move Rust sources to top level, C sources into c_src

[bcachefs-tools-debian] / c_src / linux / closure.c

diff --git a/c_src/linux/closure.c b/c_src/linux/closure.c
new file mode 100644 (file)
index 0000000..c165405
--- /dev/null
+++ b/c_src/linux/closure.c
@@ -0,0 +1,211 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Asynchronous refcounty things
+ *
+ * Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
+ * Copyright 2012 Google, Inc.
+ */
+
+#include <linux/closure.h>
+#include <linux/debugfs.h>
+#include <linux/export.h>
+#include <linux/rcupdate.h>
+#include <linux/seq_file.h>
+#include <linux/sched/debug.h>
+
+static inline void closure_put_after_sub(struct closure *cl, int flags)
+{
+       int r = flags & CLOSURE_REMAINING_MASK;
+
+       BUG_ON(flags & CLOSURE_GUARD_MASK);
+       BUG_ON(!r && (flags & ~CLOSURE_DESTRUCTOR));
+
+       if (!r) {
+               smp_acquire__after_ctrl_dep();
+
+               cl->closure_get_happened = false;
+
+               if (cl->fn && !(flags & CLOSURE_DESTRUCTOR)) {
+                       atomic_set(&cl->remaining,
+                                  CLOSURE_REMAINING_INITIALIZER);
+                       closure_queue(cl);
+               } else {
+                       struct closure *parent = cl->parent;
+                       closure_fn *destructor = cl->fn;
+
+                       closure_debug_destroy(cl);
+
+                       if (destructor)
+                               destructor(&cl->work);
+
+                       if (parent)
+                               closure_put(parent);
+               }
+       }
+}
+
+/* For clearing flags with the same atomic op as a put */
+void closure_sub(struct closure *cl, int v)
+{
+       closure_put_after_sub(cl, atomic_sub_return_release(v, &cl->remaining));
+}
+EXPORT_SYMBOL(closure_sub);
+
+/*
+ * closure_put - decrement a closure's refcount
+ */
+void closure_put(struct closure *cl)
+{
+       closure_put_after_sub(cl, atomic_dec_return_release(&cl->remaining));
+}
+EXPORT_SYMBOL(closure_put);
+
+/*
+ * closure_wake_up - wake up all closures on a wait list, without memory barrier
+ */
+void __closure_wake_up(struct closure_waitlist *wait_list)
+{
+       struct llist_node *list;
+       struct closure *cl, *t;
+       struct llist_node *reverse = NULL;
+
+       list = llist_del_all(&wait_list->list);
+
+       /* We first reverse the list to preserve FIFO ordering and fairness */
+       reverse = llist_reverse_order(list);
+
+       /* Then do the wakeups */
+       llist_for_each_entry_safe(cl, t, reverse, list) {
+               closure_set_waiting(cl, 0);
+               closure_sub(cl, CLOSURE_WAITING + 1);
+       }
+}
+EXPORT_SYMBOL(__closure_wake_up);
+
+/**
+ * closure_wait - add a closure to a waitlist
+ * @waitlist: will own a ref on @cl, which will be released when
+ * closure_wake_up() is called on @waitlist.
+ * @cl: closure pointer.
+ *
+ */
+bool closure_wait(struct closure_waitlist *waitlist, struct closure *cl)
+{
+       if (atomic_read(&cl->remaining) & CLOSURE_WAITING)
+               return false;
+
+       cl->closure_get_happened = true;
+       closure_set_waiting(cl, _RET_IP_);
+       atomic_add(CLOSURE_WAITING + 1, &cl->remaining);
+       llist_add(&cl->list, &waitlist->list);
+
+       return true;
+}
+EXPORT_SYMBOL(closure_wait);
+
+struct closure_syncer {
+       struct task_struct      *task;
+       int                     done;
+};
+
+static CLOSURE_CALLBACK(closure_sync_fn)
+{
+       struct closure *cl = container_of(ws, struct closure, work);
+       struct closure_syncer *s = cl->s;
+       struct task_struct *p;
+
+       rcu_read_lock();
+       p = READ_ONCE(s->task);
+       s->done = 1;
+       wake_up_process(p);
+       rcu_read_unlock();
+}
+
+void __sched __closure_sync(struct closure *cl)
+{
+       struct closure_syncer s = { .task = current };
+
+       cl->s = &s;
+       continue_at(cl, closure_sync_fn, NULL);
+
+       while (1) {
+               set_current_state(TASK_UNINTERRUPTIBLE);
+               if (s.done)
+                       break;
+               schedule();
+       }
+
+       __set_current_state(TASK_RUNNING);
+}
+EXPORT_SYMBOL(__closure_sync);
+
+#ifdef CONFIG_DEBUG_CLOSURES
+
+static LIST_HEAD(closure_list);
+static DEFINE_SPINLOCK(closure_list_lock);
+
+void closure_debug_create(struct closure *cl)
+{
+       unsigned long flags;
+
+       BUG_ON(cl->magic == CLOSURE_MAGIC_ALIVE);
+       cl->magic = CLOSURE_MAGIC_ALIVE;
+
+       spin_lock_irqsave(&closure_list_lock, flags);
+       list_add(&cl->all, &closure_list);
+       spin_unlock_irqrestore(&closure_list_lock, flags);
+}
+EXPORT_SYMBOL(closure_debug_create);
+
+void closure_debug_destroy(struct closure *cl)
+{
+       unsigned long flags;
+
+       BUG_ON(cl->magic != CLOSURE_MAGIC_ALIVE);
+       cl->magic = CLOSURE_MAGIC_DEAD;
+
+       spin_lock_irqsave(&closure_list_lock, flags);
+       list_del(&cl->all);
+       spin_unlock_irqrestore(&closure_list_lock, flags);
+}
+EXPORT_SYMBOL(closure_debug_destroy);
+
+static int debug_show(struct seq_file *f, void *data)
+{
+       struct closure *cl;
+
+       spin_lock_irq(&closure_list_lock);
+
+       list_for_each_entry(cl, &closure_list, all) {
+               int r = atomic_read(&cl->remaining);
+
+               seq_printf(f, "%p: %pS -> %pS p %p r %i ",
+                          cl, (void *) cl->ip, cl->fn, cl->parent,
+                          r & CLOSURE_REMAINING_MASK);
+
+               seq_printf(f, "%s%s\n",
+                          test_bit(WORK_STRUCT_PENDING_BIT,
+                                   work_data_bits(&cl->work)) ? "Q" : "",
+                          r & CLOSURE_RUNNING  ? "R" : "");
+
+               if (r & CLOSURE_WAITING)
+                       seq_printf(f, " W %pS\n",
+                                  (void *) cl->waiting_on);
+
+               seq_puts(f, "\n");
+       }
+
+       spin_unlock_irq(&closure_list_lock);
+       return 0;
+}
+
+DEFINE_SHOW_ATTRIBUTE(debug);
+
+static int __init closure_debug_init(void)
+{
+       debugfs_create_file("closures", 0400, NULL, NULL, &debug_fops);
+       return 0;
+}
+late_initcall(closure_debug_init)
+
+#endif