1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 2004, 2005 MIPS Technologies, Inc. All rights reserved.
7 * Copyright (C) 2013 Imagination Technologies Ltd.
8 *
9 * VPE spport module for loading a MIPS SP program into VPE1. The SP
10 * environment is rather simple since there are no TLBs. It needs
11 * to be relocatable (or partiall linked). Initialize your stack in
12 * the startup-code. The loader looks for the symbol __start and sets
13 * up the execution to resume from there. To load and run, simply do
14 * a cat SP 'binary' to the /dev/vpe1 device.
15 */
16#include <linux/kernel.h>
17#include <linux/device.h>
18#include <linux/fs.h>
19#include <linux/init.h>
20#include <linux/slab.h>
21#include <linux/list.h>
22#include <linux/vmalloc.h>
23#include <linux/elf.h>
24#include <linux/seq_file.h>
25#include <linux/syscalls.h>
26#include <linux/moduleloader.h>
27#include <linux/interrupt.h>
28#include <linux/poll.h>
29#include <linux/memblock.h>
30#include <asm/mipsregs.h>
31#include <asm/mipsmtregs.h>
32#include <asm/cacheflush.h>
33#include <linux/atomic.h>
34#include <asm/mips_mt.h>
35#include <asm/processor.h>
36#include <asm/vpe.h>
37
38#ifndef ARCH_SHF_SMALL
39#define ARCH_SHF_SMALL 0
40#endif
41
42/* If this is set, the section belongs in the init part of the module */
43#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
44
45struct vpe_control vpecontrol = {
46 .vpe_list_lock = __SPIN_LOCK_UNLOCKED(vpe_list_lock),
47 .vpe_list = LIST_HEAD_INIT(vpecontrol.vpe_list),
48 .tc_list_lock = __SPIN_LOCK_UNLOCKED(tc_list_lock),
49 .tc_list = LIST_HEAD_INIT(vpecontrol.tc_list)
50};
51
52/* get the vpe associated with this minor */
53struct vpe *get_vpe(int minor)
54{
55 struct vpe *res, *v;
56
57 if (!cpu_has_mipsmt)
58 return NULL;
59
60 res = NULL;
61 spin_lock(lock: &vpecontrol.vpe_list_lock);
62 list_for_each_entry(v, &vpecontrol.vpe_list, list) {
63 if (v->minor == VPE_MODULE_MINOR) {
64 res = v;
65 break;
66 }
67 }
68 spin_unlock(lock: &vpecontrol.vpe_list_lock);
69
70 return res;
71}
72
73/* get the vpe associated with this minor */
74struct tc *get_tc(int index)
75{
76 struct tc *res, *t;
77
78 res = NULL;
79 spin_lock(lock: &vpecontrol.tc_list_lock);
80 list_for_each_entry(t, &vpecontrol.tc_list, list) {
81 if (t->index == index) {
82 res = t;
83 break;
84 }
85 }
86 spin_unlock(lock: &vpecontrol.tc_list_lock);
87
88 return res;
89}
90
91/* allocate a vpe and associate it with this minor (or index) */
92struct vpe *alloc_vpe(int minor)
93{
94 struct vpe *v;
95
96 v = kzalloc(sizeof(struct vpe), GFP_KERNEL);
97 if (v == NULL)
98 goto out;
99
100 INIT_LIST_HEAD(list: &v->tc);
101 spin_lock(lock: &vpecontrol.vpe_list_lock);
102 list_add_tail(new: &v->list, head: &vpecontrol.vpe_list);
103 spin_unlock(lock: &vpecontrol.vpe_list_lock);
104
105 INIT_LIST_HEAD(list: &v->notify);
106 v->minor = VPE_MODULE_MINOR;
107
108out:
109 return v;
110}
111
112/* allocate a tc. At startup only tc0 is running, all other can be halted. */
113struct tc *alloc_tc(int index)
114{
115 struct tc *tc;
116
117 tc = kzalloc(sizeof(struct tc), GFP_KERNEL);
118 if (tc == NULL)
119 goto out;
120
121 INIT_LIST_HEAD(list: &tc->tc);
122 tc->index = index;
123
124 spin_lock(lock: &vpecontrol.tc_list_lock);
125 list_add_tail(new: &tc->list, head: &vpecontrol.tc_list);
126 spin_unlock(lock: &vpecontrol.tc_list_lock);
127
128out:
129 return tc;
130}
131
132/* clean up and free everything */
133void release_vpe(struct vpe *v)
134{
135 list_del(entry: &v->list);
136 if (v->load_addr)
137 release_progmem(v->load_addr);
138 kfree(objp: v);
139}
140
141/* Find some VPE program space */
142void *alloc_progmem(unsigned long len)
143{
144 void *addr;
145
146#ifdef CONFIG_MIPS_VPE_LOADER_TOM
147 /*
148 * This means you must tell Linux to use less memory than you
149 * physically have, for example by passing a mem= boot argument.
