xref: /openbmc/linux/arch/mips/kernel/vpe.c (revision 7dd65feb)
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;
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 	spinlock_t vpe_list_lock;
148 	struct list_head vpe_list;	/* Virtual processing elements */
149 	spinlock_t tc_list_lock;
150 	struct list_head tc_list;	/* Thread contexts */
151 } vpecontrol = {
152 	.vpe_list_lock	= SPIN_LOCK_UNLOCKED,
153 	.vpe_list	= LIST_HEAD_INIT(vpecontrol.vpe_list),
154 	.tc_list_lock	= SPIN_LOCK_UNLOCKED,
155 	.tc_list	= LIST_HEAD_INIT(vpecontrol.tc_list)
156 };
157 
158 static void release_progmem(void *ptr);
159 
160 /* get the vpe associated with this minor */
161 static struct vpe *get_vpe(int minor)
162 {
163 	struct vpe *res, *v;
164 
165 	if (!cpu_has_mipsmt)
166 		return NULL;
167 
168 	res = NULL;
169 	spin_lock(&vpecontrol.vpe_list_lock);
170 	list_for_each_entry(v, &vpecontrol.vpe_list, list) {
171 		if (v->minor == minor) {
172 			res = v;
173 			break;
174 		}
175 	}
176 	spin_unlock(&vpecontrol.vpe_list_lock);
177 
178 	return res;
179 }
180 
181 /* get the vpe associated with this minor */
182 static struct tc *get_tc(int index)
183 {
184 	struct tc *res, *t;
185 
186 	res = NULL;
187 	spin_lock(&vpecontrol.tc_list_lock);
188 	list_for_each_entry(t, &vpecontrol.tc_list, list) {
189 		if (t->index == index) {
190 			res = t;
191 			break;
192 		}
193 	}
194 	spin_unlock(&vpecontrol.tc_list_lock);
195 
196 	return NULL;
197 }
198 
199 /* allocate a vpe and associate it with this minor (or index) */
200 static struct vpe *alloc_vpe(int minor)
201 {
202 	struct vpe *v;
203 
204 	if ((v = kzalloc(sizeof(struct vpe), GFP_KERNEL)) == NULL)
205 		return NULL;
206 
207 	INIT_LIST_HEAD(&v->tc);
208 	spin_lock(&vpecontrol.vpe_list_lock);
209 	list_add_tail(&v->list, &vpecontrol.vpe_list);
210 	spin_unlock(&vpecontrol.vpe_list_lock);
211 
212 	INIT_LIST_HEAD(&v->notify);
213 	v->minor = minor;
214 
215 	return v;
216 }
217 
218 /* allocate a tc. At startup only tc0 is running, all other can be halted. */
219 static 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 
229 	spin_lock(&vpecontrol.tc_list_lock);
230 	list_add_tail(&tc->list, &vpecontrol.tc_list);
231 	spin_unlock(&vpecontrol.tc_list_lock);
232 
233 out:
234 	return tc;
235 }
236 
237 /* clean up and free everything */
238 static void release_vpe(struct vpe *v)
239 {
240 	list_del(&v->list);
241 	if (v->load_addr)
242 		release_progmem(v);
243 	kfree(v);
244 }
245 
246 static void __maybe_unused dump_mtregs(void)
247 {
248 	unsigned long val;
249 
250 	val = read_c0_config3();
251 	printk("config3 0x%lx MT %ld\n", val,
252 	       (val & CONFIG3_MT) >> CONFIG3_MT_SHIFT);
253 
254 	val = read_c0_mvpcontrol();
255 	printk("MVPControl 0x%lx, STLB %ld VPC %ld EVP %ld\n", val,
256 	       (val & MVPCONTROL_STLB) >> MVPCONTROL_STLB_SHIFT,
257 	       (val & MVPCONTROL_VPC) >> MVPCONTROL_VPC_SHIFT,
258 	       (val & MVPCONTROL_EVP));
259 
260 	val = read_c0_mvpconf0();
261 	printk("mvpconf0 0x%lx, PVPE %ld PTC %ld M %ld\n", val,
262 	       (val & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT,
263 	       val & MVPCONF0_PTC, (val & MVPCONF0_M) >> MVPCONF0_M_SHIFT);
264 }
265 
266 /* Find some VPE program space  */
267 static void *alloc_progmem(unsigned long len)
268 {
269 	void *addr;
270 
271 #ifdef CONFIG_MIPS_VPE_LOADER_TOM
272 	/*
273 	 * This means you must tell Linux to use less memory than you
274 	 * physically have, for example by passing a mem= boot argument.
275 	 */
276 	addr = pfn_to_kaddr(max_low_pfn);
277 	memset(addr, 0, len);
278 #else
279 	/* simple grab some mem for now */
280 	addr = kzalloc(len, GFP_KERNEL);
281 #endif
282 
283 	return addr;
284 }
285 
286 static void release_progmem(void *ptr)
287 {
288 #ifndef CONFIG_MIPS_VPE_LOADER_TOM
289 	kfree(ptr);
290 #endif
291 }
292 
293 /* Update size with this section: return offset. */
294 static long get_offset(unsigned long *size, Elf_Shdr * sechdr)
295 {
296 	long ret;
297 
298 	ret = ALIGN(*size, sechdr->sh_addralign ? : 1);
299 	*size = ret + sechdr->sh_size;
300 	return ret;
301 }
302 
303 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
304    might -- code, read-only data, read-write data, small data.  Tally
305    sizes, and place the offsets into sh_entsize fields: high bit means it
306    belongs in init. */
307 static void layout_sections(struct module *mod, const Elf_Ehdr * hdr,
308 			    Elf_Shdr * sechdrs, const char *secstrings)
309 {
310 	static unsigned long const masks[][2] = {
311 		/* NOTE: all executable code must be the first section
312 		 * in this array; otherwise modify the text_size
313 		 * finder in the two loops below */
314 		{SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL},
315 		{SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL},
316 		{SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL},
317 		{ARCH_SHF_SMALL | SHF_ALLOC, 0}
318 	};
319 	unsigned int m, i;
320 
321 	for (i = 0; i < hdr->e_shnum; i++)
322 		sechdrs[i].sh_entsize = ~0UL;
323 
324 	for (m = 0; m < ARRAY_SIZE(masks); ++m) {
325 		for (i = 0; i < hdr->e_shnum; ++i) {
