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

source code of linux/arch/csky/kernel/module.c