From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- arch/mips/kernel/jump_label.c | 109 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 109 insertions(+) create mode 100644 arch/mips/kernel/jump_label.c (limited to 'arch/mips/kernel/jump_label.c') diff --git a/arch/mips/kernel/jump_label.c b/arch/mips/kernel/jump_label.c new file mode 100644 index 0000000000..f7978d50a2 --- /dev/null +++ b/arch/mips/kernel/jump_label.c @@ -0,0 +1,109 @@ +/* + * 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 +#include +#include +#include +#include +#include + +#include +#include + +/* + * 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; + long offset; + + insn_p = (union mips_instruction *)msk_isa16_mode(e->code); + + /* 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) { + if (!IS_ENABLED(CONFIG_CPU_MICROMIPS) && MIPS_ISA_REV >= 6) { + offset = e->target - ((unsigned long)insn_p + 4); + offset >>= 2; + + /* + * The branch offset must fit in the instruction's 26 + * bit field. + */ + WARN_ON((offset >= (long)BIT(25)) || + (offset < -(long)BIT(25))); + + insn.j_format.opcode = bc6_op; + insn.j_format.target = offset; + } else { + /* + * Jump only works within an aligned region its delay + * slot is in. + */ + WARN_ON((e->target & ~J_RANGE_MASK) != + ((e->code + 4) & ~J_RANGE_MASK)); + + 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); +} + +#ifdef CONFIG_MODULES +void jump_label_apply_nops(struct module *mod) +{ + struct jump_entry *iter_start = mod->jump_entries; + struct jump_entry *iter_stop = iter_start + mod->num_jump_entries; + struct jump_entry *iter; + + /* if the module doesn't have jump label entries, just return */ + if (iter_start == iter_stop) + return; + + for (iter = iter_start; iter < iter_stop; iter++) { + /* Only write NOPs for arch_branch_static(). */ + if (jump_label_init_type(iter) == JUMP_LABEL_NOP) + arch_jump_label_transform(iter, JUMP_LABEL_NOP); + } +} +#endif -- cgit v1.2.3