[mirror_ubuntu-jammy-kernel.git] / arch / riscv / include / asm / module.h

/* 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>

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 */
Commit	Line	Data
ab1ef68e ZL	1	/* SPDX-License-Identifier: GPL-2.0 */
	2	/* Copyright (C) 2017 Andes Technology Corporation */
	3
	4	#ifndef _ASM_RISCV_MODULE_H
	5	#define _ASM_RISCV_MODULE_H
	6
	7	#include <asm-generic/module.h>
	8
0138ebb9	9	struct module;
2cffc956 ZL	10	unsigned long module_emit_got_entry(struct module *mod, unsigned long val);
2cffc956 ZL	11	unsigned long module_emit_plt_entry(struct module *mod, unsigned long val);
ab1ef68e ZL	12
	13	#ifdef CONFIG_MODULE_SECTIONS
	14	struct mod_section {
2cffc956	15	Elf_Shdr *shdr;
ab1ef68e ZL	16	int num_entries;
	17	int max_entries;
	18	};
	19
	20	struct mod_arch_specific {
	21	struct mod_section got;
	22	struct mod_section plt;
b8bde0ef	23	struct mod_section got_plt;
ab1ef68e ZL	24	};
	25
	26	struct got_entry {
2cffc956	27	unsigned long symbol_addr; /* the real variable address */
ab1ef68e ZL	28	};
ab1ef68e ZL	29
2cffc956	30	static inline struct got_entry emit_got_entry(unsigned long val)
ab1ef68e ZL	31	{
	32	return (struct got_entry) {val};
	33	}
	34
2cffc956	35	static inline struct got_entry *get_got_entry(unsigned long val,
ab1ef68e ZL	36	const struct mod_section *sec)
ab1ef68e ZL	37	{
2cffc956	38	struct got_entry got = (struct got_entry )(sec->shdr->sh_addr);
ab1ef68e ZL	39	int i;
	40	for (i = 0; i < sec->num_entries; i++) {
	41	if (got[i].symbol_addr == val)
	42	return &got[i];
	43	}
	44	return NULL;
	45	}
	46
	47	struct plt_entry {
	48	/*
	49	* Trampoline code to real target address. The return address
	50	* should be the original (pc+4) before entring plt entry.
ab1ef68e ZL	51	*/
	52	u32 insn_auipc; /* auipc t0, 0x0 */
	53	u32 insn_ld; /* ld t1, 0x10(t0) */
	54	u32 insn_jr; /* jr t1 */
ab1ef68e ZL	55	};
	56
	57	#define OPC_AUIPC 0x0017
	58	#define OPC_LD 0x3003
	59	#define OPC_JALR 0x0067
	60	#define REG_T0 0x5
	61	#define REG_T1 0x6
ab1ef68e	62
2cffc956 ZL	63	static inline struct plt_entry emit_plt_entry(unsigned long val,
	64	unsigned long plt,
	65	unsigned long got_plt)
ab1ef68e ZL	66	{
	67	/*
	68	* U-Type encoding:
	69	* +------------+----------+----------+
	70	* \| imm[31:12] \| rd[11:7] \| opc[6:0] \|
	71	* +------------+----------+----------+
	72	*
	73	* I-Type encoding:
	74	* +------------+------------+--------+----------+----------+
	75	* \| imm[31:20] \| rs1[19:15] \| funct3 \| rd[11:7] \| opc[6:0] \|
	76	* +------------+------------+--------+----------+----------+
	77	*
	78	*/
2cffc956	79	unsigned long offset = got_plt - plt;
b8bde0ef ZL	80	u32 hi20 = (offset + 0x800) & 0xfffff000;
b8bde0ef ZL	81	u32 lo12 = (offset - hi20);
ab1ef68e	82	return (struct plt_entry) {
b8bde0ef ZL	83	OPC_AUIPC \| (REG_T0 << 7) \| hi20,
	84	OPC_LD \| (lo12 << 20) \| (REG_T0 << 15) \| (REG_T1 << 7),
	85	OPC_JALR \| (REG_T1 << 15)
ab1ef68e ZL	86	};
	87	}
	88
2cffc956	89	static inline int get_got_plt_idx(unsigned long val, const struct mod_section *sec)
ab1ef68e	90	{
b8bde0ef	91	struct got_entry got_plt = (struct got_entry )sec->shdr->sh_addr;
ab1ef68e ZL	92	int i;
ab1ef68e ZL	93	for (i = 0; i < sec->num_entries; i++) {
b8bde0ef ZL	94	if (got_plt[i].symbol_addr == val)
b8bde0ef ZL	95	return i;
ab1ef68e	96	}
b8bde0ef ZL	97	return -1;
	98	}
	99
2cffc956 ZL	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)
b8bde0ef ZL	103	{
	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;
	108	else
	109	return NULL;
ab1ef68e ZL	110	}
	111
	112	#endif /* CONFIG_MODULE_SECTIONS */
	113
	114	#endif /* _ASM_RISCV_MODULE_H */