b0b3b2c78e
Convert powerpc to relative jump labels.
Before the patch, pseries_defconfig vmlinux.o has:
9074 __jump_table 0003f2a0 0000000000000000 0000000000000000 01321fa8 2**0
With the patch, the same config gets:
9074 __jump_table 0002a0e0 0000000000000000 0000000000000000 01321fb4 2**0
Size is 258720 without the patch, 172256 with the patch.
That's a 33% size reduction.
Largely copied from commit c296146c05 ("arm64/kernel: jump_label:
Switch to relative references")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/828348da7868eda953ce023994404dfc49603b64.1616514473.git.christophe.leroy@csgroup.eu
58 lines
1.3 KiB
C
58 lines
1.3 KiB
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
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#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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#ifndef __ASSEMBLY__
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#include <linux/types.h>
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#include <asm/feature-fixups.h>
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#include <asm/asm-const.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 static_key *key, bool branch)
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{
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asm_volatile_goto("1:\n\t"
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"nop # arch_static_branch\n\t"
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".pushsection __jump_table, \"aw\"\n\t"
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".long 1b - ., %l[l_yes] - .\n\t"
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JUMP_ENTRY_TYPE "%c0 - .\n\t"
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".popsection \n\t"
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: : "i" (&((char *)key)[branch]) : : 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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static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch)
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{
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asm_volatile_goto("1:\n\t"
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"b %l[l_yes] # arch_static_branch_jump\n\t"
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".pushsection __jump_table, \"aw\"\n\t"
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".long 1b - ., %l[l_yes] - .\n\t"
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JUMP_ENTRY_TYPE "%c0 - .\n\t"
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".popsection \n\t"
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: : "i" (&((char *)key)[branch]) : : 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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#else
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#define ARCH_STATIC_BRANCH(LABEL, KEY) \
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1098: nop; \
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.pushsection __jump_table, "aw"; \
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.long 1098b - ., LABEL - .; \
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FTR_ENTRY_LONG KEY; \
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.popsection
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#endif
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#endif /* _ASM_POWERPC_JUMP_LABEL_H */
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