From a6aa8fca4d792c72947e341d7842d2f700534335 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Thu, 29 Jun 2017 13:59:27 +0100
Subject: [PATCH] dma-buf/sw-sync: Reduce irqsave/irqrestore from known context
Git-commit: a6aa8fca4d792c72947e341d7842d2f700534335
Patch-mainline: v4.14-rc1
References: bsc#794563

If we know the context under which we are called, then we can use the
simpler form of spin_lock_irq (saving the save/restore).

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: Gustavo Padovan <gustavo@padovan.org>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170629125930.821-4-chris@chris-wilson.co.uk
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/dma-buf/sw_sync.c    | 15 +++++++++------
 drivers/dma-buf/sync_debug.c | 14 ++++++--------
 2 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/drivers/dma-buf/sw_sync.c b/drivers/dma-buf/sw_sync.c
index 0e676d08aa70..fc733621987d 100644
--- a/drivers/dma-buf/sw_sync.c
+++ b/drivers/dma-buf/sw_sync.c
@@ -135,12 +135,11 @@ static void sync_timeline_put(struct sync_timeline *obj)
  */
 static void sync_timeline_signal(struct sync_timeline *obj, unsigned int inc)
 {
-	unsigned long flags;
 	struct sync_pt *pt, *next;
 
 	trace_sync_timeline(obj);
 
-	spin_lock_irqsave(&obj->child_list_lock, flags);
+	spin_lock_irq(&obj->child_list_lock);
 
 	obj->value += inc;
 
@@ -150,7 +149,7 @@ static void sync_timeline_signal(struct sync_timeline *obj, unsigned int inc)
 			list_del_init(&pt->active_list);
 	}
 
-	spin_unlock_irqrestore(&obj->child_list_lock, flags);
+	spin_unlock_irq(&obj->child_list_lock);
 }
 
 /**
@@ -167,7 +166,6 @@ static void sync_timeline_signal(struct sync_timeline *obj, unsigned int inc)
 static struct sync_pt *sync_pt_create(struct sync_timeline *obj, int size,
 			     unsigned int value)
 {
-	unsigned long flags;
 	struct sync_pt *pt;
 
 	if (size < sizeof(*pt))
@@ -177,13 +175,16 @@ static struct sync_pt *sync_pt_create(struct sync_timeline *obj, int size,
 	if (!pt)
 		return NULL;
 
-	spin_lock_irqsave(&obj->child_list_lock, flags);
+	spin_lock_irq(&obj->child_list_lock);
+
 	sync_timeline_get(obj);
 	dma_fence_init(&pt->base, &timeline_fence_ops, &obj->child_list_lock,
 		       obj->context, value);
 	list_add_tail(&pt->child_list, &obj->child_list_head);
 	INIT_LIST_HEAD(&pt->active_list);
-	spin_unlock_irqrestore(&obj->child_list_lock, flags);
+
+	spin_unlock_irq(&obj->child_list_lock);
+
 	return pt;
 }
 
@@ -206,9 +207,11 @@ static void timeline_fence_release(struct dma_fence *fence)
 	unsigned long flags;
 
 	spin_lock_irqsave(fence->lock, flags);
+
 	list_del(&pt->child_list);
 	if (!list_empty(&pt->active_list))
 		list_del(&pt->active_list);
+
 	spin_unlock_irqrestore(fence->lock, flags);
 
 	sync_timeline_put(parent);
diff --git a/drivers/dma-buf/sync_debug.c b/drivers/dma-buf/sync_debug.c
index 82a6e7f6d37f..0e91632248ba 100644
--- a/drivers/dma-buf/sync_debug.c
+++ b/drivers/dma-buf/sync_debug.c
@@ -116,17 +116,16 @@ static void sync_print_fence(struct seq_file *s,
 static void sync_print_obj(struct seq_file *s, struct sync_timeline *obj)
 {
 	struct list_head *pos;
-	unsigned long flags;
 
 	seq_printf(s, "%s: %d\n", obj->name, obj->value);
 
-	spin_lock_irqsave(&obj->child_list_lock, flags);
+	spin_lock_irq(&obj->child_list_lock);
 	list_for_each(pos, &obj->child_list_head) {
 		struct sync_pt *pt =
 			container_of(pos, struct sync_pt, child_list);
 		sync_print_fence(s, &pt->base, false);
 	}
-	spin_unlock_irqrestore(&obj->child_list_lock, flags);
+	spin_unlock_irq(&obj->child_list_lock);
 }
 
 static void sync_print_sync_file(struct seq_file *s,
@@ -151,12 +150,11 @@ static void sync_print_sync_file(struct seq_file *s,
 
 static int sync_debugfs_show(struct seq_file *s, void *unused)
 {
-	unsigned long flags;
 	struct list_head *pos;
 
 	seq_puts(s, "objs:\n--------------\n");
 
-	spin_lock_irqsave(&sync_timeline_list_lock, flags);
+	spin_lock_irq(&sync_timeline_list_lock);
 	list_for_each(pos, &sync_timeline_list_head) {
 		struct sync_timeline *obj =
 			container_of(pos, struct sync_timeline,
@@ -165,11 +163,11 @@ static int sync_debugfs_show(struct seq_file *s, void *unused)
 		sync_print_obj(s, obj);
 		seq_putc(s, '\n');
 	}
-	spin_unlock_irqrestore(&sync_timeline_list_lock, flags);
+	spin_unlock_irq(&sync_timeline_list_lock);
 
 	seq_puts(s, "fences:\n--------------\n");
 
-	spin_lock_irqsave(&sync_file_list_lock, flags);
+	spin_lock_irq(&sync_file_list_lock);
 	list_for_each(pos, &sync_file_list_head) {
 		struct sync_file *sync_file =
 			container_of(pos, struct sync_file, sync_file_list);
@@ -177,7 +175,7 @@ static int sync_debugfs_show(struct seq_file *s, void *unused)
 		sync_print_sync_file(s, sync_file);
 		seq_putc(s, '\n');
 	}
-	spin_unlock_irqrestore(&sync_file_list_lock, flags);
+	spin_unlock_irq(&sync_file_list_lock);
 	return 0;
 }
 
-- 
2.20.1