326 			Elf_Shdr *s = &sechdrs[i];
327 
328 			//  || strncmp(secstrings + s->sh_name, ".init", 5) == 0)
329 			if ((s->sh_flags & masks[m][0]) != masks[m][0]
330 			    || (s->sh_flags & masks[m][1])
331 			    || s->sh_entsize != ~0UL)
332 				continue;
333 			s->sh_entsize =
334 				get_offset((unsigned long *)&mod->core_size, s);
335 		}
336 
337 		if (m == 0)
338 			mod->core_text_size = mod->core_size;
339 
340 	}
341 }
342 
343 
344 /* from module-elf32.c, but subverted a little */
345 
346 struct mips_hi16 {
347 	struct mips_hi16 *next;
348 	Elf32_Addr *addr;
349 	Elf32_Addr value;
350 };
351 
352 static struct mips_hi16 *mips_hi16_list;
353 static unsigned int gp_offs, gp_addr;
354 
355 static int apply_r_mips_none(struct module *me, uint32_t *location,
356 			     Elf32_Addr v)
357 {
358 	return 0;
359 }
360 
361 static int apply_r_mips_gprel16(struct module *me, uint32_t *location,
362 				Elf32_Addr v)
363 {
364 	int rel;
365 
366 	if( !(*location & 0xffff) ) {
367 		rel = (int)v - gp_addr;
368 	}
369 	else {
370 		/* .sbss + gp(relative) + offset */
371 		/* kludge! */
372 		rel =  (int)(short)((int)v + gp_offs +
373 				    (int)(short)(*location & 0xffff) - gp_addr);
374 	}
375 
376 	if( (rel > 32768) || (rel < -32768) ) {
377 		printk(KERN_DEBUG "VPE loader: apply_r_mips_gprel16: "
378 		       "relative address 0x%x out of range of gp register\n",
379 		       rel);
380 		return -ENOEXEC;
381 	}
382 
383 	*location = (*location & 0xffff0000) | (rel & 0xffff);
384 
385 	return 0;
386 }
387 
388 static int apply_r_mips_pc16(struct module *me, uint32_t *location,
389 			     Elf32_Addr v)
390 {
391 	int rel;
392 	rel = (((unsigned int)v - (unsigned int)location));
393 	rel >>= 2;		// because the offset is in _instructions_ not bytes.
394 	rel -= 1;		// and one instruction less due to the branch delay slot.
395 
396 	if( (rel > 32768) || (rel < -32768) ) {
397 		printk(KERN_DEBUG "VPE loader: "
398  		       "apply_r_mips_pc16: relative address out of range 0x%x\n", rel);
399 		return -ENOEXEC;
400 	}
401 
402 	*location = (*location & 0xffff0000) | (rel & 0xffff);
403 
404 	return 0;
405 }
406 
407 static int apply_r_mips_32(struct module *me, uint32_t *location,
408 			   Elf32_Addr v)
409 {
410 	*location += v;
411 
412 	return 0;
413 }
414 
415 static int apply_r_mips_26(struct module *me, uint32_t *location,
416 			   Elf32_Addr v)
417 {
418 	if (v % 4) {
419 		printk(KERN_DEBUG "VPE loader: apply_r_mips_26 "
420 		       " unaligned relocation\n");
421 		return -ENOEXEC;
422 	}
423 
424 /*
425  * Not desperately convinced this is a good check of an overflow condition
426  * anyway. But it gets in the way of handling undefined weak symbols which
427  * we want to set to zero.
428  * if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
429  * printk(KERN_ERR
430  * "module %s: relocation overflow\n",
431  * me->name);
432  * return -ENOEXEC;
433  * }
434  */
435 
436 	*location = (*location & ~0x03ffffff) |
437 		((*location + (v >> 2)) & 0x03ffffff);
438 	return 0;
439 }
440 
441 static int apply_r_mips_hi16(struct module *me, uint32_t *location,
442 			     Elf32_Addr v)
443 {
444 	struct mips_hi16 *n;
445 
446 	/*
447 	 * We cannot relocate this one now because we don't know the value of
448 	 * the carry we need to add.  Save the information, and let LO16 do the
449 	 * actual relocation.
450 	 */
451 	n = kmalloc(sizeof *n, GFP_KERNEL);
452 	if (!n)
453 		return -ENOMEM;
454 
455 	n->addr = location;
456 	n->value = v;
457 	n->next = mips_hi16_list;
458 	mips_hi16_list = n;
459 
460 	return 0;
461 }
462 
463 static int apply_r_mips_lo16(struct module *me, uint32_t *location,
464 			     Elf32_Addr v)
465 {
466 	unsigned long insnlo = *location;
467 	Elf32_Addr val, vallo;
468 	struct mips_hi16 *l, *next;
469 
470 	/* Sign extend the addend we extract from the lo insn.  */
471 	vallo = ((insnlo & 0xffff) ^ 0x8000) - 0x8000;
472 
473 	if (mips_hi16_list != NULL) {
474 
475 		l = mips_hi16_list;
476 		while (l != NULL) {
477 			unsigned long insn;
478 
479 			/*
480 			 * The value for the HI16 had best be the same.
481 			 */
482  			if (v != l->value) {
483 				printk(KERN_DEBUG "VPE loader: "
484 				       "apply_r_mips_lo16/hi16: \t"
485 				       "inconsistent value information\n");
486 				goto out_free;
487 			}
488 
489 			/*
490 			 * Do the HI16 relocation.  Note that we actually don't
491 			 * need to know anything about the LO16 itself, except
492 			 * where to find the low 16 bits of the addend needed
493 			 * by the LO16.
494 			 */
495 			insn = *l->addr;
496 			val = ((insn & 0xffff) << 16) + vallo;
497 			val += v;
498 
499 			/*
500 			 * Account for the sign extension that will happen in
501 			 * the low bits.
502 			 */
503 			val = ((val >> 16) + ((val & 0x8000) != 0)) & 0xffff;
504 
505 			insn = (insn & ~0xffff) | val;
506 			*l->addr = insn;
507 
508 			next = l->next;
509 			kfree(l);
510 			l = next;
511 		}
512 
513 		mips_hi16_list = NULL;
514 	}
515 
516 	/*
517 	 * Ok, we're done with the HI16 relocs.  Now deal with the LO16.
