1// SPDX-License-Identifier: GPL-2.0
2// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
3
4#include <linux/moduleloader.h>
5#include <linux/elf.h>
6#include <linux/mm.h>
7#include <linux/vmalloc.h>
8#include <linux/slab.h>
9#include <linux/fs.h>
10#include <linux/string.h>
11#include <linux/kernel.h>
12#include <linux/spinlock.h>
13
14#ifdef CONFIG_CPU_CK810
15#define IS_BSR32(hi16, lo16)		(((hi16) & 0xFC00) == 0xE000)
16#define IS_JSRI32(hi16, lo16)		((hi16) == 0xEAE0)
17
18#define CHANGE_JSRI_TO_LRW(addr) do {					\
19	*(uint16_t *)(addr) = (*(uint16_t *)(addr) & 0xFF9F) | 0x001a;	\
20	*((uint16_t *)(addr) + 1) = *((uint16_t *)(addr) + 1) & 0xFFFF;	\
21} while (0)
22
23#define SET_JSR32_R26(addr) do {		\
24	*(uint16_t *)(addr) = 0xE8Fa;		\
25	*((uint16_t *)(addr) + 1) = 0x0000;	\
26} while (0)
27
28static void jsri_2_lrw_jsr(uint32_t *location)
29{
30	uint16_t *location_tmp = (uint16_t *)location;
31
32	if (IS_BSR32(*location_tmp, *(location_tmp + 1)))
33		return;
34
35	if (IS_JSRI32(*location_tmp, *(location_tmp + 1))) {
36		/* jsri 0x...  --> lrw r26, 0x... */
37		CHANGE_JSRI_TO_LRW(location);
38		/* lsli r0, r0 --> jsr r26 */
39		SET_JSR32_R26(location + 1);
40	}
41}
42#else
43static inline void jsri_2_lrw_jsr(uint32_t *location)
44{
45	return;
46}
47#endif
48
49int apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,
50		unsigned int symindex, unsigned int relsec, struct module *me)
51{
52	unsigned int i;
53	Elf32_Rela	*rel = (void *) sechdrs[relsec].sh_addr;
54	Elf32_Sym	*sym;
55	uint32_t	*location;
56	short		*temp;
57
58	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
59		/* This is where to make the change */
60		location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
61							+ rel[i].r_offset;
62		sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
63						+ ELF32_R_SYM(rel[i].r_info);
64
65		switch (ELF32_R_TYPE(rel[i].r_info)) {
66		case R_CSKY_32:
67			/* We add the value into the location given */
68			*location = rel[i].r_addend + sym->st_value;
69			break;
70		case R_CSKY_PC32:
71			/* Add the value, subtract its position */
72			*location = rel[i].r_addend + sym->st_value
73							- (uint32_t)location;
74			break;
75		case R_CSKY_PCRELJSR_IMM11BY2:
76			break;
77		case R_CSKY_PCRELJSR_IMM26BY2:
78			jsri_2_lrw_jsr(location);
79			break;
80		case R_CSKY_ADDR_HI16:
81			temp = ((short  *)location) + 1;
82			*temp = (short)
83				((rel[i].r_addend + sym->st_value) >> 16);
84			break;
85		case R_CSKY_ADDR_LO16:
86			temp = ((short  *)location) + 1;
87			*temp = (short)
88				((rel[i].r_addend + sym->st_value) & 0xffff);
89			break;
90		default:
91			pr_err("module %s: Unknown relocation: %u\n",
92				me->name, ELF32_R_TYPE(rel[i].r_info));
93			return -ENOEXEC;
94		}
95	}
96	return 0;
97}
98