Commit 588de8c6 authored by George Guo's avatar George Guo Committed by Will Deacon
Browse files

arm64: simplify arch_static_branch/_jump function 



Extracted the jump table definition code from the arch_static_branch and
arch_static_branch_jump functions into a macro JUMP_TABLE_ENTRY to reduce
code duplication.

Signed-off-by: default avatarGeorge Guo <guodongtai@kylinos.cn>
Link: https://lore.kernel.org/r/20240430085655.2798551-2-dongtai.guo@linux.dev


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent 1279e8d0

arch/arm64/include/asm/jump_label.h

+15 −13
Original line number Diff line number Diff line
@@ -15,17 +15,23 @@ 


#define JUMP_LABEL_NOP_SIZE		AARCH64_INSN_SIZE



#define JUMP_TABLE_ENTRY(key, label)			\

	".pushsection	__jump_table, \"aw\"\n\t"	\

	".align		3\n\t"				\

	".long		1b - ., %l["#label"] - .\n\t"	\

	".quad		%c0 - .\n\t"			\

	".popsection\n\t"				\

	:  :  "i"(key) :  : label



static __always_inline bool arch_static_branch(struct static_key * const key,

					       const bool branch)

{

	char *k = &((char *)key)[branch];



	asm goto(

		"1:	nop					\n\t"

		 "	.pushsection	__jump_table, \"aw\"	\n\t"

		 "	.align		3			\n\t"

		 "	.long		1b - ., %l[l_yes] - .	\n\t"

		 "	.quad		%c0 - .			\n\t"

		 "	.popsection				\n\t"

		 :  :  "i"(&((char *)key)[branch]) :  : l_yes);

		JUMP_TABLE_ENTRY(k, l_yes)

		);



	return false;

l_yes:
@@ -35,15 +41,11 @@ static __always_inline bool arch_static_branch(struct static_key * const key, 
static __always_inline bool arch_static_branch_jump(struct static_key * const key,

						    const bool branch)

{

	char *k = &((char *)key)[branch];

	asm goto(

		"1:	b		%l[l_yes]		\n\t"

		 "	.pushsection	__jump_table, \"aw\"	\n\t"

		 "	.align		3			\n\t"

		 "	.long		1b - ., %l[l_yes] - .	\n\t"

		 "	.quad		%c0 - .			\n\t"

		 "	.popsection				\n\t"

		 :  :  "i"(&((char *)key)[branch]) :  : l_yes);



		JUMP_TABLE_ENTRY(k, l_yes)

		);

	return false;

l_yes:

	return true;