From ef0da55a84a345f323ceddda3b6c78b25de90435 Mon Sep 17 00:00:00 2001
From: Catalin Marinas <catalin.marinas@arm.com>
Date: Mon, 5 Sep 2016 18:25:47 +0100
Subject: [PATCH] jump_labels: Allow array initialisers
The static key API is currently designed around single variable
definitions. There are cases where an array of static keys is desirable,
so extend the API to allow this rather than using the internal static
key implementation directly.
Cc: Jason Baron <jbaron@akamai.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Suggested-by: Dave P Martin <Dave.Martin@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
---
Documentation/static-keys.txt | 9 +++++++++
include/linux/jump_label.h | 12 ++++++++++++
2 files changed, 21 insertions(+)
diff --git a/Documentation/static-keys.txt b/Documentation/static-keys.txt
index 477927becacb..ea8d7b4e53f0 100644
--- a/Documentation/static-keys.txt
+++ b/Documentation/static-keys.txt
@@ -15,6 +15,8 @@ The updated API replacements are:
DEFINE_STATIC_KEY_TRUE(key);
DEFINE_STATIC_KEY_FALSE(key);
+DEFINE_STATIC_KEY_ARRAY_TRUE(keys, count);
+DEFINE_STATIC_KEY_ARRAY_FALSE(keys, count);
static_branch_likely()
static_branch_unlikely()
@@ -140,6 +142,13 @@ static_branch_inc(), will change the branch back to true. Likewise, if the
key is initialized false, a 'static_branch_inc()', will change the branch to
true. And then a 'static_branch_dec()', will again make the branch false.
+Where an array of keys is required, it can be defined as:
+
+ DEFINE_STATIC_KEY_ARRAY_TRUE(keys, count);
+
+or:
+
+ DEFINE_STATIC_KEY_ARRAY_FALSE(keys, count);
4) Architecture level code patching interface, 'jump labels'
diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h
index 661af564fae8..a534c7f15a61 100644
--- a/include/linux/jump_label.h
+++ b/include/linux/jump_label.h
@@ -21,6 +21,8 @@
*
* DEFINE_STATIC_KEY_TRUE(key);
* DEFINE_STATIC_KEY_FALSE(key);
+ * DEFINE_STATIC_KEY_ARRAY_TRUE(keys, count);
+ * DEFINE_STATIC_KEY_ARRAY_FALSE(keys, count);
* static_branch_likely()
* static_branch_unlikely()
*
@@ -270,6 +272,16 @@ struct static_key_false {
#define DEFINE_STATIC_KEY_FALSE(name) \
struct static_key_false name = STATIC_KEY_FALSE_INIT
+#define DEFINE_STATIC_KEY_ARRAY_TRUE(name, count) \
+ struct static_key_true name[count] = { \
+ [0 ... (count) - 1] = STATIC_KEY_TRUE_INIT, \
+ }
+
+#define DEFINE_STATIC_KEY_ARRAY_FALSE(name, count) \
+ struct static_key_false name[count] = { \
+ [0 ... (count) - 1] = STATIC_KEY_FALSE_INIT, \
+ }
+
extern bool ____wrong_branch_error(void);
#define static_key_enabled(x) \