linux_dsm_epyc7002/arch/s390/include/asm/jump_label.h
Anton Blanchard 55dd0df781 jump_label: Allow asm/jump_label.h to be included in assembly
Wrap asm/jump_label.h for all archs with #ifndef __ASSEMBLY__.
Since these are kernel only headers, we don't need #ifdef
__KERNEL__ so can simplify things a bit.

If an architecture wants to use jump labels in assembly, it
will still need to define a macro to create the __jump_table
entries (see ARCH_STATIC_BRANCH in the powerpc asm/jump_label.h
for an example).

Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: benh@kernel.crashing.org
Cc: catalin.marinas@arm.com
Cc: davem@davemloft.net
Cc: heiko.carstens@de.ibm.com
Cc: jbaron@akamai.com
Cc: linux@arm.linux.org.uk
Cc: linuxppc-dev@lists.ozlabs.org
Cc: liuj97@gmail.com
Cc: mgorman@suse.de
Cc: mmarek@suse.cz
Cc: mpe@ellerman.id.au
Cc: paulus@samba.org
Cc: ralf@linux-mips.org
Cc: rostedt@goodmis.org
Cc: schwidefsky@de.ibm.com
Cc: will.deacon@arm.com
Link: http://lkml.kernel.org/r/1428551492-21977-1-git-send-email-anton@samba.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-04-09 09:40:23 +02:00

46 lines
938 B
C

#ifndef _ASM_S390_JUMP_LABEL_H
#define _ASM_S390_JUMP_LABEL_H
#ifndef __ASSEMBLY__
#include <linux/types.h>
#define JUMP_LABEL_NOP_SIZE 6
#define JUMP_LABEL_NOP_OFFSET 2
#ifdef CONFIG_64BIT
#define ASM_PTR ".quad"
#define ASM_ALIGN ".balign 8"
#else
#define ASM_PTR ".long"
#define ASM_ALIGN ".balign 4"
#endif
/*
* We use a brcl 0,2 instruction for jump labels at compile time so it
* can be easily distinguished from a hotpatch generated instruction.
*/
static __always_inline bool arch_static_branch(struct static_key *key)
{
asm_volatile_goto("0: brcl 0,"__stringify(JUMP_LABEL_NOP_OFFSET)"\n"
".pushsection __jump_table, \"aw\"\n"
ASM_ALIGN "\n"
ASM_PTR " 0b, %l[label], %0\n"
".popsection\n"
: : "X" (key) : : label);
return false;
label:
return true;
}
typedef unsigned long jump_label_t;
struct jump_entry {
jump_label_t code;
jump_label_t target;
jump_label_t key;
};
#endif /* __ASSEMBLY__ */
#endif