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 support 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 partially 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(&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 */
74struct 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) */
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(&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
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(&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
128out:
129	return tc;
130}
131
132/* clean up and free everything */
133void 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 */
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(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(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((unsigned long *)&mod_mem->size, 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(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(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(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, 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(mod.name, "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(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, hdr, sechdrs, secstrings);
641	}
642
643	v->load_addr = alloc_progmem(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				 hdr->e_shnum, &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, i, &mod);
689			else if (sechdrs[i].sh_type == SHT_RELA)
690				err = apply_relocate_add(sechdrs, strtab,
691							 symindex, i, &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((unsigned long)v->load_addr,
731			   (unsigned long)v->load_addr + v->len);
732
733	if ((find_vpe_symbols(v, sechdrs, symindex, strtab, &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(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(aprp_cpu_index()));
778	}
779
780	/* this of-course trashes what was there before... */
781	v->pbuffer = vmalloc(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(file_inode(file)) != VPE_MODULE_MINOR)
844		return -ENODEV;
845
846	v = get_vpe(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(v->pbuffer + v->len, buffer, 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(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(index);
886
887	if (v == NULL)
888		return -1;
889
890	list_add(&notify->list, &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