518 	 */
519 	val = v + vallo;
520 	insnlo = (insnlo & ~0xffff) | (val & 0xffff);
521 	*location = insnlo;
522 
523 	return 0;
524 
525 out_free:
526 	while (l != NULL) {
527 		next = l->next;
528 		kfree(l);
529 		l = next;
530 	}
531 	mips_hi16_list = NULL;
532 
533 	return -ENOEXEC;
534 }
535 
536 static int (*reloc_handlers[]) (struct module *me, uint32_t *location,
537 				Elf32_Addr v) = {
538 	[R_MIPS_NONE]	= apply_r_mips_none,
539 	[R_MIPS_32]	= apply_r_mips_32,
540 	[R_MIPS_26]	= apply_r_mips_26,
541 	[R_MIPS_HI16]	= apply_r_mips_hi16,
542 	[R_MIPS_LO16]	= apply_r_mips_lo16,
543 	[R_MIPS_GPREL16] = apply_r_mips_gprel16,
544 	[R_MIPS_PC16] = apply_r_mips_pc16
545 };
546 
547 static char *rstrs[] = {
548 	[R_MIPS_NONE]	= "MIPS_NONE",
549 	[R_MIPS_32]	= "MIPS_32",
550 	[R_MIPS_26]	= "MIPS_26",
551 	[R_MIPS_HI16]	= "MIPS_HI16",
552 	[R_MIPS_LO16]	= "MIPS_LO16",
553 	[R_MIPS_GPREL16] = "MIPS_GPREL16",
554 	[R_MIPS_PC16] = "MIPS_PC16"
555 };
556 
557 static int apply_relocations(Elf32_Shdr *sechdrs,
558 		      const char *strtab,
559 		      unsigned int symindex,
560 		      unsigned int relsec,
561 		      struct module *me)
562 {
563 	Elf32_Rel *rel = (void *) sechdrs[relsec].sh_addr;
564 	Elf32_Sym *sym;
565 	uint32_t *location;
566 	unsigned int i;
567 	Elf32_Addr v;
568 	int res;
569 
570 	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
571 		Elf32_Word r_info = rel[i].r_info;
572 
573 		/* This is where to make the change */
574 		location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
575 			+ rel[i].r_offset;
576 		/* This is the symbol it is referring to */
577 		sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
578 			+ ELF32_R_SYM(r_info);
579 
580 		if (!sym->st_value) {
581 			printk(KERN_DEBUG "%s: undefined weak symbol %s\n",
582 			       me->name, strtab + sym->st_name);
583 			/* just print the warning, dont barf */
584 		}
585 
586 		v = sym->st_value;
587 
588 		res = reloc_handlers[ELF32_R_TYPE(r_info)](me, location, v);
589 		if( res ) {
590 			char *r = rstrs[ELF32_R_TYPE(r_info)];
591 		    	printk(KERN_WARNING "VPE loader: .text+0x%x "
592 			       "relocation type %s for symbol \"%s\" failed\n",
593 			       rel[i].r_offset, r ? r : "UNKNOWN",
594 			       strtab + sym->st_name);
595 			return res;
596 		}
597 	}
598 
599 	return 0;
600 }
601 
602 static inline void save_gp_address(unsigned int secbase, unsigned int rel)
603 {
604 	gp_addr = secbase + rel;
605 	gp_offs = gp_addr - (secbase & 0xffff0000);
606 }
607 /* end module-elf32.c */
608 
609 
610 
611 /* Change all symbols so that sh_value encodes the pointer directly. */
612 static void simplify_symbols(Elf_Shdr * sechdrs,
613 			    unsigned int symindex,
614 			    const char *strtab,
615 			    const char *secstrings,
616 			    unsigned int nsecs, struct module *mod)
617 {
618 	Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
619 	unsigned long secbase, bssbase = 0;
620 	unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
621 	int size;
622 
623 	/* find the .bss section for COMMON symbols */
624 	for (i = 0; i < nsecs; i++) {
625 		if (strncmp(secstrings + sechdrs[i].sh_name, ".bss", 4) == 0) {
626 			bssbase = sechdrs[i].sh_addr;
627 			break;
628 		}
629 	}
630 
631 	for (i = 1; i < n; i++) {
632 		switch (sym[i].st_shndx) {
633 		case SHN_COMMON:
634 			/* Allocate space for the symbol in the .bss section.
635 			   st_value is currently size.
636 			   We want it to have the address of the symbol. */
637 
638 			size = sym[i].st_value;
639 			sym[i].st_value = bssbase;
640 
641 			bssbase += size;
642 			break;
643 
644 		case SHN_ABS:
645 			/* Don't need to do anything */
646 			break;
647 
648 		case SHN_UNDEF:
649 			/* ret = -ENOENT; */
650 			break;
651 
652 		case SHN_MIPS_SCOMMON:
653 			printk(KERN_DEBUG "simplify_symbols: ignoring SHN_MIPS_SCOMMON "
654 			       "symbol <%s> st_shndx %d\n", strtab + sym[i].st_name,
655 			       sym[i].st_shndx);
656 			// .sbss section
657 			break;
658 
659 		default:
660 			secbase = sechdrs[sym[i].st_shndx].sh_addr;
661 
662 			if (strncmp(strtab + sym[i].st_name, "_gp", 3) == 0) {
663 				save_gp_address(secbase, sym[i].st_value);
664 			}
665 
666 			sym[i].st_value += secbase;
667 			break;
668 		}
669 	}
670 }
671 
672 #ifdef DEBUG_ELFLOADER
673 static void dump_elfsymbols(Elf_Shdr * sechdrs, unsigned int symindex,
674 			    const char *strtab, struct module *mod)
675 {
676 	Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
677 	unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
678 
679 	printk(KERN_DEBUG "dump_elfsymbols: n %d\n", n);
680 	for (i = 1; i < n; i++) {
681 		printk(KERN_DEBUG " i %d name <%s> 0x%x\n", i,
