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 
45 struct 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 */
get_vpe(int minor)53 struct 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(&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(&vpecontrol.vpe_list_lock);
69 
70 	return res;
71 }
72 
73 /* get the vpe associated with this minor */
get_tc(int index)74 struct tc *get_tc(int index)
75 {
76 	struct tc *res, *t;
77 
78 	res = NULL;
79 	spin_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(&vpecontrol.tc_list_lock);
87 
88 	return res;
89 }
90 
91 /* allocate a vpe and associate it with this minor (or index) */
alloc_vpe(int minor)92 struct 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(&v->tc);
101 	spin_lock(&vpecontrol.vpe_list_lock);
102 	list_add_tail(&v->list, &vpecontrol.vpe_list);
103 	spin_unlock(&vpecontrol.vpe_list_lock);
104 
105 	INIT_LIST_HEAD(&v->notify);
106 	v->minor = VPE_MODULE_MINOR;
107 
108 out:
109 	return v;
110 }
111 
112 /* allocate a tc. At startup only tc0 is running, all other can be halted. */
alloc_tc(int index)113 struct 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(&tc->tc);
122 	tc->index = index;
123 
124 	spin_lock(&vpecontrol.tc_list_lock);
125 	list_add_tail(&tc->list, &vpecontrol.tc_list);
126 	spin_unlock(&vpecontrol.tc_list_lock);
127 
128 out:
129 	return tc;
130 }
131 
132 /* clean up and free everything */
release_vpe(struct vpe * v)133 void release_vpe(struct vpe *v)
134 {
135 	list_del(&v->list);
136 	if (v->load_addr)
137 		release_progmem(v->load_addr);
138 	kfree(v);
139 }
140 
141 /* Find some VPE program space */
alloc_progmem(unsigned long len)142 void *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(len, GFP_KERNEL);
156 #endif
157 
158 	return addr;
159 }
160 
release_progmem(void * ptr)161 void release_progmem(void *ptr)
162 {
163 #ifndef CONFIG_MIPS_VPE_LOADER_TOM
164 	kfree(ptr);
165 #endif
166 }
167 
168 /* Update size with this section: return offset. */
get_offset(unsigned long * size,Elf_Shdr * sechdr)169 static 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. */
layout_sections(struct module * mod,const Elf_Ehdr * hdr,Elf_Shdr * sechdrs,const char * secstrings)182 static 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 
203 			if ((s->sh_flags & masks[m][0]) != masks[m][0]
204 			    || (s->sh_flags & masks[m][1])
205 			    || s->sh_entsize != ~0UL)
206 				continue;
207 			s->sh_entsize =
208 				get_offset((unsigned long *)&mod->core_layout.size, s);
209 		}
210 
211 		if (m == 0)
212 			mod->core_layout.text_size = mod->core_layout.size;
213 
214 	}
215 }
216 
217 /* from module-elf32.c, but subverted a little */
218 
219 struct mips_hi16 {
220 	struct mips_hi16 *next;
221 	Elf32_Addr *addr;
222 	Elf32_Addr value;
223 };
224 
225 static struct mips_hi16 *mips_hi16_list;
226 static unsigned int gp_offs, gp_addr;
227 
apply_r_mips_none(struct module * me,uint32_t * location,Elf32_Addr v)228 static int apply_r_mips_none(struct module *me, uint32_t *location,
229 			     Elf32_Addr v)
230 {
231 	return 0;
232 }
233 
apply_r_mips_gprel16(struct module * me,uint32_t * location,Elf32_Addr v)234 static int apply_r_mips_gprel16(struct module *me, uint32_t *location,
235 				Elf32_Addr v)
236 {
237 	int rel;
238 
239 	if (!(*location & 0xffff)) {
240 		rel = (int)v - gp_addr;
241 	} else {
242 		/* .sbss + gp(relative) + offset */
243 		/* kludge! */
244 		rel =  (int)(short)((int)v + gp_offs +
245 				    (int)(short)(*location & 0xffff) - gp_addr);
246 	}
247 
