diff mbox

[v2,1/2] jump_labels: Allow array initialisers

Message ID 1473096348-19548-2-git-send-email-catalin.marinas@arm.com
State Accepted
Commit ef0da55a84a345f323ceddda3b6c78b25de90435
Headers show

Commit Message

Catalin Marinas Sept. 5, 2016, 5:25 p.m. UTC 
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.

Suggested-by: Dave P Martin <Dave.Martin@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

---
 Documentation/static-keys.txt |  9 +++++++++
 include/linux/jump_label.h    | 12 ++++++++++++
 2 files changed, 21 insertions(+)

Comments

Will Deacon Sept. 6, 2016, 6:11 p.m. UTC | #1 
On Mon, Sep 05, 2016 at 06:25:47PM +0100, Catalin Marinas wrote:
> 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.

> 

> Suggested-by: Dave P Martin <Dave.Martin@arm.com>

> Cc: Peter Zijlstra <peterz@infradead.org>

> Cc: Jason Baron <jbaron@akamai.com>

> Cc: Jonathan Corbet <corbet@lwn.net>

> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

> ---

>  Documentation/static-keys.txt |  9 +++++++++

>  include/linux/jump_label.h    | 12 ++++++++++++

>  2 files changed, 21 insertions(+)


This looks pretty straightforward to me, and I'd like to take it via
the arm64 tree given that your subsequent patch depends on it.

Peter -- are you ok with this?

Cheers,

Will
diff mbox

Patch

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)							\