};
void wakeme_after_rcu(struct rcu_head *head);
+void __wait_rcu_gp(bool checktiny, int n, call_rcu_func_t *crcu_array,
+ struct rcu_synchronize *rs_array);
+
+#define _wait_rcu_gp(checktiny, ...) \
+do { \
+ call_rcu_func_t __crcu_array[] = { __VA_ARGS__ }; \
+ const int __n = ARRAY_SIZE(__crcu_array); \
+ struct rcu_synchronize __rs_array[__n]; \
+ \
+ __wait_rcu_gp(checktiny, __n, __crcu_array, __rs_array); \
+} while (0)
+
+#define wait_rcu_gp(...) _wait_rcu_gp(false, __VA_ARGS__)
+
+/**
+ * synchronize_rcu_mult - Wait concurrently for multiple grace periods
+ * @...: List of call_rcu() functions for the flavors to wait on.
+ *
+ * This macro waits concurrently for multiple flavors of RCU grace periods.
+ * For example, synchronize_rcu_mult(call_rcu, call_rcu_bh) would wait
+ * on concurrent RCU and RCU-bh grace periods. Waiting on a give SRCU
+ * domain requires you to write a wrapper function for that SRCU domain's
+ * call_srcu() function, supplying the corresponding srcu_struct.
+ *
+ * If Tiny RCU, tell _wait_rcu_gp() not to bother waiting for RCU
+ * or RCU-bh, given that anywhere synchronize_rcu_mult() can be called
+ * is automatically a grace period.
+ */
+#define synchronize_rcu_mult(...) \
+ _wait_rcu_gp(IS_ENABLED(CONFIG_TINY_RCU), __VA_ARGS__)
+
/**
* call_rcu_tasks() - Queue an RCU for invocation task-based grace period
* @head: structure to be used for queueing the RCU updates.
}
#endif /* #else #ifdef CONFIG_RCU_STALL_COMMON */
-#ifdef CONFIG_RCU_USER_QS
+#ifdef CONFIG_NO_HZ_FULL
void rcu_user_enter(void);
void rcu_user_exit(void);
#else
static inline void rcu_user_exit(void) { }
static inline void rcu_user_hooks_switch(struct task_struct *prev,
struct task_struct *next) { }
-#endif /* CONFIG_RCU_USER_QS */
+#endif /* CONFIG_NO_HZ_FULL */
#ifdef CONFIG_RCU_NOCB_CPU
void rcu_init_nohz(void);
* TREE_RCU and rcu_barrier_() primitives in TINY_RCU.
*/
-typedef void call_rcu_func_t(struct rcu_head *head,
- void (*func)(struct rcu_head *head));
-void wait_rcu_gp(call_rcu_func_t crf);
-
#if defined(CONFIG_TREE_RCU) || defined(CONFIG_PREEMPT_RCU)
#include <linux/rcutree.h>
#elif defined(CONFIG_TINY_RCU)
* If CONFIG_DEBUG_LOCK_ALLOC is selected, returns nonzero iff in an
* RCU-sched read-side critical section. In absence of
* CONFIG_DEBUG_LOCK_ALLOC, this assumes we are in an RCU-sched read-side
- * critical section unless it can prove otherwise. Note that disabling
- * of preemption (including disabling irqs) counts as an RCU-sched
- * read-side critical section. This is useful for debug checks in functions
- * that required that they be called within an RCU-sched read-side
- * critical section.
- *
- * Check debug_lockdep_rcu_enabled() to prevent false positives during boot
- * and while lockdep is disabled.
- *
- * Note that if the CPU is in the idle loop from an RCU point of
- * view (ie: that we are in the section between rcu_idle_enter() and
- * rcu_idle_exit()) then rcu_read_lock_held() returns false even if the CPU
- * did an rcu_read_lock(). The reason for this is that RCU ignores CPUs
- * that are in such a section, considering these as in extended quiescent
- * state, so such a CPU is effectively never in an RCU read-side critical
- * section regardless of what RCU primitives it invokes. This state of
- * affairs is required --- we need to keep an RCU-free window in idle
- * where the CPU may possibly enter into low power mode. This way we can
- * notice an extended quiescent state to other CPUs that started a grace
- * period. Otherwise we would delay any grace period as long as we run in
- * the idle task.
