xref: /linux/arch/mips/kernel/vpe.c (revision 0d456bad36d42d16022be045c8a53ddbb59ee478)
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 environment 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/fs.h>
33 #include <linux/init.h>
34 #include <asm/uaccess.h>
35 #include <linux/slab.h>
36 #include <linux/list.h>
37 #include <linux/vmalloc.h>
38 #include <linux/elf.h>
39 #include <linux/seq_file.h>
40 #include <linux/syscalls.h>
41 #include <linux/moduleloader.h>
42 #include <linux/interrupt.h>
43 #include <linux/poll.h>
44 #include <linux/bootmem.h>
45 #include <asm/mipsregs.h>
46 #include <asm/mipsmtregs.h>
47 #include <asm/cacheflush.h>
48 #include <linux/atomic.h>
49 #include <asm/cpu.h>
50 #include <asm/mips_mt.h>
51 #include <asm/processor.h>
52 #include <asm/vpe.h>
53 
54 typedef void *vpe_handle;
55 
56 #ifndef ARCH_SHF_SMALL
57 #define ARCH_SHF_SMALL 0
58 #endif
59 
60 /* If this is set, the section belongs in the init part of the module */
61 #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
62 
63 /*
64  * The number of TCs and VPEs physically available on the core
65  */
66 static int hw_tcs, hw_vpes;
67 static char module_name[] = "vpe";
68 static int major;
69 static const int minor = 1;	/* fixed for now  */
70 
71 /* grab the likely amount of memory we will need. */
72 #ifdef CONFIG_MIPS_VPE_LOADER_TOM
73 #define P_SIZE (2 * 1024 * 1024)
74 #else
75 /* add an overhead to the max kmalloc size for non-striped symbols/etc */
76 #define P_SIZE (256 * 1024)
77 #endif
78 
79 extern unsigned long physical_memsize;
80 
81 #define MAX_VPES 16
82 #define VPE_PATH_MAX 256
83 
84 enum vpe_state {
85 	VPE_STATE_UNUSED = 0,
86 	VPE_STATE_INUSE,
87 	VPE_STATE_RUNNING
88 };
89 
90 enum tc_state {
91 	TC_STATE_UNUSED = 0,
92 	TC_STATE_INUSE,
93 	TC_STATE_RUNNING,
94 	TC_STATE_DYNAMIC
95 };
96 
97 struct vpe {
98 	enum vpe_state state;
99 
100 	/* (device) minor associated with this vpe */
101 	int minor;
102 
103 	/* elfloader stuff */
104 	void *load_addr;
105 	unsigned long len;
106 	char *pbuffer;
107 	unsigned long plen;
108 	unsigned int uid, gid;
109 	char cwd[VPE_PATH_MAX];
110 
111 	unsigned long __start;
112 
113 	/* tc's associated with this vpe */
114 	struct list_head tc;
115 
116 	/* The list of vpe's */
117 	struct list_head list;
118 
119 	/* shared symbol address */
120 	void *shared_ptr;
121 
122 	/* the list of who wants to know when something major happens */
123 	struct list_head notify;
124 
125 	unsigned int ntcs;
126 };
127 
128 struct tc {
129 	enum tc_state state;
130 	int index;
131 
132 	struct vpe *pvpe;	/* parent VPE */
133 	struct list_head tc;	/* The list of TC's with this VPE */
134 	struct list_head list;	/* The global list of tc's */
135 };
136 
137 struct {
138 	spinlock_t vpe_list_lock;
139 	struct list_head vpe_list;	/* Virtual processing elements */
140 	spinlock_t tc_list_lock;
141 	struct list_head tc_list;	/* Thread contexts */
142 } vpecontrol = {
143 	.vpe_list_lock	= __SPIN_LOCK_UNLOCKED(vpe_list_lock),
144 	.vpe_list	= LIST_HEAD_INIT(vpecontrol.vpe_list),
145 	.tc_list_lock	= __SPIN_LOCK_UNLOCKED(tc_list_lock),
146 	.tc_list	= LIST_HEAD_INIT(vpecontrol.tc_list)
147 };
148 
149 static void release_progmem(void *ptr);
150 
151 /* get the vpe associated with this minor */
152 static struct vpe *get_vpe(int minor)
153 {
154 	struct vpe *res, *v;
155 
156 	if (!cpu_has_mipsmt)
157 		return NULL;
158 
159 	res = NULL;
160 	spin_lock(&vpecontrol.vpe_list_lock);
161 	list_for_each_entry(v, &vpecontrol.vpe_list, list) {
162 		if (v->minor == minor) {
163 			res = v;
164 			break;
165 		}
166 	}
167 	spin_unlock(&vpecontrol.vpe_list_lock);
168 
169 	return res;
170 }
171 
172 /* get the vpe associated with this minor */
173 static struct tc *get_tc(int index)
174 {
175 	struct tc *res, *t;
176 
177 	res = NULL;
178 	spin_lock(&vpecontrol.tc_list_lock);
179 	list_for_each_entry(t, &vpecontrol.tc_list, list) {
180 		if (t->index == index) {
181 			res = t;
182 			break;
183 		}
184 	}
185 	spin_unlock(&vpecontrol.tc_list_lock);
186 
187 	return res;
188 }
189 
190 /* allocate a vpe and associate it with this minor (or index) */
191 static struct vpe *alloc_vpe(int minor)
192 {
193 	struct vpe *v;
194 
195 	if ((v = kzalloc(sizeof(struct vpe), GFP_KERNEL)) == NULL)
196 		return NULL;
197 
198 	INIT_LIST_HEAD(&v->tc);
199 	spin_lock(&vpecontrol.vpe_list_lock);
200 	list_add_tail(&v->list, &vpecontrol.vpe_list);
201 	spin_unlock(&vpecontrol.vpe_list_lock);
202 
203 	INIT_LIST_HEAD(&v->notify);
204 	v->minor = minor;
205 
206 	return v;
207 }
208 
209 /* allocate a tc. At startup only tc0 is running, all other can be halted. */
210 static struct tc *alloc_tc(int index)
211 {
212 	struct tc *tc;
213 
214 	if ((tc = kzalloc(sizeof(struct tc), GFP_KERNEL)) == NULL)
215 		goto out;
216 
217 	INIT_LIST_HEAD(&tc->tc);
218 	tc->index = index;
219 
220 	spin_lock(&vpecontrol.tc_list_lock);
221 	list_add_tail(&tc->list, &vpecontrol.tc_list);
222 	spin_unlock(&vpecontrol.tc_list_lock);
223 
224 out:
225 	return tc;
226 }
227 
228 /* clean up and free everything */
229 static void release_vpe(struct vpe *v)
230 {
231 	list_del(&v->list);
232 	if (v->load_addr)
233 		release_progmem(v);
234 	kfree(v);
235 }
236 
237 static void __maybe_unused dump_mtregs(void)
238 {
239 	unsigned long val;
240 
241 	val = read_c0_config3();
242 	printk("config3 0x%lx MT %ld\n", val,
243 	       (val & CONFIG3_MT) >> CONFIG3_MT_SHIFT);
244 
245 	val = read_c0_mvpcontrol();
246 	printk("MVPControl 0x%lx, STLB %ld VPC %ld EVP %ld\n", val,
247 	       (val & MVPCONTROL_STLB) >> MVPCONTROL_STLB_SHIFT,
248 	       (val & MVPCONTROL_VPC) >> MVPCONTROL_VPC_SHIFT,
249 	       (val & MVPCONTROL_EVP));
250 
251 	val = read_c0_mvpconf0();
252 	printk("mvpconf0 0x%lx, PVPE %ld PTC %ld M %ld\n", val,
253 	       (val & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT,
254 	       val & MVPCONF0_PTC, (val & MVPCONF0_M) >> MVPCONF0_M_SHIFT);
255 }
256 
257 /* Find some VPE program space  */
258 static void *alloc_progmem(unsigned long len)
259 {
260 	void *addr;
261 
262 #ifdef CONFIG_MIPS_VPE_LOADER_TOM
263 	/*
264 	 * This means you must tell Linux to use less memory than you
265 	 * physically have, for example by passing a mem= boot argument.
