raw_write_unlock(lock);        \
+        local_irq_enable();     \
+        preempt_enable();       \
+        __release(lock); \
+} while (0)
+
+#endif /* !SMP */
+
+/*
+ * Define the various spin_lock and rw_lock methods.  Note we define these
+ * regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The various
+ * methods are defined as nops in the case they are not required.
+ */
+#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)
+
+#ifdef CONFIG_SMP
+#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)
+#else
+#define spin_lock_irqsave(lock, flags)  _spin_lock_irqsave(lock, flags)
+#define read_lock_irqsave(lock, flags)  _read_lock_irqsave(lock, flags)
+#define write_lock_irqsave(lock, flags) _write_lock_irqsave(lock, flags)
+#endif
+
+#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)
+
+#define spin_unlock(lock)       _spin_unlock(lock)
+#define write_unlock(lock)      _write_unlock(lock)
+#define read_unlock(lock)       _read_unlock(lock)
+
+#define spin_unlock_irqrestore(lock, flags)     _spin_unlock_irqrestore(lock, flags)
+#define spin_unlock_irq(lock)           _spin_unlock_irq(lock)
+#define spin_unlock_bh(lock)            _spin_unlock_bh(lock)
+
+#define read_unlock_irqrestore(lock, flags)     _read_unlock_irqrestore(lock, flags)
+#define read_unlock_irq(lock)                   _read_unlock_irq(lock)
+#define read_unlock_bh(lock)                    _read_unlock_bh(lock)
+
+#define write_unlock_irqrestore(lock, flags)    _write_unlock_irqrestore(lock, flags)
+#define write_unlock_irq(lock)                  _write_unlock_irq(lock)
+#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;}); \
+})
+
+#ifdef CONFIG_LOCKMETER
+extern void _metered_spin_lock   (spinlock_t *lock);
+extern void _metered_spin_unlock (spinlock_t *lock);
+extern int  _metered_spin_trylock(spinlock_t *lock);
+extern void _metered_read_lock    (rwlock_t *lock);
+extern void _metered_read_unlock  (rwlock_t *lock);
+extern void _metered_write_lock   (rwlock_t *lock);
+extern void _metered_write_unlock (rwlock_t *lock);
+extern int  _metered_read_trylock (rwlock_t *lock);
+extern int  _metered_write_trylock(rwlock_t *lock);
+#endif
+
+/* "lock on reference count zero" */
+#ifndef ATOMIC_DEC_AND_LOCK
+#include <asm/atomic.h>
+extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock);
+#endif
+
+#define atomic_dec_and_lock(atomic,lock) __cond_lock(_atomic_dec_and_lock(atomic,lock))
+
+/*
+ *  bit-based spin_lock()
+ *
+ * Don't use this unless you really need to: spin_lock() and spin_unlock()
+ * are significantly faster.
+ */
+static inline void bit_spin_lock(int bitnum, unsigned long *addr)
+{
+        /*
+         * Assuming the lock is uncontended, this never enters
+         * the body of the outer loop. If it is contended, then
+         * within the inner loop a non-atomic test is used to
+         * busywait with less bus contention for a good time to
+         * attempt to acquire the lock bit.
+         */
+        preempt_disable();
+#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
+        while (test_and_set_bit(bitnum, addr)) {
+                while (test_bit(bitnum, addr)) {
+                        preempt_enable();
+                        cpu_relax();
+                        preempt_disable();
+                }
+        }
+#endif
+        __acquire(bitlock);
+}
+
+/*
+ * Return true if it was acquired
+ */
+static inline int bit_spin_trylock(int bitnum, unsigned long *addr)
+{
+        preempt_disable();      
+#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
+        if (test_and_set_bit(bitnum, addr)) {
+                preempt_enable();
+                return 0;
+        }
+#endif
+        __acquire(bitlock);
+        return 1;
+}
+
+/*
+ *  bit-based spin_unlock()
+ */
+static inline void bit_spin_unlock(int bitnum, unsigned long *addr)
+{
+#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
+        BUG_ON(!test_bit(bitnum, addr));
+        smp_mb__before_clear_bit();
+        clear_bit(bitnum, addr);
+#endif
+        preempt_enable();
+        __release(bitlock);
+}
+
+/*
+ * Return true if the lock is held.
+ */
+static inline int bit_spin_is_locked(int bitnum, unsigned long *addr)
+{
+#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
+        return test_bit(bitnum, addr);
+#elif defined CONFIG_PREEMPT
+        return preempt_count();
+#else
+        return 1;
+#endif
+}
+
+#define DEFINE_SPINLOCK(x) spinlock_t x = SPIN_LOCK_UNLOCKED
+#define DEFINE_RWLOCK(x) rwlock_t x = RW_LOCK_UNLOCKED
+
+/**
+ * spin_can_lock - would spin_trylock() succeed?
+ * @lock: the spinlock in question.
+ */
+#define spin_can_lock(lock)             (!spin_is_locked(lock))
+
+#endif /* __LINUX_SPINLOCK_H */