xref: /openbmc/linux/arch/mips/kernel/vpe.c (revision 643d1f7f)
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/syscalls.h>
42 #include <linux/moduleloader.h>
43 #include <linux/interrupt.h>
44 #include <linux/poll.h>
45 #include <linux/bootmem.h>
46 #include <asm/mipsregs.h>
47 #include <asm/mipsmtregs.h>
48 #include <asm/cacheflush.h>
49 #include <asm/atomic.h>
50 #include <asm/cpu.h>
51 #include <asm/mips_mt.h>
52 #include <asm/processor.h>
53 #include <asm/system.h>
54 #include <asm/vpe.h>
55 #include <asm/kspd.h>
56 
57 typedef void *vpe_handle;
58 
59 #ifndef ARCH_SHF_SMALL
60 #define ARCH_SHF_SMALL 0
61 #endif
62 
63 /* If this is set, the section belongs in the init part of the module */
64 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
65 
66 /*
67  * The number of TCs and VPEs physically available on the core
68  */
69 static int hw_tcs, hw_vpes;
70 static char module_name[] = "vpe";
71 static int major;
72 static const int minor = 1;	/* fixed for now  */
73 
74 #ifdef CONFIG_MIPS_APSP_KSPD
75  static struct kspd_notifications kspd_events;
76 static int kspd_events_reqd = 0;
77 #endif
78 
79 /* grab the likely amount of memory we will need. */
80 #ifdef CONFIG_MIPS_VPE_LOADER_TOM
81 #define P_SIZE (2 * 1024 * 1024)
82 #else
83 /* add an overhead to the max kmalloc size for non-striped symbols/etc */
84 #define P_SIZE (256 * 1024)
85 #endif
86 
87 extern unsigned long physical_memsize;
88 
89 #define MAX_VPES 16
90 #define VPE_PATH_MAX 256
91 
92 enum vpe_state {
93 	VPE_STATE_UNUSED = 0,
94 	VPE_STATE_INUSE,
95 	VPE_STATE_RUNNING
96 };
97 
98 enum tc_state {
99 	TC_STATE_UNUSED = 0,
100 	TC_STATE_INUSE,
101 	TC_STATE_RUNNING,
102 	TC_STATE_DYNAMIC
103 };
104 
105 struct vpe {
106 	enum vpe_state state;
107 
108 	/* (device) minor associated with this vpe */
109 	int minor;
110 
111 	/* elfloader stuff */
112 	void *load_addr;
113 	unsigned long len;
114 	char *pbuffer;
115 	unsigned long plen;
116 	unsigned int uid, gid;
117 	char cwd[VPE_PATH_MAX];
118 
119 	unsigned long __start;
120 
121 	/* tc's associated with this vpe */
122 	struct list_head tc;
123 
124 	/* The list of vpe's */
125 	struct list_head list;
126 
127 	/* shared symbol address */
128 	void *shared_ptr;
129 
130 	/* the list of who wants to know when something major happens */
131 	struct list_head notify;
132 
133 	unsigned int ntcs;
134 };
135 
136 struct tc {
137 	enum tc_state state;
138 	int index;
139 
140 	struct vpe *pvpe;	/* parent VPE */
141 	struct list_head tc;	/* The list of TC's with this VPE */
142 	struct list_head list;	/* The global list of tc's */
143 };
144 
145 struct {
146 	/* Virtual processing elements */
147 	struct list_head vpe_list;
148 
149 	/* Thread contexts */
150 	struct list_head tc_list;
151 } vpecontrol = {
152 	.vpe_list = LIST_HEAD_INIT(vpecontrol.vpe_list),
153 	.tc_list = LIST_HEAD_INIT(vpecontrol.tc_list)
154 };
155 
156 static void release_progmem(void *ptr);
157 extern void save_gp_address(unsigned int secbase, unsigned int rel);
158 
159 /* get the vpe associated with this minor */
160 struct vpe *get_vpe(int minor)
161 {
162 	struct vpe *v;
163 
164 	if (!cpu_has_mipsmt)
165 		return NULL;
166 
167 	list_for_each_entry(v, &vpecontrol.vpe_list, list) {
168 		if (v->minor == minor)
169 			return v;
170 	}
171 
172 	return NULL;
173 }
174 
175 /* get the vpe associated with this minor */
176 struct tc *get_tc(int index)
177 {
178 	struct tc *t;
179 
180 	list_for_each_entry(t, &vpecontrol.tc_list, list) {
181 		if (t->index == index)
182 			return t;
183 	}
184 
185 	return NULL;
186 }
187 
188 struct tc *get_tc_unused(void)
189 {
190 	struct tc *t;
191 
192 	list_for_each_entry(t, &vpecontrol.tc_list, list) {
193 		if (t->state == TC_STATE_UNUSED)
194 			return t;
195 	}
196 
197 	return NULL;
198 }
199 
200 /* allocate a vpe and associate it with this minor (or index) */
201 struct vpe *alloc_vpe(int minor)
202 {
203 	struct vpe *v;
204 
205 	if ((v = kzalloc(sizeof(struct vpe), GFP_KERNEL)) == NULL) {
206 		return NULL;
207 	}
208 
209 	INIT_LIST_HEAD(&v->tc);
210 	list_add_tail(&v->list, &vpecontrol.vpe_list);
211 
212 	INIT_LIST_HEAD(&v->notify);
213 	v->minor = minor;
214 	return v;
215 }
216 
217 /* allocate a tc. At startup only tc0 is running, all other can be halted. */
218 struct tc *alloc_tc(int index)
219 {
220 	struct tc *tc;
221 
222 	if ((tc = kzalloc(sizeof(struct tc), GFP_KERNEL)) == NULL)
223 		goto out;
224 
225 	INIT_LIST_HEAD(&tc->tc);
226 	tc->index = index;
227 	list_add_tail(&tc->list, &vpecontrol.tc_list);
228 
229 out:
230 	return tc;
231 }
232 
233 /* clean up and free everything */
234 void release_vpe(struct vpe *v)
235 {
236 	list_del(&v->list);
237 	if (v->load_addr)
238 		release_progmem(v);
239 	kfree(v);
240 }
241 
242 void dump_mtregs(void)
243 {
244 	unsigned long val;
245 
246 	val = read_c0_config3();
247 	printk("config3 0x%lx MT %ld\n", val,
248 	       (val & CONFIG3_MT) >> CONFIG3_MT_SHIFT);
249 
250 	val = read_c0_mvpcontrol();
251 	printk("MVPControl 0x%lx, STLB %ld VPC %ld EVP %ld\n", val,
252 	       (val & MVPCONTROL_STLB) >> MVPCONTROL_STLB_SHIFT,
253 	       (val & MVPCONTROL_VPC) >> MVPCONTROL_VPC_SHIFT,
254 	       (val & MVPCONTROL_EVP));
255 
256 	val = read_c0_mvpconf0();
257 	printk("mvpconf0 0x%lx, PVPE %ld PTC %ld M %ld\n", val,
258 	       (val & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT,
259 	       val & MVPCONF0_PTC, (val & MVPCONF0_M) >> MVPCONF0_M_SHIFT);
260 }
261 
262 /* Find some VPE program space  */
263 static void *alloc_progmem(unsigned long len)
264 {
265 #ifdef CONFIG_MIPS_VPE_LOADER_TOM
266 	/* this means you must tell linux to use less memory than you physically have */