266 	 */
267 	addr = pfn_to_kaddr(max_low_pfn);
268 	memset(addr, 0, len);
269 #else
270 	/* simple grab some mem for now */
271 	addr = kzalloc(len, GFP_KERNEL);
272 #endif
273 
274 	return addr;
275 }
276 
277 static void release_progmem(void *ptr)
278 {
279 #ifndef CONFIG_MIPS_VPE_LOADER_TOM
280 	kfree(ptr);
281 #endif
282 }
283 
284 /* Update size with this section: return offset. */
285 static long get_offset(unsigned long *size, Elf_Shdr * sechdr)
286 {
287 	long ret;
288 
289 	ret = ALIGN(*size, sechdr->sh_addralign ? : 1);
290 	*size = ret + sechdr->sh_size;
291 	return ret;
292 }
293 
294 /* Lay out the SHF_ALLOC sections in a way not dissimilar to how ld
295    might -- code, read-only data, read-write data, small data.  Tally
296    sizes, and place the offsets into sh_entsize fields: high bit means it
297    belongs in init. */
298 static void layout_sections(struct module *mod, const Elf_Ehdr * hdr,
299 			    Elf_Shdr * sechdrs, const char *secstrings)
300 {
301 	static unsigned long const masks[][2] = {
302 		/* NOTE: all executable code must be the first section
303 		 * in this array; otherwise modify the text_size
304 		 * finder in the two loops below */
305 		{SHF_EXECINSTR | SHF_ALLOC, ARCH_SHF_SMALL},
306 		{SHF_ALLOC, SHF_WRITE | ARCH_SHF_SMALL},
307 		{SHF_WRITE | SHF_ALLOC, ARCH_SHF_SMALL},
308 		{ARCH_SHF_SMALL | SHF_ALLOC, 0}
309 	};
310 	unsigned int m, i;
311 
312 	for (i = 0; i < hdr->e_shnum; i++)
313 		sechdrs[i].sh_entsize = ~0UL;
314 
315 	for (m = 0; m < ARRAY_SIZE(masks); ++m) {
316 		for (i = 0; i < hdr->e_shnum; ++i) {
317 			Elf_Shdr *s = &sechdrs[i];
318 
319 			//  || strncmp(secstrings + s->sh_name, ".init", 5) == 0)
320 			if ((s->sh_flags & masks[m][0]) != masks[m][0]
321 			    || (s->sh_flags & masks[m][1])
322 			    || s->sh_entsize != ~0UL)
323 				continue;
324 			s->sh_entsize =
325 				get_offset((unsigned long *)&mod->core_size, s);
326 		}
327 
328 		if (m == 0)
329 			mod->core_text_size = mod->core_size;
330 
331 	}
332 }
333 
334 
335 /* from module-elf32.c, but subverted a little */
336 
337 struct mips_hi16 {
338 	struct mips_hi16 *next;
339 	Elf32_Addr *addr;
340 	Elf32_Addr value;
341 };
342 
343 static struct mips_hi16 *mips_hi16_list;
344 static unsigned int gp_offs, gp_addr;
345 
346 static int apply_r_mips_none(struct module *me, uint32_t *location,
347 			     Elf32_Addr v)
348 {
349 	return 0;
350 }
351 
352 static int apply_r_mips_gprel16(struct module *me, uint32_t *location,
353 				Elf32_Addr v)
354 {
355 	int rel;
356 
357 	if( !(*location & 0xffff) ) {
358 		rel = (int)v - gp_addr;
359 	}
360 	else {
361 		/* .sbss + gp(relative) + offset */
362 		/* kludge! */
363 		rel =  (int)(short)((int)v + gp_offs +
364 				    (int)(short)(*location & 0xffff) - gp_addr);
365 	}
366 
367 	if( (rel > 32768) || (rel < -32768) ) {
368 		printk(KERN_DEBUG "VPE loader: apply_r_mips_gprel16: "
369 		       "relative address 0x%x out of range of gp register\n",
370 		       rel);
371 		return -ENOEXEC;
372 	}
373 
374 	*location = (*location & 0xffff0000) | (rel & 0xffff);
375 
376 	return 0;
377 }
378 
379 static int apply_r_mips_pc16(struct module *me, uint32_t *location,
380 			     Elf32_Addr v)
381 {
382 	int rel;
383 	rel = (((unsigned int)v - (unsigned int)location));
384 	rel >>= 2;		// because the offset is in _instructions_ not bytes.
385 	rel -= 1;		// and one instruction less due to the branch delay slot.
386 
387 	if( (rel > 32768) || (rel < -32768) ) {
388 		printk(KERN_DEBUG "VPE loader: "
389  		       "apply_r_mips_pc16: relative address out of range 0x%x\n", rel);
390 		return -ENOEXEC;
391 	}
392 
393 	*location = (*location & 0xffff0000) | (rel & 0xffff);
394 
395 	return 0;
396 }
397 
398 static int apply_r_mips_32(struct module *me, uint32_t *location,
399 			   Elf32_Addr v)
400 {
401 	*location += v;
402 
403 	return 0;
404 }
405 
406 static int apply_r_mips_26(struct module *me, uint32_t *location,
407 			   Elf32_Addr v)
408 {
409 	if (v % 4) {
410 		printk(KERN_DEBUG "VPE loader: apply_r_mips_26 "
411 		       " unaligned relocation\n");
412 		return -ENOEXEC;
413 	}
414 
415 /*
416  * Not desperately convinced this is a good check of an overflow condition
417  * anyway. But it gets in the way of handling undefined weak symbols which
418  * we want to set to zero.
