mirror of
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2025-11-01 09:13:37 +00:00
ac5f89c7d8
This patch adds support for the new "jump label" feature. Unlike x86 and sparc we just merrily patch the code with no locks etc, as far as I know this is safe, but I'm not really sure what the x86/sparc code is protecting against so maybe it's not. I also don't see any reason for us to implement the poke_early() routine, even though sparc does. [BenH: Updated the patch to upstream generic changes] Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
47 lines
1 KiB
C
47 lines
1 KiB
C
#ifndef _ASM_POWERPC_JUMP_LABEL_H
|
|
#define _ASM_POWERPC_JUMP_LABEL_H
|
|
|
|
/*
|
|
* Copyright 2010 Michael Ellerman, IBM Corp.
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the License, or (at your option) any later version.
|
|
*/
|
|
|
|
#include <linux/types.h>
|
|
|
|
#include <asm/feature-fixups.h>
|
|
|
|
#define JUMP_ENTRY_TYPE stringify_in_c(FTR_ENTRY_LONG)
|
|
#define JUMP_LABEL_NOP_SIZE 4
|
|
|
|
static __always_inline bool arch_static_branch(struct jump_label_key *key)
|
|
{
|
|
asm goto("1:\n\t"
|
|
"nop\n\t"
|
|
".pushsection __jump_table, \"aw\"\n\t"
|
|
".align 4\n\t"
|
|
JUMP_ENTRY_TYPE "1b, %l[l_yes], %c0\n\t"
|
|
".popsection \n\t"
|
|
: : "i" (key) : : l_yes);
|
|
return false;
|
|
l_yes:
|
|
return true;
|
|
}
|
|
|
|
#ifdef CONFIG_PPC64
|
|
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;
|
|
jump_label_t pad;
|
|
};
|
|
|
|
#endif /* _ASM_POWERPC_JUMP_LABEL_H */
|