248 	if ((rel > 32768) || (rel < -32768)) {
249 		pr_debug("VPE loader: apply_r_mips_gprel16: relative address 0x%x out of range of gp register\n",
250 			 rel);
251 		return -ENOEXEC;
252 	}
253 
254 	*location = (*location & 0xffff0000) | (rel & 0xffff);
255 
256 	return 0;
257 }
258 
apply_r_mips_pc16(struct module * me,uint32_t * location,Elf32_Addr v)259 static int apply_r_mips_pc16(struct module *me, uint32_t *location,
260 			     Elf32_Addr v)
261 {
262 	int rel;
263 	rel = (((unsigned int)v - (unsigned int)location));
264 	rel >>= 2; /* because the offset is in _instructions_ not bytes. */
265 	rel -= 1;  /* and one instruction less due to the branch delay slot. */
266 
267 	if ((rel > 32768) || (rel < -32768)) {
268 		pr_debug("VPE loader: apply_r_mips_pc16: relative address out of range 0x%x\n",
269 			 rel);
270 		return -ENOEXEC;
271 	}
272 
273 	*location = (*location & 0xffff0000) | (rel & 0xffff);
274 
275 	return 0;
276 }
277 
apply_r_mips_32(struct module * me,uint32_t * location,Elf32_Addr v)278 static int apply_r_mips_32(struct module *me, uint32_t *location,
279 			   Elf32_Addr v)
280 {
281 	*location += v;
282 
283 	return 0;
284 }
285 
apply_r_mips_26(struct module * me,uint32_t * location,Elf32_Addr v)286 static int apply_r_mips_26(struct module *me, uint32_t *location,
287 			   Elf32_Addr v)
288 {
289 	if (v % 4) {
290 		pr_debug("VPE loader: apply_r_mips_26: unaligned relocation\n");
291 		return -ENOEXEC;
292 	}
293 
294 /*
295  * Not desperately convinced this is a good check of an overflow condition
296  * anyway. But it gets in the way of handling undefined weak symbols which
297  * we want to set to zero.
298  * if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
299  * printk(KERN_ERR
300  * "module %s: relocation overflow\n",
301  * me->name);
302  * return -ENOEXEC;
303  * }
304  */
305 
306 	*location = (*location & ~0x03ffffff) |
307 		((*location + (v >> 2)) & 0x03ffffff);
308 	return 0;
309 }
310 
apply_r_mips_hi16(struct module * me,uint32_t * location,Elf32_Addr v)311 static int apply_r_mips_hi16(struct module *me, uint32_t *location,
312 			     Elf32_Addr v)
313 {
314 	struct mips_hi16 *n;
315 
316 	/*
317 	 * We cannot relocate this one now because we don't know the value of
318 	 * the carry we need to add.  Save the information, and let LO16 do the
319 	 * actual relocation.
320 	 */
321 	n = kmalloc(sizeof(*n), GFP_KERNEL);
322 	if (!n)
323 		return -ENOMEM;
324 
325 	n->addr = location;
326 	n->value = v;
327 	n->next = mips_hi16_list;
328 	mips_hi16_list = n;
329 
330 	return 0;
331 }
332 
apply_r_mips_lo16(struct module * me,uint32_t * location,Elf32_Addr v)333 static int apply_r_mips_lo16(struct module *me, uint32_t *location,
334 			     Elf32_Addr v)
335 {
336 	unsigned long insnlo = *location;
337 	Elf32_Addr val, vallo;
338 	struct mips_hi16 *l, *next;
339 
340 	/* Sign extend the addend we extract from the lo insn.	*/
341 	vallo = ((insnlo & 0xffff) ^ 0x8000) - 0x8000;
342 
343 	if (mips_hi16_list != NULL) {
344 
345 		l = mips_hi16_list;
346 		while (l != NULL) {
347 			unsigned long insn;
348 
349 			/*
350 			 * The value for the HI16 had best be the same.
351 			 */
352 			if (v != l->value) {
353 				pr_debug("VPE loader: apply_r_mips_lo16/hi16: inconsistent value information\n");
354 				goto out_free;
355 			}
356 
357 			/*
358 			 * Do the HI16 relocation.  Note that we actually don't
359 			 * need to know anything about the LO16 itself, except
360 			 * where to find the low 16 bits of the addend needed
361 			 * by the LO16.