419  * if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
420  * printk(KERN_ERR
421  * "module %s: relocation overflow\n",
422  * me->name);
423  * return -ENOEXEC;
424  * }
425  */
426 
427 	*location = (*location & ~0x03ffffff) |
428 		((*location + (v >> 2)) & 0x03ffffff);
429 	return 0;
430 }
431 
432 static int apply_r_mips_hi16(struct module *me, uint32_t *location,
433 			     Elf32_Addr v)
434 {
435 	struct mips_hi16 *n;
436 
437 	/*
438 	 * We cannot relocate this one now because we don't know the value of
439 	 * the carry we need to add.  Save the information, and let LO16 do the
440 	 * actual relocation.
441 	 */
442 	n = kmalloc(sizeof *n, GFP_KERNEL);
443 	if (!n)
444 		return -ENOMEM;
445 
446 	n->addr = location;
447 	n->value = v;
448 	n->next = mips_hi16_list;
449 	mips_hi16_list = n;
450 
451 	return 0;
452 }
453 
454 static int apply_r_mips_lo16(struct module *me, uint32_t *location,
455 			     Elf32_Addr v)
456 {
457 	unsigned long insnlo = *location;
458 	Elf32_Addr val, vallo;
459 	struct mips_hi16 *l, *next;
460 
461 	/* Sign extend the addend we extract from the lo insn.  */
462 	vallo = ((insnlo & 0xffff) ^ 0x8000) - 0x8000;
463 
464 	if (mips_hi16_list != NULL) {
465 
466 		l = mips_hi16_list;
467 		while (l != NULL) {
468 			unsigned long insn;
469 
470 			/*
471 			 * The value for the HI16 had best be the same.
472 			 */
473  			if (v != l->value) {
474 				printk(KERN_DEBUG "VPE loader: "
475 				       "apply_r_mips_lo16/hi16: \t"
476 				       "inconsistent value information\n");
477 				goto out_free;
478 			}
479 
480 			/*
481 			 * Do the HI16 relocation.  Note that we actually don't
482 			 * need to know anything about the LO16 itself, except
483 			 * where to find the low 16 bits of the addend needed
484 			 * by the LO16.
485 			 */
486 			insn = *l->addr;
487 			val = ((insn & 0xffff) << 16) + vallo;
488 			val += v;
489 
490 			/*
491 			 * Account for the sign extension that will happen in
492 			 * the low bits.
493 			 */
494 			val = ((val >> 16) + ((val & 0x8000) != 0)) & 0xffff;
495 
496 			insn = (insn & ~0xffff) | val;
497 			*l->addr = insn;
498 
499 			next = l->next;
500 			kfree(l);
501 			l = next;
502 		}
503 
504 		mips_hi16_list = NULL;
505 	}
506 
507 	/*
508 	 * Ok, we're done with the HI16 relocs.  Now deal with the LO16.
509 	 */
510 	val = v + vallo;
511 	insnlo = (insnlo & ~0xffff) | (val & 0xffff);
512 	*location = insnlo;
513 
514 	return 0;
515 
516 out_free:
517 	while (l != NULL) {
518 		next = l->next;
519 		kfree(l);
520 		l = next;
521 	}
522 	mips_hi16_list = NULL;
523 
524 	return -ENOEXEC;
525 }
526 
527 static int (*reloc_handlers[]) (struct module *me, uint32_t *location,
528 				Elf32_Addr v) = {
529 	[R_MIPS_NONE]	= apply_r_mips_none,
530 	[R_MIPS_32]	= apply_r_mips_32,
531 	[R_MIPS_26]	= apply_r_mips_26,
532 	[R_MIPS_HI16]	= apply_r_mips_hi16,
533 	[R_MIPS_LO16]	= apply_r_mips_lo16,
534 	[R_MIPS_GPREL16] = apply_r_mips_gprel16,
535 	[R_MIPS_PC16] = apply_r_mips_pc16
536 };
537 
538 static char *rstrs[] = {
539 	[R_MIPS_NONE]	= "MIPS_NONE",
540 	[R_MIPS_32]	= "MIPS_32",
541 	[R_MIPS_26]	= "MIPS_26",
542 	[R_MIPS_HI16]	= "MIPS_HI16",
543 	[R_MIPS_LO16]	= "MIPS_LO16",
544 	[R_MIPS_GPREL16] = "MIPS_GPREL16",
545 	[R_MIPS_PC16] = "MIPS_PC16"
546 };
547 
548 static int apply_relocations(Elf32_Shdr *sechdrs,
549 		      const char *strtab,
550 		      unsigned int symindex,
551 		      unsigned int relsec,
552 		      struct module *me)
553 {
554 	Elf32_Rel *rel = (void *) sechdrs[relsec].sh_addr;
555 	Elf32_Sym *sym;
556 	uint32_t *location;
557 	unsigned int i;
558 	Elf32_Addr v;
559 	int res;
560 
561 	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
562 		Elf32_Word r_info = rel[i].r_info;
563 
564 		/* This is where to make the change */
565 		location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
566 			+ rel[i].r_offset;
567 		/* This is the symbol it is referring to */
568 		sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
569 			+ ELF32_R_SYM(r_info);
570 
571 		if (!sym->st_value) {
572 			printk(KERN_DEBUG "%s: undefined weak symbol %s\n",
573 			       me->name, strtab + sym->st_name);
574 			/* just print the warning, dont barf */
575 		}
576 
577 		v = sym->st_value;
578 
579 		res = reloc_handlers[ELF32_R_TYPE(r_info)](me, location, v);
580 		if( res ) {
581 			char *r = rstrs[ELF32_R_TYPE(r_info)];
582 		    	printk(KERN_WARNING "VPE loader: .text+0x%x "
583 			       "relocation type %s for symbol \"%s\" failed\n",
584 			       rel[i].r_offset, r ? r : "UNKNOWN",
585 			       strtab + sym->st_name);
586 			return res;
587 		}
588 	}
589 
590 	return 0;
591 }
592 
593 static inline void save_gp_address(unsigned int secbase, unsigned int rel)
594 {
595 	gp_addr = secbase + rel;
596 	gp_offs = gp_addr - (secbase & 0xffff0000);
597 }
598 /* end module-elf32.c */
599 
600 
601 
602 /* Change all symbols so that sh_value encodes the pointer directly. */
603 static void simplify_symbols(Elf_Shdr * sechdrs,
604 			    unsigned int symindex,
605 			    const char *strtab,
606 			    const char *secstrings,
607 			    unsigned int nsecs, struct module *mod)
608 {
609 	Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
610 	unsigned long secbase, bssbase = 0;
611 	unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
612 	int size;
613 
614 	/* find the .bss section for COMMON symbols */
615 	for (i = 0; i < nsecs; i++) {
616 		if (strncmp(secstrings + sechdrs[i].sh_name, ".bss", 4) == 0) {
617 			bssbase = sechdrs[i].sh_addr;
618 			break;
619 		}
620 	}
621 
622 	for (i = 1; i < n; i++) {
623 		switch (sym[i].st_shndx) {
624 		case SHN_COMMON:
625 			/* Allocate space for the symbol in the .bss section.
626 			   st_value is currently size.
