Merge branch '4.0.8-rt6'

[zynq/linux.git] / kernel / locking / lglock.c

diff --git a/kernel/locking/lglock.c b/kernel/locking/lglock.c
index 86ae2aebf00432f4d681a413febebff79406889d..9397974b142fa37adde39c83095528fd6b715467 100644 (file)
--- a/kernel/locking/lglock.c
+++ b/kernel/locking/lglock.c
@@ -4,6 +4,15 @@
 #include <linux/cpu.h>
 #include <linux/string.h>
 
+#ifndef CONFIG_PREEMPT_RT_FULL
+# define lg_lock_ptr           arch_spinlock_t
+# define lg_do_lock(l)         arch_spin_lock(l)
+# define lg_do_unlock(l)       arch_spin_unlock(l)
+#else
+# define lg_lock_ptr           struct rt_mutex
+# define lg_do_lock(l)         __rt_spin_lock(l)
+# define lg_do_unlock(l)       __rt_spin_unlock(l)
+#endif
 /*
  * Note there is no uninit, so lglocks cannot be defined in
  * modules (but it's fine to use them from there)
@@ -12,51 +21,60 @@
 
 void lg_lock_init(struct lglock *lg, char *name)
 {
+#ifdef CONFIG_PREEMPT_RT_FULL
+       int i;
+
+       for_each_possible_cpu(i) {
+               struct rt_mutex *lock = per_cpu_ptr(lg->lock, i);
+
+               rt_mutex_init(lock);
+       }
+#endif
        LOCKDEP_INIT_MAP(&lg->lock_dep_map, name, &lg->lock_key, 0);
 }
 EXPORT_SYMBOL(lg_lock_init);
 
 void lg_local_lock(struct lglock *lg)
 {
-       arch_spinlock_t *lock;
+       lg_lock_ptr *lock;
 
-       preempt_disable();
+       migrate_disable();
        lock_acquire_shared(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
        lock = this_cpu_ptr(lg->lock);
-       arch_spin_lock(lock);
+       lg_do_lock(lock);
 }
 EXPORT_SYMBOL(lg_local_lock);
 
 void lg_local_unlock(struct lglock *lg)
 {
-       arch_spinlock_t *lock;
+       lg_lock_ptr *lock;
 
        lock_release(&lg->lock_dep_map, 1, _RET_IP_);
        lock = this_cpu_ptr(lg->lock);
-       arch_spin_unlock(lock);
-       preempt_enable();
+       lg_do_unlock(lock);
+       migrate_enable();
 }
 EXPORT_SYMBOL(lg_local_unlock);
 
 void lg_local_lock_cpu(struct lglock *lg, int cpu)
 {
-       arch_spinlock_t *lock;
+       lg_lock_ptr *lock;
 
-       preempt_disable();
+       preempt_disable_nort();
        lock_acquire_shared(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
        lock = per_cpu_ptr(lg->lock, cpu);
-       arch_spin_lock(lock);
+       lg_do_lock(lock);
 }
 EXPORT_SYMBOL(lg_local_lock_cpu);
 
 void lg_local_unlock_cpu(struct lglock *lg, int cpu)
 {
-       arch_spinlock_t *lock;
+       lg_lock_ptr *lock;
 
        lock_release(&lg->lock_dep_map, 1, _RET_IP_);
        lock = per_cpu_ptr(lg->lock, cpu);
-       arch_spin_unlock(lock);
-       preempt_enable();
+       lg_do_unlock(lock);
+       preempt_enable_nort();
 }
 EXPORT_SYMBOL(lg_local_unlock_cpu);
 
@@ -64,12 +82,12 @@ void lg_global_lock(struct lglock *lg)
 {
        int i;
 
-       preempt_disable();
+       preempt_disable_nort();
        lock_acquire_exclusive(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
        for_each_possible_cpu(i) {
-               arch_spinlock_t *lock;
+               lg_lock_ptr *lock;
                lock = per_cpu_ptr(lg->lock, i);
-               arch_spin_lock(lock);
+               lg_do_lock(lock);
        }
 }
 EXPORT_SYMBOL(lg_global_lock);
@@ -80,10 +98,35 @@ void lg_global_unlock(struct lglock *lg)
 
        lock_release(&lg->lock_dep_map, 1, _RET_IP_);
        for_each_possible_cpu(i) {
-               arch_spinlock_t *lock;
+               lg_lock_ptr *lock;
                lock = per_cpu_ptr(lg->lock, i);
-               arch_spin_unlock(lock);
+               lg_do_unlock(lock);
        }
-       preempt_enable();
+       preempt_enable_nort();
 }
 EXPORT_SYMBOL(lg_global_unlock);
+
+#ifdef CONFIG_PREEMPT_RT_FULL
+/*
+ * HACK: If you use this, you get to keep the pieces.
+ * Used in queue_stop_cpus_work() when stop machinery
+ * is called from inactive CPU, so we can't schedule.
+ */
+# define lg_do_trylock_relax(l)                        \
+       do {                                    \
+               while (!__rt_spin_trylock(l))   \
+                       cpu_relax();            \
+       } while (0)
+
+void lg_global_trylock_relax(struct lglock *lg)
+{
+       int i;
+
+       lock_acquire_exclusive(&lg->lock_dep_map, 0, 0, NULL, _RET_IP_);
+       for_each_possible_cpu(i) {
+               lg_lock_ptr *lock;
+               lock = per_cpu_ptr(lg->lock, i);
+               lg_do_trylock_relax(lock);
+       }
+}
+#endif