| /* SPDX-License-Identifier: GPL-2.0 */ |
| /* Copyright (C) 2017 Andes Technology Corporation */ |
| |
| #ifndef _ASM_RISCV_MODULE_H |
| #define _ASM_RISCV_MODULE_H |
| |
| #include <asm-generic/module.h> |
| |
| #define MODULE_ARCH_VERMAGIC "riscv" |
| |
| struct module; |
| unsigned long module_emit_got_entry(struct module *mod, unsigned long val); |
| unsigned long module_emit_plt_entry(struct module *mod, unsigned long val); |
| |
| #ifdef CONFIG_MODULE_SECTIONS |
| struct mod_section { |
| Elf_Shdr *shdr; |
| int num_entries; |
| int max_entries; |
| }; |
| |
| struct mod_arch_specific { |
| struct mod_section got; |
| struct mod_section plt; |
| struct mod_section got_plt; |
| }; |
| |
| struct got_entry { |
| unsigned long symbol_addr; /* the real variable address */ |
| }; |
| |
| static inline struct got_entry emit_got_entry(unsigned long val) |
| { |
| return (struct got_entry) {val}; |
| } |
| |
| static inline struct got_entry *get_got_entry(unsigned long val, |
| const struct mod_section *sec) |
| { |
| struct got_entry *got = (struct got_entry *)(sec->shdr->sh_addr); |
| int i; |
| for (i = 0; i < sec->num_entries; i++) { |
| if (got[i].symbol_addr == val) |
| return &got[i]; |
| } |
| return NULL; |
| } |
| |
| struct plt_entry { |
| /* |
| * Trampoline code to real target address. The return address |
| * should be the original (pc+4) before entring plt entry. |
| */ |
| u32 insn_auipc; /* auipc t0, 0x0 */ |
| u32 insn_ld; /* ld t1, 0x10(t0) */ |
| u32 insn_jr; /* jr t1 */ |
| }; |
| |
| #define OPC_AUIPC 0x0017 |
| #define OPC_LD 0x3003 |
| #define OPC_JALR 0x0067 |
| #define REG_T0 0x5 |
| #define REG_T1 0x6 |
| |
| static inline struct plt_entry emit_plt_entry(unsigned long val, |
| unsigned long plt, |
| unsigned long got_plt) |
| { |
| /* |
| * U-Type encoding: |
| * +------------+----------+----------+ |
| * | imm[31:12] | rd[11:7] | opc[6:0] | |
| * +------------+----------+----------+ |
| * |
| * I-Type encoding: |
| * +------------+------------+--------+----------+----------+ |
| * | imm[31:20] | rs1[19:15] | funct3 | rd[11:7] | opc[6:0] | |
| * +------------+------------+--------+----------+----------+ |
| * |
| */ |
| unsigned long offset = got_plt - plt; |
| u32 hi20 = (offset + 0x800) & 0xfffff000; |
| u32 lo12 = (offset - hi20); |
| return (struct plt_entry) { |
| OPC_AUIPC | (REG_T0 << 7) | hi20, |
| OPC_LD | (lo12 << 20) | (REG_T0 << 15) | (REG_T1 << 7), |
| OPC_JALR | (REG_T1 << 15) |
| }; |
| } |
| |
| static inline int get_got_plt_idx(unsigned long val, const struct mod_section *sec) |
| { |
| struct got_entry *got_plt = (struct got_entry *)sec->shdr->sh_addr; |
| int i; |
| for (i = 0; i < sec->num_entries; i++) { |
| if (got_plt[i].symbol_addr == val) |
| return i; |
| } |
| return -1; |
| } |
| |
| static inline struct plt_entry *get_plt_entry(unsigned long val, |
| const struct mod_section *sec_plt, |
| const struct mod_section *sec_got_plt) |
| { |
| struct plt_entry *plt = (struct plt_entry *)sec_plt->shdr->sh_addr; |
| int got_plt_idx = get_got_plt_idx(val, sec_got_plt); |
| if (got_plt_idx >= 0) |
| return plt + got_plt_idx; |
| else |
| return NULL; |
| } |
| |
| #endif /* CONFIG_MODULE_SECTIONS */ |
| |
| #endif /* _ASM_RISCV_MODULE_H */ |