267 	return pfn_to_kaddr(max_pfn);
268 #else
269 	// simple grab some mem for now
270 	return kmalloc(len, GFP_KERNEL);
271 #endif
272 }
273 
274 static void release_progmem(void *ptr)
275 {
276 #ifndef CONFIG_MIPS_VPE_LOADER_TOM
277 	kfree(ptr);
278 #endif
279 }
280 
281 /* Update size with this section: return offset. */
282 static long get_offset(unsigned long *size, Elf_Shdr * sechdr)
283 {
284 	long ret;
285 
286 	ret = ALIGN(*size, sechdr->sh_addralign ? : 1);
287 	*size = ret + sechdr->sh_size;
288 	return ret;
289 }
290 
291 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
292    might -- code, read-only data, read-write data, small data.  Tally
293    sizes, and place the offsets into sh_entsize fields: high bit means it
294    belongs in init. */
295 static void layout_sections(struct module *mod, const Elf_Ehdr * hdr,
296 			    Elf_Shdr * sechdrs, const char *secstrings)
297 {
298 	static unsigned long const masks[][2] = {
299 		/* NOTE: all executable code must be the first section
300 		 * in this array; otherwise modify the text_size
301 		 * finder in the two loops below */
302 		{SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL},
303 		{SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL},
304 		{SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL},
305 		{ARCH_SHF_SMALL | SHF_ALLOC, 0}
306 	};
307 	unsigned int m, i;
308 
309 	for (i = 0; i < hdr->e_shnum; i++)
310 		sechdrs[i].sh_entsize = ~0UL;
311 
312 	for (m = 0; m < ARRAY_SIZE(masks); ++m) {
313 		for (i = 0; i < hdr->e_shnum; ++i) {
314 			Elf_Shdr *s = &sechdrs[i];
315 
316 			//  || strncmp(secstrings + s->sh_name, ".init", 5) == 0)
317 			if ((s->sh_flags & masks[m][0]) != masks[m][0]
318 			    || (s->sh_flags & masks[m][1])
319 			    || s->sh_entsize != ~0UL)
320 				continue;
321 			s->sh_entsize = get_offset(&mod->core_size, s);
322 		}
323 
324 		if (m == 0)
325 			mod->core_text_size = mod->core_size;
326 
327 	}
328 }
329 
330 
331 /* from module-elf32.c, but subverted a little */
332 
333 struct mips_hi16 {
334 	struct mips_hi16 *next;
335 	Elf32_Addr *addr;
336 	Elf32_Addr value;
337 };
338 
339 static struct mips_hi16 *mips_hi16_list;
340 static unsigned int gp_offs, gp_addr;
341 
342 static int apply_r_mips_none(struct module *me, uint32_t *location,
343 			     Elf32_Addr v)
344 {
345 	return 0;
346 }
347 
348 static int apply_r_mips_gprel16(struct module *me, uint32_t *location,
349 				Elf32_Addr v)
350 {
351 	int rel;
352 
353 	if( !(*location & 0xffff) ) {
354 		rel = (int)v - gp_addr;
355 	}
356 	else {
357 		/* .sbss + gp(relative) + offset */
358 		/* kludge! */
359 		rel =  (int)(short)((int)v + gp_offs +
360 				    (int)(short)(*location & 0xffff) - gp_addr);
361 	}
362 
363 	if( (rel > 32768) || (rel < -32768) ) {
364 		printk(KERN_DEBUG "VPE loader: apply_r_mips_gprel16: "
365 		       "relative address 0x%x out of range of gp register\n",
366 		       rel);
367 		return -ENOEXEC;
368 	}
369 
370 	*location = (*location & 0xffff0000) | (rel & 0xffff);
371 
372 	return 0;
373 }
374 
375 static int apply_r_mips_pc16(struct module *me, uint32_t *location,
376 			     Elf32_Addr v)
377 {
378 	int rel;
379 	rel = (((unsigned int)v - (unsigned int)location));
380 	rel >>= 2;		// because the offset is in _instructions_ not bytes.
381 	rel -= 1;		// and one instruction less due to the branch delay slot.
382 
383 	if( (rel > 32768) || (rel < -32768) ) {
384 		printk(KERN_DEBUG "VPE loader: "
385  		       "apply_r_mips_pc16: relative address out of range 0x%x\n", rel);
386 		return -ENOEXEC;
387 	}
388 
389 	*location = (*location & 0xffff0000) | (rel & 0xffff);
390 
391 	return 0;
392 }
393 
394 static int apply_r_mips_32(struct module *me, uint32_t *location,
395 			   Elf32_Addr v)
396 {
397 	*location += v;
398 
399 	return 0;
400 }
401 
402 static int apply_r_mips_26(struct module *me, uint32_t *location,
403 			   Elf32_Addr v)
404 {
405 	if (v % 4) {
406 		printk(KERN_DEBUG "VPE loader: apply_r_mips_26 "
407 		       " unaligned relocation\n");
408 		return -ENOEXEC;
409 	}
410 
411 /*
412  * Not desperately convinced this is a good check of an overflow condition
413  * anyway. But it gets in the way of handling undefined weak symbols which
414  * we want to set to zero.
415  * if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
416  * printk(KERN_ERR
417  * "module %s: relocation overflow\n",
418  * me->name);
419  * return -ENOEXEC;
420  * }
421  */
422 
423 	*location = (*location & ~0x03ffffff) |
424 		((*location + (v >> 2)) & 0x03ffffff);
425 	return 0;
426 }
427 
428 static int apply_r_mips_hi16(struct module *me, uint32_t *location,
429 			     Elf32_Addr v)
430 {
431 	struct mips_hi16 *n;
432 
433 	/*
434 	 * We cannot relocate this one now because we don't know the value of
435 	 * the carry we need to add.  Save the information, and let LO16 do the
436 	 * actual relocation.
437 	 */
438 	n = kmalloc(sizeof *n, GFP_KERNEL);
439 	if (!n)
440 		return -ENOMEM;
441 
442 	n->addr = location;
443 	n->value = v;
444 	n->next = mips_hi16_list;
445 	mips_hi16_list = n;
446 
447 	return 0;
448 }
449 
450 static int apply_r_mips_lo16(struct module *me, uint32_t *location,
451 			     Elf32_Addr v)
452 {
453 	unsigned long insnlo = *location;
454 	Elf32_Addr val, vallo;
455 
456 	/* Sign extend the addend we extract from the lo insn.  */
457 	vallo = ((insnlo & 0xffff) ^ 0x8000) - 0x8000;
458 
459 	if (mips_hi16_list != NULL) {
460 		struct mips_hi16 *l;
461 
462 		l = mips_hi16_list;
463 		while (l != NULL) {
464 			struct mips_hi16 *next;
465 			unsigned long insn;
466 
467 			/*
468 			 * The value for the HI16 had best be the same.