362 			 */
363 			insn = *l->addr;
364 			val = ((insn & 0xffff) << 16) + vallo;
365 			val += v;
366 
367 			/*
368 			 * Account for the sign extension that will happen in
369 			 * the low bits.
370 			 */
371 			val = ((val >> 16) + ((val & 0x8000) != 0)) & 0xffff;
372 
373 			insn = (insn & ~0xffff) | val;
374 			*l->addr = insn;
375 
376 			next = l->next;
377 			kfree(l);
378 			l = next;
379 		}
380 
381 		mips_hi16_list = NULL;
382 	}
383 
384 	/*
385 	 * Ok, we're done with the HI16 relocs.	 Now deal with the LO16.
386 	 */
387 	val = v + vallo;
388 	insnlo = (insnlo & ~0xffff) | (val & 0xffff);
389 	*location = insnlo;
390 
391 	return 0;
392 
393 out_free:
394 	while (l != NULL) {
395 		next = l->next;
396 		kfree(l);
397 		l = next;
398 	}
399 	mips_hi16_list = NULL;
400 
401 	return -ENOEXEC;
402 }
403 
404 static int (*reloc_handlers[]) (struct module *me, uint32_t *location,
405 				Elf32_Addr v) = {
406 	[R_MIPS_NONE]	= apply_r_mips_none,
407 	[R_MIPS_32]	= apply_r_mips_32,
408 	[R_MIPS_26]	= apply_r_mips_26,
409 	[R_MIPS_HI16]	= apply_r_mips_hi16,
410 	[R_MIPS_LO16]	= apply_r_mips_lo16,
411 	[R_MIPS_GPREL16] = apply_r_mips_gprel16,
412 	[R_MIPS_PC16] = apply_r_mips_pc16
413 };
414 
415 static char *rstrs[] = {
416 	[R_MIPS_NONE]	= "MIPS_NONE",
417 	[R_MIPS_32]	= "MIPS_32",
418 	[R_MIPS_26]	= "MIPS_26",
419 	[R_MIPS_HI16]	= "MIPS_HI16",
420 	[R_MIPS_LO16]	= "MIPS_LO16",
421 	[R_MIPS_GPREL16] = "MIPS_GPREL16",
422 	[R_MIPS_PC16] = "MIPS_PC16"
423 };
424 
apply_relocations(Elf32_Shdr * sechdrs,const char * strtab,unsigned int symindex,unsigned int relsec,struct module * me)425 static int apply_relocations(Elf32_Shdr *sechdrs,
426 		      const char *strtab,
427 		      unsigned int symindex,
428 		      unsigned int relsec,
429 		      struct module *me)
430 {
431 	Elf32_Rel *rel = (void *) sechdrs[relsec].sh_addr;
432 	Elf32_Sym *sym;
433 	uint32_t *location;
434 	unsigned int i;
435 	Elf32_Addr v;
436 	int res;
437 
438 	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
439 		Elf32_Word r_info = rel[i].r_info;
440 
441 		/* This is where to make the change */
442 		location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
443 			+ rel[i].r_offset;
444 		/* This is the symbol it is referring to */
445 		sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
446 			+ ELF32_R_SYM(r_info);
447 
448 		if (!sym->st_value) {
449 			pr_debug("%s: undefined weak symbol %s\n",
450 				 me->name, strtab + sym->st_name);
451 			/* just print the warning, dont barf */
452 		}
453 
454 		v = sym->st_value;
455 
456 		res = reloc_handlers[ELF32_R_TYPE(r_info)](me, location, v);
457 		if (res) {
458 			char *r = rstrs[ELF32_R_TYPE(r_info)];
459 			pr_warn("VPE loader: .text+0x%x relocation type %s for symbol \"%s\" failed\n",
460 				rel[i].r_offset, r ? r : "UNKNOWN",
461 				strtab + sym->st_name);
462 			return res;
463 		}
464 	}
465 
466 	return 0;
467 }
468 
save_gp_address(unsigned int secbase,unsigned int rel)469 static inline void save_gp_address(unsigned int secbase, unsigned int rel)
470 {
471 	gp_addr = secbase + rel;
472 	gp_offs = gp_addr - (secbase & 0xffff0000);
473 }
474 /* end module-elf32.c */
475 
476 /* Change all symbols so that sh_value encodes the pointer directly. */
