mirror of https://gitee.com/openkylin/linux.git
113 lines
2.4 KiB
C
113 lines
2.4 KiB
C
#ifndef _ASM_X86_JUMP_LABEL_H
|
|
#define _ASM_X86_JUMP_LABEL_H
|
|
|
|
#ifndef HAVE_JUMP_LABEL
|
|
/*
|
|
* For better or for worse, if jump labels (the gcc extension) are missing,
|
|
* then the entire static branch patching infrastructure is compiled out.
|
|
* If that happens, the code in here will malfunction. Raise a compiler
|
|
* error instead.
|
|
*
|
|
* In theory, jump labels and the static branch patching infrastructure
|
|
* could be decoupled to fix this.
|
|
*/
|
|
#error asm/jump_label.h included on a non-jump-label kernel
|
|
#endif
|
|
|
|
#define JUMP_LABEL_NOP_SIZE 5
|
|
|
|
#ifdef CONFIG_X86_64
|
|
# define STATIC_KEY_INIT_NOP P6_NOP5_ATOMIC
|
|
#else
|
|
# define STATIC_KEY_INIT_NOP GENERIC_NOP5_ATOMIC
|
|
#endif
|
|
|
|
#include <asm/asm.h>
|
|
#include <asm/nops.h>
|
|
|
|
#ifndef __ASSEMBLY__
|
|
|
|
#include <linux/stringify.h>
|
|
#include <linux/types.h>
|
|
|
|
static __always_inline bool arch_static_branch(struct static_key *key, bool branch)
|
|
{
|
|
asm_volatile_goto("1:"
|
|
".byte " __stringify(STATIC_KEY_INIT_NOP) "\n\t"
|
|
".pushsection __jump_table, \"aw\" \n\t"
|
|
_ASM_ALIGN "\n\t"
|
|
_ASM_PTR "1b, %l[l_yes], %c0 + %c1 \n\t"
|
|
".popsection \n\t"
|
|
: : "i" (key), "i" (branch) : : l_yes);
|
|
|
|
return false;
|
|
l_yes:
|
|
return true;
|
|
}
|
|
|
|
static __always_inline bool arch_static_branch_jump(struct static_key *key, 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"
|
|
_ASM_PTR "1b, %l[l_yes], %c0 + %c1 \n\t"
|
|
".popsection \n\t"
|
|
: : "i" (key), "i" (branch) : : l_yes);
|
|
|
|
return false;
|
|
l_yes:
|
|
return true;
|
|
}
|
|
|
|
#ifdef CONFIG_X86_64
|
|
typedef u64 jump_label_t;
|
|
#else
|
|
typedef u32 jump_label_t;
|
|
#endif
|
|
|
|
struct jump_entry {
|
|
jump_label_t code;
|
|
jump_label_t target;
|
|
jump_label_t key;
|
|
};
|
|
|
|
#else /* __ASSEMBLY__ */
|
|
|
|
.macro STATIC_JUMP_IF_TRUE target, key, def
|
|
.Lstatic_jump_\@:
|
|
.if \def
|
|
/* Equivalent to "jmp.d32 \target" */
|
|
.byte 0xe9
|
|
.long \target - .Lstatic_jump_after_\@
|
|
.Lstatic_jump_after_\@:
|
|
.else
|
|
.byte STATIC_KEY_INIT_NOP
|
|
.endif
|
|
.pushsection __jump_table, "aw"
|
|
_ASM_ALIGN
|
|
_ASM_PTR .Lstatic_jump_\@, \target, \key
|
|
.popsection
|
|
.endm
|
|
|
|
.macro STATIC_JUMP_IF_FALSE target, key, def
|
|
.Lstatic_jump_\@:
|
|
.if \def
|
|
.byte STATIC_KEY_INIT_NOP
|
|
.else
|
|
/* Equivalent to "jmp.d32 \target" */
|
|
.byte 0xe9
|
|
.long \target - .Lstatic_jump_after_\@
|
|
.Lstatic_jump_after_\@:
|
|
.endif
|
|
.pushsection __jump_table, "aw"
|
|
_ASM_ALIGN
|
|
_ASM_PTR .Lstatic_jump_\@, \target, \key + 1
|
|
.popsection
|
|
.endm
|
|
|
|
#endif /* __ASSEMBLY__ */
|
|
|
|
#endif
|