Commit e1aa35c4 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

jump_label, x86: Factor out the __jump_table generation 



Both arch_static_branch() and arch_static_branch_jump() have the same
blurb to generate the __jump_table entry, share it.

Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210506194157.663132781@infradead.org
parent 8bfafcdc

arch/x86/include/asm/jump_label.h

+12 −12
Original line number Diff line number Diff line
@@ -14,15 +14,19 @@ 
#include <linux/stringify.h>

#include <linux/types.h>



#define JUMP_TABLE_ENTRY				\

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

	_ASM_ALIGN "\n\t"				\

	".long 1b - . \n\t"				\

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

	_ASM_PTR "%c0 + %c1 - .\n\t"			\

	".popsection \n\t"



static __always_inline bool arch_static_branch(struct static_key * const key, const bool branch)

{

	asm_volatile_goto("1:"

		".byte " __stringify(BYTES_NOP5) "\n\t"

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

		_ASM_ALIGN "\n\t"

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

		_ASM_PTR "%c0 + %c1 - .\n\t"

		".popsection \n\t"

		JUMP_TABLE_ENTRY

		: :  "i" (key), "i" (branch) : : l_yes);



	return false;
@@ -33,13 +37,9 @@ static __always_inline bool arch_static_branch(struct static_key * const key, co 
static __always_inline bool arch_static_branch_jump(struct static_key * const key, const bool branch)

{

	asm_volatile_goto("1:"

		".byte 0xe9\n\t .long %l[l_yes] - 2f\n\t"

		"2:\n\t"

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

		_ASM_ALIGN "\n\t"

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

		_ASM_PTR "%c0 + %c1 - .\n\t"

		".popsection \n\t"

		".byte 0xe9 \n\t"

		".long %l[l_yes] - (. + 4) \n\t"

		JUMP_TABLE_ENTRY

		: :  "i" (key), "i" (branch) : : l_yes);



	return false;