simplify_symbols(Elf_Shdr * sechdrs,unsigned int symindex,const char * strtab,const char * secstrings,unsigned int nsecs,struct module * mod)477 static void simplify_symbols(Elf_Shdr *sechdrs,
478 			    unsigned int symindex,
479 			    const char *strtab,
480 			    const char *secstrings,
481 			    unsigned int nsecs, struct module *mod)
482 {
483 	Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
484 	unsigned long secbase, bssbase = 0;
485 	unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
486 	int size;
487 
488 	/* find the .bss section for COMMON symbols */
489 	for (i = 0; i < nsecs; i++) {
490 		if (strncmp(secstrings + sechdrs[i].sh_name, ".bss", 4) == 0) {
491 			bssbase = sechdrs[i].sh_addr;
492 			break;
493 		}
494 	}
495 
496 	for (i = 1; i < n; i++) {
497 		switch (sym[i].st_shndx) {
498 		case SHN_COMMON:
499 			/* Allocate space for the symbol in the .bss section.
500 			   st_value is currently size.
501 			   We want it to have the address of the symbol. */
502 
503 			size = sym[i].st_value;
504 			sym[i].st_value = bssbase;
505 
506 			bssbase += size;
507 			break;
508 
509 		case SHN_ABS:
510 			/* Don't need to do anything */
511 			break;
512 
513 		case SHN_UNDEF:
514 			/* ret = -ENOENT; */
515 			break;
516 
517 		case SHN_MIPS_SCOMMON:
518 			pr_debug("simplify_symbols: ignoring SHN_MIPS_SCOMMON symbol <%s> st_shndx %d\n",
519 				 strtab + sym[i].st_name, sym[i].st_shndx);
520 			/* .sbss section */
521 			break;
522 
523 		default:
524 			secbase = sechdrs[sym[i].st_shndx].sh_addr;
525 
526 			if (strncmp(strtab + sym[i].st_name, "_gp", 3) == 0)
527 				save_gp_address(secbase, sym[i].st_value);
528 
529 			sym[i].st_value += secbase;
530 			break;
531 		}
532 	}
533 }
534 
535 #ifdef DEBUG_ELFLOADER
dump_elfsymbols(Elf_Shdr * sechdrs,unsigned int symindex,const char * strtab,struct module * mod)536 static void dump_elfsymbols(Elf_Shdr *sechdrs, unsigned int symindex,
537 			    const char *strtab, struct module *mod)
538 {
539 	Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
540 	unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
541 
542 	pr_debug("dump_elfsymbols: n %d\n", n);
543 	for (i = 1; i < n; i++) {
544 		pr_debug(" i %d name <%s> 0x%x\n", i, strtab + sym[i].st_name,
545 			 sym[i].st_value);
546 	}
547 }
548 #endif
549 
find_vpe_symbols(struct vpe * v,Elf_Shdr * sechdrs,unsigned int symindex,const char * strtab,struct module * mod)550 static int find_vpe_symbols(struct vpe *v, Elf_Shdr *sechdrs,
551 				      unsigned int symindex, const char *strtab,
552 				      struct module *mod)
553 {
554 	Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
555 	unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
556 
557 	for (i = 1; i < n; i++) {
558 		if (strcmp(strtab + sym[i].st_name, "__start") == 0)
559 			v->__start = sym[i].st_value;
560 
561 		if (strcmp(strtab + sym[i].st_name, "vpe_shared") == 0)
562 			v->shared_ptr = (void *)sym[i].st_value;
563 	}
564 
565 	if ((v->__start == 0) || (v->shared_ptr == NULL))
566 		return -1;
567 
568 	return 0;
569 }
570 
571 /*
572  * Allocates a VPE with some program code space(the load address), copies the
573  * contents of the program (p)buffer performing relocatations/etc, free's it
574  * when finished.