627 			   We want it to have the address of the symbol. */
628 
629 			size = sym[i].st_value;
630 			sym[i].st_value = bssbase;
631 
632 			bssbase += size;
633 			break;
634 
635 		case SHN_ABS:
636 			/* Don't need to do anything */
637 			break;
638 
639 		case SHN_UNDEF:
640 			/* ret = -ENOENT; */
641 			break;
642 
643 		case SHN_MIPS_SCOMMON:
644 			printk(KERN_DEBUG "simplify_symbols: ignoring SHN_MIPS_SCOMMON "
645 			       "symbol <%s> st_shndx %d\n", strtab + sym[i].st_name,
646 			       sym[i].st_shndx);
647 			// .sbss section
648 			break;
649 
650 		default:
651 			secbase = sechdrs[sym[i].st_shndx].sh_addr;
652 
653 			if (strncmp(strtab + sym[i].st_name, "_gp", 3) == 0) {
654 				save_gp_address(secbase, sym[i].st_value);
655 			}
656 
657 			sym[i].st_value += secbase;
658 			break;
659 		}
660 	}
661 }
662 
663 #ifdef DEBUG_ELFLOADER
664 static void dump_elfsymbols(Elf_Shdr * sechdrs, unsigned int symindex,
665 			    const char *strtab, struct module *mod)
666 {
667 	Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
668 	unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
669 
670 	printk(KERN_DEBUG "dump_elfsymbols: n %d\n", n);
671 	for (i = 1; i < n; i++) {
672 		printk(KERN_DEBUG " i %d name <%s> 0x%x\n", i,
673 		       strtab + sym[i].st_name, sym[i].st_value);
674 	}
675 }
676 #endif
677 
678 /* We are prepared so configure and start the VPE... */
679 static int vpe_run(struct vpe * v)
680 {
681 	unsigned long flags, val, dmt_flag;
682 	struct vpe_notifications *n;
683 	unsigned int vpeflags;
684 	struct tc *t;
685 
686 	/* check we are the Master VPE */
687 	local_irq_save(flags);
688 	val = read_c0_vpeconf0();
689 	if (!(val & VPECONF0_MVP)) {
690 		printk(KERN_WARNING
691 		       "VPE loader: only Master VPE's are allowed to configure MT\n");
692 		local_irq_restore(flags);
693 
694 		return -1;
695 	}
696 
697 	dmt_flag = dmt();
698 	vpeflags = dvpe();
699 
700 	if (!list_empty(&v->tc)) {
701 		if ((t = list_entry(v->tc.next, struct tc, tc)) == NULL) {
702 			evpe(vpeflags);
703 			emt(dmt_flag);
704 			local_irq_restore(flags);
705 
706 			printk(KERN_WARNING
707 			       "VPE loader: TC %d is already in use.\n",
708                                t->index);
709 			return -ENOEXEC;
710 		}
711 	} else {
712 		evpe(vpeflags);
713 		emt(dmt_flag);
714 		local_irq_restore(flags);
715 
716 		printk(KERN_WARNING
717 		       "VPE loader: No TC's associated with VPE %d\n",
718 		       v->minor);
719 
720 		return -ENOEXEC;
721 	}
722 
723 	/* Put MVPE's into 'configuration state' */
724 	set_c0_mvpcontrol(MVPCONTROL_VPC);
725 
726 	settc(t->index);
727 
728 	/* should check it is halted, and not activated */
729 	if ((read_tc_c0_tcstatus() & TCSTATUS_A) || !(read_tc_c0_tchalt() & TCHALT_H)) {
730 		evpe(vpeflags);
731 		emt(dmt_flag);
732 		local_irq_restore(flags);
733 
734 		printk(KERN_WARNING "VPE loader: TC %d is already active!\n",
735 		       t->index);
736 
737 		return -ENOEXEC;
738 	}
739 
740 	/* Write the address we want it to start running from in the TCPC register. */
741 	write_tc_c0_tcrestart((unsigned long)v->__start);
742 	write_tc_c0_tccontext((unsigned long)0);
743 
744 	/*
745 	 * Mark the TC as activated, not interrupt exempt and not dynamically
746 	 * allocatable
747 	 */
748 	val = read_tc_c0_tcstatus();
749 	val = (val & ~(TCSTATUS_DA | TCSTATUS_IXMT)) | TCSTATUS_A;
750 	write_tc_c0_tcstatus(val);
751 
752 	write_tc_c0_tchalt(read_tc_c0_tchalt() & ~TCHALT_H);
753 
754 	/*
755 	 * The sde-kit passes 'memsize' to __start in $a3, so set something
756 	 * here...  Or set $a3 to zero and define DFLT_STACK_SIZE and
757 	 * DFLT_HEAP_SIZE when you compile your program
758 	 */
759 	mttgpr(6, v->ntcs);
760 	mttgpr(7, physical_memsize);
761 
762 	/* set up VPE1 */
763 	/*
764 	 * bind the TC to VPE 1 as late as possible so we only have the final
765 	 * VPE registers to set up, and so an EJTAG probe can trigger on it
766 	 */
767 	write_tc_c0_tcbind((read_tc_c0_tcbind() & ~TCBIND_CURVPE) | 1);
768 
769 	write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() & ~(VPECONF0_VPA));
770 
771 	back_to_back_c0_hazard();
772 
773 	/* Set up the XTC bit in vpeconf0 to point at our tc */
774 	write_vpe_c0_vpeconf0( (read_vpe_c0_vpeconf0() & ~(VPECONF0_XTC))
775 	                      | (t->index << VPECONF0_XTC_SHIFT));
776 
777 	back_to_back_c0_hazard();
778 
779 	/* enable this VPE */
780 	write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() | VPECONF0_VPA);
781 
782 	/* clear out any left overs from a previous program */
783 	write_vpe_c0_status(0);
784 	write_vpe_c0_cause(0);
785 
786 	/* take system out of configuration state */
787 	clear_c0_mvpcontrol(MVPCONTROL_VPC);
788 
789 	/*
790 	 * SMTC/SMVP kernels manage VPE enable independently,
791 	 * but uniprocessor kernels need to turn it on, even
792 	 * if that wasn't the pre-dvpe() state.
793 	 */
794 #ifdef CONFIG_SMP
795 	evpe(vpeflags);
796 #else
797 	evpe(EVPE_ENABLE);
798 #endif
799 	emt(dmt_flag);
800 	local_irq_restore(flags);
801 
802 	list_for_each_entry(n, &v->notify, list)
803 		n->start(minor);
804 
805 	return 0;
806 }
807 
808 static int find_vpe_symbols(struct vpe * v, Elf_Shdr * sechdrs,
809 				      unsigned int symindex, const char *strtab,
810 				      struct module *mod)
811 {
812 	Elf_Sym *sym = (void *)sechdrs[symindex].sh_addr;
813 	unsigned int i, n = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
814 
815 	for (i = 1; i < n; i++) {
816 		if (strcmp(strtab + sym[i].st_name, "__start") == 0) {
817 			v->__start = sym[i].st_value;
818 		}
819 
820 		if (strcmp(strtab + sym[i].st_name, "vpe_shared") == 0) {
821 			v->shared_ptr = (void *)sym[i].st_value;
822 		}
823 	}
824 
825 	if ( (v->__start == 0) || (v->shared_ptr == NULL))
826 		return -1;
827 
828 	return 0;
829 }
830 
831 /*
832  * Allocates a VPE with some program code space(the load address), copies the
833  * contents of the program (p)buffer performing relocatations/etc, free's it
834  * when finished.
