/* * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. * * Copyright (c) 2010 Cavium Networks, Inc. */ #include <linux/jump_label.h> #include <linux/kernel.h> #include <linux/memory.h> #include <linux/mutex.h> #include <linux/types.h> #include <linux/cpu.h> #include <asm/cacheflush.h> #include <asm/inst.h> #ifdef HAVE_JUMP_LABEL /* * Define parameters for the standard MIPS and the microMIPS jump * instruction encoding respectively: * * - the ISA bit of the target, either 0 or 1 respectively, * * - the amount the jump target address is shifted right to fit in the * immediate field of the machine instruction, either 2 or 1, * * - the mask determining the size of the jump region relative to the * delay-slot instruction, either 256MB or 128MB, * * - the jump target alignment, either 4 or 2 bytes. */ #define J_ISA_BIT IS_ENABLED(CONFIG_CPU_MICROMIPS) #define J_RANGE_SHIFT (2 - J_ISA_BIT) #define J_RANGE_MASK ((1ul << (26 + J_RANGE_SHIFT)) - 1) #define J_ALIGN_MASK ((1ul << J_RANGE_SHIFT) - 1) void arch_jump_label_transform(struct jump_entry *e, enum jump_label_type type) { union mips_instruction *insn_p; union mips_instruction insn; insn_p = (union mips_instruction *)msk_isa16_mode(e->code); /* Jump only works within an aligned region its delay slot is in. */ BUG_ON((e->target & ~J_RANGE_MASK) != ((e->code + 4) & ~J_RANGE_MASK)); /* Target must have the right alignment and ISA must be preserved. */ BUG_ON((e->target & J_ALIGN_MASK) != J_ISA_BIT); if (type == JUMP_LABEL_JMP) { insn.j_format.opcode = J_ISA_BIT ? mm_j32_op : j_op; insn.j_format.target = e->target >> J_RANGE_SHIFT; } else { insn.word = 0; /* nop */ } mutex_lock(&text_mutex); if (IS_ENABLED(CONFIG_CPU_MICROMIPS)) { insn_p->halfword[0] = insn.word >> 16; insn_p->halfword[1] = insn.word; } else *insn_p = insn; flush_icache_range((unsigned long)insn_p, (unsigned long)insn_p + sizeof(*insn_p)); mutex_unlock(&text_mutex); } #endif /* HAVE_JUMP_LABEL */