575  */
vpe_elfload(struct vpe * v)576 static int vpe_elfload(struct vpe *v)
577 {
578 	Elf_Ehdr *hdr;
579 	Elf_Shdr *sechdrs;
580 	long err = 0;
581 	char *secstrings, *strtab = NULL;
582 	unsigned int len, i, symindex = 0, strindex = 0, relocate = 0;
583 	struct module mod; /* so we can re-use the relocations code */
584 
585 	memset(&mod, 0, sizeof(struct module));
586 	strcpy(mod.name, "VPE loader");
587 
588 	hdr = (Elf_Ehdr *) v->pbuffer;
589 	len = v->plen;
590 
591 	/* Sanity checks against insmoding binaries or wrong arch,
592 	   weird elf version */
593 	if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0
594 	    || (hdr->e_type != ET_REL && hdr->e_type != ET_EXEC)
595 	    || !elf_check_arch(hdr)
596 	    || hdr->e_shentsize != sizeof(*sechdrs)) {
597 		pr_warn("VPE loader: program wrong arch or weird elf version\n");
598 
599 		return -ENOEXEC;
600 	}
601 
602 	if (hdr->e_type == ET_REL)
603 		relocate = 1;
604 
605 	if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr)) {
606 		pr_err("VPE loader: program length %u truncated\n", len);
607 
608 		return -ENOEXEC;
609 	}
610 
611 	/* Convenience variables */
612 	sechdrs = (void *)hdr + hdr->e_shoff;
613 	secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
614 	sechdrs[0].sh_addr = 0;
615 
616 	/* And these should exist, but gcc whinges if we don't init them */
617 	symindex = strindex = 0;
618 
619 	if (relocate) {
620 		for (i = 1; i < hdr->e_shnum; i++) {
621 			if ((sechdrs[i].sh_type != SHT_NOBITS) &&
622 			    (len < sechdrs[i].sh_offset + sechdrs[i].sh_size)) {
623 				pr_err("VPE program length %u truncated\n",
624 				       len);
625 				return -ENOEXEC;
626 			}
627 
628 			/* Mark all sections sh_addr with their address in the
629 			   temporary image. */
630 			sechdrs[i].sh_addr = (size_t) hdr +
631 				sechdrs[i].sh_offset;
632 
633 			/* Internal symbols and strings. */
634 			if (sechdrs[i].sh_type == SHT_SYMTAB) {
635 				symindex = i;
636 				strindex = sechdrs[i].sh_link;
637 				strtab = (char *)hdr +
638 					sechdrs[strindex].sh_offset;
639 			}
640 		}
641 		layout_sections(&mod, hdr, sechdrs, secstrings);
642 	}
643 
644 	v->load_addr = alloc_progmem(mod.core_layout.size);
645 	if (!v->load_addr)
646 		return -ENOMEM;
647 
648 	pr_info("VPE loader: loading to %p\n", v->load_addr);
649 
650 	if (relocate) {
651 		for (i = 0; i < hdr->e_shnum; i++) {
652 			void *dest;
653 
654 			if (!(sechdrs[i].sh_flags & SHF_ALLOC))
655 				continue;
656 
657 			dest = v->load_addr + sechdrs[i].sh_entsize;
658 
659 			if (sechdrs[i].sh_type != SHT_NOBITS)
660 				memcpy(dest, (void *)sechdrs[i].sh_addr,
661 				       sechdrs[i].sh_size);
662 			/* Update sh_addr to point to copy in image. */
663 			sechdrs[i].sh_addr = (unsigned long)dest;
664 
665 			pr_debug(" section sh_name %s sh_addr 0x%x\n",
666 				 secstrings + sechdrs[i].sh_name,
667 				 sechdrs[i].sh_addr);
668 		}
669 
670 		/* Fix up syms, so that st_value is a pointer to location. */
671 		simplify_symbols(sechdrs, symindex, strtab, secstrings,
672 				 hdr->e_shnum, &mod);
673 
674 		/* Now do relocations. */
675 		for (i = 1; i < hdr->e_shnum; i++) {