835  */
836 static int vpe_elfload(struct vpe * v)
837 {
838 	Elf_Ehdr *hdr;
839 	Elf_Shdr *sechdrs;
840 	long err = 0;
841 	char *secstrings, *strtab = NULL;
842 	unsigned int len, i, symindex = 0, strindex = 0, relocate = 0;
843 	struct module mod;	// so we can re-use the relocations code
844 
845 	memset(&mod, 0, sizeof(struct module));
846 	strcpy(mod.name, "VPE loader");
847 
848 	hdr = (Elf_Ehdr *) v->pbuffer;
849 	len = v->plen;
850 
851 	/* Sanity checks against insmoding binaries or wrong arch,
852 	   weird elf version */
853 	if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0
854 	    || (hdr->e_type != ET_REL && hdr->e_type != ET_EXEC)
855 	    || !elf_check_arch(hdr)
856 	    || hdr->e_shentsize != sizeof(*sechdrs)) {
857 		printk(KERN_WARNING
858 		       "VPE loader: program wrong arch or weird elf version\n");
859 
860 		return -ENOEXEC;
861 	}
862 
863 	if (hdr->e_type == ET_REL)
864 		relocate = 1;
865 
866 	if (len < hdr->e_shoff + hdr->e_shnum * sizeof(Elf_Shdr)) {
867 		printk(KERN_ERR "VPE loader: program length %u truncated\n",
868 		       len);
869 
870 		return -ENOEXEC;
871 	}
872 
873 	/* Convenience variables */
874 	sechdrs = (void *)hdr + hdr->e_shoff;
875 	secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
876 	sechdrs[0].sh_addr = 0;
877 
878 	/* And these should exist, but gcc whinges if we don't init them */
879 	symindex = strindex = 0;
880 
881 	if (relocate) {
882 		for (i = 1; i < hdr->e_shnum; i++) {
883 			if (sechdrs[i].sh_type != SHT_NOBITS
884 			    && len < sechdrs[i].sh_offset + sechdrs[i].sh_size) {
885 				printk(KERN_ERR "VPE program length %u truncated\n",
886 				       len);
887 				return -ENOEXEC;
888 			}
889 
890 			/* Mark all sections sh_addr with their address in the
891 			   temporary image. */
892 			sechdrs[i].sh_addr = (size_t) hdr + sechdrs[i].sh_offset;
893 
894 			/* Internal symbols and strings. */
895 			if (sechdrs[i].sh_type == SHT_SYMTAB) {
896 				symindex = i;
897 				strindex = sechdrs[i].sh_link;
898 				strtab = (char *)hdr + sechdrs[strindex].sh_offset;
899 			}
900 		}
901 		layout_sections(&mod, hdr, sechdrs, secstrings);
902 	}
903 
904 	v->load_addr = alloc_progmem(mod.core_size);
905 	if (!v->load_addr)
906 		return -ENOMEM;
907 
908 	pr_info("VPE loader: loading to %p\n", v->load_addr);
909 
910 	if (relocate) {
911 		for (i = 0; i < hdr->e_shnum; i++) {
912 			void *dest;
913 
914 			if (!(sechdrs[i].sh_flags & SHF_ALLOC))
915 				continue;
916 
917 			dest = v->load_addr + sechdrs[i].sh_entsize;
918 
919 			if (sechdrs[i].sh_type != SHT_NOBITS)
920 				memcpy(dest, (void *)sechdrs[i].sh_addr,
921 				       sechdrs[i].sh_size);
922 			/* Update sh_addr to point to copy in image. */
923 			sechdrs[i].sh_addr = (unsigned long)dest;
924 
925 			printk(KERN_DEBUG " section sh_name %s sh_addr 0x%x\n",
926 			       secstrings + sechdrs[i].sh_name, sechdrs[i].sh_addr);
927 		}
928 
929  		/* Fix up syms, so that st_value is a pointer to location. */
930  		simplify_symbols(sechdrs, symindex, strtab, secstrings,
931  				 hdr->e_shnum, &mod);
932 
933  		/* Now do relocations. */
934  		for (i = 1; i < hdr->e_shnum; i++) {
935  			const char *strtab = (char *)sechdrs[strindex].sh_addr;
936  			unsigned int info = sechdrs[i].sh_info;
937 
938  			/* Not a valid relocation section? */
939  			if (info >= hdr->e_shnum)
940  				continue;
941 
942  			/* Don't bother with non-allocated sections */
943  			if (!(sechdrs[info].sh_flags & SHF_ALLOC))
944  				continue;
945 
946  			if (sechdrs[i].sh_type == SHT_REL)
947  				err = apply_relocations(sechdrs, strtab, symindex, i,
948  							&mod);
949  			else if (sechdrs[i].sh_type == SHT_RELA)
950  				err = apply_relocate_add(sechdrs, strtab, symindex, i,
951  							 &mod);
952  			if (err < 0)
953  				return err;
954 
955   		}
956   	} else {
957 		struct elf_phdr *phdr = (struct elf_phdr *) ((char *)hdr + hdr->e_phoff);
958 
959 		for (i = 0; i < hdr->e_phnum; i++) {
960 			if (phdr->p_type == PT_LOAD) {
961 				memcpy((void *)phdr->p_paddr,
962 				       (char *)hdr + phdr->p_offset,
963 				       phdr->p_filesz);
964 				memset((void *)phdr->p_paddr + phdr->p_filesz,
965 				       0, phdr->p_memsz - phdr->p_filesz);
966 		    }
967 		    phdr++;
968 		}
969 
970 		for (i = 0; i < hdr->e_shnum; i++) {
971  			/* Internal symbols and strings. */
972  			if (sechdrs[i].sh_type == SHT_SYMTAB) {
973  				symindex = i;
974  				strindex = sechdrs[i].sh_link;
975  				strtab = (char *)hdr + sechdrs[strindex].sh_offset;
976 
977  				/* mark the symtab's address for when we try to find the
978  				   magic symbols */
979  				sechdrs[i].sh_addr = (size_t) hdr + sechdrs[i].sh_offset;
980  			}
981 		}
982 	}
983 
984 	/* make sure it's physically written out */
985 	flush_icache_range((unsigned long)v->load_addr,
986 			   (unsigned long)v->load_addr + v->len);
987 
988 	if ((find_vpe_symbols(v, sechdrs, symindex, strtab, &mod)) < 0) {
989 		if (v->__start == 0) {
990 			printk(KERN_WARNING "VPE loader: program does not contain "
