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author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2017-05-09 22:28:51 +0200 |
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committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2017-06-09 03:52:38 +0200 |
commit | 83d40bd3bc3ab3d6b5a4a331f7667d627948a099 (patch) | |
tree | cce0a86de1eebac31ad32077906d973f2cd1e285 /kernel/rcu | |
parent | rcu: Convert rnp->lock wrappers to macros for SRCU use (diff) | |
download | linux-83d40bd3bc3ab3d6b5a4a331f7667d627948a099.tar.xz linux-83d40bd3bc3ab3d6b5a4a331f7667d627948a099.zip |
rcu: Move rnp->lock wrappers for SRCU use
This commit moves the now-generic rnp->lock wrapper macros from
kernel/rcu/tree.h to kernel/rcu/rcu.h, thus allowing SRCU to use them.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcu')
-rw-r--r-- | kernel/rcu/rcu.h | 53 | ||||
-rw-r--r-- | kernel/rcu/tree.h | 53 |
2 files changed, 53 insertions, 53 deletions
diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h index 6a1e85bd2eac..2a75beb883c8 100644 --- a/kernel/rcu/rcu.h +++ b/kernel/rcu/rcu.h @@ -303,6 +303,59 @@ static inline void rcu_init_levelspread(int *levelspread, const int *levelcnt) cpu <= rnp->grphi; \ cpu = cpumask_next((cpu), cpu_possible_mask)) +/* + * Wrappers for the rcu_node::lock acquire and release. + * + * Because the rcu_nodes form a tree, the tree traversal locking will observe + * different lock values, this in turn means that an UNLOCK of one level + * followed by a LOCK of another level does not imply a full memory barrier; + * and most importantly transitivity is lost. + * + * In order to restore full ordering between tree levels, augment the regular + * lock acquire functions with smp_mb__after_unlock_lock(). + * + * As ->lock of struct rcu_node is a __private field, therefore one should use + * these wrappers rather than directly call raw_spin_{lock,unlock}* on ->lock. + */ +#define raw_spin_lock_rcu_node(p) \ +do { \ + raw_spin_lock(&ACCESS_PRIVATE(p, lock)); \ + smp_mb__after_unlock_lock(); \ +} while (0) + +#define raw_spin_unlock_rcu_node(p) raw_spin_unlock(&ACCESS_PRIVATE(p, lock)) + +#define raw_spin_lock_irq_rcu_node(p) \ +do { \ + raw_spin_lock_irq(&ACCESS_PRIVATE(p, lock)); \ + smp_mb__after_unlock_lock(); \ +} while (0) + +#define raw_spin_unlock_irq_rcu_node(p) \ + raw_spin_unlock_irq(&ACCESS_PRIVATE(p, lock)) + +#define raw_spin_lock_irqsave_rcu_node(rnp, flags) \ +do { \ + typecheck(unsigned long, flags); \ + raw_spin_lock_irqsave(&ACCESS_PRIVATE(rnp, lock), flags); \ + smp_mb__after_unlock_lock(); \ +} while (0) + +#define raw_spin_unlock_irqrestore_rcu_node(rnp, flags) \ +do { \ + typecheck(unsigned long, flags); \ + raw_spin_unlock_irqrestore(&ACCESS_PRIVATE(rnp, lock), flags); \ +} while (0) + +#define raw_spin_trylock_rcu_node(p) \ +({ \ + bool ___locked = raw_spin_trylock(&ACCESS_PRIVATE(p, lock)); \ + \ + if (___locked) \ + smp_mb__after_unlock_lock(); \ + ___locked; \ +}) + #endif /* #if defined(SRCU) || !defined(TINY_RCU) */ #ifdef CONFIG_TINY_RCU diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index a7f63f1074b4..baa0bac8da2a 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -565,56 +565,3 @@ static inline void rcu_nocb_q_lengths(struct rcu_data *rdp, long *ql, long *qll) #endif /* #else #ifdef CONFIG_RCU_NOCB_CPU */ } #endif /* #ifdef CONFIG_RCU_TRACE */ - -/* - * Wrappers for the rcu_node::lock acquire and release. - * - * Because the rcu_nodes form a tree, the tree traversal locking will observe - * different lock values, this in turn means that an UNLOCK of one level - * followed by a LOCK of another level does not imply a full memory barrier; - * and most importantly transitivity is lost. - * - * In order to restore full ordering between tree levels, augment the regular - * lock acquire functions with smp_mb__after_unlock_lock(). - * - * As ->lock of struct rcu_node is a __private field, therefore one should use - * these wrappers rather than directly call raw_spin_{lock,unlock}* on ->lock. - */ -#define raw_spin_lock_rcu_node(p) \ -do { \ - raw_spin_lock(&ACCESS_PRIVATE(p, lock)); \ - smp_mb__after_unlock_lock(); \ -} while (0) - -#define raw_spin_unlock_rcu_node(p) raw_spin_unlock(&ACCESS_PRIVATE(p, lock)) - -#define raw_spin_lock_irq_rcu_node(p) \ -do { \ - raw_spin_lock_irq(&ACCESS_PRIVATE(p, lock)); \ - smp_mb__after_unlock_lock(); \ -} while (0) - -#define raw_spin_unlock_irq_rcu_node(p) \ - raw_spin_unlock_irq(&ACCESS_PRIVATE(p, lock)) - -#define raw_spin_lock_irqsave_rcu_node(rnp, flags) \ -do { \ - typecheck(unsigned long, flags); \ - raw_spin_lock_irqsave(&ACCESS_PRIVATE(rnp, lock), flags); \ - smp_mb__after_unlock_lock(); \ -} while (0) - -#define raw_spin_unlock_irqrestore_rcu_node(rnp, flags) \ -do { \ - typecheck(unsigned long, flags); \ - raw_spin_unlock_irqrestore(&ACCESS_PRIVATE(rnp, lock), flags); \ -} while (0) - -#define raw_spin_trylock_rcu_node(p) \ -({ \ - bool ___locked = raw_spin_trylock(&ACCESS_PRIVATE(p, lock)); \ - \ - if (___locked) \ - smp_mb__after_unlock_lock(); \ - ___locked; \ -}) |