- *
- * Similarly, we avoid claiming an SRCU read lock held if the current
- * CPU is offline.
+ * critical section unless it can prove otherwise.
*/
#ifdef CONFIG_PREEMPT_COUNT
-static inline int rcu_read_lock_sched_held(void)
-{
- int lockdep_opinion = 0;
-
- if (!debug_lockdep_rcu_enabled())
- return 1;
- if (!rcu_is_watching())
- return 0;
- if (!rcu_lockdep_current_cpu_online())
- return 0;
- if (debug_locks)
- lockdep_opinion = lock_is_held(&rcu_sched_lock_map);
- return lockdep_opinion || preempt_count() != 0 || irqs_disabled();
-}
+int rcu_read_lock_sched_held(void);
#else /* #ifdef CONFIG_PREEMPT_COUNT */
static inline int rcu_read_lock_sched_held(void)
{
#endif /* #else #ifdef CONFIG_DEBUG_LOCK_ALLOC */
+/* Deprecate rcu_lockdep_assert(): Use RCU_LOCKDEP_WARN() instead. */
+static inline void __attribute((deprecated)) deprecate_rcu_lockdep_assert(void)
+{
+}
+
#ifdef CONFIG_PROVE_RCU
/**
#define rcu_lockdep_assert(c, s) \
do { \
static bool __section(.data.unlikely) __warned; \
+ deprecate_rcu_lockdep_assert(); \
if (debug_lockdep_rcu_enabled() && !__warned && !(c)) { \
__warned = true; \
lockdep_rcu_suspicious(__FILE__, __LINE__, s); \
} \
} while (0)
+/**
+ * RCU_LOCKDEP_WARN - emit lockdep splat if specified condition is met
+ * @c: condition to check
+ * @s: informative message
+ */
+#define RCU_LOCKDEP_WARN(c, s) \
+ do { \
+ static bool __section(.data.unlikely) __warned; \
+ if (debug_lockdep_rcu_enabled() && !__warned && (c)) { \
+ __warned = true; \
+ lockdep_rcu_suspicious(__FILE__, __LINE__, s); \
+ } \
+ } while (0)
+
#if defined(CONFIG_PROVE_RCU) && !defined(CONFIG_PREEMPT_RCU)
static inline void rcu_preempt_sleep_check(void)
{
- rcu_lockdep_assert(!lock_is_held(&rcu_lock_map),
- "Illegal context switch in RCU read-side critical section");
+ RCU_LOCKDEP_WARN(lock_is_held(&rcu_lock_map),
+ "Illegal context switch in RCU read-side critical section");
}
#else /* #ifdef CONFIG_PROVE_RCU */
static inline void rcu_preempt_sleep_check(void)
#define rcu_sleep_check() \
do { \
rcu_preempt_sleep_check(); \
- rcu_lockdep_assert(!lock_is_held(&rcu_bh_lock_map), \
- "Illegal context switch in RCU-bh read-side critical section"); \
- rcu_lockdep_assert(!lock_is_held(&rcu_sched_lock_map), \
- "Illegal context switch in RCU-sched read-side critical section"); \
+ RCU_LOCKDEP_WARN(lock_is_held(&rcu_bh_lock_map), \
+ "Illegal context switch in RCU-bh read-side critical section"); \
+ RCU_LOCKDEP_WARN(lock_is_held(&rcu_sched_lock_map), \
+ "Illegal context switch in RCU-sched read-side critical section"); \
} while (0)
#else /* #ifdef CONFIG_PROVE_RCU */
-#define rcu_lockdep_assert(c, s) do { } while (0)
+#define rcu_lockdep_assert(c, s) deprecate_rcu_lockdep_assert()
+#define RCU_LOCKDEP_WARN(c, s) do { } while (0)