991 			       "a __start symbol\n");
992 			return -ENOEXEC;
993 		}
994 
995 		if (v->shared_ptr == NULL)
996 			printk(KERN_WARNING "VPE loader: "
997 			       "program does not contain vpe_shared symbol.\n"
998 			       " Unable to use AMVP (AP/SP) facilities.\n");
999 	}
1000 
1001 	printk(" elf loaded\n");
1002 	return 0;
1003 }
1004 
1005 static void cleanup_tc(struct tc *tc)
1006 {
1007 	unsigned long flags;
1008 	unsigned int mtflags, vpflags;
1009 	int tmp;
1010 
1011 	local_irq_save(flags);
1012 	mtflags = dmt();
1013 	vpflags = dvpe();
1014 	/* Put MVPE's into 'configuration state' */
1015 	set_c0_mvpcontrol(MVPCONTROL_VPC);
1016 
1017 	settc(tc->index);
1018 	tmp = read_tc_c0_tcstatus();
1019 
1020 	/* mark not allocated and not dynamically allocatable */
1021 	tmp &= ~(TCSTATUS_A | TCSTATUS_DA);
1022 	tmp |= TCSTATUS_IXMT;	/* interrupt exempt */
1023 	write_tc_c0_tcstatus(tmp);
1024 
1025 	write_tc_c0_tchalt(TCHALT_H);
1026 	mips_ihb();
1027 
1028 	/* bind it to anything other than VPE1 */
1029 //	write_tc_c0_tcbind(read_tc_c0_tcbind() & ~TCBIND_CURVPE); // | TCBIND_CURVPE
1030 
1031 	clear_c0_mvpcontrol(MVPCONTROL_VPC);
1032 	evpe(vpflags);
1033 	emt(mtflags);
1034 	local_irq_restore(flags);
1035 }
1036 
1037 static int getcwd(char *buff, int size)
1038 {
1039 	mm_segment_t old_fs;
1040 	int ret;
1041 
1042 	old_fs = get_fs();
1043 	set_fs(KERNEL_DS);
1044 
1045 	ret = sys_getcwd(buff, size);
1046 
1047 	set_fs(old_fs);
1048 
1049 	return ret;
1050 }
1051 
1052 /* checks VPE is unused and gets ready to load program  */
1053 static int vpe_open(struct inode *inode, struct file *filp)
1054 {
1055 	enum vpe_state state;
1056 	struct vpe_notifications *not;
1057 	struct vpe *v;
1058 	int ret;
1059 
1060 	if (minor != iminor(inode)) {
1061 		/* assume only 1 device at the moment. */
1062 		pr_warning("VPE loader: only vpe1 is supported\n");
1063 
1064 		return -ENODEV;
1065 	}
1066 
1067 	if ((v = get_vpe(tclimit)) == NULL) {
1068 		pr_warning("VPE loader: unable to get vpe\n");
1069 
1070 		return -ENODEV;
1071 	}
1072 
1073 	state = xchg(&v->state, VPE_STATE_INUSE);
1074 	if (state != VPE_STATE_UNUSED) {
1075 		printk(KERN_DEBUG "VPE loader: tc in use dumping regs\n");
1076 
1077 		list_for_each_entry(not, &v->notify, list) {
1078 			not->stop(tclimit);
1079 		}
1080 
1081 		release_progmem(v->load_addr);
1082 		cleanup_tc(get_tc(tclimit));
1083 	}
1084 
1085 	/* this of-course trashes what was there before... */
1086 	v->pbuffer = vmalloc(P_SIZE);
1087 	if (!v->pbuffer) {
1088 		pr_warning("VPE loader: unable to allocate memory\n");
1089 		return -ENOMEM;
1090 	}
1091 	v->plen = P_SIZE;
1092 	v->load_addr = NULL;
1093 	v->len = 0;
1094 
1095 	v->uid = filp->f_cred->fsuid;
1096 	v->gid = filp->f_cred->fsgid;
1097 
1098 	v->cwd[0] = 0;
1099 	ret = getcwd(v->cwd, VPE_PATH_MAX);
1100 	if (ret < 0)
1101 		printk(KERN_WARNING "VPE loader: open, getcwd returned %d\n", ret);
1102 
1103 	v->shared_ptr = NULL;
1104 	v->__start = 0;
1105 
1106 	return 0;
1107 }
1108 
1109 static int vpe_release(struct inode *inode, struct file *filp)
1110 {
1111 	struct vpe *v;
1112 	Elf_Ehdr *hdr;
1113 	int ret = 0;
1114 
1115 	v = get_vpe(tclimit);
1116 	if (v == NULL)
1117 		return -ENODEV;
1118 
1119 	hdr = (Elf_Ehdr *) v->pbuffer;
1120 	if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) == 0) {
1121 		if (vpe_elfload(v) >= 0) {
1122 			vpe_run(v);
1123 		} else {
1124  			printk(KERN_WARNING "VPE loader: ELF load failed.\n");
1125 			ret = -ENOEXEC;
1126 		}
1127 	} else {
1128  		printk(KERN_WARNING "VPE loader: only elf files are supported\n");
1129 		ret = -ENOEXEC;
1130 	}
1131 
1132 	/* It's good to be able to run the SP and if it chokes have a look at
1133 	   the /dev/rt?. But if we reset the pointer to the shared struct we
1134 	   lose what has happened. So perhaps if garbage is sent to the vpe
1135 	   device, use it as a trigger for the reset. Hopefully a nice
1136 	   executable will be along shortly. */
1137 	if (ret < 0)
1138 		v->shared_ptr = NULL;
1139 
1140 	vfree(v->pbuffer);
1141 	v->plen = 0;
1142 
1143 	return ret;
1144 }
1145 
1146 static ssize_t vpe_write(struct file *file, const char __user * buffer,
1147 			 size_t count, loff_t * ppos)
1148 {
1149 	size_t ret = count;
1150 	struct vpe *v;
1151 
1152 	if (iminor(file->f_path.dentry->d_inode) != minor)
1153 		return -ENODEV;
1154 
1155 	v = get_vpe(tclimit);
1156 	if (v == NULL)
1157 		return -ENODEV;
1158 
1159 	if ((count + v->len) > v->plen) {
1160 		printk(KERN_WARNING
1161 		       "VPE loader: elf size too big. Perhaps strip uneeded symbols\n");
1162 		return -ENOMEM;
1163 	}
1164 
1165 	count -= copy_from_user(v->pbuffer + v->len, buffer, count);
1166 	if (!count)
1167 		return -EFAULT;
1168 
1169 	v->len += count;
1170 	return ret;
1171 }
1172 
1173 static const struct file_operations vpe_fops = {
1174 	.owner = THIS_MODULE,
1175 	.open = vpe_open,
1176 	.release = vpe_release,
1177 	.write = vpe_write,
1178 	.llseek = noop_llseek,
1179 };
1180 
1181 /* module wrapper entry points */
1182 /* give me a vpe */
