xref: /openbmc/linux/arch/csky/kernel/module.c (revision 37744fee)
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 #include <asm/pgtable.h>
14 
15 #ifdef CONFIG_CPU_CK810
16 #define IS_BSR32(hi16, lo16)		(((hi16) & 0xFC00) == 0xE000)
17 #define IS_JSRI32(hi16, lo16)		((hi16) == 0xEAE0)
18 
19 #define CHANGE_JSRI_TO_LRW(addr) do {					\
20 	*(uint16_t *)(addr) = (*(uint16_t *)(addr) & 0xFF9F) | 0x001a;	\
21 	*((uint16_t *)(addr) + 1) = *((uint16_t *)(addr) + 1) & 0xFFFF;	\
22 } while (0)
23 
24 #define SET_JSR32_R26(addr) do {		\
25 	*(uint16_t *)(addr) = 0xE8Fa;		\
26 	*((uint16_t *)(addr) + 1) = 0x0000;	\
27 } while (0)
28 
29 static void jsri_2_lrw_jsr(uint32_t *location)
30 {
31 	uint16_t *location_tmp = (uint16_t *)location;
32 
33 	if (IS_BSR32(*location_tmp, *(location_tmp + 1)))
34 		return;
35 
36 	if (IS_JSRI32(*location_tmp, *(location_tmp + 1))) {
37 		/* jsri 0x...  --> lrw r26, 0x... */
38 		CHANGE_JSRI_TO_LRW(location);
39 		/* lsli r0, r0 --> jsr r26 */
40 		SET_JSR32_R26(location + 1);
41 	}
42 }
43 #else
44 static void inline jsri_2_lrw_jsr(uint32_t *location)
45 {
46 	return;
47 }
48 #endif
49 
50 int apply_relocate_add(Elf32_Shdr *sechdrs, const char *strtab,
51 		unsigned int symindex, unsigned int relsec, struct module *me)
52 {
53 	unsigned int i;
54 	Elf32_Rela	*rel = (void *) sechdrs[relsec].sh_addr;
55 	Elf32_Sym	*sym;
56 	uint32_t	*location;
57 	short		*temp;
58 
59 	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
60 		/* This is where to make the change */
61 		location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
62 							+ rel[i].r_offset;
63 		sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
64 						+ ELF32_R_SYM(rel[i].r_info);
65 
66 		switch (ELF32_R_TYPE(rel[i].r_info)) {
67 		case R_CSKY_32:
68 			/* We add the value into the location given */
69 			*location = rel[i].r_addend + sym->st_value;
70 			break;
71 		case R_CSKY_PC32:
72 			/* Add the value, subtract its postition */
73 			*location = rel[i].r_addend + sym->st_value
74 							- (uint32_t)location;
75 			break;
76 		case R_CSKY_PCRELJSR_IMM11BY2:
77 			break;
78 		case R_CSKY_PCRELJSR_IMM26BY2:
79 			jsri_2_lrw_jsr(location);
80 			break;
81 		case R_CSKY_ADDR_HI16:
82 			temp = ((short  *)location) + 1;
83 			*temp = (short)
84 				((rel[i].r_addend + sym->st_value) >> 16);
85 			break;
86 		case R_CSKY_ADDR_LO16:
87 			temp = ((short  *)location) + 1;
88 			*temp = (short)
89 				((rel[i].r_addend + sym->st_value) & 0xffff);
90 			break;
91 		default:
92 			pr_err("module %s: Unknown relocation: %u\n",
93 				me->name, ELF32_R_TYPE(rel[i].r_info));
94 			return -ENOEXEC;
95 		}
96 	}
97 	return 0;
98 }
99