xref: /openbmc/linux/arch/mips/kernel/vpe.c (revision 545e4006)
1 /*
2  * Copyright (C) 2004, 2005 MIPS Technologies, Inc.  All rights reserved.
3  *
4  *  This program is free software; you can distribute it and/or modify it
5  *  under the terms of the GNU General Public License (Version 2) as
6  *  published by the Free Software Foundation.
7  *
8  *  This program is distributed in the hope it will be useful, but WITHOUT
9  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
11  *  for more details.
12  *
13  *  You should have received a copy of the GNU General Public License along
14  *  with this program; if not, write to the Free Software Foundation, Inc.,
15  *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
16  */
17 
18 /*
19  * VPE support module
20  *
21  * Provides support for loading a MIPS SP program on VPE1.
22  * The SP enviroment is rather simple, no tlb's.  It needs to be relocatable
23  * (or partially linked). You should initialise your stack in the startup
24  * code. This loader looks for the symbol __start and sets up
25  * execution to resume from there. The MIPS SDE kit contains suitable examples.
26  *
27  * To load and run, simply cat a SP 'program file' to /dev/vpe1.
28  * i.e cat spapp >/dev/vpe1.
29  */
30 #include <linux/kernel.h>
31 #include <linux/device.h>
32 #include <linux/module.h>
33 #include <linux/fs.h>
34 #include <linux/init.h>
35 #include <asm/uaccess.h>
36 #include <linux/slab.h>
37 #include <linux/list.h>
38 #include <linux/vmalloc.h>
39 #include <linux/elf.h>
40 #include <linux/seq_file.h>
41 #include <linux/smp_lock.h>
42 #include <linux/syscalls.h>
43 #include <linux/moduleloader.h>
44 #include <linux/interrupt.h>
45 #include <linux/poll.h>
46 #include <linux/bootmem.h>
47 #include <asm/mipsregs.h>
48 #include <asm/mipsmtregs.h>
49 #include <asm/cacheflush.h>
50 #include <asm/atomic.h>
51 #include <asm/cpu.h>
52 #include <asm/mips_mt.h>
53 #include <asm/processor.h>
54 #include <asm/system.h>
55 #include <asm/vpe.h>
56 #include <asm/kspd.h>
57 
58 typedef void *vpe_handle;
59 
60 #ifndef ARCH_SHF_SMALL
61 #define ARCH_SHF_SMALL 0
62 #endif
63 
64 /* If this is set, the section belongs in the init part of the module */
65 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
66 
67 /*
68  * The number of TCs and VPEs physically available on the core
69  */
70 static int hw_tcs, hw_vpes;
71 static char module_name[] = "vpe";
72 static int major;
73 static const int minor = 1;	/* fixed for now  */
74 
75 #ifdef CONFIG_MIPS_APSP_KSPD
76  static struct kspd_notifications kspd_events;
77 static int kspd_events_reqd = 0;
78 #endif
79 
80 /* grab the likely amount of memory we will need. */
81 #ifdef CONFIG_MIPS_VPE_LOADER_TOM
82 #define P_SIZE (2 * 1024 * 1024)
83 #else
84 /* add an overhead to the max kmalloc size for non-striped symbols/etc */
85 #define P_SIZE (256 * 1024)
86 #endif
87 
88 extern unsigned long physical_memsize;
89 
90 #define MAX_VPES 16
91 #define VPE_PATH_MAX 256
92 
93 enum vpe_state {
94 	VPE_STATE_UNUSED = 0,
95 	VPE_STATE_INUSE,
96 	VPE_STATE_RUNNING
97 };
98 
99 enum tc_state {
100 	TC_STATE_UNUSED = 0,
101 	TC_STATE_INUSE,
102 	TC_STATE_RUNNING,
103 	TC_STATE_DYNAMIC
104 };
105 
106 struct vpe {
107 	enum vpe_state state;
108 
109 	/* (device) minor associated with this vpe */
110 	int minor;
111 
112 	/* elfloader stuff */
113 	void *load_addr;
114 	unsigned long len;
115 	char *pbuffer;
116 	unsigned long plen;
117 	unsigned int uid, gid;
118 	char cwd[VPE_PATH_MAX];
119 
120 	unsigned long __start;
121 
122 	/* tc's associated with this vpe */
123 	struct list_head tc;
124 
125 	/* The list of vpe's */
126 	struct list_head list;
127 
128 	/* shared symbol address */
129 	void *shared_ptr;
130 
131 	/* the list of who wants to know when something major happens */
132 	struct list_head notify;
133 
134 	unsigned int ntcs;
135 };
136 
137 struct tc {
138 	enum tc_state state;
139 	int index;
140 
141 	struct vpe *pvpe;	/* parent VPE */
142 	struct list_head tc;	/* The list of TC's with this VPE */
143 	struct list_head list;	/* The global list of tc's */
144 };
145 
146 struct {
147 	/* Virtual processing elements */
148 	struct list_head vpe_list;
149 
150 	/* Thread contexts */
151 	struct list_head tc_list;
152 } vpecontrol = {
153 	.vpe_list = LIST_HEAD_INIT(vpecontrol.vpe_list),
154 	.tc_list = LIST_HEAD_INIT(vpecontrol.tc_list)
155 };
156 
157 static void release_progmem(void *ptr);
158 extern void save_gp_address(unsigned int secbase, unsigned int rel);
159 
160 /* get the vpe associated with this minor */
161 struct vpe *get_vpe(int minor)
162 {
163 	struct vpe *v;
164 
165 	if (!cpu_has_mipsmt)
166 		return NULL;
167 
168 	list_for_each_entry(v, &vpecontrol.vpe_list, list) {
169 		if (v->minor == minor)
170 			return v;
171 	}
172 
173 	return NULL;
174 }
175 
176 /* get the vpe associated with this minor */
177 struct tc *get_tc(int index)
178 {
179 	struct tc *t;
180 
181 	list_for_each_entry(t, &vpecontrol.tc_list, list) {
182 		if (t->index == index)
183 			return t;
184 	}
185 
186 	return NULL;
187 }
188 
189 struct tc *get_tc_unused(void)
190 {
191 	struct tc *t;
192 
193 	list_for_each_entry(t, &vpecontrol.tc_list, list) {
194 		if (t->state == TC_STATE_UNUSED)
195 			return t;
196 	}
197 
198 	return NULL;
199 }
200 
201 /* allocate a vpe and associate it with this minor (or index) */
202 struct vpe *alloc_vpe(int minor)
203 {
204 	struct vpe *v;
205 
206 	if ((v = kzalloc(sizeof(struct vpe), GFP_KERNEL)) == NULL) {
207 		return NULL;
208 	}
209 
210 	INIT_LIST_HEAD(&v->tc);
211 	list_add_tail(&v->list, &vpecontrol.vpe_list);
212 
213 	INIT_LIST_HEAD(&v->notify);
214 	v->minor = minor;
215 	return v;
216 }
217 
218 /* allocate a tc. At startup only tc0 is running, all other can be halted. */
219 struct tc *alloc_tc(int index)
220 {
221 	struct tc *tc;
222 
223 	if ((tc = kzalloc(sizeof(struct tc), GFP_KERNEL)) == NULL)
224 		goto out;
225 
226 	INIT_LIST_HEAD(&tc->tc);
227 	tc->index = index;
228 	list_add_tail(&tc->list, &vpecontrol.tc_list);
229 
230 out:
231 	return tc;
232 }
233 
234 /* clean up and free everything */
235 void release_vpe(struct vpe *v)
236 {
237 	list_del(&v->list);
238 	if (v->load_addr)
239 		release_progmem(v);
240 	kfree(v);
241 }
242 
243 void dump_mtregs(void)
244 {
245 	unsigned long val;
246 
247 	val = read_c0_config3();
248 	printk("config3 0x%lx MT %ld\n", val,
249 	       (val & CONFIG3_MT) >> CONFIG3_MT_SHIFT);
250 
251 	val = read_c0_mvpcontrol();
252 	printk("MVPControl 0x%lx, STLB %ld VPC %ld EVP %ld\n", val,
253 	       (val & MVPCONTROL_STLB) >> MVPCONTROL_STLB_SHIFT,
254 	       (val & MVPCONTROL_VPC) >> MVPCONTROL_VPC_SHIFT,
255 	       (val & MVPCONTROL_EVP));
256 
257 	val = read_c0_mvpconf0();
258 	printk("mvpconf0 0x%lx, PVPE %ld PTC %ld M %ld\n", val,
259 	       (val & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT,
260 	       val & MVPCONF0_PTC, (val & MVPCONF0_M) >> MVPCONF0_M_SHIFT);
261 }
262 
263 /* Find some VPE program space  */
264 static void *alloc_progmem(unsigned long len)
265 {
266 	void *addr;
267 
268 #ifdef CONFIG_MIPS_VPE_LOADER_TOM
269 	/*
270 	 * This means you must tell Linux to use less memory than you
271 	 * physically have, for example by passing a mem= boot argument.
