9b6584e35f
MIPSr6 introduced compact branches which have no delay slots. Make use of them for jump labels in order to avoid the need for a nop to fill the branch or jump delay slot, saving 4 bytes of code for each static branch. Signed-off-by: Paul Burton <paul.burton@mips.com> Cc: linux-mips@vger.kernel.org
76 lines
1.5 KiB
C
76 lines
1.5 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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#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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