150 */
151 addr = pfn_to_kaddr(max_low_pfn);
152 memset(addr, 0, len);
153#else
154 /* simple grab some mem for now */
155 addr = kzalloc(size: len, GFP_KERNEL);
156#endif
157
158 return addr;
159}
160
161void release_progmem(void *ptr)
162{
163#ifndef CONFIG_MIPS_VPE_LOADER_TOM
164 kfree(objp: ptr);
165#endif
166}
167
168/* Update size with this section: return offset. */
169static long get_offset(unsigned long *size, Elf_Shdr *sechdr)
170{
171 long ret;
172
173 ret = ALIGN(*size, sechdr->sh_addralign ? : 1);
174 *size = ret + sechdr->sh_size;
175 return ret;
176}
177
178/* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
179 might -- code, read-only data, read-write data, small data. Tally
180 sizes, and place the offsets into sh_entsize fields: high bit means it
181 belongs in init. */
182static void layout_sections(struct module *mod, const Elf_Ehdr *hdr,
183 Elf_Shdr *sechdrs, const char *secstrings)
184{
185 static unsigned long const masks[][2] = {
186 /* NOTE: all executable code must be the first section
187 * in this array; otherwise modify the text_size
188 * finder in the two loops below */
189 {SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL},
190 {SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL},
191 {SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL},
192 {ARCH_SHF_SMALL | SHF_ALLOC, 0}
193 };
194 unsigned int m, i;
195
196 for (i = 0; i < hdr->e_shnum; i++)
197 sechdrs[i].sh_entsize = ~0UL;
198
199 for (m = 0; m < ARRAY_SIZE(masks); ++m) {
200 for (i = 0; i < hdr->e_shnum; ++i) {
201 Elf_Shdr *s = &sechdrs[i];
202 struct module_memory *mod_mem;
203
204 mod_mem = &mod->mem[MOD_TEXT];
205
206 if ((s->sh_flags & masks[m][0]) != masks[m][0]
207 || (s->sh_flags & masks[m][1])
208 || s->sh_entsize != ~0UL)
209 continue;
210 s->sh_entsize =
211 get_offset(size: (unsigned long *)&mod_mem->size, sechdr: s);
212 }
213 }
214}
215
216/* from module-elf32.c, but subverted a little */
217
218struct mips_hi16 {
219 struct mips_hi16 *next;
220 Elf32_Addr *addr;
221 Elf32_Addr value;
222};
223
224static struct mips_hi16 *mips_hi16_list;
225static unsigned int gp_offs, gp_addr;
226
227static int apply_r_mips_none(struct module *me, uint32_t *location,
228 Elf32_Addr v)
229{
230 return 0;
231}
232
233static int apply_r_mips_gprel16(struct module *me, uint32_t *location,
234 Elf32_Addr v)
235{
236 int rel;
237
238 if (!(*location & 0xffff)) {
239 rel = (int)v - gp_addr;
240 } else {
241 /* .sbss + gp(relative) + offset */
242 /* kludge! */
243 rel = (int)(short)((int)v + gp_offs +
244 (int)(short)(*location & 0xffff) - gp_addr);
245 }
246
247 if ((rel > 32768) || (rel < -32768)) {
248 pr_debug("VPE loader: apply_r_mips_gprel16: relative address 0x%x out of range of gp register\n",
249 rel);
250 return -ENOEXEC;
251 }
252
253 *location = (*location & 0xffff0000) | (rel & 0xffff);
254
255 return 0;
256}
257
258static int apply_r_mips_pc16(struct module *me, uint32_t *location,
259 Elf32_Addr v)
260{
261 int rel;
262 rel = (((unsigned int)v - (unsigned int)location));
263 rel >>= 2; /* because the offset is in _instructions_ not bytes. */
264 rel -= 1; /* and one instruction less due to the branch delay slot. */
265
266 if ((rel > 32768) || (rel < -32768)) {
267 pr_debug("VPE loader: apply_r_mips_pc16: relative address out of range 0x%x\n",
268 rel);
269 return -ENOEXEC;
270 }
271
272 *location = (*location & 0xffff0000) | (rel & 0xffff);
273
274 return 0;
275}
276
277static int apply_r_mips_32(struct module *me, uint32_t *location,
278 Elf32_Addr v)
279{
280 *location += v;
281
282 return 0;
283}
284
285static int apply_r_mips_26(struct module *me, uint32_t *location,
286 Elf32_Addr v)
287{
288 if (v % 4) {
289 pr_debug("VPE loader: apply_r_mips_26: unaligned relocation\n");
290 return -ENOEXEC;
291 }
292
293/*
294 * Not desperately convinced this is a good check of an overflow condition
295 * anyway. But it gets in the way of handling undefined weak symbols which
296 * we want to set to zero.
