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Linux/arch/mips/kernel/vpe.c

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  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 

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