Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit ef0da55a authored by Catalin Marinas's avatar Catalin Marinas Committed by Will Deacon
Browse files

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: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Suggested-by: default avatarDave P Martin <Dave.Martin@arm.com>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
parent dae8c235

Documentation/static-keys.txt

+9 −0
Original line number Diff line number Diff line
@@ -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'

include/linux/jump_label.h

+12 −0
Original line number Diff line number Diff line
@@ -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)							\