New upstream version 0.7.2

[mirror_spl-debian.git] / include / linux / rwsem_compat.h

diff --git a/include/linux/rwsem_compat.h b/include/linux/rwsem_compat.h
index fe69f01548df42e97e0c0a7d8344fb8e4c885ee9..de513debeafe6445f5ae4f6e21abd5c20b738411 100644 (file)
--- a/include/linux/rwsem_compat.h
+++ b/include/linux/rwsem_compat.h
@@ -6,7 +6,7 @@
  *  UCRL-CODE-235197
  *
  *  This file is part of the SPL, Solaris Porting Layer.
- *  For details, see <http://github.com/behlendorf/spl/>.
+ *  For details, see <http://zfsonlinux.org/>.
  *
  *  The SPL is free software; you can redistribute it and/or modify it
  *  under the terms of the GNU General Public License as published by the
@@ -27,57 +27,41 @@
 
 #include <linux/rwsem.h>
 
-#ifdef RWSEM_SPINLOCK_IS_RAW
-#define spl_rwsem_lock_irqsave(lock, flags)       \
-({                                                \
-       raw_spin_lock_irqsave(lock, flags);       \
-})
-#define spl_rwsem_unlock_irqrestore(lock, flags)  \
-({                                                \
-       raw_spin_unlock_irqrestore(lock, flags);  \
-})
+#if defined(CONFIG_PREEMPT_RT_FULL)
+#define        SPL_RWSEM_SINGLE_READER_VALUE   (1)
+#define        SPL_RWSEM_SINGLE_WRITER_VALUE   (0)
+#elif defined(CONFIG_RWSEM_GENERIC_SPINLOCK)
+#define        SPL_RWSEM_SINGLE_READER_VALUE   (1)
+#define        SPL_RWSEM_SINGLE_WRITER_VALUE   (-1)
 #else
-#define spl_rwsem_lock_irqsave(lock, flags)       \
-({                                                \
-       spin_lock_irqsave(lock, flags);           \
-})
-#define spl_rwsem_unlock_irqrestore(lock, flags)  \
-({                                                \
-       spin_unlock_irqrestore(lock, flags);      \
-})
-#endif /* RWSEM_SPINLOCK_IS_RAW */
-
-#ifdef RWSEM_IS_LOCKED_TAKES_WAIT_LOCK
-/*
- * A race condition in rwsem_is_locked() was fixed in Linux 2.6.33 and the fix
- * was backported to RHEL5 as of kernel 2.6.18-190.el5.  Details can be found
- * here:
- *
- * https://bugzilla.redhat.com/show_bug.cgi?id=526092
+#define        SPL_RWSEM_SINGLE_READER_VALUE   (RWSEM_ACTIVE_READ_BIAS)
+#define        SPL_RWSEM_SINGLE_WRITER_VALUE   (RWSEM_ACTIVE_WRITE_BIAS)
+#endif
 
- * The race condition was fixed in the kernel by acquiring the semaphore's
- * wait_lock inside rwsem_is_locked().  The SPL worked around the race
- * condition by acquiring the wait_lock before calling that function, but
- * with the fix in place we must not do that.
- */
+/* Linux 3.16 changed activity to count for rwsem-spinlock */
+#if defined(CONFIG_PREEMPT_RT_FULL)
+#define        RWSEM_COUNT(sem)        sem->read_depth
+#elif defined(HAVE_RWSEM_ACTIVITY)
+#define        RWSEM_COUNT(sem)        sem->activity
+/* Linux 4.8 changed count to an atomic_long_t for !rwsem-spinlock */
+#elif defined(HAVE_RWSEM_ATOMIC_LONG_COUNT)
+#define        RWSEM_COUNT(sem)        atomic_long_read(&(sem)->count)
+#else
+#define        RWSEM_COUNT(sem)        sem->count
+#endif
 
-#define spl_rwsem_is_locked(rwsem)                                     \
-({                                                                     \
-       rwsem_is_locked(rwsem);                                         \
-})
+int rwsem_tryupgrade(struct rw_semaphore *rwsem);
 
+#if defined(RWSEM_SPINLOCK_IS_RAW)
+#define spl_rwsem_lock_irqsave(lk, fl)       raw_spin_lock_irqsave(lk, fl)
+#define spl_rwsem_unlock_irqrestore(lk, fl)  raw_spin_unlock_irqrestore(lk, fl)
+#define spl_rwsem_trylock_irqsave(lk, fl)    raw_spin_trylock_irqsave(lk, fl)
 #else
+#define spl_rwsem_lock_irqsave(lk, fl)       spin_lock_irqsave(lk, fl)
+#define spl_rwsem_unlock_irqrestore(lk, fl)  spin_unlock_irqrestore(lk, fl)
+#define spl_rwsem_trylock_irqsave(lk, fl)    spin_trylock_irqsave(lk, fl)
+#endif /* RWSEM_SPINLOCK_IS_RAW */
 
-#define spl_rwsem_is_locked(rwsem)                                \
-({                                                                \
-       unsigned long _flags_;                                    \
-       int _rc_;                                                 \
-       spl_rwsem_lock_irqsave(&rwsem->wait_lock, _flags_);       \
-       _rc_ = rwsem_is_locked(rwsem);                            \
-       spl_rwsem_unlock_irqrestore(&rwsem->wait_lock, _flags_);  \
-       _rc_;                                                     \
-})
-
-#endif /* RWSEM_IS_LOCKED_TAKES_WAIT_LOCK */
+#define spl_rwsem_is_locked(rwsem)           rwsem_is_locked(rwsem)
 
 #endif /* _SPL_RWSEM_COMPAT_H */