272 	 */
273 	addr = pfn_to_kaddr(max_low_pfn);
274 	memset(addr, 0, len);
275 #else
276 	/* simple grab some mem for now */
277 	addr = kzalloc(len, GFP_KERNEL);
278 #endif
279 
280 	return addr;
281 }
282 
283 static void release_progmem(void *ptr)
284 {
285 #ifndef CONFIG_MIPS_VPE_LOADER_TOM
286 	kfree(ptr);
287 #endif
288 }
289 
290 /* Update size with this section: return offset. */
291 static long get_offset(unsigned long *size, Elf_Shdr * sechdr)
292 {
293 	long ret;
294 
295 	ret = ALIGN(*size, sechdr->sh_addralign ? : 1);
296 	*size = ret + sechdr->sh_size;
297 	return ret;
298 }
299 
300 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
301    might -- code, read-only data, read-write data, small data.  Tally
302    sizes, and place the offsets into sh_entsize fields: high bit means it
303    belongs in init. */
304 static void layout_sections(struct module *mod, const Elf_Ehdr * hdr,
305 			    Elf_Shdr * sechdrs, const char *secstrings)
306 {
307 	static unsigned long const masks[][2] = {
308 		/* NOTE: all executable code must be the first section
309 		 * in this array; otherwise modify the text_size
310 		 * finder in the two loops below */
311 		{SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL},
312 		{SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL},
313 		{SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL},
314 		{ARCH_SHF_SMALL | SHF_ALLOC, 0}
315 	};
316 	unsigned int m, i;
317 
318 	for (i = 0; i < hdr->e_shnum; i++)
319 		sechdrs[i].sh_entsize = ~0UL;
320 
321 	for (m = 0; m < ARRAY_SIZE(masks); ++m) {
322 		for (i = 0; i < hdr->e_shnum; ++i) {
323 			Elf_Shdr *s = &sechdrs[i];
324 
325 			//  || strncmp(secstrings + s->sh_name, ".init", 5) == 0)
326 			if ((s->sh_flags & masks[m][0]) != masks[m][0]
327 			    || (s->sh_flags & masks[m][1])
328 			    || s->sh_entsize != ~0UL)
329 				continue;
330 			s->sh_entsize = get_offset(&mod->core_size, s);
331 		}
332 
333 		if (m == 0)
334 			mod->core_text_size = mod->core_size;
335 
336 	}
337 }
338 
339 
340 /* from module-elf32.c, but subverted a little */
341 
342 struct mips_hi16 {
343 	struct mips_hi16 *next;
344 	Elf32_Addr *addr;
345 	Elf32_Addr value;
346 };
347 
348 static struct mips_hi16 *mips_hi16_list;
349 static unsigned int gp_offs, gp_addr;
350 
351 static int apply_r_mips_none(struct module *me, uint32_t *location,
352 			     Elf32_Addr v)
353 {
354 	return 0;
355 }
356 
357 static int apply_r_mips_gprel16(struct module *me, uint32_t *location,
358 				Elf32_Addr v)
359 {
360 	int rel;
361 
362 	if( !(*location & 0xffff) ) {
363 		rel = (int)v - gp_addr;
364 	}
365 	else {
366 		/* .sbss + gp(relative) + offset */
367 		/* kludge! */
368 		rel =  (int)(short)((int)v + gp_offs +
369 				    (int)(short)(*location & 0xffff) - gp_addr);
370 	}
371 
372 	if( (rel > 32768) || (rel < -32768) ) {
373 		printk(KERN_DEBUG "VPE loader: apply_r_mips_gprel16: "
374 		       "relative address 0x%x out of range of gp register\n",
375 		       rel);
376 		return -ENOEXEC;
377 	}
378 
379 	*location = (*location & 0xffff0000) | (rel & 0xffff);
380 
381 	return 0;
382 }
383 
384 static int apply_r_mips_pc16(struct module *me, uint32_t *location,
385 			     Elf32_Addr v)
386 {
387 	int rel;
388 	rel = (((unsigned int)v - (unsigned int)location));
389 	rel >>= 2;		// because the offset is in _instructions_ not bytes.
390 	rel -= 1;		// and one instruction less due to the branch delay slot.
391 
392 	if( (rel > 32768) || (rel < -32768) ) {
393 		printk(KERN_DEBUG "VPE loader: "
394  		       "apply_r_mips_pc16: relative address out of range 0x%x\n", rel);
395 		return -ENOEXEC;
396 	}
397 
398 	*location = (*location & 0xffff0000) | (rel & 0xffff);
399 
400 	return 0;
401 }
402 
403 static int apply_r_mips_32(struct module *me, uint32_t *location,
404 			   Elf32_Addr v)
405 {
406 	*location += v;
407 
408 	return 0;
409 }
410 
411 static int apply_r_mips_26(struct module *me, uint32_t *location,
412 			   Elf32_Addr v)
413 {
414 	if (v % 4) {
415 		printk(KERN_DEBUG "VPE loader: apply_r_mips_26 "
416 		       " unaligned relocation\n");
417 		return -ENOEXEC;
418 	}
419 
420 /*
421  * Not desperately convinced this is a good check of an overflow condition
422  * anyway. But it gets in the way of handling undefined weak symbols which
423  * we want to set to zero.
