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>
48 lines
1.0 KiB
C
48 lines
1.0 KiB
C
#ifndef _ASM_POWERPC_JUMP_LABEL_H
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#define _ASM_POWERPC_JUMP_LABEL_H
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/*
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* Copyright 2010 Michael Ellerman, IBM Corp.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/types.h>
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#include <asm/feature-fixups.h>
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#define JUMP_ENTRY_TYPE stringify_in_c(FTR_ENTRY_LONG)
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#define JUMP_LABEL_NOP_SIZE 4
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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("1:\n\t"
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"nop\n\t"
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".pushsection __jump_table, \"aw\"\n\t"
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".align 4\n\t"
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JUMP_ENTRY_TYPE "1b, %l[l_yes], %c0\n\t"
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".popsection \n\t"
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: : "i" (key) : : l_yes);
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return false;
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l_yes:
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return true;
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}
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#ifdef CONFIG_PPC64
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typedef u64 jump_label_t;
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#else
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typedef u32 jump_label_t;
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#endif
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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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jump_label_t pad;
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};
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#endif /* _ASM_POWERPC_JUMP_LABEL_H */
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