[POWERPC] 4xx: Add AMCC 460EX/460GT support to cputable.c & cpu_setup_44x.S
[linux-2.6] / arch / powerpc / kernel / module_32.c
1 /*  Kernel module help for PPC.
2     Copyright (C) 2001 Rusty Russell.
3
4     This program is free software; you can redistribute it and/or modify
5     it under the terms of the GNU General Public License as published by
6     the Free Software Foundation; either version 2 of the License, or
7     (at your option) any later version.
8
9     This program is distributed in the hope that it will be useful,
10     but WITHOUT ANY WARRANTY; without even the implied warranty of
11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12     GNU General Public License for more details.
13
14     You should have received a copy of the GNU General Public License
15     along with this program; if not, write to the Free Software
16     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
17 */
18 #include <linux/module.h>
19 #include <linux/moduleloader.h>
20 #include <linux/elf.h>
21 #include <linux/vmalloc.h>
22 #include <linux/fs.h>
23 #include <linux/string.h>
24 #include <linux/kernel.h>
25 #include <linux/cache.h>
26 #include <linux/bug.h>
27 #include <linux/sort.h>
28
29 #include "setup.h"
30
31 #if 0
32 #define DEBUGP printk
33 #else
34 #define DEBUGP(fmt , ...)
35 #endif
36
37 LIST_HEAD(module_bug_list);
38
39 void *module_alloc(unsigned long size)
40 {
41         if (size == 0)
42                 return NULL;
43         return vmalloc(size);
44 }
45
46 /* Free memory returned from module_alloc */
47 void module_free(struct module *mod, void *module_region)
48 {
49         vfree(module_region);
50         /* FIXME: If module_region == mod->init_region, trim exception
51            table entries. */
52 }
53
54 /* Count how many different relocations (different symbol, different
55    addend) */
56 static unsigned int count_relocs(const Elf32_Rela *rela, unsigned int num)
57 {
58         unsigned int i, r_info, r_addend, _count_relocs;
59
60         _count_relocs = 0;
61         r_info = 0;
62         r_addend = 0;
63         for (i = 0; i < num; i++)
64                 /* Only count 24-bit relocs, others don't need stubs */
65                 if (ELF32_R_TYPE(rela[i].r_info) == R_PPC_REL24 &&
66                     (r_info != ELF32_R_SYM(rela[i].r_info) ||
67                      r_addend != rela[i].r_addend)) {
68                         _count_relocs++;
69                         r_info = ELF32_R_SYM(rela[i].r_info);
70                         r_addend = rela[i].r_addend;
71                 }
72
73         return _count_relocs;
74 }
75
76 static int relacmp(const void *_x, const void *_y)
77 {
78         const Elf32_Rela *x, *y;
79
80         y = (Elf32_Rela *)_x;
81         x = (Elf32_Rela *)_y;
82
83         /* Compare the entire r_info (as opposed to ELF32_R_SYM(r_info) only) to
84          * make the comparison cheaper/faster. It won't affect the sorting or
85          * the counting algorithms' performance
86          */
87         if (x->r_info < y->r_info)
88                 return -1;
89         else if (x->r_info > y->r_info)
90                 return 1;
91         else if (x->r_addend < y->r_addend)
92                 return -1;
93         else if (x->r_addend > y->r_addend)
94                 return 1;
95         else
96                 return 0;
97 }
98
99 static void relaswap(void *_x, void *_y, int size)
100 {
101         uint32_t *x, *y, tmp;
102         int i;
103
104         y = (uint32_t *)_x;
105         x = (uint32_t *)_y;
106
107         for (i = 0; i < sizeof(Elf32_Rela) / sizeof(uint32_t); i++) {
108                 tmp = x[i];
109                 x[i] = y[i];
110                 y[i] = tmp;
111         }
112 }
113
114 /* Get the potential trampolines size required of the init and
115    non-init sections */
116 static unsigned long get_plt_size(const Elf32_Ehdr *hdr,
117                                   const Elf32_Shdr *sechdrs,
118                                   const char *secstrings,
119                                   int is_init)
120 {
121         unsigned long ret = 0;
122         unsigned i;
123
124         /* Everything marked ALLOC (this includes the exported
125            symbols) */
126         for (i = 1; i < hdr->e_shnum; i++) {
127                 /* If it's called *.init*, and we're not init, we're
128                    not interested */
129                 if ((strstr(secstrings + sechdrs[i].sh_name, ".init") != 0)
130                     != is_init)
131                         continue;
132
133                 /* We don't want to look at debug sections. */
134                 if (strstr(secstrings + sechdrs[i].sh_name, ".debug") != 0)
135                         continue;
136
137                 if (sechdrs[i].sh_type == SHT_RELA) {
138                         DEBUGP("Found relocations in section %u\n", i);
139                         DEBUGP("Ptr: %p.  Number: %u\n",
140                                (void *)hdr + sechdrs[i].sh_offset,
141                                sechdrs[i].sh_size / sizeof(Elf32_Rela));
142
143                         /* Sort the relocation information based on a symbol and
144                          * addend key. This is a stable O(n*log n) complexity
145                          * alogrithm but it will reduce the complexity of
146                          * count_relocs() to linear complexity O(n)
147                          */
148                         sort((void *)hdr + sechdrs[i].sh_offset,
149                              sechdrs[i].sh_size / sizeof(Elf32_Rela),
150                              sizeof(Elf32_Rela), relacmp, relaswap);
151
152                         ret += count_relocs((void *)hdr