469 			 */
470  			if (v != l->value) {
471 				printk(KERN_DEBUG "VPE loader: "
472 				       "apply_r_mips_lo16/hi16: \t"
473 				       "inconsistent value information\n");
474 				return -ENOEXEC;
475 			}
476 
477 			/*
478 			 * Do the HI16 relocation.  Note that we actually don't
479 			 * need to know anything about the LO16 itself, except
480 			 * where to find the low 16 bits of the addend needed
481 			 * by the LO16.
482 			 */
483 			insn = *l->addr;
484 			val = ((insn & 0xffff) << 16) + vallo;
485 			val += v;
486 
487 			/*
488 			 * Account for the sign extension that will happen in
489 			 * the low bits.
490 			 */
491 			val = ((val >> 16) + ((val & 0x8000) != 0)) & 0xffff;
492 
493 			insn = (insn & ~0xffff) | val;
494 			*l->addr = insn;
495 
496 			next = l->next;
497 			kfree(l);
498 			l = next;
499 		}
500 
501 		mips_hi16_list = NULL;
502 	}
503 
504 	/*
505 	 * Ok, we're done with the HI16 relocs.  Now deal with the LO16.
506 	 */
507 	val = v + vallo;
508 	insnlo = (insnlo & ~0xffff) | (val & 0xffff);
509 	*location = insnlo;
510 
511 	return 0;
512 }
513 
514 static int (*reloc_handlers[]) (struct module *me, uint32_t *location,
515 				Elf32_Addr v) = {
516 	[R_MIPS_NONE]	= apply_r_mips_none,
517 	[R_MIPS_32]	= apply_r_mips_32,
518 	[R_MIPS_26]	= apply_r_mips_26,
519 	[R_MIPS_HI16]	= apply_r_mips_hi16,
520 	[R_MIPS_LO16]	= apply_r_mips_lo16,
521 	[R_MIPS_GPREL16] = apply_r_mips_gprel16,
522 	[R_MIPS_PC16] = apply_r_mips_pc16
523 };
524 
525 static char *rstrs[] = {
526 	[R_MIPS_NONE]	= "MIPS_NONE",
527 	[R_MIPS_32]	= "MIPS_32",
528 	[R_MIPS_26]	= "MIPS_26",
529 	[R_MIPS_HI16]	= "MIPS_HI16",
530 	[R_MIPS_LO16]	= "MIPS_LO16",
531 	[R_MIPS_GPREL16] = "MIPS_GPREL16",
532 	[R_MIPS_PC16] = "MIPS_PC16"
533 };
534 
535 int apply_relocations(Elf32_Shdr *sechdrs,
536 		      const char *strtab,
537 		      unsigned int symindex,
538 		      unsigned int relsec,
539 		      struct module *me)
540 {
541 	Elf32_Rel *rel = (void *) sechdrs[relsec].sh_addr;
542 	Elf32_Sym *sym;
543 	uint32_t *location;
544 	unsigned int i;
545 	Elf32_Addr v;
546 	int res;
547 
548 	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
549 		Elf32_Word r_info = rel[i].r_info;
550 
551 		/* This is where to make the change */
552 		location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
553 			+ rel[i].r_offset;
554 		/* This is the symbol it is referring to */
555 		sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
556 			+ ELF32_R_SYM(r_info);
557 
558 		if (!sym->st_value) {
559 			printk(KERN_DEBUG "%s: undefined weak symbol %s\n",
560 			       me->name, strtab + sym->st_name);
561 			/* just print the warning, dont barf */
562 		}
563 
564 		v = sym->st_value;
565 
566 		res = reloc_handlers[ELF32_R_TYPE(r_info)](me, location, v);
567 		if( res ) {
568 			char *r = rstrs[ELF32_R_TYPE(r_info)];
569 		    	printk(KERN_WARNING "VPE loader: .text+0x%x "
570 			       "relocation type %s for symbol \"%s\" failed\n",
571 			       rel[i].r_offset, r ? r : "UNKNOWN",
572 			       strtab + sym->st_name);
573 			return res;
574 		}
575 	}
576 
577 	return 0;
578 }
579 
580 void save_gp_address(unsigned int secbase, unsigned int rel)
581 {
582 	gp_addr = secbase + rel;
583 	gp_offs = gp_addr - (secbase & 0xffff0000);
584 }
585 /* end module-elf32.c */
586 
587 
588 
589 /* Change all symbols so that sh_value encodes the pointer directly. */
590 static void simplify_symbols(Elf_Shdr * sechdrs,
591 			    unsigned int symindex,
592 			    const char *strtab,
593 			    const char *secstrings,
594 			    unsigned int nsecs, struct module *mod)
595 {
596 	Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
597 	unsigned long secbase, bssbase = 0;
598 	unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
599 	int size;
600 
601 	/* find the .bss section for COMMON symbols */
602 	for (i = 0; i < nsecs; i++) {
603 		if (strncmp(secstrings + sechdrs[i].sh_name, ".bss", 4) == 0) {
604 			bssbase = sechdrs[i].sh_addr;
605 			break;
606 		}
607 	}
608 
609 	for (i = 1; i < n; i++) {
610 		switch (sym[i].st_shndx) {
611 		case SHN_COMMON:
612 			/* Allocate space for the symbol in the .bss section.
613 			   st_value is currently size.