297 * if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
298 * printk(KERN_ERR
299 * "module %s: relocation overflow\n",
300 * me->name);
301 * return -ENOEXEC;
302 * }
303 */
304
305 *location = (*location & ~0x03ffffff) |
306 ((*location + (v >> 2)) & 0x03ffffff);
307 return 0;
308}
309
310static int apply_r_mips_hi16(struct module *me, uint32_t *location,
311 Elf32_Addr v)
312{
313 struct mips_hi16 *n;
314
315 /*
316 * We cannot relocate this one now because we don't know the value of
317 * the carry we need to add. Save the information, and let LO16 do the
318 * actual relocation.
319 */
320 n = kmalloc(size: sizeof(*n), GFP_KERNEL);
321 if (!n)
322 return -ENOMEM;
323
324 n->addr = location;
325 n->value = v;
326 n->next = mips_hi16_list;
327 mips_hi16_list = n;
328
329 return 0;
330}
331
332static int apply_r_mips_lo16(struct module *me, uint32_t *location,
333 Elf32_Addr v)
334{
335 unsigned long insnlo = *location;
336 Elf32_Addr val, vallo;
337 struct mips_hi16 *l, *next;
338
339 /* Sign extend the addend we extract from the lo insn. */
340 vallo = ((insnlo & 0xffff) ^ 0x8000) - 0x8000;
341
342 if (mips_hi16_list != NULL) {
343
344 l = mips_hi16_list;
345 while (l != NULL) {
346 unsigned long insn;
347
348 /*
349 * The value for the HI16 had best be the same.
350 */
351 if (v != l->value) {
352 pr_debug("VPE loader: apply_r_mips_lo16/hi16: inconsistent value information\n");
353 goto out_free;
354 }
355
356 /*
357 * Do the HI16 relocation. Note that we actually don't
358 * need to know anything about the LO16 itself, except
359 * where to find the low 16 bits of the addend needed
360 * by the LO16.
361 */
362 insn = *l->addr;
363 val = ((insn & 0xffff) << 16) + vallo;
364 val += v;
365
366 /*
367 * Account for the sign extension that will happen in
368 * the low bits.
369 */
370 val = ((val >> 16) + ((val & 0x8000) != 0)) & 0xffff;
371
372 insn = (insn & ~0xffff) | val;
373 *l->addr = insn;
374
375 next = l->next;
376 kfree(objp: l);
377 l = next;
378 }
379
380 mips_hi16_list = NULL;
381 }
382
383 /*
384 * Ok, we're done with the HI16 relocs. Now deal with the LO16.