424  * if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
425  * printk(KERN_ERR
426  * "module %s: relocation overflow\n",
427  * me->name);
428  * return -ENOEXEC;
429  * }
430  */
431 
432 	*location = (*location & ~0x03ffffff) |
433 		((*location + (v >> 2)) & 0x03ffffff);
434 	return 0;
435 }
436 
437 static int apply_r_mips_hi16(struct module *me, uint32_t *location,
438 			     Elf32_Addr v)
439 {
440 	struct mips_hi16 *n;
441 
442 	/*
443 	 * We cannot relocate this one now because we don't know the value of
444 	 * the carry we need to add.  Save the information, and let LO16 do the
445 	 * actual relocation.
446 	 */
447 	n = kmalloc(sizeof *n, GFP_KERNEL);
448 	if (!n)
449 		return -ENOMEM;
450 
451 	n->addr = location;
452 	n->value = v;
453 	n->next = mips_hi16_list;
454 	mips_hi16_list = n;
455 
456 	return 0;
457 }
458 
459 static int apply_r_mips_lo16(struct module *me, uint32_t *location,
460 			     Elf32_Addr v)
461 {
462 	unsigned long insnlo = *location;
463 	Elf32_Addr val, vallo;
464 
465 	/* Sign extend the addend we extract from the lo insn.  */
466 	vallo = ((insnlo & 0xffff) ^ 0x8000) - 0x8000;
467 
468 	if (mips_hi16_list != NULL) {
469 		struct mips_hi16 *l;
470 
471 		l = mips_hi16_list;
472 		while (l != NULL) {
473 			struct mips_hi16 *next;
474 			unsigned long insn;
475 
476 			/*
477 			 * The value for the HI16 had best be the same.
478 			 */
479  			if (v != l->value) {
480 				printk(KERN_DEBUG "VPE loader: "
481 				       "apply_r_mips_lo16/hi16: \t"
482 				       "inconsistent value information\n");
483 				return -ENOEXEC;
484 			}
485 
486 			/*
487 			 * Do the HI16 relocation.  Note that we actually don't
488 			 * need to know anything about the LO16 itself, except
489 			 * where to find the low 16 bits of the addend needed
490 			 * by the LO16.
491 			 */
492 			insn = *l->addr;
493 			val = ((insn & 0xffff) << 16) + vallo;
494 			val += v;
495 
496 			/*
497 			 * Account for the sign extension that will happen in
498 			 * the low bits.
499 			 */
500 			val = ((val >> 16) + ((val & 0x8000) != 0)) & 0xffff;
501 
502 			insn = (insn & ~0xffff) | val;
503 			*l->addr = insn;
504 
505 			next = l->next;
506 			kfree(l);
507 			l = next;
508 		}
509 
510 		mips_hi16_list = NULL;
511 	}
512 
513 	/*
514 	 * Ok, we're done with the HI16 relocs.  Now deal with the LO16.
515 	 */
516 	val = v + vallo;
517 	insnlo = (insnlo & ~0xffff) | (val & 0xffff);
518 	*location = insnlo;
519 
520 	return 0;
521 }
522 
523 static int (*reloc_handlers[]) (struct module *me, uint32_t *location,
524 				Elf32_Addr v) = {
525 	[R_MIPS_NONE]	= apply_r_mips_none,
526 	[R_MIPS_32]	= apply_r_mips_32,
527 	[R_MIPS_26]	= apply_r_mips_26,
528 	[R_MIPS_HI16]	= apply_r_mips_hi16,
529 	[R_MIPS_LO16]	= apply_r_mips_lo16,
530 	[R_MIPS_GPREL16] = apply_r_mips_gprel16,
531 	[R_MIPS_PC16] = apply_r_mips_pc16
532 };
533 
534 static char *rstrs[] = {
535 	[R_MIPS_NONE]	= "MIPS_NONE",
536 	[R_MIPS_32]	= "MIPS_32",
537 	[R_MIPS_26]	= "MIPS_26",
538 	[R_MIPS_HI16]	= "MIPS_HI16",
539 	[R_MIPS_LO16]	= "MIPS_LO16",
540 	[R_MIPS_GPREL16] = "MIPS_GPREL16",
541 	[R_MIPS_PC16] = "MIPS_PC16"
542 };
543 
544 int apply_relocations(Elf32_Shdr *sechdrs,
545 		      const char *strtab,
546 		      unsigned int symindex,
547 		      unsigned int relsec,
548 		      struct module *me)
549 {
550 	Elf32_Rel *rel = (void *) sechdrs[relsec].sh_addr;
551 	Elf32_Sym *sym;
552 	uint32_t *location;
553 	unsigned int i;
554 	Elf32_Addr v;
555 	int res;
556 
557 	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
558 		Elf32_Word r_info = rel[i].r_info;
559 
560 		/* This is where to make the change */
561 		location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
562 			+ rel[i].r_offset;
563 		/* This is the symbol it is referring to */
564 		sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
565 			+ ELF32_R_SYM(r_info);
566 
567 		if (!sym->st_value) {
568 			printk(KERN_DEBUG "%s: undefined weak symbol %s\n",
569 			       me->name, strtab + sym->st_name);
570 			/* just print the warning, dont barf */
571 		}
572 
573 		v = sym->st_value;
574 
575 		res = reloc_handlers[ELF32_R_TYPE(r_info)](me, location, v);
576 		if( res ) {
577 			char *r = rstrs[ELF32_R_TYPE(r_info)];
578 		    	printk(KERN_WARNING "VPE loader: .text+0x%x "
579 			       "relocation type %s for symbol \"%s\" failed\n",
580 			       rel[i].r_offset, r ? r : "UNKNOWN",
581 			       strtab + sym->st_name);
582 			return res;
583 		}
584 	}
585 
586 	return 0;
587 }
588 
589 void save_gp_address(unsigned int secbase, unsigned int rel)
590 {
591 	gp_addr = secbase + rel;
592 	gp_offs = gp_addr - (secbase & 0xffff0000);
593 }
594 /* end module-elf32.c */
595 
596 
597 
598 /* Change all symbols so that sh_value encodes the pointer directly. */
599 static void simplify_symbols(Elf_Shdr * sechdrs,
600 			    unsigned int symindex,
601 			    const char *strtab,
602 			    const char *secstrings,
603 			    unsigned int nsecs, struct module *mod)
604 {
605 	Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
606 	unsigned long secbase, bssbase = 0;
607 	unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
608 	int size;
609 
610 	/* find the .bss section for COMMON symbols */
611 	for (i = 0; i < nsecs; i++) {
612 		if (strncmp(secstrings + sechdrs[i].sh_name, ".bss", 4) == 0) {
613 			bssbase = sechdrs[i].sh_addr;
614 			break;
615 		}
616 	}
617 
618 	for (i = 1; i < n; i++) {
619 		switch (sym[i].st_shndx) {
620 		case SHN_COMMON:
621 			/* Allocate space for the symbol in the .bss section.
622 			   st_value is currently size.