614 			   We want it to have the address of the symbol. */
615 
616 			size = sym[i].st_value;
617 			sym[i].st_value = bssbase;
618 
619 			bssbase += size;
620 			break;
621 
622 		case SHN_ABS:
623 			/* Don't need to do anything */
624 			break;
625 
626 		case SHN_UNDEF:
627 			/* ret = -ENOENT; */
628 			break;
629 
630 		case SHN_MIPS_SCOMMON:
631 			printk(KERN_DEBUG "simplify_symbols: ignoring SHN_MIPS_SCOMMON "
632 			       "symbol <%s> st_shndx %d\n", strtab + sym[i].st_name,
633 			       sym[i].st_shndx);
634 			// .sbss section
635 			break;
636 
637 		default:
638 			secbase = sechdrs[sym[i].st_shndx].sh_addr;
639 
640 			if (strncmp(strtab + sym[i].st_name, "_gp", 3) == 0) {
641 				save_gp_address(secbase, sym[i].st_value);
642 			}
643 
644 			sym[i].st_value += secbase;
645 			break;
646 		}
647 	}
648 }
649 
650 #ifdef DEBUG_ELFLOADER
651 static void dump_elfsymbols(Elf_Shdr * sechdrs, unsigned int symindex,
652 			    const char *strtab, struct module *mod)
653 {
654 	Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
655 	unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
656 
657 	printk(KERN_DEBUG "dump_elfsymbols: n %d\n", n);
658 	for (i = 1; i < n; i++) {
659 		printk(KERN_DEBUG " i %d name <%s> 0x%x\n", i,
660 		       strtab + sym[i].st_name, sym[i].st_value);
661 	}
662 }
663 #endif
664 
665 /* We are prepared so configure and start the VPE... */
666 static int vpe_run(struct vpe * v)
667 {
668 	unsigned long flags, val, dmt_flag;
669 	struct vpe_notifications *n;
670 	unsigned int vpeflags;
671 	struct tc *t;
672 
673 	/* check we are the Master VPE */
674 	local_irq_save(flags);
675 	val = read_c0_vpeconf0();
676 	if (!(val & VPECONF0_MVP)) {
677 		printk(KERN_WARNING
678 		       "VPE loader: only Master VPE's are allowed to configure MT\n");
679 		local_irq_restore(flags);
680 
681 		return -1;
682 	}
683 
684 	dmt_flag = dmt();
685 	vpeflags = dvpe();
686 
687 	if (!list_empty(&v->tc)) {
688 		if ((t = list_entry(v->tc.next, struct tc, tc)) == NULL) {
689 			evpe(vpeflags);
690 			emt(dmt_flag);
691 			local_irq_restore(flags);
692 
693 			printk(KERN_WARNING
694 			       "VPE loader: TC %d is already in use.\n",
695                                t->index);
696 			return -ENOEXEC;
697 		}
698 	} else {
699 		evpe(vpeflags);
700 		emt(dmt_flag);
701 		local_irq_restore(flags);
702 
703 		printk(KERN_WARNING
704 		       "VPE loader: No TC's associated with VPE %d\n",
705 		       v->minor);
706 
707 		return -ENOEXEC;
708 	}
709 
710 	/* Put MVPE's into 'configuration state' */
711 	set_c0_mvpcontrol(MVPCONTROL_VPC);
712 
713 	settc(t->index);
714 
715 	/* should check it is halted, and not activated */
716 	if ((read_tc_c0_tcstatus() & TCSTATUS_A) || !(read_tc_c0_tchalt() & TCHALT_H)) {
717 		evpe(vpeflags);
718 		emt(dmt_flag);
719 		local_irq_restore(flags);
720 
721 		printk(KERN_WARNING "VPE loader: TC %d is already active!\n",
722 		       t->index);
723 
724 		return -ENOEXEC;
725 	}
726 
727 	/* Write the address we want it to start running from in the TCPC register. */
728 	write_tc_c0_tcrestart((unsigned long)v->__start);
729 	write_tc_c0_tccontext((unsigned long)0);
730 
731 	/*
732 	 * Mark the TC as activated, not interrupt exempt and not dynamically
733 	 * allocatable
734 	 */
735 	val = read_tc_c0_tcstatus();
736 	val = (val & ~(TCSTATUS_DA | TCSTATUS_IXMT)) | TCSTATUS_A;
737 	write_tc_c0_tcstatus(val);
738 
739 	write_tc_c0_tchalt(read_tc_c0_tchalt() & ~TCHALT_H);
740 
741 	/*
742 	 * The sde-kit passes 'memsize' to __start in $a3, so set something
743 	 * here...  Or set $a3 to zero and define DFLT_STACK_SIZE and
744 	 * DFLT_HEAP_SIZE when you compile your program
745 	 */
746 	mttgpr(6, v->ntcs);
747 	mttgpr(7, physical_memsize);
748 
749 	/* set up VPE1 */
750 	/*
751 	 * bind the TC to VPE 1 as late as possible so we only have the final
752 	 * VPE registers to set up, and so an EJTAG probe can trigger on it
753 	 */
754 	write_tc_c0_tcbind((read_tc_c0_tcbind() & ~TCBIND_CURVPE) | 1);
755 
756 	write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() & ~(VPECONF0_VPA));
757 
758 	back_to_back_c0_hazard();
759 
760 	/* Set up the XTC bit in vpeconf0 to point at our tc */
761 	write_vpe_c0_vpeconf0( (read_vpe_c0_vpeconf0() & ~(VPECONF0_XTC))
762 	                      | (t->index << VPECONF0_XTC_SHIFT));
763 
764 	back_to_back_c0_hazard();
765 
766 	/* enable this VPE */
767 	write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() | VPECONF0_VPA);
768 
769 	/* clear out any left overs from a previous program */
770 	write_vpe_c0_status(0);
771 	write_vpe_c0_cause(0);
772 
773 	/* take system out of configuration state */
774 	clear_c0_mvpcontrol(MVPCONTROL_VPC);
775 
776 #ifdef CONFIG_SMP
777 	evpe(EVPE_ENABLE);
778 #else
779 	evpe(vpeflags);
780 #endif
781 	emt(dmt_flag);
782 	local_irq_restore(flags);
783 
784 	list_for_each_entry(n, &v->notify, list)
785 		n->start(minor);
786 
787 	return 0;
788 }
789 
790 static int find_vpe_symbols(struct vpe * v, Elf_Shdr * sechdrs,
791 				      unsigned int symindex, const char *strtab,
792 				      struct module *mod)
793 {
794 	Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
795 	unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
796 
797 	for (i = 1; i < n; i++) {
798 		if (strcmp(strtab + sym[i].st_name, "__start") == 0) {
799 			v->__start = sym[i].st_value;
800 		}
801 
802 		if (strcmp(strtab + sym[i].st_name, "vpe_shared") == 0) {
803 			v->shared_ptr = (void *)sym[i].st_value;
804 		}
805 	}
806 
807 	if ( (v->__start == 0) || (v->shared_ptr == NULL))
808 		return -1;
809 
810 	return 0;
811 }
812 
813 /*
814  * Allocates a VPE with some program code space(the load address), copies the
815  * contents of the program (p)buffer performing relocatations/etc, free's it
816  * when finished.