153                                              + sechdrs[i].sh_offset,
154                                              sechdrs[i].sh_size
155                                              / sizeof(Elf32_Rela))
156                                 * sizeof(struct ppc_plt_entry);
157                 }
158         }
159
160         return ret;
161 }
162
163 int module_frob_arch_sections(Elf32_Ehdr *hdr,
164                               Elf32_Shdr *sechdrs,
165                               char *secstrings,
166                               struct module *me)
167 {
168         unsigned int i;
169
170         /* Find .plt and .init.plt sections */
171         for (i = 0; i < hdr->e_shnum; i++) {
172                 if (strcmp(secstrings + sechdrs[i].sh_name, ".init.plt") == 0)
173                         me->arch.init_plt_section = i;
174                 else if (strcmp(secstrings + sechdrs[i].sh_name, ".plt") == 0)
175                         me->arch.core_plt_section = i;
176         }
177         if (!me->arch.core_plt_section || !me->arch.init_plt_section) {
178                 printk("Module doesn't contain .plt or .init.plt sections.\n");
179                 return -ENOEXEC;
180         }
181
182         /* Override their sizes */
183         sechdrs[me->arch.core_plt_section].sh_size
184                 = get_plt_size(hdr, sechdrs, secstrings, 0);
185         sechdrs[me->arch.init_plt_section].sh_size
186                 = get_plt_size(hdr, sechdrs, secstrings, 1);
187         return 0;
188 }
189
190 int apply_relocate(Elf32_Shdr *sechdrs,
191                    const char *strtab,
192                    unsigned int symindex,
193                    unsigned int relsec,
194                    struct module *module)
195 {
196         printk(KERN_ERR "%s: Non-ADD RELOCATION unsupported\n",
197                module->name);
198         return -ENOEXEC;
199 }
200
201 static inline int entry_matches(struct ppc_plt_entry *entry, Elf32_Addr val)
202 {
203         if (entry->jump[0] == 0x3d600000 + ((val + 0x8000) >> 16)
204             && entry->jump[1] == 0x396b0000 + (val & 0xffff))
205                 return 1;
206         return 0;
207 }
208
209 /* Set up a trampoline in the PLT to bounce us to the distant function */
210 static uint32_t do_plt_call(void *location,
211                             Elf32_Addr val,
212                             Elf32_Shdr *sechdrs,
213                             struct module *mod)
214 {
215         struct ppc_plt_entry *entry;
216
217         DEBUGP("Doing plt for call to 0x%x at 0x%x\n", val, (unsigned int)location);
218         /* Init, or core PLT? */
219         if (location >= mod->module_core
220             && location < mod->module_core + mod->core_size)
221                 entry = (void *)sechdrs[mod->arch.core_plt_section].sh_addr;
222         else
223                 entry = (void *)sechdrs[mod->arch.init_plt_section].sh_addr;
224
225         /* Find this entry, or if that fails, the next avail. entry */
226         while (entry->jump[0]) {
227                 if (entry_matches(entry, val)) return (uint32_t)entry;
228                 entry++;
229         }
230
231         /* Stolen from Paul Mackerras as well... */
232         entry->jump[0] = 0x3d600000+((val+0x8000)>>16); /* lis r11,sym@ha */
233         entry->jump[1] = 0x396b0000 + (val&0xffff);     /* addi r11,r11,sym@l*/
234         entry->jump[2] = 0x7d6903a6;                    /* mtctr r11 */
235         entry->jump[3] = 0x4e800420;                    /* bctr */
236
237         DEBUGP("Initialized plt for 0x%x at %p\n", val, entry);
238         return (uint32_t)entry;
239 }
240
241 int apply_relocate_add(Elf32_Shdr *sechdrs,
242                        const char *strtab,
243                        unsigned int symindex,
244                        unsigned int relsec,
245                        struct module *module)
246 {
247         unsigned int i;
248         Elf32_Rela *rela = (void *)sechdrs[relsec].sh_addr;
249         Elf32_Sym *sym;
250         uint32_t *location;
251         uint32_t value;
252
253         DEBUGP("Applying ADD relocate section %u to %u\n", relsec,
254                sechdrs[relsec].sh_info);
255         for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rela); i++) {
256                 /* This is where to make the change */
257                 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
258                         + rela[i].r_offset;
259                 /* This is the symbol it is referring to.  Note that all
260                    undefined symbols have been resolved.  */
261                 sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
262                         + ELF32_R_SYM(rela[i].r_info);
263                 /* `Everything is relative'. */
264                 value = sym->st_value + rela[i].r_addend;
265
266                 switch (ELF32_R_TYPE(rela[i].r_info)) {
267                 case R_PPC_ADDR32:
268                         /* Simply set it */
269                         *(uint32_t *)location = value;
270                         break;
271
272                 case R_PPC_ADDR16_LO:
273                         /* Low half of the symbol */
274                         *(uint16_t *)location = value;
275                         break;
276
277                 case R_PPC_ADDR16_HI:
278                         /* Higher half of the symbol */
279                         *(uint16_t *)location = (value >> 16);
280                         break;
281
282                 case R_PPC_ADDR16_HA:
283                         /* Sign-adjusted lower 16 bits: PPC ELF ABI says:
284                            (((x >> 16) + ((x & 0x8000) ? 1 : 0))) & 0xFFFF.