623 			   We want it to have the address of the symbol. */
624 
625 			size = sym[i].st_value;
626 			sym[i].st_value = bssbase;
627 
628 			bssbase += size;
629 			break;
630 
631 		case SHN_ABS:
632 			/* Don't need to do anything */
633 			break;
634 
635 		case SHN_UNDEF:
636 			/* ret = -ENOENT; */
637 			break;
638 
639 		case SHN_MIPS_SCOMMON:
640 			printk(KERN_DEBUG "simplify_symbols: ignoring SHN_MIPS_SCOMMON "
641 			       "symbol <%s> st_shndx %d\n", strtab + sym[i].st_name,
642 			       sym[i].st_shndx);
643 			// .sbss section
644 			break;
645 
646 		default:
647 			secbase = sechdrs[sym[i].st_shndx].sh_addr;
648 
649 			if (strncmp(strtab + sym[i].st_name, "_gp", 3) == 0) {
650 				save_gp_address(secbase, sym[i].st_value);
651 			}
652 
653 			sym[i].st_value += secbase;
654 			break;
655 		}
656 	}
657 }
658 
659 #ifdef DEBUG_ELFLOADER
660 static void dump_elfsymbols(Elf_Shdr * sechdrs, unsigned int symindex,
661 			    const char *strtab, struct module *mod)
662 {
663 	Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
664 	unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
665 
666 	printk(KERN_DEBUG "dump_elfsymbols: n %d\n", n);
667 	for (i = 1; i < n; i++) {
668 		printk(KERN_DEBUG " i %d name <%s> 0x%x\n", i,
669 		       strtab + sym[i].st_name, sym[i].st_value);
670 	}
671 }
672 #endif
673 
674 /* We are prepared so configure and start the VPE... */
675 static int vpe_run(struct vpe * v)
676 {
677 	unsigned long flags, val, dmt_flag;
678 	struct vpe_notifications *n;
679 	unsigned int vpeflags;
680 	struct tc *t;
681 
682 	/* check we are the Master VPE */
683 	local_irq_save(flags);
684 	val = read_c0_vpeconf0();
685 	if (!(val & VPECONF0_MVP)) {
686 		printk(KERN_WARNING
687 		       "VPE loader: only Master VPE's are allowed to configure MT\n");
688 		local_irq_restore(flags);
689 
690 		return -1;
691 	}
692 
693 	dmt_flag = dmt();
694 	vpeflags = dvpe();
695 
696 	if (!list_empty(&v->tc)) {
697 		if ((t = list_entry(v->tc.next, struct tc, tc)) == NULL) {
698 			evpe(vpeflags);
699 			emt(dmt_flag);
700 			local_irq_restore(flags);
701 
702 			printk(KERN_WARNING
703 			       "VPE loader: TC %d is already in use.\n",
704                                t->index);
705 			return -ENOEXEC;
706 		}
707 	} else {
708 		evpe(vpeflags);
709 		emt(dmt_flag);
710 		local_irq_restore(flags);
711 
712 		printk(KERN_WARNING
713 		       "VPE loader: No TC's associated with VPE %d\n",
714 		       v->minor);
715 
716 		return -ENOEXEC;
717 	}
718 
719 	/* Put MVPE's into 'configuration state' */
720 	set_c0_mvpcontrol(MVPCONTROL_VPC);
721 
722 	settc(t->index);
723 
724 	/* should check it is halted, and not activated */
725 	if ((read_tc_c0_tcstatus() & TCSTATUS_A) || !(read_tc_c0_tchalt() & TCHALT_H)) {
726 		evpe(vpeflags);
727 		emt(dmt_flag);
728 		local_irq_restore(flags);
729 
730 		printk(KERN_WARNING "VPE loader: TC %d is already active!\n",
731 		       t->index);
732 
733 		return -ENOEXEC;
734 	}
735 
736 	/* Write the address we want it to start running from in the TCPC register. */
737 	write_tc_c0_tcrestart((unsigned long)v->__start);
738 	write_tc_c0_tccontext((unsigned long)0);
739 
740 	/*
741 	 * Mark the TC as activated, not interrupt exempt and not dynamically
742 	 * allocatable
743 	 */
744 	val = read_tc_c0_tcstatus();
745 	val = (val & ~(TCSTATUS_DA | TCSTATUS_IXMT)) | TCSTATUS_A;
746 	write_tc_c0_tcstatus(val);
747 
748 	write_tc_c0_tchalt(read_tc_c0_tchalt() & ~TCHALT_H);
749 
750 	/*
751 	 * The sde-kit passes 'memsize' to __start in $a3, so set something
752 	 * here...  Or set $a3 to zero and define DFLT_STACK_SIZE and
753 	 * DFLT_HEAP_SIZE when you compile your program
754 	 */
755 	mttgpr(6, v->ntcs);
756 	mttgpr(7, physical_memsize);
757 
758 	/* set up VPE1 */
759 	/*
760 	 * bind the TC to VPE 1 as late as possible so we only have the final
761 	 * VPE registers to set up, and so an EJTAG probe can trigger on it
762 	 */
763 	write_tc_c0_tcbind((read_tc_c0_tcbind() & ~TCBIND_CURVPE) | 1);
764 
765 	write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() & ~(VPECONF0_VPA));
766 
767 	back_to_back_c0_hazard();
768 
769 	/* Set up the XTC bit in vpeconf0 to point at our tc */
770 	write_vpe_c0_vpeconf0( (read_vpe_c0_vpeconf0() & ~(VPECONF0_XTC))
771 	                      | (t->index << VPECONF0_XTC_SHIFT));
772 
773 	back_to_back_c0_hazard();
774 
775 	/* enable this VPE */
776 	write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() | VPECONF0_VPA);
777 
778 	/* clear out any left overs from a previous program */
779 	write_vpe_c0_status(0);
780 	write_vpe_c0_cause(0);
781 
782 	/* take system out of configuration state */
783 	clear_c0_mvpcontrol(MVPCONTROL_VPC);
784 
785 	/*
786 	 * SMTC/SMVP kernels manage VPE enable independently,
787 	 * but uniprocessor kernels need to turn it on, even
788 	 * if that wasn't the pre-dvpe() state.
789 	 */
790 #ifdef CONFIG_SMP
791 	evpe(vpeflags);
792 #else
793 	evpe(EVPE_ENABLE);
794 #endif
795 	emt(dmt_flag);
796 	local_irq_restore(flags);
797 
798 	list_for_each_entry(n, &v->notify, list)
799 		n->start(minor);
800 
801 	return 0;
802 }
803 
804 static int find_vpe_symbols(struct vpe * v, Elf_Shdr * sechdrs,
805 				      unsigned int symindex, const char *strtab,
806 				      struct module *mod)
807 {
808 	Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
809 	unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
810 
811 	for (i = 1; i < n; i++) {
812 		if (strcmp(strtab + sym[i].st_name, "__start") == 0) {
813 			v->__start = sym[i].st_value;
814 		}
815 
816 		if (strcmp(strtab + sym[i].st_name, "vpe_shared") == 0) {
817 			v->shared_ptr = (void *)sym[i].st_value;
818 		}
819 	}
820 
821 	if ( (v->__start == 0) || (v->shared_ptr == NULL))
822 		return -1;
823 
824 	return 0;
825 }
826 
827 /*
828  * Allocates a VPE with some program code space(the load address), copies the
829  * contents of the program (p)buffer performing relocatations/etc, free's it
830  * when finished.
