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/bootmem.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);
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
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_size, s);
209		}
210
211		if (m == 0)
212			mod->core_text_size = mod->core_size;
213
214	}
215}
216
217/* from module-elf32.c, but subverted a little */
218
219struct mips_hi16 {
220	struct mips_hi16 *next;
221	Elf32_Addr *addr;
222	Elf32_Addr value;
223};
224
225static struct mips_hi16 *mips_hi16_list;
226static unsigned int gp_offs, gp_addr;
227
228static int apply_r_mips_none(struct module *me, uint32_t *location,
229			     Elf32_Addr v)
230{
231	return 0;
232}
233
234static 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
259static 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
278static 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
286static 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
311static 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
333static 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
393out_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
404static 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
415static 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
425static 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
469static 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. */
477static 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
536static 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
550static 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 */
576static 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_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
749static int getcwd(char *buff, int size)
750{
751	mm_segment_t old_fs;
752	int ret;
753
754	old_fs = get_fs();
755	set_fs(KERNEL_DS);
756
757	ret = sys_getcwd(buff, size);
758
759	set_fs(old_fs);
760
761	return ret;
762}
763
764/* checks VPE is unused and gets ready to load program	*/
765static int vpe_open(struct inode *inode, struct file *filp)
766{
767	enum vpe_state state;
768	struct vpe_notifications *notifier;
769	struct vpe *v;
770	int ret;
771
772	if (VPE_MODULE_MINOR != iminor(inode)) {
773		/* assume only 1 device at the moment. */
774		pr_warn("VPE loader: only vpe1 is supported\n");
775
776		return -ENODEV;
777	}
778
779	v = get_vpe(aprp_cpu_index());
780	if (v == NULL) {
781		pr_warn("VPE loader: unable to get vpe\n");
782
783		return -ENODEV;
784	}
785
786	state = xchg(&v->state, VPE_STATE_INUSE);
787	if (state != VPE_STATE_UNUSED) {
788		pr_debug("VPE loader: tc in use dumping regs\n");
789
790		list_for_each_entry(notifier, &v->notify, list)
791			notifier->stop(aprp_cpu_index());
792
793		release_progmem(v->load_addr);
794		cleanup_tc(get_tc(aprp_cpu_index()));
795	}
796
797	/* this of-course trashes what was there before... */
798	v->pbuffer = vmalloc(P_SIZE);
799	if (!v->pbuffer) {
800		pr_warn("VPE loader: unable to allocate memory\n");
801		return -ENOMEM;
802	}
803	v->plen = P_SIZE;
804	v->load_addr = NULL;
805	v->len = 0;
806
807	v->cwd[0] = 0;
808	ret = getcwd(v->cwd, VPE_PATH_MAX);
809	if (ret < 0)
810		pr_warn("VPE loader: open, getcwd returned %d\n", ret);
811
812	v->shared_ptr = NULL;
813	v->__start = 0;
814
815	return 0;
816}
817
818static int vpe_release(struct inode *inode, struct file *filp)
819{
820	struct vpe *v;
821	Elf_Ehdr *hdr;
822	int ret = 0;
823
824	v = get_vpe(aprp_cpu_index());
825	if (v == NULL)
826		return -ENODEV;
827
828	hdr = (Elf_Ehdr *) v->pbuffer;
829	if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) == 0) {
830		if ((vpe_elfload(v) >= 0) && vpe_run) {
831			vpe_run(v);
832		} else {
833			pr_warn("VPE loader: ELF load failed.\n");
834			ret = -ENOEXEC;
835		}
836	} else {
837		pr_warn("VPE loader: only elf files are supported\n");
838		ret = -ENOEXEC;
839	}
840
841	/* It's good to be able to run the SP and if it chokes have a look at
842	   the /dev/rt?. But if we reset the pointer to the shared struct we
843	   lose what has happened. So perhaps if garbage is sent to the vpe
844	   device, use it as a trigger for the reset. Hopefully a nice
845	   executable will be along shortly. */
846	if (ret < 0)
847		v->shared_ptr = NULL;
848
849	vfree(v->pbuffer);
850	v->plen = 0;
851
852	return ret;
853}
854
855static ssize_t vpe_write(struct file *file, const char __user *buffer,
856			 size_t count, loff_t *ppos)
857{
858	size_t ret = count;
859	struct vpe *v;
860
861	if (iminor(file_inode(file)) != VPE_MODULE_MINOR)
862		return -ENODEV;
863
864	v = get_vpe(aprp_cpu_index());
865
866	if (v == NULL)
867		return -ENODEV;
868
869	if ((count + v->len) > v->plen) {
870		pr_warn("VPE loader: elf size too big. Perhaps strip uneeded symbols\n");
871		return -ENOMEM;
872	}
873
874	count -= copy_from_user(v->pbuffer + v->len, buffer, count);
875	if (!count)
876		return -EFAULT;
877
878	v->len += count;
879	return ret;
880}
881
882const struct file_operations vpe_fops = {
883	.owner = THIS_MODULE,
884	.open = vpe_open,
885	.release = vpe_release,
886	.write = vpe_write,
887	.llseek = noop_llseek,
888};
889
890void *vpe_get_shared(int index)
891{
892	struct vpe *v = get_vpe(index);
893
894	if (v == NULL)
895		return NULL;
896
897	return v->shared_ptr;
898}
899EXPORT_SYMBOL(vpe_get_shared);
900
901int vpe_notify(int index, struct vpe_notifications *notify)
902{
903	struct vpe *v = get_vpe(index);
904
905	if (v == NULL)
906		return -1;
907
908	list_add(&notify->list, &v->notify);
909	return 0;
910}
911EXPORT_SYMBOL(vpe_notify);
912
913char *vpe_getcwd(int index)
914{
915	struct vpe *v = get_vpe(index);
916
917	if (v == NULL)
918		return NULL;
919
920	return v->cwd;
921}
922EXPORT_SYMBOL(vpe_getcwd);
923
924module_init(vpe_module_init);
925module_exit(vpe_module_exit);
926MODULE_DESCRIPTION("MIPS VPE Loader");
927MODULE_AUTHOR("Elizabeth Oldham, MIPS Technologies, Inc.");
928MODULE_LICENSE("GPL");
929