385 */
386 val = v + vallo;
387 insnlo = (insnlo & ~0xffff) | (val & 0xffff);
388 *location = insnlo;
389
390 return 0;
391
392out_free:
393 while (l != NULL) {
394 next = l->next;
395 kfree(objp: l);
396 l = next;
397 }
398 mips_hi16_list = NULL;
399
400 return -ENOEXEC;
401}
402
403static int (*reloc_handlers[]) (struct module *me, uint32_t *location,
404 Elf32_Addr v) = {
405 [R_MIPS_NONE] = apply_r_mips_none,
406 [R_MIPS_32] = apply_r_mips_32,
407 [R_MIPS_26] = apply_r_mips_26,
408 [R_MIPS_HI16] = apply_r_mips_hi16,
409 [R_MIPS_LO16] = apply_r_mips_lo16,
410 [R_MIPS_GPREL16] = apply_r_mips_gprel16,
411 [R_MIPS_PC16] = apply_r_mips_pc16
412};
413
414static char *rstrs[] = {
415 [R_MIPS_NONE] = "MIPS_NONE",
416 [R_MIPS_32] = "MIPS_32",
417 [R_MIPS_26] = "MIPS_26",
418 [R_MIPS_HI16] = "MIPS_HI16",
419 [R_MIPS_LO16] = "MIPS_LO16",
420 [R_MIPS_GPREL16] = "MIPS_GPREL16",
421 [R_MIPS_PC16] = "MIPS_PC16"
422};
423
424static int apply_relocations(Elf32_Shdr *sechdrs,
425 const char *strtab,
426 unsigned int symindex,
427 unsigned int relsec,
428 struct module *me)
429{
430 Elf32_Rel *rel = (void *) sechdrs[relsec].sh_addr;
431 Elf32_Sym *sym;
432 uint32_t *location;
433 unsigned int i;
434 Elf32_Addr v;
435 int res;
436
437 for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
438 Elf32_Word r_info = rel[i].r_info;
439
440 /* This is where to make the change */
441 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
442 + rel[i].r_offset;
443 /* This is the symbol it is referring to */
444 sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
445 + ELF32_R_SYM(r_info);
446
447 if (!sym->st_value) {
448 pr_debug("%s: undefined weak symbol %s\n",
449 me->name, strtab + sym->st_name);
450 /* just print the warning, dont barf */
451 }
452
453 v = sym->st_value;
454
455 res = reloc_handlers[ELF32_R_TYPE(r_info)](me, location, v);
456 if (res) {
457 char *r = rstrs[ELF32_R_TYPE(r_info)];
458 pr_warn("VPE loader: .text+0x%x relocation type %s for symbol \"%s\" failed\n",
459 rel[i].r_offset, r ? r : "UNKNOWN",
460 strtab + sym->st_name);
461 return res;
462 }
463 }
464
465 return 0;
466}
467
468static inline void save_gp_address(unsigned int secbase, unsigned int rel)
469{
470 gp_addr = secbase + rel;
471 gp_offs = gp_addr - (secbase & 0xffff0000);
472}
473/* end module-elf32.c */
474
475/* Change all symbols so that sh_value encodes the pointer directly. */
476static void simplify_symbols(Elf_Shdr *sechdrs,
477 unsigned int symindex,
478 const char *strtab,
479 const char *secstrings,
480 unsigned int nsecs, struct module *mod)
481{
482 Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
483 unsigned long secbase, bssbase = 0;
484 unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
485 int size;
486
487 /* find the .bss section for COMMON symbols */
488 for (i = 0; i < nsecs; i++) {
489 if (strncmp(secstrings + sechdrs[i].sh_name, ".bss", 4) == 0) {
490 bssbase = sechdrs[i].sh_addr;
491 break;
492 }
493 }
494
495 for (i = 1; i < n; i++) {
496 switch (sym[i].st_shndx) {
497 case SHN_COMMON:
498 /* Allocate space for the symbol in the .bss section.
499 st_value is currently size.