831  */
832 static int vpe_elfload(struct vpe * v)
833 {
834 	Elf_Ehdr *hdr;
835 	Elf_Shdr *sechdrs;
836 	long err = 0;
837 	char *secstrings, *strtab = NULL;
838 	unsigned int len, i, symindex = 0, strindex = 0, relocate = 0;
839 	struct module mod;	// so we can re-use the relocations code
840 
841 	memset(&mod, 0, sizeof(struct module));
842 	strcpy(mod.name, "VPE loader");
843 
844 	hdr = (Elf_Ehdr *) v->pbuffer;
845 	len = v->plen;
846 
847 	/* Sanity checks against insmoding binaries or wrong arch,
848 	   weird elf version */
849 	if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0
850 	    || (hdr->e_type != ET_REL && hdr->e_type != ET_EXEC)
851 	    || !elf_check_arch(hdr)
852 	    || hdr->e_shentsize != sizeof(*sechdrs)) {
853 		printk(KERN_WARNING
854 		       "VPE loader: program wrong arch or weird elf version\n");
855 
856 		return -ENOEXEC;
857 	}
858 
859 	if (hdr->e_type == ET_REL)
860 		relocate = 1;
861 
862 	if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr)) {
863 		printk(KERN_ERR "VPE loader: program length %u truncated\n",
864 		       len);
865 
866 		return -ENOEXEC;
867 	}
868 
869 	/* Convenience variables */
870 	sechdrs = (void *)hdr + hdr->e_shoff;
871 	secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
872 	sechdrs[0].sh_addr = 0;
873 
874 	/* And these should exist, but gcc whinges if we don't init them */
875 	symindex = strindex = 0;
876 
877 	if (relocate) {
878 		for (i = 1; i < hdr->e_shnum; i++) {
879 			if (sechdrs[i].sh_type != SHT_NOBITS
880 			    && len < sechdrs[i].sh_offset + sechdrs[i].sh_size) {
881 				printk(KERN_ERR "VPE program length %u truncated\n",
882 				       len);
883 				return -ENOEXEC;
884 			}
885 
886 			/* Mark all sections sh_addr with their address in the
887 			   temporary image. */
888 			sechdrs[i].sh_addr = (size_t) hdr + sechdrs[i].sh_offset;
889 
890 			/* Internal symbols and strings. */
891 			if (sechdrs[i].sh_type == SHT_SYMTAB) {
892 				symindex = i;
893 				strindex = sechdrs[i].sh_link;
894 				strtab = (char *)hdr + sechdrs[strindex].sh_offset;
895 			}
896 		}
897 		layout_sections(&mod, hdr, sechdrs, secstrings);
898 	}
899 
900 	v->load_addr = alloc_progmem(mod.core_size);
901 	if (!v->load_addr)
902 		return -ENOMEM;
903 
904 	pr_info("VPE loader: loading to %p\n", v->load_addr);
905 
906 	if (relocate) {
907 		for (i = 0; i < hdr->e_shnum; i++) {
908 			void *dest;
909 
910 			if (!(sechdrs[i].sh_flags & SHF_ALLOC))
911 				continue;
912 
913 			dest = v->load_addr + sechdrs[i].sh_entsize;
914 
915 			if (sechdrs[i].sh_type != SHT_NOBITS)
916 				memcpy(dest, (void *)sechdrs[i].sh_addr,
917 				       sechdrs[i].sh_size);
918 			/* Update sh_addr to point to copy in image. */
919 			sechdrs[i].sh_addr = (unsigned long)dest;
920 
921 			printk(KERN_DEBUG " section sh_name %s sh_addr 0x%x\n",
922 			       secstrings + sechdrs[i].sh_name, sechdrs[i].sh_addr);
923 		}
924 
925  		/* Fix up syms, so that st_value is a pointer to location. */
926  		simplify_symbols(sechdrs, symindex, strtab, secstrings,
927  				 hdr->e_shnum, &mod);
928 
929  		/* Now do relocations. */
930  		for (i = 1; i < hdr->e_shnum; i++) {
931  			const char *strtab = (char *)sechdrs[strindex].sh_addr;
932  			unsigned int info = sechdrs[i].sh_info;
933 
934  			/* Not a valid relocation section? */
935  			if (info >= hdr->e_shnum)
936  				continue;
937 
938  			/* Don't bother with non-allocated sections */
939  			if (!(sechdrs[info].sh_flags & SHF_ALLOC))
940  				continue;
941 
942  			if (sechdrs[i].sh_type == SHT_REL)
943  				err = apply_relocations(sechdrs, strtab, symindex, i,
944  							&mod);
945  			else if (sechdrs[i].sh_type == SHT_RELA)
946  				err = apply_relocate_add(sechdrs, strtab, symindex, i,
947  							 &mod);
948  			if (err < 0)
949  				return err;
950 
951   		}
952   	} else {
953 		struct elf_phdr *phdr = (struct elf_phdr *) ((char *)hdr + hdr->e_phoff);
954 
955 		for (i = 0; i < hdr->e_phnum; i++) {
956 			if (phdr->p_type == PT_LOAD) {
957 				memcpy((void *)phdr->p_paddr,
958 				       (char *)hdr + phdr->p_offset,
959 				       phdr->p_filesz);
960 				memset((void *)phdr->p_paddr + phdr->p_filesz,
961 				       0, phdr->p_memsz - phdr->p_filesz);
962 		    }
963 		    phdr++;
964 		}
965 
966 		for (i = 0; i < hdr->e_shnum; i++) {
967  			/* Internal symbols and strings. */
968  			if (sechdrs[i].sh_type == SHT_SYMTAB) {
969  				symindex = i;
970  				strindex = sechdrs[i].sh_link;
971  				strtab = (char *)hdr + sechdrs[strindex].sh_offset;
972 
973  				/* mark the symtab's address for when we try to find the
974  				   magic symbols */
975  				sechdrs[i].sh_addr = (size_t) hdr + sechdrs[i].sh_offset;
976  			}
977 		}
978 	}
979 
980 	/* make sure it's physically written out */
981 	flush_icache_range((unsigned long)v->load_addr,
982 			   (unsigned long)v->load_addr + v->len);
983 
984 	if ((find_vpe_symbols(v, sechdrs, symindex, strtab, &mod)) < 0) {
985 		if (v->__start == 0) {
986 			printk(KERN_WARNING "VPE loader: program does not contain "
987 			       "a __start symbol\n");
988 			return -ENOEXEC;
989 		}
990 
991 		if (v->shared_ptr == NULL)
992 			printk(KERN_WARNING "VPE loader: "
