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| author | Jason Baron <jbaron@redhat.com> | 2010-09-17 19:09:22 +0400 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2010-09-23 00:33:03 +0400 |
| commit | d9f5ab7b1c0a520867af389bab5d5fcdbd0e407e (patch) | |
| tree | 23c9b85999b4340ec03ba0cef075b8ad73c4c994 /arch/x86/include/asm/jump_label.h | |
| parent | 52159d98be6f26c48f5e02c7ab3c9848a85979b5 (diff) | |
| download | linux-d9f5ab7b1c0a520867af389bab5d5fcdbd0e407e.tar.xz | |
jump label: x86 support
add x86 support for jump label. I'm keeping this patch separate so its clear
to arch maintainers what was required for x86 support this new feature.
Hopefully, it wouldn't be too painful for other archs.
Signed-off-by: Jason Baron <jbaron@redhat.com>
LKML-Reference: <f838f49f40fbea0254036194be66dc48b598dcea.1284733808.git.jbaron@redhat.com>
[ cleaned up some formatting ]
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'arch/x86/include/asm/jump_label.h')
| -rw-r--r-- | arch/x86/include/asm/jump_label.h | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/arch/x86/include/asm/jump_label.h b/arch/x86/include/asm/jump_label.h new file mode 100644 index 000000000000..b4a2cb403370 --- /dev/null +++ b/arch/x86/include/asm/jump_label.h @@ -0,0 +1,47 @@ +#ifndef _ASM_X86_JUMP_LABEL_H +#define _ASM_X86_JUMP_LABEL_H + +#ifdef __KERNEL__ + +#include <linux/types.h> +#include <asm/nops.h> + +#define JUMP_LABEL_NOP_SIZE 5 + +# define JUMP_LABEL_INITIAL_NOP ".byte 0xe9 \n\t .long 0\n\t" + +# define JUMP_LABEL(key, label) \ + do { \ + asm goto("1:" \ + JUMP_LABEL_INITIAL_NOP \ + ".pushsection __jump_table, \"a\" \n\t"\ + _ASM_PTR "1b, %l[" #label "], %c0 \n\t" \ + ".popsection \n\t" \ + : : "i" (key) : : label); \ + } while (0) + +#endif /* __KERNEL__ */ + +#ifdef CONFIG_X86_64 + +typedef u64 jump_label_t; + +struct jump_entry { + jump_label_t code; + jump_label_t target; + jump_label_t key; +}; + +#else + +typedef u32 jump_label_t; + +struct jump_entry { + jump_label_t code; + jump_label_t target; + jump_label_t key; +}; + +#endif + +#endif |