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Implement the architecture backend for jump label support on s390. For a shared kernel booted from a NSS silently disable jump labels because the NSS is read-only. Therefore jump labels will be disabled in a shared kernel and can't be activated. Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com> LKML-Reference: <6935d2c41ce111e1719176ed4bbd3dbe4de80855.1300299760.git.jbaron@redhat.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
38 lines
669 B
C
38 lines
669 B
C
#ifndef _ASM_S390_JUMP_LABEL_H
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#define _ASM_S390_JUMP_LABEL_H
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#include <linux/types.h>
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#define JUMP_LABEL_NOP_SIZE 6
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#ifdef CONFIG_64BIT
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#define ASM_PTR ".quad"
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#define ASM_ALIGN ".balign 8"
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#else
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#define ASM_PTR ".long"
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#define ASM_ALIGN ".balign 4"
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#endif
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static __always_inline bool arch_static_branch(struct jump_label_key *key)
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{
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asm goto("0: brcl 0,0\n"
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".pushsection __jump_table, \"aw\"\n"
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ASM_ALIGN "\n"
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ASM_PTR " 0b, %l[label], %0\n"
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".popsection\n"
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: : "X" (key) : : label);
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return false;
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label:
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return true;
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}
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typedef unsigned long jump_label_t;
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struct jump_entry {
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jump_label_t code;
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jump_label_t target;
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jump_label_t key;
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};
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#endif
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