993 			       "program does not contain vpe_shared symbol.\n"
994 			       " Unable to use AMVP (AP/SP) facilities.\n");
995 	}
996 
997 	printk(" elf loaded\n");
998 	return 0;
999 }
1000 
1001 static void cleanup_tc(struct tc *tc)
1002 {
1003 	unsigned long flags;
1004 	unsigned int mtflags, vpflags;
1005 	int tmp;
1006 
1007 	local_irq_save(flags);
1008 	mtflags = dmt();
1009 	vpflags = dvpe();
1010 	/* Put MVPE's into 'configuration state' */
1011 	set_c0_mvpcontrol(MVPCONTROL_VPC);
1012 
1013 	settc(tc->index);
1014 	tmp = read_tc_c0_tcstatus();
1015 
1016 	/* mark not allocated and not dynamically allocatable */
1017 	tmp &= ~(TCSTATUS_A | TCSTATUS_DA);
1018 	tmp |= TCSTATUS_IXMT;	/* interrupt exempt */
1019 	write_tc_c0_tcstatus(tmp);
1020 
1021 	write_tc_c0_tchalt(TCHALT_H);
1022 	mips_ihb();
1023 
1024 	/* bind it to anything other than VPE1 */
1025 //	write_tc_c0_tcbind(read_tc_c0_tcbind() & ~TCBIND_CURVPE); // | TCBIND_CURVPE
1026 
1027 	clear_c0_mvpcontrol(MVPCONTROL_VPC);
1028 	evpe(vpflags);
1029 	emt(mtflags);
1030 	local_irq_restore(flags);
1031 }
1032 
1033 static int getcwd(char *buff, int size)
1034 {
1035 	mm_segment_t old_fs;
1036 	int ret;
1037 
1038 	old_fs = get_fs();
1039 	set_fs(KERNEL_DS);
1040 
1041 	ret = sys_getcwd(buff, size);
1042 
1043 	set_fs(old_fs);
1044 
1045 	return ret;
1046 }
1047 
1048 /* checks VPE is unused and gets ready to load program  */
1049 static int vpe_open(struct inode *inode, struct file *filp)
1050 {
1051 	enum vpe_state state;
1052 	struct vpe_notifications *not;
1053 	struct vpe *v;
1054 	int ret, err = 0;
1055 
1056 	lock_kernel();
1057 	if (minor != iminor(inode)) {
1058 		/* assume only 1 device at the moment. */
1059 		printk(KERN_WARNING "VPE loader: only vpe1 is supported\n");
1060 		err = -ENODEV;
1061 		goto out;
1062 	}
1063 
1064 	if ((v = get_vpe(tclimit)) == NULL) {
1065 		printk(KERN_WARNING "VPE loader: unable to get vpe\n");
1066 		err = -ENODEV;
1067 		goto out;
1068 	}
1069 
1070 	state = xchg(&v->state, VPE_STATE_INUSE);
1071 	if (state != VPE_STATE_UNUSED) {
1072 		printk(KERN_DEBUG "VPE loader: tc in use dumping regs\n");
1073 
1074 		list_for_each_entry(not, &v->notify, list) {
1075 			not->stop(tclimit);
1076 		}
1077 
1078 		release_progmem(v->load_addr);
1079 		cleanup_tc(get_tc(tclimit));
1080 	}
1081 
1082 	/* this of-course trashes what was there before... */
1083 	v->pbuffer = vmalloc(P_SIZE);
1084 	v->plen = P_SIZE;
1085 	v->load_addr = NULL;
1086 	v->len = 0;
1087 
1088 	v->uid = filp->f_uid;
1089 	v->gid = filp->f_gid;
1090 
1091 #ifdef CONFIG_MIPS_APSP_KSPD
1092 	/* get kspd to tell us when a syscall_exit happens */
1093 	if (!kspd_events_reqd) {
1094 		kspd_notify(&kspd_events);
1095 		kspd_events_reqd++;
1096 	}
1097 #endif
1098 
1099 	v->cwd[0] = 0;
1100 	ret = getcwd(v->cwd, VPE_PATH_MAX);
1101 	if (ret < 0)
1102 		printk(KERN_WARNING "VPE loader: open, getcwd returned %d\n", ret);
1103 
1104 	v->shared_ptr = NULL;
1105 	v->__start = 0;
1106 
1107 out:
1108 	unlock_kernel();
1109 	return 0;
1110 }
1111 
1112 static int vpe_release(struct inode *inode, struct file *filp)
1113 {
1114 	struct vpe *v;
1115 	Elf_Ehdr *hdr;
1116 	int ret = 0;
1117 
1118 	v = get_vpe(tclimit);
1119 	if (v == NULL)
1120 		return -ENODEV;
1121 
1122 	hdr = (Elf_Ehdr *) v->pbuffer;
1123 	if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) == 0) {
1124 		if (vpe_elfload(v) >= 0) {
1125 			vpe_run(v);
1126 		} else {
1127  			printk(KERN_WARNING "VPE loader: ELF load failed.\n");
1128 			ret = -ENOEXEC;
1129 		}
1130 	} else {
1131  		printk(KERN_WARNING "VPE loader: only elf files are supported\n");
1132 		ret = -ENOEXEC;
1133 	}
1134 
1135 	/* It's good to be able to run the SP and if it chokes have a look at
1136 	   the /dev/rt?. But if we reset the pointer to the shared struct we
1137 	   loose what has happened. So perhaps if garbage is sent to the vpe
1138 	   device, use it as a trigger for the reset. Hopefully a nice
1139 	   executable will be along shortly. */
1140 	if (ret < 0)
1141 		v->shared_ptr = NULL;
1142 
1143 	// cleanup any temp buffers
1144 	if (v->pbuffer)
1145 		vfree(v->pbuffer);
1146 	v->plen = 0;
1147 	return ret;
1148 }
1149 
1150 static ssize_t vpe_write(struct file *file, const char __user * buffer,
1151 			 size_t count, loff_t * ppos)
1152 {
1153 	size_t ret = count;
1154 	struct vpe *v;
1155 
1156 	if (iminor(file->f_path.dentry->d_inode) != minor)
1157 		return -ENODEV;
1158 
1159 	v = get_vpe(tclimit);
1160 	if (v == NULL)
1161 		return -ENODEV;
1162 
1163 	if (v->pbuffer == NULL) {
1164 		printk(KERN_ERR "VPE loader: no buffer for program\n");
1165 		return -ENOMEM;
1166 	}
1167 
1168 	if ((count + v->len) > v->plen) {
1169 		printk(KERN_WARNING
1170 		       "VPE loader: elf size too big. Perhaps strip uneeded symbols\n");
1171 		return -ENOMEM;
1172 	}
1173 
1174 	count -= copy_from_user(v->pbuffer + v->len, buffer, count);
1175 	if (!count)
1176 		return -EFAULT;
1177 
1178 	v->len += count;
1179 	return ret;
1180 }
1181 
1182 static const struct file_operations vpe_fops = {
1183 	.owner = THIS_MODULE,
1184 	.open = vpe_open,
1185 	.release = vpe_release,
1186 	.write = vpe_write
1187 };
1188 
