1 /* SPDX-License-Identifier: GPL-2.0 */
2 /* Copyright (C) 2017 Andes Technology Corporation */
4 #ifndef _ASM_RISCV_MODULE_H
5 #define _ASM_RISCV_MODULE_H
7 #include <asm-generic/module.h>
10 unsigned long module_emit_got_entry(struct module *mod, unsigned long val);
11 unsigned long module_emit_plt_entry(struct module *mod, unsigned long val);
13 #ifdef CONFIG_MODULE_SECTIONS
20 struct mod_arch_specific {
21 struct mod_section got;
22 struct mod_section plt;
23 struct mod_section got_plt;
27 unsigned long symbol_addr; /* the real variable address */
30 static inline struct got_entry emit_got_entry(unsigned long val)
32 return (struct got_entry) {val};
35 static inline struct got_entry *get_got_entry(unsigned long val,
36 const struct mod_section *sec)
38 struct got_entry *got = (struct got_entry *)(sec->shdr->sh_addr);
40 for (i = 0; i < sec->num_entries; i++) {
41 if (got[i].symbol_addr == val)
49 * Trampoline code to real target address. The return address
50 * should be the original (pc+4) before entring plt entry.
52 u32 insn_auipc; /* auipc t0, 0x0 */
53 u32 insn_ld; /* ld t1, 0x10(t0) */
54 u32 insn_jr; /* jr t1 */
57 #define OPC_AUIPC 0x0017
59 #define OPC_JALR 0x0067
63 static inline struct plt_entry emit_plt_entry(unsigned long val,
65 unsigned long got_plt)
69 * +------------+----------+----------+
70 * | imm[31:12] | rd[11:7] | opc[6:0] |
71 * +------------+----------+----------+
74 * +------------+------------+--------+----------+----------+
75 * | imm[31:20] | rs1[19:15] | funct3 | rd[11:7] | opc[6:0] |
76 * +------------+------------+--------+----------+----------+
79 unsigned long offset = got_plt - plt;
80 u32 hi20 = (offset + 0x800) & 0xfffff000;
81 u32 lo12 = (offset - hi20);
82 return (struct plt_entry) {
83 OPC_AUIPC | (REG_T0 << 7) | hi20,
84 OPC_LD | (lo12 << 20) | (REG_T0 << 15) | (REG_T1 << 7),
85 OPC_JALR | (REG_T1 << 15)
89 static inline int get_got_plt_idx(unsigned long val, const struct mod_section *sec)
91 struct got_entry *got_plt = (struct got_entry *)sec->shdr->sh_addr;
93 for (i = 0; i < sec->num_entries; i++) {
94 if (got_plt[i].symbol_addr == val)
100 static inline struct plt_entry *get_plt_entry(unsigned long val,
101 const struct mod_section *sec_plt,
102 const struct mod_section *sec_got_plt)
104 struct plt_entry *plt = (struct plt_entry *)sec_plt->shdr->sh_addr;
105 int got_plt_idx = get_got_plt_idx(val, sec_got_plt);
106 if (got_plt_idx >= 0)
107 return plt + got_plt_idx;
112 #endif /* CONFIG_MODULE_SECTIONS */
114 #endif /* _ASM_RISCV_MODULE_H */