285                            This is the same, only sane.
286                          */
287                         *(uint16_t *)location = (value + 0x8000) >> 16;
288                         break;
289
290                 case R_PPC_REL24:
291                         if ((int)(value - (uint32_t)location) < -0x02000000
292                             || (int)(value - (uint32_t)location) >= 0x02000000)
293                                 value = do_plt_call(location, value,
294                                                     sechdrs, module);
295
296                         /* Only replace bits 2 through 26 */
297                         DEBUGP("REL24 value = %08X. location = %08X\n",
298                                value, (uint32_t)location);
299                         DEBUGP("Location before: %08X.\n",
300                                *(uint32_t *)location);
301                         *(uint32_t *)location
302                                 = (*(uint32_t *)location & ~0x03fffffc)
303                                 | ((value - (uint32_t)location)
304                                    & 0x03fffffc);
305                         DEBUGP("Location after: %08X.\n",
306                                *(uint32_t *)location);
307                         DEBUGP("ie. jump to %08X+%08X = %08X\n",
308                                *(uint32_t *)location & 0x03fffffc,
309                                (uint32_t)location,
310                                (*(uint32_t *)location & 0x03fffffc)
311                                + (uint32_t)location);
312                         break;
313
314                 case R_PPC_REL32:
315                         /* 32-bit relative jump. */
316                         *(uint32_t *)location = value - (uint32_t)location;
317                         break;
318
319                 default:
320                         printk("%s: unknown ADD relocation: %u\n",
321                                module->name,
322                                ELF32_R_TYPE(rela[i].r_info));
323                         return -ENOEXEC;
324                 }
325         }
326         return 0;
327 }
328
329 static const Elf_Shdr *find_section(const Elf_Ehdr *hdr,
330                                     const Elf_Shdr *sechdrs,
331                                     const char *name)
332 {
333         char *secstrings;
334         unsigned int i;
335
336         secstrings = (char *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
337         for (i = 1; i < hdr->e_shnum; i++)
338                 if (strcmp(secstrings+sechdrs[i].sh_name, name) == 0)
339                         return &sechdrs[i];
340         return NULL;
341 }
342
343 int module_finalize(const Elf_Ehdr *hdr,
344                     const Elf_Shdr *sechdrs,
345                     struct module *me)
346 {
347         const Elf_Shdr *sect;
348         int err;
349
350         err = module_bug_finalize(hdr, sechdrs, me);
351         if (err)                /* never true, currently */
352                 return err;
353
354         /* Apply feature fixups */
355         sect = find_section(hdr, sechdrs, "__ftr_fixup");
356         if (sect != NULL)
357                 do_feature_fixups(cur_cpu_spec->cpu_features,
358                                   (void *)sect->sh_addr,
359                                   (void *)sect->sh_addr + sect->sh_size);
360
361         return 0;
362 }
363
364 void module_arch_cleanup(struct module *mod)
365 {
366         module_bug_cleanup(mod);
367 }
368
369 struct bug_entry *module_find_bug(unsigned long bugaddr)
370 {
371         struct mod_arch_specific *mod;
372         unsigned int i;
373         struct bug_entry *bug;
374
375         list_for_each_entry(mod, &module_bug_list, bug_list) {
376                 bug = mod->bug_table;
377                 for (i = 0; i < mod->num_bugs; ++i, ++bug)
378                         if (bugaddr == bug->bug_addr)
379                                 return bug;
380         }
381         return NULL;
382 }