1189 /* module wrapper entry points */
1190 /* give me a vpe */
1191 vpe_handle vpe_alloc(void)
1192 {
1193 	int i;
1194 	struct vpe *v;
1195 
1196 	/* find a vpe */
1197 	for (i = 1; i < MAX_VPES; i++) {
1198 		if ((v = get_vpe(i)) != NULL) {
1199 			v->state = VPE_STATE_INUSE;
1200 			return v;
1201 		}
1202 	}
1203 	return NULL;
1204 }
1205 
1206 EXPORT_SYMBOL(vpe_alloc);
1207 
1208 /* start running from here */
1209 int vpe_start(vpe_handle vpe, unsigned long start)
1210 {
1211 	struct vpe *v = vpe;
1212 
1213 	v->__start = start;
1214 	return vpe_run(v);
1215 }
1216 
1217 EXPORT_SYMBOL(vpe_start);
1218 
1219 /* halt it for now */
1220 int vpe_stop(vpe_handle vpe)
1221 {
1222 	struct vpe *v = vpe;
1223 	struct tc *t;
1224 	unsigned int evpe_flags;
1225 
1226 	evpe_flags = dvpe();
1227 
1228 	if ((t = list_entry(v->tc.next, struct tc, tc)) != NULL) {
1229 
1230 		settc(t->index);
1231 		write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() & ~VPECONF0_VPA);
1232 	}
1233 
1234 	evpe(evpe_flags);
1235 
1236 	return 0;
1237 }
1238 
1239 EXPORT_SYMBOL(vpe_stop);
1240 
1241 /* I've done with it thank you */
1242 int vpe_free(vpe_handle vpe)
1243 {
1244 	struct vpe *v = vpe;
1245 	struct tc *t;
1246 	unsigned int evpe_flags;
1247 
1248 	if ((t = list_entry(v->tc.next, struct tc, tc)) == NULL) {
1249 		return -ENOEXEC;
1250 	}
1251 
1252 	evpe_flags = dvpe();
1253 
1254 	/* Put MVPE's into 'configuration state' */
1255 	set_c0_mvpcontrol(MVPCONTROL_VPC);
1256 
1257 	settc(t->index);
1258 	write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() & ~VPECONF0_VPA);
1259 
1260 	/* halt the TC */
1261 	write_tc_c0_tchalt(TCHALT_H);
1262 	mips_ihb();
1263 
1264 	/* mark the TC unallocated */
1265 	write_tc_c0_tcstatus(read_tc_c0_tcstatus() & ~TCSTATUS_A);
1266 
1267 	v->state = VPE_STATE_UNUSED;
1268 
1269 	clear_c0_mvpcontrol(MVPCONTROL_VPC);
1270 	evpe(evpe_flags);
1271 
1272 	return 0;
1273 }
1274 
1275 EXPORT_SYMBOL(vpe_free);
1276 
1277 void *vpe_get_shared(int index)
1278 {
1279 	struct vpe *v;
1280 
1281 	if ((v = get_vpe(index)) == NULL)
1282 		return NULL;
1283 
1284 	return v->shared_ptr;
1285 }
1286 
1287 EXPORT_SYMBOL(vpe_get_shared);
1288 
1289 int vpe_getuid(int index)
1290 {
1291 	struct vpe *v;
1292 
1293 	if ((v = get_vpe(index)) == NULL)
1294 		return -1;
1295 
1296 	return v->uid;
1297 }
1298 
1299 EXPORT_SYMBOL(vpe_getuid);
1300 
1301 int vpe_getgid(int index)
1302 {
1303 	struct vpe *v;
1304 
1305 	if ((v = get_vpe(index)) == NULL)
1306 		return -1;
1307 
1308 	return v->gid;
1309 }
1310 
1311 EXPORT_SYMBOL(vpe_getgid);
1312 
1313 int vpe_notify(int index, struct vpe_notifications *notify)
1314 {
1315 	struct vpe *v;
1316 
1317 	if ((v = get_vpe(index)) == NULL)
1318 		return -1;
1319 
1320 	list_add(&notify->list, &v->notify);
1321 	return 0;
1322 }
1323 
1324 EXPORT_SYMBOL(vpe_notify);
1325 
1326 char *vpe_getcwd(int index)
1327 {
1328 	struct vpe *v;
1329 
1330 	if ((v = get_vpe(index)) == NULL)
1331 		return NULL;
1332 
1333 	return v->cwd;
1334 }
1335 
1336 EXPORT_SYMBOL(vpe_getcwd);
1337 
1338 #ifdef CONFIG_MIPS_APSP_KSPD
1339 static void kspd_sp_exit( int sp_id)
1340 {
1341 	cleanup_tc(get_tc(sp_id));
1342 }
1343 #endif
1344 
1345 static ssize_t store_kill(struct device *dev, struct device_attribute *attr,
1346 			  const char *buf, size_t len)
1347 {
1348 	struct vpe *vpe = get_vpe(tclimit);
1349 	struct vpe_notifications *not;
1350 
1351 	list_for_each_entry(not, &vpe->notify, list) {
1352 		not->stop(tclimit);
1353 	}
1354 
1355 	release_progmem(vpe->load_addr);
1356 	cleanup_tc(get_tc(tclimit));
1357 	vpe_stop(vpe);
1358 	vpe_free(vpe);
1359 
1360 	return len;
1361 }
1362 
1363 static ssize_t show_ntcs(struct device *cd, struct device_attribute *attr,
1364 			 char *buf)
1365 {
1366 	struct vpe *vpe = get_vpe(tclimit);
1367 
1368 	return sprintf(buf, "%d\n", vpe->ntcs);
1369 }
1370 
1371 static ssize_t store_ntcs(struct device *dev, struct device_attribute *attr,
1372 			  const char *buf, size_t len)
1373 {
1374 	struct vpe *vpe = get_vpe(tclimit);
1375 	unsigned long new;
1376 	char *endp;
1377 
1378 	new = simple_strtoul(buf, &endp, 0);
1379 	if (endp == buf)
1380 		goto out_einval;
1381 
1382 	if (new == 0 || new > (hw_tcs - tclimit))
1383 		goto out_einval;
1384 
1385 	vpe->ntcs = new;
1386 
1387 	return len;
1388 
1389 out_einval:
1390 	return -EINVAL;;
1391 }
1392 
1393 static struct device_attribute vpe_class_attributes[] = {
1394 	__ATTR(kill, S_IWUSR, NULL, store_kill),
1395 	__ATTR(ntcs, S_IRUGO | S_IWUSR, show_ntcs, store_ntcs),
1396 	{}
1397 };
1398 
1399 static void vpe_device_release(struct device *cd)
1400 {
1401 	kfree(cd);
1402 }
1403 
1404 struct class vpe_class = {
1405 	.name = "vpe",
1406 	.owner = THIS_MODULE,
1407 	.dev_release = vpe_device_release,
1408 	.dev_attrs = vpe_class_attributes,
1409 };
1410 
1411 struct device vpe_device;
1412 
1413 static int __init vpe_module_init(void)
1414 {
1415 	unsigned int mtflags, vpflags;
1416 	unsigned long flags, val;
1417 	struct vpe *v = NULL;
1418 	struct tc *t;
1419 	int tc, err;
1420 
1421 	if (!cpu_has_mipsmt) {
1422 		printk("VPE loader: not a MIPS MT capable processor\n");
1423 		return -ENODEV;
1424 	}
1425 
1426 	if (vpelimit == 0) {