682 		       strtab + sym[i].st_name, sym[i].st_value);
683 	}
684 }
685 #endif
686 
687 /* We are prepared so configure and start the VPE... */
688 static int vpe_run(struct vpe * v)
689 {
690 	unsigned long flags, val, dmt_flag;
691 	struct vpe_notifications *n;
692 	unsigned int vpeflags;
693 	struct tc *t;
694 
695 	/* check we are the Master VPE */
696 	local_irq_save(flags);
697 	val = read_c0_vpeconf0();
698 	if (!(val & VPECONF0_MVP)) {
699 		printk(KERN_WARNING
700 		       "VPE loader: only Master VPE's are allowed to configure MT\n");
701 		local_irq_restore(flags);
702 
703 		return -1;
704 	}
705 
706 	dmt_flag = dmt();
707 	vpeflags = dvpe();
708 
709 	if (!list_empty(&v->tc)) {
710 		if ((t = list_entry(v->tc.next, struct tc, tc)) == NULL) {
711 			evpe(vpeflags);
712 			emt(dmt_flag);
713 			local_irq_restore(flags);
714 
715 			printk(KERN_WARNING
716 			       "VPE loader: TC %d is already in use.\n",
717                                t->index);
718 			return -ENOEXEC;
719 		}
720 	} else {
721 		evpe(vpeflags);
722 		emt(dmt_flag);
723 		local_irq_restore(flags);
724 
725 		printk(KERN_WARNING
726 		       "VPE loader: No TC's associated with VPE %d\n",
727 		       v->minor);
728 
729 		return -ENOEXEC;
730 	}
731 
732 	/* Put MVPE's into 'configuration state' */
733 	set_c0_mvpcontrol(MVPCONTROL_VPC);
734 
735 	settc(t->index);
736 
737 	/* should check it is halted, and not activated */
738 	if ((read_tc_c0_tcstatus() & TCSTATUS_A) || !(read_tc_c0_tchalt() & TCHALT_H)) {
739 		evpe(vpeflags);
740 		emt(dmt_flag);
741 		local_irq_restore(flags);
742 
743 		printk(KERN_WARNING "VPE loader: TC %d is already active!\n",
744 		       t->index);
745 
746 		return -ENOEXEC;
747 	}
748 
749 	/* Write the address we want it to start running from in the TCPC register. */
750 	write_tc_c0_tcrestart((unsigned long)v->__start);
751 	write_tc_c0_tccontext((unsigned long)0);
752 
753 	/*
754 	 * Mark the TC as activated, not interrupt exempt and not dynamically
755 	 * allocatable
756 	 */
757 	val = read_tc_c0_tcstatus();
758 	val = (val & ~(TCSTATUS_DA | TCSTATUS_IXMT)) | TCSTATUS_A;
759 	write_tc_c0_tcstatus(val);
760 
761 	write_tc_c0_tchalt(read_tc_c0_tchalt() & ~TCHALT_H);
762 
763 	/*
764 	 * The sde-kit passes 'memsize' to __start in $a3, so set something
765 	 * here...  Or set $a3 to zero and define DFLT_STACK_SIZE and
766 	 * DFLT_HEAP_SIZE when you compile your program
767 	 */
768 	mttgpr(6, v->ntcs);
769 	mttgpr(7, physical_memsize);
770 
771 	/* set up VPE1 */
772 	/*
773 	 * bind the TC to VPE 1 as late as possible so we only have the final
774 	 * VPE registers to set up, and so an EJTAG probe can trigger on it
775 	 */
776 	write_tc_c0_tcbind((read_tc_c0_tcbind() & ~TCBIND_CURVPE) | 1);
777 
778 	write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() & ~(VPECONF0_VPA));
779 
780 	back_to_back_c0_hazard();
781 
782 	/* Set up the XTC bit in vpeconf0 to point at our tc */
783 	write_vpe_c0_vpeconf0( (read_vpe_c0_vpeconf0() & ~(VPECONF0_XTC))
784 	                      | (t->index << VPECONF0_XTC_SHIFT));
785 
786 	back_to_back_c0_hazard();
787 
788 	/* enable this VPE */
789 	write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() | VPECONF0_VPA);
790 
791 	/* clear out any left overs from a previous program */
792 	write_vpe_c0_status(0);
793 	write_vpe_c0_cause(0);
794 
795 	/* take system out of configuration state */
796 	clear_c0_mvpcontrol(MVPCONTROL_VPC);
797 
798 	/*
799 	 * SMTC/SMVP kernels manage VPE enable independently,
800 	 * but uniprocessor kernels need to turn it on, even
801 	 * if that wasn't the pre-dvpe() state.
802 	 */
803 #ifdef CONFIG_SMP
804 	evpe(vpeflags);
805 #else
806 	evpe(EVPE_ENABLE);
807 #endif
808 	emt(dmt_flag);
809 	local_irq_restore(flags);
810 
811 	list_for_each_entry(n, &v->notify, list)
812 		n->start(minor);
813 
814 	return 0;
815 }
816 
817 static int find_vpe_symbols(struct vpe * v, Elf_Shdr * sechdrs,
818 				      unsigned int symindex, const char *strtab,
819 				      struct module *mod)
820 {
821 	Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
822 	unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
823 
824 	for (i = 1; i < n; i++) {
825 		if (strcmp(strtab + sym[i].st_name, "__start") == 0) {
826 			v->__start = sym[i].st_value;
827 		}
828 
829 		if (strcmp(strtab + sym[i].st_name, "vpe_shared") == 0) {
830 			v->shared_ptr = (void *)sym[i].st_value;
831 		}
832 	}
833 
834 	if ( (v->__start == 0) || (v->shared_ptr == NULL))
835 		return -1;
836 
837 	return 0;
838 }
839 
840 /*
841  * Allocates a VPE with some program code space(the load address), copies the
842  * contents of the program (p)buffer performing relocatations/etc, free's it
843  * when finished.