1183 vpe_handle vpe_alloc(void)
1184 {
1185 	int i;
1186 	struct vpe *v;
1187 
1188 	/* find a vpe */
1189 	for (i = 1; i < MAX_VPES; i++) {
1190 		if ((v = get_vpe(i)) != NULL) {
1191 			v->state = VPE_STATE_INUSE;
1192 			return v;
1193 		}
1194 	}
1195 	return NULL;
1196 }
1197 
1198 EXPORT_SYMBOL(vpe_alloc);
1199 
1200 /* start running from here */
1201 int vpe_start(vpe_handle vpe, unsigned long start)
1202 {
1203 	struct vpe *v = vpe;
1204 
1205 	v->__start = start;
1206 	return vpe_run(v);
1207 }
1208 
1209 EXPORT_SYMBOL(vpe_start);
1210 
1211 /* halt it for now */
1212 int vpe_stop(vpe_handle vpe)
1213 {
1214 	struct vpe *v = vpe;
1215 	struct tc *t;
1216 	unsigned int evpe_flags;
1217 
1218 	evpe_flags = dvpe();
1219 
1220 	if ((t = list_entry(v->tc.next, struct tc, tc)) != NULL) {
1221 
1222 		settc(t->index);
1223 		write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() & ~VPECONF0_VPA);
1224 	}
1225 
1226 	evpe(evpe_flags);
1227 
1228 	return 0;
1229 }
1230 
1231 EXPORT_SYMBOL(vpe_stop);
1232 
1233 /* I've done with it thank you */
1234 int vpe_free(vpe_handle vpe)
1235 {
1236 	struct vpe *v = vpe;
1237 	struct tc *t;
1238 	unsigned int evpe_flags;
1239 
1240 	if ((t = list_entry(v->tc.next, struct tc, tc)) == NULL) {
1241 		return -ENOEXEC;
1242 	}
1243 
1244 	evpe_flags = dvpe();
1245 
1246 	/* Put MVPE's into 'configuration state' */
1247 	set_c0_mvpcontrol(MVPCONTROL_VPC);
1248 
1249 	settc(t->index);
1250 	write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() & ~VPECONF0_VPA);
1251 
1252 	/* halt the TC */
1253 	write_tc_c0_tchalt(TCHALT_H);
1254 	mips_ihb();
1255 
1256 	/* mark the TC unallocated */
1257 	write_tc_c0_tcstatus(read_tc_c0_tcstatus() & ~TCSTATUS_A);
1258 
1259 	v->state = VPE_STATE_UNUSED;
1260 
1261 	clear_c0_mvpcontrol(MVPCONTROL_VPC);
1262 	evpe(evpe_flags);
1263 
1264 	return 0;
1265 }
1266 
1267 EXPORT_SYMBOL(vpe_free);
1268 
1269 void *vpe_get_shared(int index)
1270 {
1271 	struct vpe *v;
1272 
1273 	if ((v = get_vpe(index)) == NULL)
1274 		return NULL;
1275 
1276 	return v->shared_ptr;
1277 }
1278 
1279 EXPORT_SYMBOL(vpe_get_shared);
1280 
1281 int vpe_getuid(int index)
1282 {
1283 	struct vpe *v;
1284 
1285 	if ((v = get_vpe(index)) == NULL)
1286 		return -1;
1287 
1288 	return v->uid;
1289 }
1290 
1291 EXPORT_SYMBOL(vpe_getuid);
1292 
1293 int vpe_getgid(int index)
1294 {
1295 	struct vpe *v;
1296 
1297 	if ((v = get_vpe(index)) == NULL)
1298 		return -1;
1299 
1300 	return v->gid;
1301 }
1302 
1303 EXPORT_SYMBOL(vpe_getgid);
1304 
1305 int vpe_notify(int index, struct vpe_notifications *notify)
1306 {
1307 	struct vpe *v;
1308 
1309 	if ((v = get_vpe(index)) == NULL)
1310 		return -1;
1311 
1312 	list_add(&notify->list, &v->notify);
1313 	return 0;
1314 }
1315 
1316 EXPORT_SYMBOL(vpe_notify);
1317 
1318 char *vpe_getcwd(int index)
1319 {
1320 	struct vpe *v;
1321 
1322 	if ((v = get_vpe(index)) == NULL)
1323 		return NULL;
1324 
1325 	return v->cwd;
1326 }
1327 
1328 EXPORT_SYMBOL(vpe_getcwd);
1329 
1330 static ssize_t store_kill(struct device *dev, struct device_attribute *attr,
1331 			  const char *buf, size_t len)
1332 {
1333 	struct vpe *vpe = get_vpe(tclimit);
1334 	struct vpe_notifications *not;
1335 
1336 	list_for_each_entry(not, &vpe->notify, list) {
1337 		not->stop(tclimit);
1338 	}
1339 
1340 	release_progmem(vpe->load_addr);
1341 	cleanup_tc(get_tc(tclimit));
1342 	vpe_stop(vpe);
1343 	vpe_free(vpe);
1344 
1345 	return len;
1346 }
1347 
1348 static ssize_t show_ntcs(struct device *cd, struct device_attribute *attr,
1349 			 char *buf)
1350 {
1351 	struct vpe *vpe = get_vpe(tclimit);
1352 
1353 	return sprintf(buf, "%d\n", vpe->ntcs);
1354 }
1355 
1356 static ssize_t store_ntcs(struct device *dev, struct device_attribute *attr,
1357 			  const char *buf, size_t len)
1358 {
1359 	struct vpe *vpe = get_vpe(tclimit);
1360 	unsigned long new;
1361 	char *endp;
1362 
1363 	new = simple_strtoul(buf, &endp, 0);
1364 	if (endp == buf)
1365 		goto out_einval;
1366 
1367 	if (new == 0 || new > (hw_tcs - tclimit))
1368 		goto out_einval;
1369 
1370 	vpe->ntcs = new;
1371 
1372 	return len;
1373 
1374 out_einval:
1375 	return -EINVAL;
1376 }
1377 
1378 static struct device_attribute vpe_class_attributes[] = {
1379 	__ATTR(kill, S_IWUSR, NULL, store_kill),
1380 	__ATTR(ntcs, S_IRUGO | S_IWUSR, show_ntcs, store_ntcs),
1381 	{}
1382 };
1383 
1384 static void vpe_device_release(struct device *cd)
1385 {
1386 	kfree(cd);
1387 }
1388 
1389 struct class vpe_class = {
1390 	.name = "vpe",
1391 	.owner = THIS_MODULE,
1392 	.dev_release = vpe_device_release,
1393 	.dev_attrs = vpe_class_attributes,
1394 };
1395 
1396 struct device vpe_device;
1397 
1398 static int __init vpe_module_init(void)
1399 {
1400 	unsigned int mtflags, vpflags;
1401 	unsigned long flags, val;
1402 	struct vpe *v = NULL;
1403 	struct tc *t;
1404 	int tc, err;
1405 
1406 	if (!cpu_has_mipsmt) {
1407 		printk("VPE loader: not a MIPS MT capable processor\n");
1408 		return -ENODEV;
1409 	}
1410 
1411 	if (vpelimit == 0) {
1412 		printk(KERN_WARNING "No VPEs reserved for AP/SP, not "