#define rcu_sleep_check() do { } while (0)
#endif /* #else #ifdef CONFIG_PROVE_RCU */
({ \
/* Dependency order vs. p above. */ \
typeof(*p) *________p1 = (typeof(*p) *__force)lockless_dereference(p); \
- rcu_lockdep_assert(c, "suspicious rcu_dereference_check() usage"); \
+ RCU_LOCKDEP_WARN(!(c), "suspicious rcu_dereference_check() usage"); \
rcu_dereference_sparse(p, space); \
((typeof(*p) __force __kernel *)(________p1)); \
})
#define __rcu_dereference_protected(p, c, space) \
({ \
- rcu_lockdep_assert(c, "suspicious rcu_dereference_protected() usage"); \
+ RCU_LOCKDEP_WARN(!(c), "suspicious rcu_dereference_protected() usage"); \
rcu_dereference_sparse(p, space); \
((typeof(*p) __force __kernel *)(p)); \
})
__rcu_read_lock();
__acquire(RCU);
rcu_lock_acquire(&rcu_lock_map);
- rcu_lockdep_assert(rcu_is_watching(),
- "rcu_read_lock() used illegally while idle");
+ RCU_LOCKDEP_WARN(!rcu_is_watching(),
+ "rcu_read_lock() used illegally while idle");
}
/*
*/
static inline void rcu_read_unlock(void)
{
- rcu_lockdep_assert(rcu_is_watching(),
- "rcu_read_unlock() used illegally while idle");
+ RCU_LOCKDEP_WARN(!rcu_is_watching(),
+ "rcu_read_unlock() used illegally while idle");
__release(RCU);
__rcu_read_unlock();
rcu_lock_release(&rcu_lock_map); /* Keep acq info for rls diags. */
local_bh_disable();
__acquire(RCU_BH);
rcu_lock_acquire(&rcu_bh_lock_map);
- rcu_lockdep_assert(rcu_is_watching(),
- "rcu_read_lock_bh() used illegally while idle");
+ RCU_LOCKDEP_WARN(!rcu_is_watching(),
+ "rcu_read_lock_bh() used illegally while idle");
}
/*
*/
static inline void rcu_read_unlock_bh(void)
{
- rcu_lockdep_assert(rcu_is_watching(),
- "rcu_read_unlock_bh() used illegally while idle");
+ RCU_LOCKDEP_WARN(!rcu_is_watching(),
+ "rcu_read_unlock_bh() used illegally while idle");
rcu_lock_release(&rcu_bh_lock_map);
__release(RCU_BH);
local_bh_enable();
preempt_disable();
__acquire(RCU_SCHED);
rcu_lock_acquire(&rcu_sched_lock_map);
- rcu_lockdep_assert(rcu_is_watching(),
- "rcu_read_lock_sched() used illegally while idle");
+ RCU_LOCKDEP_WARN(!rcu_is_watching(),
+ "rcu_read_lock_sched() used illegally while idle");
}
/* Used by lockdep and tracing: cannot be traced, cannot call lockdep. */
*/
static inline void rcu_read_unlock_sched(void)
{
- rcu_lockdep_assert(rcu_is_watching(),
- "rcu_read_unlock_sched() used illegally while idle");
+ RCU_LOCKDEP_WARN(!rcu_is_watching(),
+ "rcu_read_unlock_sched() used illegally while idle");
rcu_lock_release(&rcu_sched_lock_map);
__release(RCU_SCHED);
preempt_enable();
#define RCU_INIT_POINTER(p, v) \
do { \
rcu_dereference_sparse(p, __rcu); \
- p = RCU_INITIALIZER(v); \
+ WRITE_ONCE(p, RCU_INITIALIZER(v)); \
} while (0)
/**
projects / karo-tx-linux.git / blobdiff