7e6b9db27d
Instead of defaulting to patching NOP opcodes at init time, and leaving it to the architectures to override this if this is not needed, switch to a model where doing nothing is the default. This is the common case by far, as only MIPS requires NOP patching at init time. On all other architectures, the correct encodings are emitted by the compiler and so no initial patching is needed. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220615154142.1574619-4-ardb@kernel.org
78 lines
1.6 KiB
C
78 lines
1.6 KiB
C
/*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (c) 2010 Cavium Networks, Inc.
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*/
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#ifndef _ASM_MIPS_JUMP_LABEL_H
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#define _ASM_MIPS_JUMP_LABEL_H
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#define arch_jump_label_transform_static arch_jump_label_transform
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#ifndef __ASSEMBLY__
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#include <linux/types.h>
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#include <asm/isa-rev.h>
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#define JUMP_LABEL_NOP_SIZE 4
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#ifdef CONFIG_64BIT
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#define WORD_INSN ".dword"
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#else
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#define WORD_INSN ".word"
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#endif
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#ifdef CONFIG_CPU_MICROMIPS
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# define B_INSN "b32"
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# define J_INSN "j32"
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#elif MIPS_ISA_REV >= 6
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# define B_INSN "bc"
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# define J_INSN "bc"
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#else
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# define B_INSN "b"
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# define J_INSN "j"
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#endif
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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:\t" B_INSN " 2f\n\t"
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"2:\t.insn\n\t"
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".pushsection __jump_table, \"aw\"\n\t"
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WORD_INSN " 1b, %l[l_yes], %0\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:\t" J_INSN " %l[l_yes]\n\t"
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".pushsection __jump_table, \"aw\"\n\t"
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WORD_INSN " 1b, %l[l_yes], %0\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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#ifdef CONFIG_64BIT
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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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};
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#endif /* __ASSEMBLY__ */
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#endif /* _ASM_MIPS_JUMP_LABEL_H */
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