817  */
818 static int vpe_elfload(struct vpe * v)
819 {
820 	Elf_Ehdr *hdr;
821 	Elf_Shdr *sechdrs;
822 	long err = 0;
823 	char *secstrings, *strtab = NULL;
824 	unsigned int len, i, symindex = 0, strindex = 0, relocate = 0;
825 	struct module mod;	// so we can re-use the relocations code
826 
827 	memset(&mod, 0, sizeof(struct module));
828 	strcpy(mod.name, "VPE loader");
829 
830 	hdr = (Elf_Ehdr *) v->pbuffer;
831 	len = v->plen;
832 
833 	/* Sanity checks against insmoding binaries or wrong arch,
834 	   weird elf version */
835 	if (memcmp(hdr->e_ident, ELFMAG, 4) != 0
836 	    || (hdr->e_type != ET_REL && hdr->e_type != ET_EXEC)
837 	    || !elf_check_arch(hdr)
838 	    || hdr->e_shentsize != sizeof(*sechdrs)) {
839 		printk(KERN_WARNING
840 		       "VPE loader: program wrong arch or weird elf version\n");
841 
842 		return -ENOEXEC;
843 	}
844 
845 	if (hdr->e_type == ET_REL)
846 		relocate = 1;
847 
848 	if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr)) {
849 		printk(KERN_ERR "VPE loader: program length %u truncated\n",
850 		       len);
851 
852 		return -ENOEXEC;
853 	}
854 
855 	/* Convenience variables */
856 	sechdrs = (void *)hdr + hdr->e_shoff;
857 	secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
858 	sechdrs[0].sh_addr = 0;
859 
860 	/* And these should exist, but gcc whinges if we don't init them */
861 	symindex = strindex = 0;
862 
863 	if (relocate) {
864 		for (i = 1; i < hdr->e_shnum; i++) {
865 			if (sechdrs[i].sh_type != SHT_NOBITS
866 			    && len < sechdrs[i].sh_offset + sechdrs[i].sh_size) {
867 				printk(KERN_ERR "VPE program length %u truncated\n",
868 				       len);
869 				return -ENOEXEC;
870 			}
871 
872 			/* Mark all sections sh_addr with their address in the
873 			   temporary image. */
874 			sechdrs[i].sh_addr = (size_t) hdr + sechdrs[i].sh_offset;
875 
876 			/* Internal symbols and strings. */
877 			if (sechdrs[i].sh_type == SHT_SYMTAB) {
878 				symindex = i;
879 				strindex = sechdrs[i].sh_link;
880 				strtab = (char *)hdr + sechdrs[strindex].sh_offset;
881 			}
882 		}
883 		layout_sections(&mod, hdr, sechdrs, secstrings);
884 	}
885 
886 	v->load_addr = alloc_progmem(mod.core_size);
887 	memset(v->load_addr, 0, mod.core_size);
888 
889 	printk("VPE loader: loading to %p\n", v->load_addr);
890 
891 	if (relocate) {
892 		for (i = 0; i < hdr->e_shnum; i++) {
893 			void *dest;
894 
895 			if (!(sechdrs[i].sh_flags & SHF_ALLOC))
896 				continue;
897 
898 			dest = v->load_addr + sechdrs[i].sh_entsize;
899 
900 			if (sechdrs[i].sh_type != SHT_NOBITS)
901 				memcpy(dest, (void *)sechdrs[i].sh_addr,
902 				       sechdrs[i].sh_size);
903 			/* Update sh_addr to point to copy in image. */
904 			sechdrs[i].sh_addr = (unsigned long)dest;
905 
906 			printk(KERN_DEBUG " section sh_name %s sh_addr 0x%x\n",
907 			       secstrings + sechdrs[i].sh_name, sechdrs[i].sh_addr);
908 		}
909 
910  		/* Fix up syms, so that st_value is a pointer to location. */
911  		simplify_symbols(sechdrs, symindex, strtab, secstrings,
912  				 hdr->e_shnum, &mod);
913 
914  		/* Now do relocations. */
915  		for (i = 1; i < hdr->e_shnum; i++) {
916  			const char *strtab = (char *)sechdrs[strindex].sh_addr;
917  			unsigned int info = sechdrs[i].sh_info;
918 
919  			/* Not a valid relocation section? */
920  			if (info >= hdr->e_shnum)
921  				continue;
922 
923  			/* Don't bother with non-allocated sections */
924  			if (!(sechdrs[info].sh_flags & SHF_ALLOC))
925  				continue;
926 
927  			if (sechdrs[i].sh_type == SHT_REL)
928  				err = apply_relocations(sechdrs, strtab, symindex, i,
929  							&mod);
930  			else if (sechdrs[i].sh_type == SHT_RELA)
931  				err = apply_relocate_add(sechdrs, strtab, symindex, i,
932  							 &mod);
933  			if (err < 0)
934  				return err;
935 
936   		}
937   	} else {
938 		struct elf_phdr *phdr = (struct elf_phdr *) ((char *)hdr + hdr->e_phoff);
939 
940 		for (i = 0; i < hdr->e_phnum; i++) {
941 			if (phdr->p_type != PT_LOAD)
942 				continue;
943 
944 			memcpy((void *)phdr->p_paddr, (char *)hdr + phdr->p_offset, phdr->p_filesz);
945 			memset((void *)phdr->p_paddr + phdr->p_filesz, 0, phdr->p_memsz - phdr->p_filesz);
946 			phdr++;
947 		}
948 
949 		for (i = 0; i < hdr->e_shnum; i++) {
950  			/* Internal symbols and strings. */
951  			if (sechdrs[i].sh_type == SHT_SYMTAB) {
952  				symindex = i;
953  				strindex = sechdrs[i].sh_link;
954  				strtab = (char *)hdr + sechdrs[strindex].sh_offset;
955 
956  				/* mark the symtab's address for when we try to find the
957  				   magic symbols */
958  				sechdrs[i].sh_addr = (size_t) hdr + sechdrs[i].sh_offset;
959  			}
960 		}
961 	}
962 
963 	/* make sure it's physically written out */
964 	flush_icache_range((unsigned long)v->load_addr,
965 			   (unsigned long)v->load_addr + v->len);
966 
967 	if ((find_vpe_symbols(v, sechdrs, symindex, strtab, &mod)) < 0) {
968 		if (v->__start == 0) {
969 			printk(KERN_WARNING "VPE loader: program does not contain "
970 			       "a __start symbol\n");
971 			return -ENOEXEC;
972 		}
973 
974 		if (v->shared_ptr == NULL)
975 			printk(KERN_WARNING "VPE loader: "
976 			       "program does not contain vpe_shared symbol.\n"
977 			       " Unable to use AMVP (AP/SP) facilities.\n");
978 	}
979 
980 	printk(" elf loaded\n");
981 	return 0;
982 }
983 
984 static void cleanup_tc(struct tc *tc)
985 {
986 	unsigned long flags;
987 	unsigned int mtflags, vpflags;
988 	int tmp;
989 
990 	local_irq_save(flags);
991 	mtflags = dmt();
992 	vpflags = dvpe();
993 	/* Put MVPE's into 'configuration state' */
994 	set_c0_mvpcontrol(MVPCONTROL_VPC);
995 
996 	settc(tc->index);
997 	tmp = read_tc_c0_tcstatus();
998 