1413 		       "initializing VPE loader.\nPass maxvpes=<n> argument as "
1414 		       "kernel argument\n");
1415 
1416 		return -ENODEV;
1417 	}
1418 
1419 	if (tclimit == 0) {
1420 		printk(KERN_WARNING "No TCs reserved for AP/SP, not "
1421 		       "initializing VPE loader.\nPass maxtcs=<n> argument as "
1422 		       "kernel argument\n");
1423 
1424 		return -ENODEV;
1425 	}
1426 
1427 	major = register_chrdev(0, module_name, &vpe_fops);
1428 	if (major < 0) {
1429 		printk("VPE loader: unable to register character device\n");
1430 		return major;
1431 	}
1432 
1433 	err = class_register(&vpe_class);
1434 	if (err) {
1435 		printk(KERN_ERR "vpe_class registration failed\n");
1436 		goto out_chrdev;
1437 	}
1438 
1439 	device_initialize(&vpe_device);
1440 	vpe_device.class	= &vpe_class,
1441 	vpe_device.parent	= NULL,
1442 	dev_set_name(&vpe_device, "vpe1");
1443 	vpe_device.devt = MKDEV(major, minor);
1444 	err = device_add(&vpe_device);
1445 	if (err) {
1446 		printk(KERN_ERR "Adding vpe_device failed\n");
1447 		goto out_class;
1448 	}
1449 
1450 	local_irq_save(flags);
1451 	mtflags = dmt();
1452 	vpflags = dvpe();
1453 
1454 	/* Put MVPE's into 'configuration state' */
1455 	set_c0_mvpcontrol(MVPCONTROL_VPC);
1456 
1457 	/* dump_mtregs(); */
1458 
1459 	val = read_c0_mvpconf0();
1460 	hw_tcs = (val & MVPCONF0_PTC) + 1;
1461 	hw_vpes = ((val & MVPCONF0_PVPE) >> MVPCONF0_PVPE_SHIFT) + 1;
1462 
1463 	for (tc = tclimit; tc < hw_tcs; tc++) {
1464 		/*
1465 		 * Must re-enable multithreading temporarily or in case we
1466 		 * reschedule send IPIs or similar we might hang.
1467 		 */
1468 		clear_c0_mvpcontrol(MVPCONTROL_VPC);
1469 		evpe(vpflags);
1470 		emt(mtflags);
1471 		local_irq_restore(flags);
1472 		t = alloc_tc(tc);
1473 		if (!t) {
1474 			err = -ENOMEM;
1475 			goto out;
1476 		}
1477 
1478 		local_irq_save(flags);
1479 		mtflags = dmt();
1480 		vpflags = dvpe();
1481 		set_c0_mvpcontrol(MVPCONTROL_VPC);
1482 
1483 		/* VPE's */
1484 		if (tc < hw_tcs) {
1485 			settc(tc);
1486 
1487 			if ((v = alloc_vpe(tc)) == NULL) {
1488 				printk(KERN_WARNING "VPE: unable to allocate VPE\n");
1489 
1490 				goto out_reenable;
1491 			}
1492 
1493 			v->ntcs = hw_tcs - tclimit;
1494 
1495 			/* add the tc to the list of this vpe's tc's. */
1496 			list_add(&t->tc, &v->tc);
1497 
1498 			/* deactivate all but vpe0 */
1499 			if (tc >= tclimit) {
1500 				unsigned long tmp = read_vpe_c0_vpeconf0();
1501 
1502 				tmp &= ~VPECONF0_VPA;
1503 
1504 				/* master VPE */
1505 				tmp |= VPECONF0_MVP;
1506 				write_vpe_c0_vpeconf0(tmp);
1507 			}
1508 
1509 			/* disable multi-threading with TC's */
1510 			write_vpe_c0_vpecontrol(read_vpe_c0_vpecontrol() & ~VPECONTROL_TE);
1511 
1512 			if (tc >= vpelimit) {
1513 				/*
1514 				 * Set config to be the same as vpe0,
1515 				 * particularly kseg0 coherency alg
1516 				 */
1517 				write_vpe_c0_config(read_c0_config());
1518 			}
1519 		}
1520 
1521 		/* TC's */
1522 		t->pvpe = v;	/* set the parent vpe */
1523 
1524 		if (tc >= tclimit) {
1525 			unsigned long tmp;
1526 
1527 			settc(tc);
1528 
1529 			/* Any TC that is bound to VPE0 gets left as is - in case
1530 			   we are running SMTC on VPE0. A TC that is bound to any
1531 			   other VPE gets bound to VPE0, ideally I'd like to make
1532 			   it homeless but it doesn't appear to let me bind a TC
1533 			   to a non-existent VPE. Which is perfectly reasonable.
1534 
1535 			   The (un)bound state is visible to an EJTAG probe so may
1536 			   notify GDB...
1537 			*/
1538 
1539 			if (((tmp = read_tc_c0_tcbind()) & TCBIND_CURVPE)) {
1540 				/* tc is bound >vpe0 */
1541 				write_tc_c0_tcbind(tmp & ~TCBIND_CURVPE);
1542 
1543 				t->pvpe = get_vpe(0);	/* set the parent vpe */
1544 			}
1545 
1546 			/* halt the TC */
1547 			write_tc_c0_tchalt(TCHALT_H);
1548 			mips_ihb();
1549 
1550 			tmp = read_tc_c0_tcstatus();
1551 
1552 			/* mark not activated and not dynamically allocatable */
1553 			tmp &= ~(TCSTATUS_A | TCSTATUS_DA);
1554 			tmp |= TCSTATUS_IXMT;	/* interrupt exempt */
1555 			write_tc_c0_tcstatus(tmp);
1556 		}
1557 	}
1558 
1559 out_reenable:
1560 	/* release config state */
1561 	clear_c0_mvpcontrol(MVPCONTROL_VPC);
1562 
1563 	evpe(vpflags);
1564 	emt(mtflags);
1565 	local_irq_restore(flags);
1566 
1567 	return 0;
1568 
1569 out_class:
1570 	class_unregister(&vpe_class);
1571 out_chrdev:
1572 	unregister_chrdev(major, module_name);
1573 
1574 out:
1575 	return err;
1576 }
1577 
1578 static void __exit vpe_module_exit(void)
1579 {
1580 	struct vpe *v, *n;
1581 
1582 	device_del(&vpe_device);
1583 	unregister_chrdev(major, module_name);
1584 
1585 	/* No locking needed here */
1586 	list_for_each_entry_safe(v, n, &vpecontrol.vpe_list, list) {
1587 		if (v->state != VPE_STATE_UNUSED)
1588 			release_vpe(v);
1589 	}
1590 }
1591 
1592 module_init(vpe_module_init);
1593 module_exit(vpe_module_exit);
1594 MODULE_DESCRIPTION("MIPS VPE Loader");
1595 MODULE_AUTHOR("Elizabeth Oldham, MIPS Technologies, Inc.");
1596 MODULE_LICENSE("GPL");
1597