844  */
845 static int vpe_elfload(struct vpe * v)
846 {
847 	Elf_Ehdr *hdr;
848 	Elf_Shdr *sechdrs;
849 	long err = 0;
850 	char *secstrings, *strtab = NULL;
851 	unsigned int len, i, symindex = 0, strindex = 0, relocate = 0;
852 	struct module mod;	// so we can re-use the relocations code
853 
854 	memset(&mod, 0, sizeof(struct module));
855 	strcpy(mod.name, "VPE loader");
856 
857 	hdr = (Elf_Ehdr *) v->pbuffer;
858 	len = v->plen;
859 
860 	/* Sanity checks against insmoding binaries or wrong arch,
861 	   weird elf version */
862 	if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0
863 	    || (hdr->e_type != ET_REL && hdr->e_type != ET_EXEC)
864 	    || !elf_check_arch(hdr)
865 	    || hdr->e_shentsize != sizeof(*sechdrs)) {
866 		printk(KERN_WARNING
867 		       "VPE loader: program wrong arch or weird elf version\n");
868 
869 		return -ENOEXEC;
870 	}
871 
872 	if (hdr->e_type == ET_REL)
873 		relocate = 1;
874 
875 	if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr)) {
876 		printk(KERN_ERR "VPE loader: program length %u truncated\n",
877 		       len);
878 
879 		return -ENOEXEC;
880 	}
881 
882 	/* Convenience variables */
883 	sechdrs = (void *)hdr + hdr->e_shoff;
884 	secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
885 	sechdrs[0].sh_addr = 0;
886 
887 	/* And these should exist, but gcc whinges if we don't init them */
888 	symindex = strindex = 0;
889 
890 	if (relocate) {
891 		for (i = 1; i < hdr->e_shnum; i++) {
892 			if (sechdrs[i].sh_type != SHT_NOBITS
893 			    && len < sechdrs[i].sh_offset + sechdrs[i].sh_size) {
894 				printk(KERN_ERR "VPE program length %u truncated\n",
895 				       len);
896 				return -ENOEXEC;
897 			}
898 
899 			/* Mark all sections sh_addr with their address in the
900 			   temporary image. */
901 			sechdrs[i].sh_addr = (size_t) hdr + sechdrs[i].sh_offset;
902 
903 			/* Internal symbols and strings. */
904 			if (sechdrs[i].sh_type == SHT_SYMTAB) {
905 				symindex = i;
906 				strindex = sechdrs[i].sh_link;
907 				strtab = (char *)hdr + sechdrs[strindex].sh_offset;
908 			}
909 		}
910 		layout_sections(&mod, hdr, sechdrs, secstrings);
911 	}
912 
913 	v->load_addr = alloc_progmem(mod.core_size);
914 	if (!v->load_addr)
915 		return -ENOMEM;
916 
917 	pr_info("VPE loader: loading to %p\n", v->load_addr);
918 
919 	if (relocate) {
920 		for (i = 0; i < hdr->e_shnum; i++) {
921 			void *dest;
922 
923 			if (!(sechdrs[i].sh_flags & SHF_ALLOC))
924 				continue;
925 
926 			dest = v->load_addr + sechdrs[i].sh_entsize;
927 
928 			if (sechdrs[i].sh_type != SHT_NOBITS)
929 				memcpy(dest, (void *)sechdrs[i].sh_addr,
930 				       sechdrs[i].sh_size);
931 			/* Update sh_addr to point to copy in image. */
932 			sechdrs[i].sh_addr = (unsigned long)dest;
933 
934 			printk(KERN_DEBUG " section sh_name %s sh_addr 0x%x\n",
935 			       secstrings + sechdrs[i].sh_name, sechdrs[i].sh_addr);
936 		}
937 
938  		/* Fix up syms, so that st_value is a pointer to location. */
939  		simplify_symbols(sechdrs, symindex, strtab, secstrings,
940  				 hdr->e_shnum, &mod);
941 
942  		/* Now do relocations. */
943  		for (i = 1; i < hdr->e_shnum; i++) {
944  			const char *strtab = (char *)sechdrs[strindex].sh_addr;
945  			unsigned int info = sechdrs[i].sh_info;
946 
947  			/* Not a valid relocation section? */
948  			if (info >= hdr->e_shnum)
949  				continue;
950 
951  			/* Don't bother with non-allocated sections */
952  			if (!(sechdrs[info].sh_flags & SHF_ALLOC))
953  				continue;
954 
955  			if (sechdrs[i].sh_type == SHT_REL)
956  				err = apply_relocations(sechdrs, strtab, symindex, i,
957  							&mod);
958  			else if (sechdrs[i].sh_type == SHT_RELA)
959  				err = apply_relocate_add(sechdrs, strtab, symindex, i,
960  							 &mod);
961  			if (err < 0)
962  				return err;
963 
964   		}
965   	} else {
966 		struct elf_phdr *phdr = (struct elf_phdr *) ((char *)hdr + hdr->e_phoff);
967 
968 		for (i = 0; i < hdr->e_phnum; i++) {
969 			if (phdr->p_type == PT_LOAD) {
970 				memcpy((void *)phdr->p_paddr,
971 				       (char *)hdr + phdr->p_offset,
972 				       phdr->p_filesz);
973 				memset((void *)phdr->p_paddr + phdr->p_filesz,
974 				       0, phdr->p_memsz - phdr->p_filesz);
975 		    }
976 		    phdr++;
977 		}
978 
979 		for (i = 0; i < hdr->e_shnum; i++) {
980  			/* Internal symbols and strings. */
981  			if (sechdrs[i].sh_type == SHT_SYMTAB) {
982  				symindex = i;
983  				strindex = sechdrs[i].sh_link;
984  				strtab = (char *)hdr + sechdrs[strindex].sh_offset;
985 
986  				/* mark the symtab's address for when we try to find the
987  				   magic symbols */
988  				sechdrs[i].sh_addr = (size_t) hdr + sechdrs[i].sh_offset;
989  			}
990 		}
991 	}
992 
993 	/* make sure it's physically written out */
994 	flush_icache_range((unsigned long)v->load_addr,
995 			   (unsigned long)v->load_addr + v->len);
996 
997 	if ((find_vpe_symbols(v, sechdrs, symindex, strtab, &mod)) < 0) {
998 		if (v->__start == 0) {
999 			printk(KERN_WARNING "VPE loader: program does not contain "
1000 			       "a __start symbol\n");
1001 			return -ENOEXEC;
1002 		}
1003 
1004 		if (v->shared_ptr == NULL)
1005 			printk(KERN_WARNING "VPE loader: "
1006 			       "program does not contain vpe_shared symbol.\n"
1007 			       " Unable to use AMVP (AP/SP) facilities.\n");
1008 	}
1009 
1010 	printk(" elf loaded\n");
1011 	return 0;
1012 }
1013 
1014 static void cleanup_tc(struct tc *tc)
1015 {
1016 	unsigned long flags;
1017 	unsigned int mtflags, vpflags;
1018 	int tmp;
1019 
1020 	local_irq_save(flags);
1021 	mtflags = dmt();
1022 	vpflags = dvpe();
1023 	/* Put MVPE's into 'configuration state' */
1024 	set_c0_mvpcontrol(MVPCONTROL_VPC);
1025 
1026 	settc(tc->index);
