[mirror_ubuntu-disco-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>

#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 */
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
	9	#define MODULE_ARCH_VERMAGIC "riscv"
	10
0138ebb9	11	struct module;
2cffc956 ZL	12	unsigned long module_emit_got_entry(struct module *mod, unsigned long val);
2cffc956 ZL	13	unsigned long module_emit_plt_entry(struct module *mod, unsigned long val);
ab1ef68e ZL	14
	15	#ifdef CONFIG_MODULE_SECTIONS
	16	struct mod_section {
2cffc956	17	Elf_Shdr *shdr;
ab1ef68e ZL	18	int num_entries;
	19	int max_entries;
	20	};
	21
	22	struct mod_arch_specific {
	23	struct mod_section got;
	24	struct mod_section plt;
b8bde0ef	25	struct mod_section got_plt;
ab1ef68e ZL	26	};
	27
	28	struct got_entry {
2cffc956	29	unsigned long symbol_addr; /* the real variable address */
ab1ef68e ZL	30	};
ab1ef68e ZL	31
2cffc956	32	static inline struct got_entry emit_got_entry(unsigned long val)
ab1ef68e ZL	33	{
	34	return (struct got_entry) {val};
	35	}
	36
2cffc956	37	static inline struct got_entry *get_got_entry(unsigned long val,
ab1ef68e ZL	38	const struct mod_section *sec)
ab1ef68e ZL	39	{
2cffc956	40	struct got_entry got = (struct got_entry )(sec->shdr->sh_addr);
ab1ef68e ZL	41	int i;
	42	for (i = 0; i < sec->num_entries; i++) {
	43	if (got[i].symbol_addr == val)
	44	return &got[i];
	45	}
	46	return NULL;
	47	}
	48
	49	struct plt_entry {
	50	/*
	51	* Trampoline code to real target address. The return address
	52	* should be the original (pc+4) before entring plt entry.
ab1ef68e ZL	53	*/
	54	u32 insn_auipc; /* auipc t0, 0x0 */
	55	u32 insn_ld; /* ld t1, 0x10(t0) */
	56	u32 insn_jr; /* jr t1 */
ab1ef68e ZL	57	};
	58
	59	#define OPC_AUIPC 0x0017
	60	#define OPC_LD 0x3003
	61	#define OPC_JALR 0x0067
	62	#define REG_T0 0x5
	63	#define REG_T1 0x6
ab1ef68e	64
2cffc956 ZL	65	static inline struct plt_entry emit_plt_entry(unsigned long val,
	66	unsigned long plt,
	67	unsigned long got_plt)
ab1ef68e ZL	68	{
	69	/*
	70	* U-Type encoding:
	71	* +------------+----------+----------+
	72	* \| imm[31:12] \| rd[11:7] \| opc[6:0] \|
	73	* +------------+----------+----------+
	74	*
	75	* I-Type encoding:
	76	* +------------+------------+--------+----------+----------+
	77	* \| imm[31:20] \| rs1[19:15] \| funct3 \| rd[11:7] \| opc[6:0] \|
	78	* +------------+------------+--------+----------+----------+
	79	*
	80	*/
2cffc956	81	unsigned long offset = got_plt - plt;
b8bde0ef ZL	82	u32 hi20 = (offset + 0x800) & 0xfffff000;
b8bde0ef ZL	83	u32 lo12 = (offset - hi20);
ab1ef68e	84	return (struct plt_entry) {
b8bde0ef ZL	85	OPC_AUIPC \| (REG_T0 << 7) \| hi20,
	86	OPC_LD \| (lo12 << 20) \| (REG_T0 << 15) \| (REG_T1 << 7),
	87	OPC_JALR \| (REG_T1 << 15)
ab1ef68e ZL	88	};
	89	}
	90
2cffc956	91	static inline int get_got_plt_idx(unsigned long val, const struct mod_section *sec)
ab1ef68e	92	{
b8bde0ef	93	struct got_entry got_plt = (struct got_entry )sec->shdr->sh_addr;
ab1ef68e ZL	94	int i;
ab1ef68e ZL	95	for (i = 0; i < sec->num_entries; i++) {
b8bde0ef ZL	96	if (got_plt[i].symbol_addr == val)
b8bde0ef ZL	97	return i;
ab1ef68e	98	}
b8bde0ef ZL	99	return -1;
	100	}
	101
2cffc956 ZL	102	static inline struct plt_entry *get_plt_entry(unsigned long val,
	103	const struct mod_section *sec_plt,
	104	const struct mod_section *sec_got_plt)
b8bde0ef ZL	105	{
	106	struct plt_entry plt = (struct plt_entry )sec_plt->shdr->sh_addr;
	107	int got_plt_idx = get_got_plt_idx(val, sec_got_plt);
	108	if (got_plt_idx >= 0)
	109	return plt + got_plt_idx;
	110	else
	111	return NULL;
ab1ef68e ZL	112	}
	113
	114	#endif /* CONFIG_MODULE_SECTIONS */
	115
	116	#endif /* _ASM_RISCV_MODULE_H */