676 			const char *strtab = (char *)sechdrs[strindex].sh_addr;
677 			unsigned int info = sechdrs[i].sh_info;
678 
679 			/* Not a valid relocation section? */
680 			if (info >= hdr->e_shnum)
681 				continue;
682 
683 			/* Don't bother with non-allocated sections */
684 			if (!(sechdrs[info].sh_flags & SHF_ALLOC))
685 				continue;
686 
687 			if (sechdrs[i].sh_type == SHT_REL)
688 				err = apply_relocations(sechdrs, strtab,
689 							symindex, i, &mod);
690 			else if (sechdrs[i].sh_type == SHT_RELA)
691 				err = apply_relocate_add(sechdrs, strtab,
692 							 symindex, i, &mod);
693 			if (err < 0)
694 				return err;
695 
696 		}
697 	} else {
698 		struct elf_phdr *phdr = (struct elf_phdr *)
699 						((char *)hdr + hdr->e_phoff);
700 
701 		for (i = 0; i < hdr->e_phnum; i++) {
702 			if (phdr->p_type == PT_LOAD) {
703 				memcpy((void *)phdr->p_paddr,
704 				       (char *)hdr + phdr->p_offset,
705 				       phdr->p_filesz);
706 				memset((void *)phdr->p_paddr + phdr->p_filesz,
707 				       0, phdr->p_memsz - phdr->p_filesz);
708 		    }
709 		    phdr++;
710 		}
711 
712 		for (i = 0; i < hdr->e_shnum; i++) {
713 			/* Internal symbols and strings. */
714 			if (sechdrs[i].sh_type == SHT_SYMTAB) {
715 				symindex = i;
716 				strindex = sechdrs[i].sh_link;
717 				strtab = (char *)hdr +
718 					sechdrs[strindex].sh_offset;
719 
720 				/*
721 				 * mark symtab's address for when we try
722 				 * to find the magic symbols
723 				 */
724 				sechdrs[i].sh_addr = (size_t) hdr +
725 					sechdrs[i].sh_offset;
726 			}
727 		}
728 	}
729 
730 	/* make sure it's physically written out */
731 	flush_icache_range((unsigned long)v->load_addr,
732 			   (unsigned long)v->load_addr + v->len);
733 
734 	if ((find_vpe_symbols(v, sechdrs, symindex, strtab, &mod)) < 0) {
735 		if (v->__start == 0) {
736 			pr_warn("VPE loader: program does not contain a __start symbol\n");
737 			return -ENOEXEC;
738 		}
739 
740 		if (v->shared_ptr == NULL)
741 			pr_warn("VPE loader: program does not contain vpe_shared symbol.\n"
742 				" Unable to use AMVP (AP/SP) facilities.\n");
743 	}
744 
745 	pr_info(" elf loaded\n");
746 	return 0;
747 }
748 
749 /* checks VPE is unused and gets ready to load program	*/
vpe_open(struct inode * inode,struct file * filp)750 static int vpe_open(struct inode *inode, struct file *filp)
751 {
752 	enum vpe_state state;
753 	struct vpe_notifications *notifier;
754 	struct vpe *v;
755 
756 	if (VPE_MODULE_MINOR != iminor(inode)) {
757 		/* assume only 1 device at the moment. */
758 		pr_warn("VPE loader: only vpe1 is supported\n");
759 
760 		return -ENODEV;
761 	}
762 
763 	v = get_vpe(aprp_cpu_index());
764 	if (v == NULL) {
765 		pr_warn("VPE loader: unable to get vpe\n");
766 
767 		return -ENODEV;
768 	}
769 
770 	state = xchg(&v->state, VPE_STATE_INUSE);
771 	if (state != VPE_STATE_UNUSED) {
772 		pr_debug("VPE loader: tc in use dumping regs\n");
773 
774 		list_for_each_entry(notifier, &v->notify, list)
775 			notifier->stop(aprp_cpu_index());
776 
777 		release_progmem(v->load_addr);
778 		cleanup_tc(get_tc(aprp_cpu_index()));
779 	}
780 
781 	/* this of-course trashes what was there before... */
782 	v->pbuffer = vmalloc(P_SIZE);
