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/* 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"
u64 module_emit_got_entry(struct module *mod, u64 val);
u64 module_emit_plt_entry(struct module *mod, u64 val);
#ifdef CONFIG_MODULE_SECTIONS
struct mod_section {
struct elf64_shdr *shdr;
int num_entries;
int max_entries;
};
struct mod_arch_specific {
struct mod_section got;
struct mod_section plt;
};
struct got_entry {
u64 symbol_addr; /* the real variable address */
};
static inline struct got_entry emit_got_entry(u64 val)
{
return (struct got_entry) {val};
}
static inline struct got_entry *get_got_entry(u64 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.
* For 8 byte alignment of symbol_addr,
* don't pack structure to remove the padding.
*/
u32 insn_auipc; /* auipc t0, 0x0 */
u32 insn_ld; /* ld t1, 0x10(t0) */
u32 insn_jr; /* jr t1 */
u64 symbol_addr; /* the real jump target address */
};
#define OPC_AUIPC 0x0017
#define OPC_LD 0x3003
#define OPC_JALR 0x0067
#define REG_T0 0x5
#define REG_T1 0x6
#define IMM_OFFSET 0x10
static inline struct plt_entry emit_plt_entry(u64 val)
{
/*
* 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] |
* +------------+------------+--------+----------+----------+
*
*/
return (struct plt_entry) {
OPC_AUIPC | (REG_T0 << 7),
OPC_LD | (IMM_OFFSET << 20) | (REG_T0 << 15) | (REG_T1 << 7),
OPC_JALR | (REG_T1 << 15),
val
};
}
static inline struct plt_entry *get_plt_entry(u64 val,
const struct mod_section *sec)
{
struct plt_entry *plt = (struct plt_entry *)sec->shdr->sh_addr;
int i;
for (i = 0; i < sec->num_entries; i++) {
if (plt[i].symbol_addr == val)
return &plt[i];
}
return NULL;
}
#endif /* CONFIG_MODULE_SECTIONS */
#endif /* _ASM_RISCV_MODULE_H */
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