1027 	tmp = read_tc_c0_tcstatus();
1028 
1029 	/* mark not allocated and not dynamically allocatable */
1030 	tmp &= ~(TCSTATUS_A | TCSTATUS_DA);
1031 	tmp |= TCSTATUS_IXMT;	/* interrupt exempt */
1032 	write_tc_c0_tcstatus(tmp);
1033 
1034 	write_tc_c0_tchalt(TCHALT_H);
1035 	mips_ihb();
1036 
1037 	/* bind it to anything other than VPE1 */
1038 //	write_tc_c0_tcbind(read_tc_c0_tcbind() & ~TCBIND_CURVPE); // | TCBIND_CURVPE
1039 
1040 	clear_c0_mvpcontrol(MVPCONTROL_VPC);
1041 	evpe(vpflags);
1042 	emt(mtflags);
1043 	local_irq_restore(flags);
1044 }
1045 
1046 static int getcwd(char *buff, int size)
1047 {
1048 	mm_segment_t old_fs;
1049 	int ret;
1050 
1051 	old_fs = get_fs();
1052 	set_fs(KERNEL_DS);
1053 
1054 	ret = sys_getcwd(buff, size);
1055 
1056 	set_fs(old_fs);
1057 
1058 	return ret;
1059 }
1060 
1061 /* checks VPE is unused and gets ready to load program  */
1062 static int vpe_open(struct inode *inode, struct file *filp)
1063 {
1064 	enum vpe_state state;
1065 	struct vpe_notifications *not;
1066 	struct vpe *v;
1067 	int ret;
1068 
1069 	if (minor != iminor(inode)) {
1070 		/* assume only 1 device at the moment. */
1071 		pr_warning("VPE loader: only vpe1 is supported\n");
1072 
1073 		return -ENODEV;
1074 	}
1075 
1076 	if ((v = get_vpe(tclimit)) == NULL) {
1077 		pr_warning("VPE loader: unable to get vpe\n");
1078 
1079 		return -ENODEV;
1080 	}
1081 
1082 	state = xchg(&v->state, VPE_STATE_INUSE);
1083 	if (state != VPE_STATE_UNUSED) {
1084 		printk(KERN_DEBUG "VPE loader: tc in use dumping regs\n");
1085 
1086 		list_for_each_entry(not, &v->notify, list) {
1087 			not->stop(tclimit);
1088 		}
1089 
1090 		release_progmem(v->load_addr);
1091 		cleanup_tc(get_tc(tclimit));
1092 	}
1093 
1094 	/* this of-course trashes what was there before... */
1095 	v->pbuffer = vmalloc(P_SIZE);
1096 	v->plen = P_SIZE;
1097 	v->load_addr = NULL;
1098 	v->len = 0;
1099 
1100 	v->uid = filp->f_cred->fsuid;
1101 	v->gid = filp->f_cred->fsgid;
1102 
1103 #ifdef CONFIG_MIPS_APSP_KSPD
1104 	/* get kspd to tell us when a syscall_exit happens */
1105 	if (!kspd_events_reqd) {
1106 		kspd_notify(&kspd_events);
1107 		kspd_events_reqd++;
1108 	}
1109 #endif
1110 
1111 	v->cwd[0] = 0;
1112 	ret = getcwd(v->cwd, VPE_PATH_MAX);
1113 	if (ret < 0)
1114 		printk(KERN_WARNING "VPE loader: open, getcwd returned %d\n", ret);
1115 
1116 	v->shared_ptr = NULL;
1117 	v->__start = 0;
1118 
1119 	return 0;
1120 }
1121 
1122 static int vpe_release(struct inode *inode, struct file *filp)
1123 {
1124 	struct vpe *v;
1125 	Elf_Ehdr *hdr;
1126 	int ret = 0;
1127 
1128 	v = get_vpe(tclimit);
1129 	if (v == NULL)
1130 		return -ENODEV;
1131 
1132 	hdr = (Elf_Ehdr *) v->pbuffer;
1133 	if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) == 0) {
1134 		if (vpe_elfload(v) >= 0) {
1135 			vpe_run(v);
1136 		} else {
1137  			printk(KERN_WARNING "VPE loader: ELF load failed.\n");
1138 			ret = -ENOEXEC;
1139 		}
1140 	} else {
1141  		printk(KERN_WARNING "VPE loader: only elf files are supported\n");
1142 		ret = -ENOEXEC;
1143 	}
1144 
1145 	/* It's good to be able to run the SP and if it chokes have a look at
1146 	   the /dev/rt?. But if we reset the pointer to the shared struct we
1147 	   lose what has happened. So perhaps if garbage is sent to the vpe
1148 	   device, use it as a trigger for the reset. Hopefully a nice
1149 	   executable will be along shortly. */
1150 	if (ret < 0)
1151 		v->shared_ptr = NULL;
1152 
1153 	// cleanup any temp buffers
1154 	if (v->pbuffer)
1155 		vfree(v->pbuffer);
1156 	v->plen = 0;
1157 	return ret;
1158 }
1159 
1160 static ssize_t vpe_write(struct file *file, const char __user * buffer,
1161 			 size_t count, loff_t * ppos)
1162 {
1163 	size_t ret = count;
1164 	struct vpe *v;
1165 
1166 	if (iminor(file->f_path.dentry->d_inode) != minor)
1167 		return -ENODEV;
1168 
1169 	v = get_vpe(tclimit);
1170 	if (v == NULL)
1171 		return -ENODEV;
1172 
1173 	if (v->pbuffer == NULL) {
1174 		printk(KERN_ERR "VPE loader: no buffer for program\n");
1175 		return -ENOMEM;
1176 	}
1177 
1178 	if ((count + v->len) > v->plen) {
1179 		printk(KERN_WARNING
1180 		       "VPE loader: elf size too big. Perhaps strip uneeded symbols\n");
1181 		return -ENOMEM;
1182 	}
1183 
1184 	count -= copy_from_user(v->pbuffer + v->len, buffer, count);
1185 	if (!count)
1186 		return -EFAULT;
1187 
1188 	v->len += count;
1189 	return ret;
1190 }
1191 
1192 static const struct file_operations vpe_fops = {
1193 	.owner = THIS_MODULE,
1194 	.open = vpe_open,
1195 	.release = vpe_release,
1196 	.write = vpe_write
1197 };
1198 
1199 /* module wrapper entry points */
1200 /* give me a vpe */
1201 vpe_handle vpe_alloc(void)
1202 {
1203 	int i;
1204 	struct vpe *v;
1205 
1206 	/* find a vpe */
1207 	for (i = 1; i < MAX_VPES; i++) {
1208 		if ((v = get_vpe(i)) != NULL) {
1209 			v->state = VPE_STATE_INUSE;
1210 			return v;
1211 		}
1212 	}
1213 	return NULL;
1214 }
1215 
1216 EXPORT_SYMBOL(vpe_alloc);
1217 
1218 /* start running from here */
1219 int vpe_start(vpe_handle vpe, unsigned long start)
1220 {
1221 	struct vpe *v = vpe;
1222 
1223 	v->__start = start;
1224 	return vpe_run(v);
1225 }
1226 
1227 EXPORT_SYMBOL(vpe_start);
1228 
1229 /* halt it for now */
1230 int vpe_stop(vpe_handle vpe)
1231 {
1232 	struct vpe *v = vpe;
1233 	struct tc *t;
1234 	unsigned int evpe_flags;
1235 
1236 	evpe_flags = dvpe();
1237 
1238 	if ((t = list_entry(v->tc.next, struct tc, tc)) != NULL) {
1239 
1240 		settc(t->index);
1241 		write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() & ~VPECONF0_VPA);
1242 	}
1243 
1244 	evpe(evpe_flags);
1245 
1246 	return 0;
1247 }
1248 
1249 EXPORT_SYMBOL(vpe_stop);
1250 
1251 /* I've done with it thank you */
1252 int vpe_free(vpe_handle vpe)