1427 		printk(KERN_WARNING "No VPEs reserved for AP/SP, not "
1428 		       "initializing VPE loader.\nPass maxvpes=<n> argument as "
1429 		       "kernel argument\n");
1430 
1431 		return -ENODEV;
1432 	}
1433 
1434 	if (tclimit == 0) {
1435 		printk(KERN_WARNING "No TCs reserved for AP/SP, not "
1436 		       "initializing VPE loader.\nPass maxtcs=<n> argument as "
1437 		       "kernel argument\n");
1438 
1439 		return -ENODEV;
1440 	}
1441 
1442 	major = register_chrdev(0, module_name, &vpe_fops);
1443 	if (major < 0) {
1444 		printk("VPE loader: unable to register character device\n");
1445 		return major;
1446 	}
1447 
1448 	err = class_register(&vpe_class);
1449 	if (err) {
1450 		printk(KERN_ERR "vpe_class registration failed\n");
1451 		goto out_chrdev;
1452 	}
1453 
1454 	device_initialize(&vpe_device);
1455 	vpe_device.class	= &vpe_class,
1456 	vpe_device.parent	= NULL,
1457 	strlcpy(vpe_device.bus_id, "vpe1", BUS_ID_SIZE);
1458 	vpe_device.devt = MKDEV(major, minor);
1459 	err = device_add(&vpe_device);
1460 	if (err) {
1461 		printk(KERN_ERR "Adding vpe_device failed\n");
1462 		goto out_class;
1463 	}
1464 
1465 	local_irq_save(flags);
1466 	mtflags = dmt();
1467 	vpflags = dvpe();
1468 
1469 	/* Put MVPE's into 'configuration state' */
1470 	set_c0_mvpcontrol(MVPCONTROL_VPC);
1471 
1472 	/* dump_mtregs(); */
1473 
1474 	val = read_c0_mvpconf0();
1475 	hw_tcs = (val & MVPCONF0_PTC) + 1;
1476 	hw_vpes = ((val & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT) + 1;
1477 
1478 	for (tc = tclimit; tc < hw_tcs; tc++) {
1479 		/*
1480 		 * Must re-enable multithreading temporarily or in case we
1481 		 * reschedule send IPIs or similar we might hang.
1482 		 */
1483 		clear_c0_mvpcontrol(MVPCONTROL_VPC);
1484 		evpe(vpflags);
1485 		emt(mtflags);
1486 		local_irq_restore(flags);
1487 		t = alloc_tc(tc);
1488 		if (!t) {
1489 			err = -ENOMEM;
1490 			goto out;
1491 		}
1492 
1493 		local_irq_save(flags);
1494 		mtflags = dmt();
1495 		vpflags = dvpe();
1496 		set_c0_mvpcontrol(MVPCONTROL_VPC);
1497 
1498 		/* VPE's */
1499 		if (tc < hw_tcs) {
1500 			settc(tc);
1501 
1502 			if ((v = alloc_vpe(tc)) == NULL) {
1503 				printk(KERN_WARNING "VPE: unable to allocate VPE\n");
1504 
1505 				goto out_reenable;
1506 			}
1507 
1508 			v->ntcs = hw_tcs - tclimit;
1509 
1510 			/* add the tc to the list of this vpe's tc's. */
1511 			list_add(&t->tc, &v->tc);
1512 
1513 			/* deactivate all but vpe0 */
1514 			if (tc >= tclimit) {
1515 				unsigned long tmp = read_vpe_c0_vpeconf0();
1516 
1517 				tmp &= ~VPECONF0_VPA;
1518 
1519 				/* master VPE */
1520 				tmp |= VPECONF0_MVP;
1521 				write_vpe_c0_vpeconf0(tmp);
1522 			}
1523 
1524 			/* disable multi-threading with TC's */
1525 			write_vpe_c0_vpecontrol(read_vpe_c0_vpecontrol() & ~VPECONTROL_TE);
1526 
1527 			if (tc >= vpelimit) {
1528 				/*
1529 				 * Set config to be the same as vpe0,
1530 				 * particularly kseg0 coherency alg
1531 				 */
1532 				write_vpe_c0_config(read_c0_config());
1533 			}
1534 		}
1535 
1536 		/* TC's */
1537 		t->pvpe = v;	/* set the parent vpe */
1538 
1539 		if (tc >= tclimit) {
1540 			unsigned long tmp;
1541 
1542 			settc(tc);
1543 
1544 			/* Any TC that is bound to VPE0 gets left as is - in case
1545 			   we are running SMTC on VPE0. A TC that is bound to any
1546 			   other VPE gets bound to VPE0, ideally I'd like to make
1547 			   it homeless but it doesn't appear to let me bind a TC
1548 			   to a non-existent VPE. Which is perfectly reasonable.
1549 
1550 			   The (un)bound state is visible to an EJTAG probe so may
1551 			   notify GDB...
1552 			*/
1553 
1554 			if (((tmp = read_tc_c0_tcbind()) & TCBIND_CURVPE)) {
1555 				/* tc is bound >vpe0 */
1556 				write_tc_c0_tcbind(tmp & ~TCBIND_CURVPE);
1557 
1558 				t->pvpe = get_vpe(0);	/* set the parent vpe */
1559 			}
1560 
1561 			/* halt the TC */
1562 			write_tc_c0_tchalt(TCHALT_H);
1563 			mips_ihb();
1564 
1565 			tmp = read_tc_c0_tcstatus();
1566 
1567 			/* mark not activated and not dynamically allocatable */
1568 			tmp &= ~(TCSTATUS_A | TCSTATUS_DA);
1569 			tmp |= TCSTATUS_IXMT;	/* interrupt exempt */
1570 			write_tc_c0_tcstatus(tmp);
1571 		}
1572 	}
1573 
1574 out_reenable:
1575 	/* release config state */
1576 	clear_c0_mvpcontrol(MVPCONTROL_VPC);
1577 
1578 	evpe(vpflags);
1579 	emt(mtflags);
1580 	local_irq_restore(flags);
1581 
1582 #ifdef CONFIG_MIPS_APSP_KSPD
1583 	kspd_events.kspd_sp_exit = kspd_sp_exit;
1584 #endif
1585 	return 0;
1586 
1587 out_class:
1588 	class_unregister(&vpe_class);
1589 out_chrdev:
1590 	unregister_chrdev(major, module_name);
1591 
1592 out:
1593 	return err;
1594 }
1595 
1596 static void __exit vpe_module_exit(void)
1597 {
1598 	struct vpe *v, *n;
1599 
1600 	list_for_each_entry_safe(v, n, &vpecontrol.vpe_list, list) {
1601 		if (v->state != VPE_STATE_UNUSED) {
1602 			release_vpe(v);
1603 		}
1604 	}
1605 
1606 	device_del(&vpe_device);
1607 	unregister_chrdev(major, module_name);
1608 }
1609 
1610 module_init(vpe_module_init);
1611 module_exit(vpe_module_exit);
1612 MODULE_DESCRIPTION("MIPS VPE Loader");
1613 MODULE_AUTHOR("Elizabeth Oldham, MIPS Technologies, Inc.");
1614 MODULE_LICENSE("GPL");
1615