xref: /openbmc/linux/arch/csky/kernel/module.c (revision f21e49be)
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 
28 static 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
43 static void inline jsri_2_lrw_jsr(uint32_t *location)
44 {
45 	return;
46 }
47 #endif
48 
49 int 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 postition */
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