999 	/* mark not allocated and not dynamically allocatable */
1000 	tmp &= ~(TCSTATUS_A | TCSTATUS_DA);
1001 	tmp |= TCSTATUS_IXMT;	/* interrupt exempt */
1002 	write_tc_c0_tcstatus(tmp);
1003 
1004 	write_tc_c0_tchalt(TCHALT_H);
1005 	mips_ihb();
1006 
1007 	/* bind it to anything other than VPE1 */
1008 //	write_tc_c0_tcbind(read_tc_c0_tcbind() & ~TCBIND_CURVPE); // | TCBIND_CURVPE
1009 
1010 	clear_c0_mvpcontrol(MVPCONTROL_VPC);
1011 	evpe(vpflags);
1012 	emt(mtflags);
1013 	local_irq_restore(flags);
1014 }
1015 
1016 static int getcwd(char *buff, int size)
1017 {
1018 	mm_segment_t old_fs;
1019 	int ret;
1020 
1021 	old_fs = get_fs();
1022 	set_fs(KERNEL_DS);
1023 
1024 	ret = sys_getcwd(buff, size);
1025 
1026 	set_fs(old_fs);
1027 
1028 	return ret;
1029 }
1030 
1031 /* checks VPE is unused and gets ready to load program  */
1032 static int vpe_open(struct inode *inode, struct file *filp)
1033 {
1034 	enum vpe_state state;
1035 	struct vpe_notifications *not;
1036 	struct vpe *v;
1037 	int ret;
1038 
1039 	if (minor != iminor(inode)) {
1040 		/* assume only 1 device at the moment. */
1041 		printk(KERN_WARNING "VPE loader: only vpe1 is supported\n");
1042 		return -ENODEV;
1043 	}
1044 
1045 	if ((v = get_vpe(tclimit)) == NULL) {
1046 		printk(KERN_WARNING "VPE loader: unable to get vpe\n");
1047 		return -ENODEV;
1048 	}
1049 
1050 	state = xchg(&v->state, VPE_STATE_INUSE);
1051 	if (state != VPE_STATE_UNUSED) {
1052 		printk(KERN_DEBUG "VPE loader: tc in use dumping regs\n");
1053 
1054 		list_for_each_entry(not, &v->notify, list) {
1055 			not->stop(tclimit);
1056 		}
1057 
1058 		release_progmem(v->load_addr);
1059 		cleanup_tc(get_tc(tclimit));
1060 	}
1061 
1062 	/* this of-course trashes what was there before... */
1063 	v->pbuffer = vmalloc(P_SIZE);
1064 	v->plen = P_SIZE;
1065 	v->load_addr = NULL;
1066 	v->len = 0;
1067 
1068 	v->uid = filp->f_uid;
1069 	v->gid = filp->f_gid;
1070 
1071 #ifdef CONFIG_MIPS_APSP_KSPD
1072 	/* get kspd to tell us when a syscall_exit happens */
1073 	if (!kspd_events_reqd) {
1074 		kspd_notify(&kspd_events);
1075 		kspd_events_reqd++;
1076 	}
1077 #endif
1078 
1079 	v->cwd[0] = 0;
1080 	ret = getcwd(v->cwd, VPE_PATH_MAX);
1081 	if (ret < 0)
1082 		printk(KERN_WARNING "VPE loader: open, getcwd returned %d\n", ret);
1083 
1084 	v->shared_ptr = NULL;
1085 	v->__start = 0;
1086 
1087 	return 0;
1088 }
1089 
1090 static int vpe_release(struct inode *inode, struct file *filp)
1091 {
1092 	struct vpe *v;
1093 	Elf_Ehdr *hdr;
1094 	int ret = 0;
1095 
1096 	v = get_vpe(tclimit);
1097 	if (v == NULL)
1098 		return -ENODEV;
1099 
1100 	hdr = (Elf_Ehdr *) v->pbuffer;
1101 	if (memcmp(hdr->e_ident, ELFMAG, 4) == 0) {
1102 		if (vpe_elfload(v) >= 0) {
1103 			vpe_run(v);
1104 		} else {
1105  			printk(KERN_WARNING "VPE loader: ELF load failed.\n");
1106 			ret = -ENOEXEC;
1107 		}
1108 	} else {
1109  		printk(KERN_WARNING "VPE loader: only elf files are supported\n");
1110 		ret = -ENOEXEC;
1111 	}
1112 
1113 	/* It's good to be able to run the SP and if it chokes have a look at
1114 	   the /dev/rt?. But if we reset the pointer to the shared struct we
1115 	   loose what has happened. So perhaps if garbage is sent to the vpe
1116 	   device, use it as a trigger for the reset. Hopefully a nice
1117 	   executable will be along shortly. */
1118 	if (ret < 0)
1119 		v->shared_ptr = NULL;
1120 
1121 	// cleanup any temp buffers
1122 	if (v->pbuffer)
1123 		vfree(v->pbuffer);
1124 	v->plen = 0;
1125 	return ret;
1126 }
1127 
1128 static ssize_t vpe_write(struct file *file, const char __user * buffer,
1129 			 size_t count, loff_t * ppos)
1130 {
1131 	size_t ret = count;
1132 	struct vpe *v;
1133 
1134 	if (iminor(file->f_path.dentry->d_inode) != minor)
1135 		return -ENODEV;
1136 
1137 	v = get_vpe(tclimit);
1138 	if (v == NULL)
1139 		return -ENODEV;
1140 
1141 	if (v->pbuffer == NULL) {
1142 		printk(KERN_ERR "VPE loader: no buffer for program\n");
1143 		return -ENOMEM;
1144 	}
1145 
1146 	if ((count + v->len) > v->plen) {
1147 		printk(KERN_WARNING
1148 		       "VPE loader: elf size too big. Perhaps strip uneeded symbols\n");
1149 		return -ENOMEM;
1150 	}
1151 
1152 	count -= copy_from_user(v->pbuffer + v->len, buffer, count);
1153 	if (!count)
1154 		return -EFAULT;
1155 
1156 	v->len += count;
1157 	return ret;
1158 }
1159 
1160 static const struct file_operations vpe_fops = {
1161 	.owner = THIS_MODULE,
1162 	.open = vpe_open,
1163 	.release = vpe_release,
1164 	.write = vpe_write
1165 };
1166 
1167 /* module wrapper entry points */
1168 /* give me a vpe */
1169 vpe_handle vpe_alloc(void)
1170 {
1171 	int i;
1172 	struct vpe *v;
1173 
1174 	/* find a vpe */
1175 	for (i = 1; i < MAX_VPES; i++) {
1176 		if ((v = get_vpe(i)) != NULL) {
1177 			v->state = VPE_STATE_INUSE;
1178 			return v;
1179 		}
1180 	}
1181 	return NULL;
1182 }
1183 
1184 EXPORT_SYMBOL(vpe_alloc);
1185 
1186 /* start running from here */
1187 int vpe_start(vpe_handle vpe, unsigned long start)
1188 {
1189 	struct vpe *v = vpe;
1190 
1191 	v->__start = start;
1192 	return vpe_run(v);
1193 }
1194 
1195 EXPORT_SYMBOL(vpe_start);
1196 
1197 /* halt it for now */
1198 int vpe_stop(vpe_handle vpe)
1199 {
1200 	struct vpe *v = vpe;
1201 	struct tc *t;
1202 	unsigned int evpe_flags;
1203 
1204 	evpe_flags = dvpe();
1205 
1206 	if ((t = list_entry(v->tc.next, struct tc, tc)) != NULL) {
1207 
1208 		settc(t->index);
1209 		write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() & ~VPECONF0_VPA);
1210 	}
1211 
1212 	evpe(evpe_flags);
1213 
1214 	return 0;
1215 }
1216 
1217 EXPORT_SYMBOL(vpe_stop);
1218 
1219 /* I've done with it thank you */
1220 int vpe_free(vpe_handle vpe)
1221 {
1222 	struct vpe *v = vpe;
1223 	struct tc *t;