500 We want it to have the address of the symbol. */
501
502 size = sym[i].st_value;
503 sym[i].st_value = bssbase;
504
505 bssbase += size;
506 break;
507
508 case SHN_ABS:
509 /* Don't need to do anything */
510 break;
511
512 case SHN_UNDEF:
513 /* ret = -ENOENT; */
514 break;
515
516 case SHN_MIPS_SCOMMON:
517 pr_debug("simplify_symbols: ignoring SHN_MIPS_SCOMMON symbol <%s> st_shndx %d\n",
518 strtab + sym[i].st_name, sym[i].st_shndx);
519 /* .sbss section */
520 break;
521
522 default:
523 secbase = sechdrs[sym[i].st_shndx].sh_addr;
524
525 if (strncmp(strtab + sym[i].st_name, "_gp", 3) == 0)
526 save_gp_address(secbase, rel: sym[i].st_value);
527
528 sym[i].st_value += secbase;
529 break;
530 }
531 }
532}
533
534#ifdef DEBUG_ELFLOADER
535static void dump_elfsymbols(Elf_Shdr *sechdrs, unsigned int symindex,
536 const char *strtab, struct module *mod)
537{
538 Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
539 unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
540
541 pr_debug("dump_elfsymbols: n %d\n", n);
542 for (i = 1; i < n; i++) {
543 pr_debug(" i %d name <%s> 0x%x\n", i, strtab + sym[i].st_name,
544 sym[i].st_value);
545 }
546}
547#endif
548
549static int find_vpe_symbols(struct vpe *v, Elf_Shdr *sechdrs,
550 unsigned int symindex, const char *strtab,
551 struct module *mod)
552{
553 Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
554 unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
555
556 for (i = 1; i < n; i++) {
557 if (strcmp(strtab + sym[i].st_name, "__start") == 0)
558 v->__start = sym[i].st_value;
559
560 if (strcmp(strtab + sym[i].st_name, "vpe_shared") == 0)
561 v->shared_ptr = (void *)sym[i].st_value;
562 }
563
564 if ((v->__start == 0) || (v->shared_ptr == NULL))
565 return -1;
566
567 return 0;
568}
569
570/*
571 * Allocates a VPE with some program code space(the load address), copies the
572 * contents of the program (p)buffer performing relocatations/etc, free's it
573 * when finished.
574 */
575static int vpe_elfload(struct vpe *v)
576{
577 Elf_Ehdr *hdr;
578 Elf_Shdr *sechdrs;
579 long err = 0;
580 char *secstrings, *strtab = NULL;
581 unsigned int len, i, symindex = 0, strindex = 0, relocate = 0;
582 struct module mod; /* so we can re-use the relocations code */
583
584 memset(&mod, 0, sizeof(struct module));
585 strcpy(p: mod.name, q: "VPE loader");
586
587 hdr = (Elf_Ehdr *) v->pbuffer;
588 len = v->plen;
589
590 /* Sanity checks against insmoding binaries or wrong arch,
591 weird elf version */
592 if (memcmp(p: hdr->e_ident, ELFMAG, SELFMAG) != 0
593 || (hdr->e_type != ET_REL && hdr->e_type != ET_EXEC)
594 || !elf_check_arch(hdr)
595 || hdr->e_shentsize != sizeof(*sechdrs)) {
596 pr_warn("VPE loader: program wrong arch or weird elf version\n");
597
598 return -ENOEXEC;
599 }
600
601 if (hdr->e_type == ET_REL)
602 relocate = 1;
603
604 if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr)) {
605 pr_err("VPE loader: program length %u truncated\n", len);
606
607 return -ENOEXEC;
608 }
609
610 /* Convenience variables */
611 sechdrs = (void *)hdr + hdr->e_shoff;
612 secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
613 sechdrs[0].sh_addr = 0;
614
615 /* And these should exist, but gcc whinges if we don't init them */
616 symindex = strindex = 0;
617
618 if (relocate) {
619 for (i = 1; i < hdr->e_shnum; i++) {
620 if ((sechdrs[i].sh_type != SHT_NOBITS) &&
621 (len < sechdrs[i].sh_offset + sechdrs[i].sh_size)) {
622 pr_err("VPE program length %u truncated\n",
623 len);
624 return -ENOEXEC;
625 }
626
627 /* Mark all sections sh_addr with their address in the