1253 {
1254 	struct vpe *v = vpe;
1255 	struct tc *t;
1256 	unsigned int evpe_flags;
1257 
1258 	if ((t = list_entry(v->tc.next, struct tc, tc)) == NULL) {
1259 		return -ENOEXEC;
1260 	}
1261 
1262 	evpe_flags = dvpe();
1263 
1264 	/* Put MVPE's into 'configuration state' */
1265 	set_c0_mvpcontrol(MVPCONTROL_VPC);
1266 
1267 	settc(t->index);
1268 	write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() & ~VPECONF0_VPA);
1269 
1270 	/* halt the TC */
1271 	write_tc_c0_tchalt(TCHALT_H);
1272 	mips_ihb();
1273 
1274 	/* mark the TC unallocated */
1275 	write_tc_c0_tcstatus(read_tc_c0_tcstatus() & ~TCSTATUS_A);
1276 
1277 	v->state = VPE_STATE_UNUSED;
1278 
1279 	clear_c0_mvpcontrol(MVPCONTROL_VPC);
1280 	evpe(evpe_flags);
1281 
1282 	return 0;
1283 }
1284 
1285 EXPORT_SYMBOL(vpe_free);
1286 
1287 void *vpe_get_shared(int index)
1288 {
1289 	struct vpe *v;
1290 
1291 	if ((v = get_vpe(index)) == NULL)
1292 		return NULL;
1293 
1294 	return v->shared_ptr;
1295 }
1296 
1297 EXPORT_SYMBOL(vpe_get_shared);
1298 
1299 int vpe_getuid(int index)
1300 {
1301 	struct vpe *v;
1302 
1303 	if ((v = get_vpe(index)) == NULL)
1304 		return -1;
1305 
1306 	return v->uid;
1307 }
1308 
1309 EXPORT_SYMBOL(vpe_getuid);
1310 
1311 int vpe_getgid(int index)
1312 {
1313 	struct vpe *v;
1314 
1315 	if ((v = get_vpe(index)) == NULL)
1316 		return -1;
1317 
1318 	return v->gid;
1319 }
1320 
1321 EXPORT_SYMBOL(vpe_getgid);
1322 
1323 int vpe_notify(int index, struct vpe_notifications *notify)
1324 {
1325 	struct vpe *v;
1326 
1327 	if ((v = get_vpe(index)) == NULL)
1328 		return -1;
1329 
1330 	list_add(&notify->list, &v->notify);
1331 	return 0;
1332 }
1333 
1334 EXPORT_SYMBOL(vpe_notify);
1335 
1336 char *vpe_getcwd(int index)
1337 {
1338 	struct vpe *v;
1339 
1340 	if ((v = get_vpe(index)) == NULL)
1341 		return NULL;
1342 
1343 	return v->cwd;
1344 }
1345 
1346 EXPORT_SYMBOL(vpe_getcwd);
1347 
1348 #ifdef CONFIG_MIPS_APSP_KSPD
1349 static void kspd_sp_exit( int sp_id)
1350 {
1351 	cleanup_tc(get_tc(sp_id));
1352 }
1353 #endif
1354 
1355 static ssize_t store_kill(struct device *dev, struct device_attribute *attr,
1356 			  const char *buf, size_t len)
1357 {
1358 	struct vpe *vpe = get_vpe(tclimit);
1359 	struct vpe_notifications *not;
1360 
1361 	list_for_each_entry(not, &vpe->notify, list) {
1362 		not->stop(tclimit);
1363 	}
1364 
1365 	release_progmem(vpe->load_addr);
1366 	cleanup_tc(get_tc(tclimit));
1367 	vpe_stop(vpe);
1368 	vpe_free(vpe);
1369 
1370 	return len;
1371 }
1372 
1373 static ssize_t show_ntcs(struct device *cd, struct device_attribute *attr,
1374 			 char *buf)
1375 {
1376 	struct vpe *vpe = get_vpe(tclimit);
1377 
1378 	return sprintf(buf, "%d\n", vpe->ntcs);
1379 }
1380 
1381 static ssize_t store_ntcs(struct device *dev, struct device_attribute *attr,
1382 			  const char *buf, size_t len)
1383 {
1384 	struct vpe *vpe = get_vpe(tclimit);
1385 	unsigned long new;
1386 	char *endp;
1387 
1388 	new = simple_strtoul(buf, &endp, 0);
1389 	if (endp == buf)
1390 		goto out_einval;
1391 
1392 	if (new == 0 || new > (hw_tcs - tclimit))
1393 		goto out_einval;
1394 
1395 	vpe->ntcs = new;
1396 
1397 	return len;
1398 
1399 out_einval:
1400 	return -EINVAL;
1401 }
1402 
1403 static struct device_attribute vpe_class_attributes[] = {
1404 	__ATTR(kill, S_IWUSR, NULL, store_kill),
1405 	__ATTR(ntcs, S_IRUGO | S_IWUSR, show_ntcs, store_ntcs),
1406 	{}
1407 };
1408 
1409 static void vpe_device_release(struct device *cd)
1410 {
1411 	kfree(cd);
1412 }
1413 
1414 struct class vpe_class = {
1415 	.name = "vpe",
1416 	.owner = THIS_MODULE,
1417 	.dev_release = vpe_device_release,
1418 	.dev_attrs = vpe_class_attributes,
1419 };
1420 
1421 struct device vpe_device;
1422 
1423 static int __init vpe_module_init(void)
1424 {
1425 	unsigned int mtflags, vpflags;
1426 	unsigned long flags, val;
1427 	struct vpe *v = NULL;
1428 	struct tc *t;
1429 	int tc, err;
1430 
1431 	if (!cpu_has_mipsmt) {
1432 		printk("VPE loader: not a MIPS MT capable processor\n");
1433 		return -ENODEV;
1434 	}
1435 
1436 	if (vpelimit == 0) {
1437 		printk(KERN_WARNING "No VPEs reserved for AP/SP, not "
1438 		       "initializing VPE loader.\nPass maxvpes=<n> argument as "
1439 		       "kernel argument\n");
1440 
1441 		return -ENODEV;
1442 	}
1443 
1444 	if (tclimit == 0) {
1445 		printk(KERN_WARNING "No TCs reserved for AP/SP, not "
1446 		       "initializing VPE loader.\nPass maxtcs=<n> argument as "
1447 		       "kernel argument\n");
1448 
1449 		return -ENODEV;
1450 	}
1451 
1452 	major = register_chrdev(0, module_name, &vpe_fops);
1453 	if (major < 0) {
1454 		printk("VPE loader: unable to register character device\n");
1455 		return major;
1456 	}
1457 
1458 	err = class_register(&vpe_class);
1459 	if (err) {
1460 		printk(KERN_ERR "vpe_class registration failed\n");
1461 		goto out_chrdev;
1462 	}
1463 
1464 	device_initialize(&vpe_device);
1465 	vpe_device.class	= &vpe_class,
1466 	vpe_device.parent	= NULL,
1467 	dev_set_name(&vpe_device, "vpe1");
1468 	vpe_device.devt = MKDEV(major, minor);
1469 	err = device_add(&vpe_device);
1470 	if (err) {
1471 		printk(KERN_ERR "Adding vpe_device failed\n");
1472 		goto out_class;
1473 	}
1474 
1475 	local_irq_save(flags);
1476 	mtflags = dmt();
1477 	vpflags = dvpe();
1478 
1479 	/* Put MVPE's into 'configuration state' */
1480 	set_c0_mvpcontrol(MVPCONTROL_VPC);
1481 
1482 	/* dump_mtregs(); */
1483 
1484 	val = read_c0_mvpconf0();
1485 	hw_tcs = (val & MVPCONF0_PTC) + 1;
1486 	hw_vpes = ((val & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT) + 1;
1487 
1488 	for (tc = tclimit; tc < hw_tcs; tc++) {
1489 		/*
1490 		 * Must re-enable multithreading temporarily or in case we
1491 		 * reschedule send IPIs or similar we might hang.