1224 	unsigned int evpe_flags;
1225 
1226 	if ((t = list_entry(v->tc.next, struct tc, tc)) == NULL) {
1227 		return -ENOEXEC;
1228 	}
1229 
1230 	evpe_flags = dvpe();
1231 
1232 	/* Put MVPE's into 'configuration state' */
1233 	set_c0_mvpcontrol(MVPCONTROL_VPC);
1234 
1235 	settc(t->index);
1236 	write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() & ~VPECONF0_VPA);
1237 
1238 	/* halt the TC */
1239 	write_tc_c0_tchalt(TCHALT_H);
1240 	mips_ihb();
1241 
1242 	/* mark the TC unallocated */
1243 	write_tc_c0_tcstatus(read_tc_c0_tcstatus() & ~TCSTATUS_A);
1244 
1245 	v->state = VPE_STATE_UNUSED;
1246 
1247 	clear_c0_mvpcontrol(MVPCONTROL_VPC);
1248 	evpe(evpe_flags);
1249 
1250 	return 0;
1251 }
1252 
1253 EXPORT_SYMBOL(vpe_free);
1254 
1255 void *vpe_get_shared(int index)
1256 {
1257 	struct vpe *v;
1258 
1259 	if ((v = get_vpe(index)) == NULL)
1260 		return NULL;
1261 
1262 	return v->shared_ptr;
1263 }
1264 
1265 EXPORT_SYMBOL(vpe_get_shared);
1266 
1267 int vpe_getuid(int index)
1268 {
1269 	struct vpe *v;
1270 
1271 	if ((v = get_vpe(index)) == NULL)
1272 		return -1;
1273 
1274 	return v->uid;
1275 }
1276 
1277 EXPORT_SYMBOL(vpe_getuid);
1278 
1279 int vpe_getgid(int index)
1280 {
1281 	struct vpe *v;
1282 
1283 	if ((v = get_vpe(index)) == NULL)
1284 		return -1;
1285 
1286 	return v->gid;
1287 }
1288 
1289 EXPORT_SYMBOL(vpe_getgid);
1290 
1291 int vpe_notify(int index, struct vpe_notifications *notify)
1292 {
1293 	struct vpe *v;
1294 
1295 	if ((v = get_vpe(index)) == NULL)
1296 		return -1;
1297 
1298 	list_add(&notify->list, &v->notify);
1299 	return 0;
1300 }
1301 
1302 EXPORT_SYMBOL(vpe_notify);
1303 
1304 char *vpe_getcwd(int index)
1305 {
1306 	struct vpe *v;
1307 
1308 	if ((v = get_vpe(index)) == NULL)
1309 		return NULL;
1310 
1311 	return v->cwd;
1312 }
1313 
1314 EXPORT_SYMBOL(vpe_getcwd);
1315 
1316 #ifdef CONFIG_MIPS_APSP_KSPD
1317 static void kspd_sp_exit( int sp_id)
1318 {
1319 	cleanup_tc(get_tc(sp_id));
1320 }
1321 #endif
1322 
1323 static ssize_t store_kill(struct device *dev, struct device_attribute *attr,
1324 			  const char *buf, size_t len)
1325 {
1326 	struct vpe *vpe = get_vpe(tclimit);
1327 	struct vpe_notifications *not;
1328 
1329 	list_for_each_entry(not, &vpe->notify, list) {
1330 		not->stop(tclimit);
1331 	}
1332 
1333 	release_progmem(vpe->load_addr);
1334 	cleanup_tc(get_tc(tclimit));
1335 	vpe_stop(vpe);
1336 	vpe_free(vpe);
1337 
1338 	return len;
1339 }
1340 
1341 static ssize_t show_ntcs(struct device *cd, struct device_attribute *attr,
1342 			 char *buf)
1343 {
1344 	struct vpe *vpe = get_vpe(tclimit);
1345 
1346 	return sprintf(buf, "%d\n", vpe->ntcs);
1347 }
1348 
1349 static ssize_t store_ntcs(struct device *dev, struct device_attribute *attr,
1350 			  const char *buf, size_t len)
1351 {
1352 	struct vpe *vpe = get_vpe(tclimit);
1353 	unsigned long new;
1354 	char *endp;
1355 
1356 	new = simple_strtoul(buf, &endp, 0);
1357 	if (endp == buf)
1358 		goto out_einval;
1359 
1360 	if (new == 0 || new > (hw_tcs - tclimit))
1361 		goto out_einval;
1362 
1363 	vpe->ntcs = new;
1364 
1365 	return len;
1366 
1367 out_einval:
1368 	return -EINVAL;;
1369 }
1370 
1371 static struct device_attribute vpe_class_attributes[] = {
1372 	__ATTR(kill, S_IWUSR, NULL, store_kill),
1373 	__ATTR(ntcs, S_IRUGO | S_IWUSR, show_ntcs, store_ntcs),
1374 	{}
1375 };
1376 
1377 static void vpe_device_release(struct device *cd)
1378 {
1379 	kfree(cd);
1380 }
1381 
1382 struct class vpe_class = {
1383 	.name = "vpe",
1384 	.owner = THIS_MODULE,
1385 	.dev_release = vpe_device_release,
1386 	.dev_attrs = vpe_class_attributes,
1387 };
1388 
1389 struct device vpe_device;
1390 
1391 static int __init vpe_module_init(void)
1392 {
1393 	unsigned int mtflags, vpflags;
1394 	unsigned long flags, val;
1395 	struct vpe *v = NULL;
1396 	struct tc *t;
1397 	int tc, err;
1398 
1399 	if (!cpu_has_mipsmt) {
1400 		printk("VPE loader: not a MIPS MT capable processor\n");
1401 		return -ENODEV;
1402 	}
1403 
1404 	if (vpelimit == 0) {
1405 		printk(KERN_WARNING "No VPEs reserved for AP/SP, not "
1406 		       "initializing VPE loader.\nPass maxvpes=<n> argument as "
1407 		       "kernel argument\n");
1408 
1409 		return -ENODEV;
1410 	}
1411 
1412 	if (tclimit == 0) {
1413 		printk(KERN_WARNING "No TCs reserved for AP/SP, not "
1414 		       "initializing VPE loader.\nPass maxtcs=<n> argument as "
1415 		       "kernel argument\n");
1416 
1417 		return -ENODEV;
1418 	}
1419 
1420 	major = register_chrdev(0, module_name, &vpe_fops);
1421 	if (major < 0) {
1422 		printk("VPE loader: unable to register character device\n");
1423 		return major;
1424 	}
1425 
1426 	err = class_register(&vpe_class);
1427 	if (err) {
1428 		printk(KERN_ERR "vpe_class registration failed\n");
1429 		goto out_chrdev;
1430 	}
1431 
1432 	device_initialize(&vpe_device);
1433 	vpe_device.class	= &vpe_class,
1434 	vpe_device.parent	= NULL,
1435 	strlcpy(vpe_device.bus_id, "vpe1", BUS_ID_SIZE);
1436 	vpe_device.devt = MKDEV(major, minor);
1437 	err = device_add(&vpe_device);
1438 	if (err) {
1439 		printk(KERN_ERR "Adding vpe_device failed\n");
1440 		goto out_class;
1441 	}
1442 
1443 	local_irq_save(flags);
1444 	mtflags = dmt();
1445 	vpflags = dvpe();
1446 
1447 	/* Put MVPE's into 'configuration state' */
1448 	set_c0_mvpcontrol(MVPCONTROL_VPC);
1449 
1450 	/* dump_mtregs(); */
1451 
1452 	val = read_c0_mvpconf0();
1453 	hw_tcs = (val & MVPCONF0_PTC) + 1;
1454 	hw_vpes = ((val & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT) + 1;
1455 
1456 	for (tc = tclimit; tc < hw_tcs; tc++) {
1457 		/*
1458 		 * Must re-enable multithreading temporarily or in case we
1459 		 * reschedule send IPIs or similar we might hang.