628 temporary image. */
629 sechdrs[i].sh_addr = (size_t) hdr +
630 sechdrs[i].sh_offset;
631
632 /* Internal symbols and strings. */
633 if (sechdrs[i].sh_type == SHT_SYMTAB) {
634 symindex = i;
635 strindex = sechdrs[i].sh_link;
636 strtab = (char *)hdr +
637 sechdrs[strindex].sh_offset;
638 }
639 }
640 layout_sections(mod: &mod, hdr, sechdrs, secstrings);
641 }
642
643 v->load_addr = alloc_progmem(len: mod.mem[MOD_TEXT].size);
644 if (!v->load_addr)
645 return -ENOMEM;
646
647 pr_info("VPE loader: loading to %p\n", v->load_addr);
648
649 if (relocate) {
650 for (i = 0; i < hdr->e_shnum; i++) {
651 void *dest;
652
653 if (!(sechdrs[i].sh_flags & SHF_ALLOC))
654 continue;
655
656 dest = v->load_addr + sechdrs[i].sh_entsize;
657
658 if (sechdrs[i].sh_type != SHT_NOBITS)
659 memcpy(dest, (void *)sechdrs[i].sh_addr,
660 sechdrs[i].sh_size);
661 /* Update sh_addr to point to copy in image. */
662 sechdrs[i].sh_addr = (unsigned long)dest;
663
664 pr_debug(" section sh_name %s sh_addr 0x%x\n",
665 secstrings + sechdrs[i].sh_name,
666 sechdrs[i].sh_addr);
667 }
668
669 /* Fix up syms, so that st_value is a pointer to location. */
670 simplify_symbols(sechdrs, symindex, strtab, secstrings,
671 nsecs: hdr->e_shnum, mod: &mod);
672
673 /* Now do relocations. */
674 for (i = 1; i < hdr->e_shnum; i++) {
675 const char *strtab = (char *)sechdrs[strindex].sh_addr;
676 unsigned int info = sechdrs[i].sh_info;
677
678 /* Not a valid relocation section? */
679 if (info >= hdr->e_shnum)
680 continue;
681
682 /* Don't bother with non-allocated sections */
683 if (!(sechdrs[info].sh_flags & SHF_ALLOC))
684 continue;
685
686 if (sechdrs[i].sh_type == SHT_REL)
687 err = apply_relocations(sechdrs, strtab,
688 symindex, relsec: i, me: &mod);
689 else if (sechdrs[i].sh_type == SHT_RELA)
690 err = apply_relocate_add(sechdrs, strtab,
691 symindex, relsec: i, mod: &mod);
692 if (err < 0)
693 return err;
694
695 }
696 } else {
697 struct elf_phdr *phdr = (struct elf_phdr *)
698 ((char *)hdr + hdr->e_phoff);
699
700 for (i = 0; i < hdr->e_phnum; i++) {
701 if (phdr->p_type == PT_LOAD) {
702 memcpy((void *)phdr->p_paddr,
703 (char *)hdr + phdr->p_offset,
704 phdr->p_filesz);
705 memset((void *)phdr->p_paddr + phdr->p_filesz,
706 0, phdr->p_memsz - phdr->p_filesz);
707 }
708 phdr++;
709 }
710
711 for (i = 0; i < hdr->e_shnum; i++) {
712 /* Internal symbols and strings. */
713 if (sechdrs[i].sh_type == SHT_SYMTAB) {
714 symindex = i;
715 strindex = sechdrs[i].sh_link;
716 strtab = (char *)hdr +
717 sechdrs[strindex].sh_offset;
718
719 /*
720 * mark symtab's address for when we try
721 * to find the magic symbols
722 */
723 sechdrs[i].sh_addr = (size_t) hdr +
724 sechdrs[i].sh_offset;
725 }
726 }
727 }
728
729 /* make sure it's physically written out */
730 flush_icache_range(start: (unsigned long)v->load_addr,
731 end: (unsigned long)v->load_addr + v->len);
732
733 if ((find_vpe_symbols(v, sechdrs, symindex, strtab, mod: &mod)) < 0) {
734 if (v->__start == 0) {
735 pr_warn("VPE loader: program does not contain a __start symbol\n");
736 return -ENOEXEC;
737 }
738
739 if (v->shared_ptr == NULL)
740 pr_warn("VPE loader: program does not contain vpe_shared symbol.\n"
741 " Unable to use AMVP (AP/SP) facilities.\n");
742 }
743
744 pr_info(" elf loaded\n");
745 return 0;
746}
747
748/* checks VPE is unused and gets ready to load program */
749static int vpe_open(struct inode *inode, struct file *filp)
750{
751 enum vpe_state state;
752 struct vpe_notifications *notifier;
753 struct vpe *v;
754
755 if (VPE_MODULE_MINOR != iminor(inode)) {