783 	if (!v->pbuffer) {
784 		pr_warn("VPE loader: unable to allocate memory\n");
785 		return -ENOMEM;
786 	}
787 	v->plen = P_SIZE;
788 	v->load_addr = NULL;
789 	v->len = 0;
790 	v->shared_ptr = NULL;
791 	v->__start = 0;
792 
793 	return 0;
794 }
795 
vpe_release(struct inode * inode,struct file * filp)796 static int vpe_release(struct inode *inode, struct file *filp)
797 {
798 #if defined(CONFIG_MIPS_VPE_LOADER_MT) || defined(CONFIG_MIPS_VPE_LOADER_CMP)
799 	struct vpe *v;
800 	Elf_Ehdr *hdr;
801 	int ret = 0;
802 
803 	v = get_vpe(aprp_cpu_index());
804 	if (v == NULL)
805 		return -ENODEV;
806 
807 	hdr = (Elf_Ehdr *) v->pbuffer;
808 	if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) == 0) {
809 		if (vpe_elfload(v) >= 0) {
810 			vpe_run(v);
811 		} else {
812 			pr_warn("VPE loader: ELF load failed.\n");
813 			ret = -ENOEXEC;
814 		}
815 	} else {
816 		pr_warn("VPE loader: only elf files are supported\n");
817 		ret = -ENOEXEC;
818 	}
819 
820 	/* It's good to be able to run the SP and if it chokes have a look at
821 	   the /dev/rt?. But if we reset the pointer to the shared struct we
822 	   lose what has happened. So perhaps if garbage is sent to the vpe
823 	   device, use it as a trigger for the reset. Hopefully a nice
824 	   executable will be along shortly. */
825 	if (ret < 0)
826 		v->shared_ptr = NULL;
827 
828 	vfree(v->pbuffer);
829 	v->plen = 0;
830 
831 	return ret;
832 #else
833 	pr_warn("VPE loader: ELF load failed.\n");
834 	return -ENOEXEC;
835 #endif
836 }
837 
vpe_write(struct file * file,const char __user * buffer,size_t count,loff_t * ppos)838 static ssize_t vpe_write(struct file *file, const char __user *buffer,
839 			 size_t count, loff_t *ppos)
840 {
841 	size_t ret = count;
842 	struct vpe *v;
843 
844 	if (iminor(file_inode(file)) != VPE_MODULE_MINOR)
845 		return -ENODEV;
846 
847 	v = get_vpe(aprp_cpu_index());
848 
849 	if (v == NULL)
850 		return -ENODEV;
851 
852 	if ((count + v->len) > v->plen) {
853 		pr_warn("VPE loader: elf size too big. Perhaps strip unneeded symbols\n");
854 		return -ENOMEM;
855 	}
856 
857 	count -= copy_from_user(v->pbuffer + v->len, buffer, count);
858 	if (!count)
859 		return -EFAULT;
860 
861 	v->len += count;
862 	return ret;
863 }
864 
865 const struct file_operations vpe_fops = {
866 	.owner = THIS_MODULE,
867 	.open = vpe_open,
868 	.release = vpe_release,
869 	.write = vpe_write,
870 	.llseek = noop_llseek,
871 };
872 
vpe_get_shared(int index)873 void *vpe_get_shared(int index)
874 {
875 	struct vpe *v = get_vpe(index);
876 
877 	if (v == NULL)
878 		return NULL;
879 
880 	return v->shared_ptr;
881 }
882 EXPORT_SYMBOL(vpe_get_shared);
883 
vpe_notify(int index,struct vpe_notifications * notify)884 int vpe_notify(int index, struct vpe_notifications *notify)
885 {
886 	struct vpe *v = get_vpe(index);
887 
888 	if (v == NULL)
889 		return -1;
890 
891 	list_add(&notify->list, &v->notify);
892 	return 0;
893 }
894 EXPORT_SYMBOL(vpe_notify);
895 
896 module_init(vpe_module_init);
897 module_exit(vpe_module_exit);
898 MODULE_DESCRIPTION("MIPS VPE Loader");
899 MODULE_AUTHOR("Elizabeth Oldham, MIPS Technologies, Inc.");
900 MODULE_LICENSE("GPL");
901