1492 		 */
1493 		clear_c0_mvpcontrol(MVPCONTROL_VPC);
1494 		evpe(vpflags);
1495 		emt(mtflags);
1496 		local_irq_restore(flags);
1497 		t = alloc_tc(tc);
1498 		if (!t) {
1499 			err = -ENOMEM;
1500 			goto out;
1501 		}
1502 
1503 		local_irq_save(flags);
1504 		mtflags = dmt();
1505 		vpflags = dvpe();
1506 		set_c0_mvpcontrol(MVPCONTROL_VPC);
1507 
1508 		/* VPE's */
1509 		if (tc < hw_tcs) {
1510 			settc(tc);
1511 
1512 			if ((v = alloc_vpe(tc)) == NULL) {
1513 				printk(KERN_WARNING "VPE: unable to allocate VPE\n");
1514 
1515 				goto out_reenable;
1516 			}
1517 
1518 			v->ntcs = hw_tcs - tclimit;
1519 
1520 			/* add the tc to the list of this vpe's tc's. */
1521 			list_add(&t->tc, &v->tc);
1522 
1523 			/* deactivate all but vpe0 */
1524 			if (tc >= tclimit) {
1525 				unsigned long tmp = read_vpe_c0_vpeconf0();
1526 
1527 				tmp &= ~VPECONF0_VPA;
1528 
1529 				/* master VPE */
1530 				tmp |= VPECONF0_MVP;
1531 				write_vpe_c0_vpeconf0(tmp);
1532 			}
1533 
1534 			/* disable multi-threading with TC's */
1535 			write_vpe_c0_vpecontrol(read_vpe_c0_vpecontrol() & ~VPECONTROL_TE);
1536 
1537 			if (tc >= vpelimit) {
1538 				/*
1539 				 * Set config to be the same as vpe0,
1540 				 * particularly kseg0 coherency alg
1541 				 */
1542 				write_vpe_c0_config(read_c0_config());
1543 			}
1544 		}
1545 
1546 		/* TC's */
1547 		t->pvpe = v;	/* set the parent vpe */
1548 
1549 		if (tc >= tclimit) {
1550 			unsigned long tmp;
1551 
1552 			settc(tc);
1553 
1554 			/* Any TC that is bound to VPE0 gets left as is - in case
1555 			   we are running SMTC on VPE0. A TC that is bound to any
1556 			   other VPE gets bound to VPE0, ideally I'd like to make
1557 			   it homeless but it doesn't appear to let me bind a TC
1558 			   to a non-existent VPE. Which is perfectly reasonable.
1559 
1560 			   The (un)bound state is visible to an EJTAG probe so may
1561 			   notify GDB...
1562 			*/
1563 
1564 			if (((tmp = read_tc_c0_tcbind()) & TCBIND_CURVPE)) {
1565 				/* tc is bound >vpe0 */
1566 				write_tc_c0_tcbind(tmp & ~TCBIND_CURVPE);
1567 
1568 				t->pvpe = get_vpe(0);	/* set the parent vpe */
1569 			}
1570 
1571 			/* halt the TC */
1572 			write_tc_c0_tchalt(TCHALT_H);
1573 			mips_ihb();
1574 
1575 			tmp = read_tc_c0_tcstatus();
1576 
1577 			/* mark not activated and not dynamically allocatable */
1578 			tmp &= ~(TCSTATUS_A | TCSTATUS_DA);
1579 			tmp |= TCSTATUS_IXMT;	/* interrupt exempt */
1580 			write_tc_c0_tcstatus(tmp);
1581 		}
1582 	}
1583 
1584 out_reenable:
1585 	/* release config state */
1586 	clear_c0_mvpcontrol(MVPCONTROL_VPC);
1587 
1588 	evpe(vpflags);
1589 	emt(mtflags);
1590 	local_irq_restore(flags);
1591 
1592 #ifdef CONFIG_MIPS_APSP_KSPD
1593 	kspd_events.kspd_sp_exit = kspd_sp_exit;
1594 #endif
1595 	return 0;
1596 
1597 out_class:
1598 	class_unregister(&vpe_class);
1599 out_chrdev:
1600 	unregister_chrdev(major, module_name);
1601 
1602 out:
1603 	return err;
1604 }
1605 
1606 static void __exit vpe_module_exit(void)
1607 {
1608 	struct vpe *v, *n;
1609 
1610 	device_del(&vpe_device);
1611 	unregister_chrdev(major, module_name);
1612 
1613 	/* No locking needed here */
1614 	list_for_each_entry_safe(v, n, &vpecontrol.vpe_list, list) {
1615 		if (v->state != VPE_STATE_UNUSED)
1616 			release_vpe(v);
1617 	}
1618 }
1619 
1620 module_init(vpe_module_init);
1621 module_exit(vpe_module_exit);
1622 MODULE_DESCRIPTION("MIPS VPE Loader");
1623 MODULE_AUTHOR("Elizabeth Oldham, MIPS Technologies, Inc.");
1624 MODULE_LICENSE("GPL");
1625