756 /* assume only 1 device at the moment. */
757 pr_warn("VPE loader: only vpe1 is supported\n");
758
759 return -ENODEV;
760 }
761
762 v = get_vpe(minor: aprp_cpu_index());
763 if (v == NULL) {
764 pr_warn("VPE loader: unable to get vpe\n");
765
766 return -ENODEV;
767 }
768
769 state = xchg(&v->state, VPE_STATE_INUSE);
770 if (state != VPE_STATE_UNUSED) {
771 pr_debug("VPE loader: tc in use dumping regs\n");
772
773 list_for_each_entry(notifier, &v->notify, list)
774 notifier->stop(aprp_cpu_index());
775
776 release_progmem(v->load_addr);
777 cleanup_tc(get_tc(index: aprp_cpu_index()));
778 }
779
780 /* this of-course trashes what was there before... */
781 v->pbuffer = vmalloc(size: P_SIZE);
782 if (!v->pbuffer) {
783 pr_warn("VPE loader: unable to allocate memory\n");
784 return -ENOMEM;
785 }
786 v->plen = P_SIZE;
787 v->load_addr = NULL;
788 v->len = 0;
789 v->shared_ptr = NULL;
790 v->__start = 0;
791
792 return 0;
793}
794
795static int vpe_release(struct inode *inode, struct file *filp)
796{
797#ifdef CONFIG_MIPS_VPE_LOADER_MT
798 struct vpe *v;
799 Elf_Ehdr *hdr;
800 int ret = 0;
801
802 v = get_vpe(aprp_cpu_index());
803 if (v == NULL)
804 return -ENODEV;
805
806 hdr = (Elf_Ehdr *) v->pbuffer;
807 if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) == 0) {
808 if (vpe_elfload(v) >= 0) {
809 vpe_run(v);
810 } else {
811 pr_warn("VPE loader: ELF load failed.\n");
812 ret = -ENOEXEC;
813 }
814 } else {
815 pr_warn("VPE loader: only elf files are supported\n");
816 ret = -ENOEXEC;
817 }
818
819 /* It's good to be able to run the SP and if it chokes have a look at
820 the /dev/rt?. But if we reset the pointer to the shared struct we
821 lose what has happened. So perhaps if garbage is sent to the vpe
822 device, use it as a trigger for the reset. Hopefully a nice
823 executable will be along shortly. */
824 if (ret < 0)
825 v->shared_ptr = NULL;
826
827 vfree(v->pbuffer);
828 v->plen = 0;
829
830 return ret;
831#else
832 pr_warn("VPE loader: ELF load failed.\n");
833 return -ENOEXEC;
834#endif
835}
836
837static ssize_t vpe_write(struct file *file, const char __user *buffer,
838 size_t count, loff_t *ppos)
839{
840 size_t ret = count;
841 struct vpe *v;
842
843 if (iminor(inode: file_inode(f: file)) != VPE_MODULE_MINOR)
844 return -ENODEV;
845
846 v = get_vpe(minor: aprp_cpu_index());
847
848 if (v == NULL)
849 return -ENODEV;
850
851 if ((count + v->len) > v->plen) {
852 pr_warn("VPE loader: elf size too big. Perhaps strip unneeded symbols\n");
853 return -ENOMEM;
854 }
855
856 count -= copy_from_user(to: v->pbuffer + v->len, from: buffer, n: count);
857 if (!count)
858 return -EFAULT;
859
860 v->len += count;
861 return ret;
862}
863
864const struct file_operations vpe_fops = {
865 .owner = THIS_MODULE,
866 .open = vpe_open,
867 .release = vpe_release,
868 .write = vpe_write,
869 .llseek = noop_llseek,
870};
871
872void *vpe_get_shared(int index)
873{
874 struct vpe *v = get_vpe(minor: index);
875
876 if (v == NULL)
877 return NULL;
878
879 return v->shared_ptr;
880}
881EXPORT_SYMBOL(vpe_get_shared);
882
883int vpe_notify(int index, struct vpe_notifications *notify)
884{
885 struct vpe *v = get_vpe(minor: index);
886
887 if (v == NULL)
888 return -1;
889
890 list_add(new: &notify->list, head: &v->notify);
891 return 0;
892}
893EXPORT_SYMBOL(vpe_notify);
894
895module_init(vpe_module_init);
896module_exit(vpe_module_exit);
897MODULE_DESCRIPTION("MIPS VPE Loader");
898MODULE_AUTHOR("Elizabeth Oldham, MIPS Technologies, Inc.");
899MODULE_LICENSE("GPL");
900

source code of linux/arch/mips/kernel/vpe.c