[tip: perf/kprobes] llist: Add nonatomic __llist_add() and __llist_dell_all()

tip-bot2 for Peter Zijlstra
2020-10-12T17:08:35Z

The following commit has been merged into the perf/kprobes branch of tip:

Commit-ID: 476c5818c37a7828d558f34ae01f0c32f8bfadde
Gitweb: https://git.kernel.org/tip/476c5818c37a7828d558f34ae01f0c32f8bfadde
Author: Peter Zijlstra <peterz@infradead.org>
AuthorDate: Sat, 29 Aug 2020 22:03:13 +09:00
Committer: Ingo Molnar <mingo@kernel.org>
CommitterDate: Mon, 12 Oct 2020 18:27:27 +02:00

llist: Add nonatomic __llist_add() and __llist_dell_all()

We'll use these in the new, lockless kretprobes code.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/159870619318.1229682.13027387548510028721.stgit@devnote2
---
drivers/gpu/drm/i915/i915_request.c | 6 ------
include/linux/llist.h | 23 +++++++++++++++++++++++
2 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index 0b2fe55..0e851b9 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -357,12 +357,6 @@ void i915_request_retire_upto(struct i915_request *rq)
} while (i915_request_retire(tmp) && tmp != rq);
}

-static void __llist_add(struct llist_node *node, struct llist_head *head)
-{
- node->next = head->first;
- head->first = node;
-}
-
static struct i915_request * const *
__engine_active(struct intel_engine_cs *engine)
{
diff --git a/include/linux/llist.h b/include/linux/llist.h
index 2e9c721..24f207b 100644
--- a/include/linux/llist.h
+++ b/include/linux/llist.h
@@ -197,6 +197,16 @@ static inline struct llist_node *llist_next(struct llist_node *node)
extern bool llist_add_batch(struct llist_node *new_first,
struct llist_node *new_last,
struct llist_head *head);
+
+static inline bool __llist_add_batch(struct llist_node *new_first,
+ struct llist_node *new_last,
+ struct llist_head *head)
+{
+ new_last->next = head->first;
+ head->first = new_first;
+ return new_last->next == NULL;
+}
+
/**
* llist_add - add a new entry
* @new: new entry to be added
@@ -209,6 +219,11 @@ static inline bool llist_add(struct llist_node *new, struct llist_head *head)
return llist_add_batch(new, new, head);
}

+static inline bool __llist_add(struct llist_node *new, struct llist_head *head)
+{
+ return __llist_add_batch(new, new, head);
+}
+
/**
* llist_del_all - delete all entries from lock-less list
* @head: the head of lock-less list to delete all entries
@@ -222,6 +237,14 @@ static inline struct llist_node *llist_del_all(struct llist_head *head)
return xchg(&head->first, NULL);
}

+static inline struct llist_node *__llist_del_all(struct llist_head *head)
+{
+ struct llist_node *first = head->first;
+
+ head->first = NULL;
+ return first;
+}
+
extern struct llist_node *llist_del_first(struct llist_head *head);

struct llist_node *llist_reverse_order(struct llist_node *head);