1460 		 */
1461 		clear_c0_mvpcontrol(MVPCONTROL_VPC);
1462 		evpe(vpflags);
1463 		emt(mtflags);
1464 		local_irq_restore(flags);
1465 		t = alloc_tc(tc);
1466 		if (!t) {
1467 			err = -ENOMEM;
1468 			goto out;
1469 		}
1470 
1471 		local_irq_save(flags);
1472 		mtflags = dmt();
1473 		vpflags = dvpe();
1474 		set_c0_mvpcontrol(MVPCONTROL_VPC);
1475 
1476 		/* VPE's */
1477 		if (tc < hw_tcs) {
1478 			settc(tc);
1479 
1480 			if ((v = alloc_vpe(tc)) == NULL) {
1481 				printk(KERN_WARNING "VPE: unable to allocate VPE\n");
1482 
1483 				goto out_reenable;
1484 			}
1485 
1486 			v->ntcs = hw_tcs - tclimit;
1487 
1488 			/* add the tc to the list of this vpe's tc's. */
1489 			list_add(&t->tc, &v->tc);
1490 
1491 			/* deactivate all but vpe0 */
1492 			if (tc >= tclimit) {
1493 				unsigned long tmp = read_vpe_c0_vpeconf0();
1494 
1495 				tmp &= ~VPECONF0_VPA;
1496 
1497 				/* master VPE */
1498 				tmp |= VPECONF0_MVP;
1499 				write_vpe_c0_vpeconf0(tmp);
1500 			}
1501 
1502 			/* disable multi-threading with TC's */
1503 			write_vpe_c0_vpecontrol(read_vpe_c0_vpecontrol() & ~VPECONTROL_TE);
1504 
1505 			if (tc >= vpelimit) {
1506 				/*
1507 				 * Set config to be the same as vpe0,
1508 				 * particularly kseg0 coherency alg
1509 				 */
1510 				write_vpe_c0_config(read_c0_config());
1511 			}
1512 		}
1513 
1514 		/* TC's */
1515 		t->pvpe = v;	/* set the parent vpe */
1516 
1517 		if (tc >= tclimit) {
1518 			unsigned long tmp;
1519 
1520 			settc(tc);
1521 
1522 			/* Any TC that is bound to VPE0 gets left as is - in case
1523 			   we are running SMTC on VPE0. A TC that is bound to any
1524 			   other VPE gets bound to VPE0, ideally I'd like to make
1525 			   it homeless but it doesn't appear to let me bind a TC
1526 			   to a non-existent VPE. Which is perfectly reasonable.
1527 
1528 			   The (un)bound state is visible to an EJTAG probe so may
1529 			   notify GDB...
1530 			*/
1531 
1532 			if (((tmp = read_tc_c0_tcbind()) & TCBIND_CURVPE)) {
1533 				/* tc is bound >vpe0 */
1534 				write_tc_c0_tcbind(tmp & ~TCBIND_CURVPE);
1535 
1536 				t->pvpe = get_vpe(0);	/* set the parent vpe */
1537 			}
1538 
1539 			/* halt the TC */
1540 			write_tc_c0_tchalt(TCHALT_H);
1541 			mips_ihb();
1542 
1543 			tmp = read_tc_c0_tcstatus();
1544 
1545 			/* mark not activated and not dynamically allocatable */
1546 			tmp &= ~(TCSTATUS_A | TCSTATUS_DA);
1547 			tmp |= TCSTATUS_IXMT;	/* interrupt exempt */
1548 			write_tc_c0_tcstatus(tmp);
1549 		}
1550 	}
1551 
1552 out_reenable:
1553 	/* release config state */
1554 	clear_c0_mvpcontrol(MVPCONTROL_VPC);
1555 
1556 	evpe(vpflags);
1557 	emt(mtflags);
1558 	local_irq_restore(flags);
1559 
1560 #ifdef CONFIG_MIPS_APSP_KSPD
1561 	kspd_events.kspd_sp_exit = kspd_sp_exit;
1562 #endif
1563 	return 0;
1564 
1565 out_class:
1566 	class_unregister(&vpe_class);
1567 out_chrdev:
1568 	unregister_chrdev(major, module_name);
1569 
1570 out:
1571 	return err;
1572 }
1573 
1574 static void __exit vpe_module_exit(void)
1575 {
1576 	struct vpe *v, *n;
1577 
1578 	list_for_each_entry_safe(v, n, &vpecontrol.vpe_list, list) {
1579 		if (v->state != VPE_STATE_UNUSED) {
1580 			release_vpe(v);
1581 		}
1582 	}
1583 
1584 	device_del(&vpe_device);
1585 	unregister_chrdev(major, module_name);
1586 }
1587 
1588 module_init(vpe_module_init);
1589 module_exit(vpe_module_exit);
1590 MODULE_DESCRIPTION("MIPS VPE Loader");
1591 MODULE_AUTHOR("Elizabeth Oldham, MIPS Technologies, Inc.");
1592 MODULE_LICENSE("GPL");
1593