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move die notifier handling to common code
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / sparc / mm / fault.c
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1da177e4
LT		 1/* $Id: fault.c,v 1.122 2001/11/17 07:19:26 davem Exp $
2 * fault.c: Page fault handlers for the Sparc.
3 *
4 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
5 * Copyright (C) 1996 Eddie C. Dost (ecd@skynet.be)
6 * Copyright (C) 1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
7 */
8
9#include <asm/head.h>
10
11#include <linux/string.h>
12#include <linux/types.h>
13#include <linux/sched.h>
14#include <linux/ptrace.h>
15#include <linux/mman.h>
16#include <linux/threads.h>
17#include <linux/kernel.h>
18#include <linux/signal.h>
19#include <linux/mm.h>
20#include <linux/smp.h>
21#include <linux/smp_lock.h>
22#include <linux/interrupt.h>
23#include <linux/module.h>
1eeb66a1 24#include <linux/kdebug.h>
1da177e4
LT		 25
26#include <asm/system.h>
1da177e4
LT		 27#include <asm/page.h>
28#include <asm/pgtable.h>
29#include <asm/memreg.h>
30#include <asm/openprom.h>
31#include <asm/oplib.h>
32#include <asm/smp.h>
33#include <asm/traps.h>
1da177e4
LT		 34#include <asm/uaccess.h>
35
1da177e4
LT		 36extern int prom_node_root;
37
38/* At boot time we determine these two values necessary for setting
39 * up the segment maps and page table entries (pte's).
40 */
41
42int num_segmaps, num_contexts;
43int invalid_segment;
44
45/* various Virtual Address Cache parameters we find at boot time... */
46
47int vac_size, vac_linesize, vac_do_hw_vac_flushes;
48int vac_entries_per_context, vac_entries_per_segment;
49int vac_entries_per_page;
50
51/* Nice, simple, prom library does all the sweating for us. ;) */
52int prom_probe_memory (void)
53{
54 register struct linux_mlist_v0 *mlist;
55 register unsigned long bytes, base_paddr, tally;
56 register int i;
57
58 i = 0;
59 mlist= *prom_meminfo()->v0_available;
60 bytes = tally = mlist->num_bytes;
61 base_paddr = (unsigned long) mlist->start_adr;
62
63 sp_banks[0].base_addr = base_paddr;
64 sp_banks[0].num_bytes = bytes;
65
66 while (mlist->theres_more != (void *) 0){
67 i++;
68 mlist = mlist->theres_more;
69 bytes = mlist->num_bytes;
70 tally += bytes;
71 if (i > SPARC_PHYS_BANKS-1) {
72 printk ("The machine has more banks than "
73 "this kernel can support\n"
74 "Increase the SPARC_PHYS_BANKS "
75 "setting (currently %d)\n",
76 SPARC_PHYS_BANKS);
77 i = SPARC_PHYS_BANKS-1;
78 break;
79 }
80
81 sp_banks[i].base_addr = (unsigned long) mlist->start_adr;
82 sp_banks[i].num_bytes = mlist->num_bytes;
83 }
84
85 i++;
86 sp_banks[i].base_addr = 0xdeadbeef;
87 sp_banks[i].num_bytes = 0;
88
89 /* Now mask all bank sizes on a page boundary, it is all we can
90 * use anyways.
91 */
92 for(i=0; sp_banks[i].num_bytes != 0; i++)
93 sp_banks[i].num_bytes &= PAGE_MASK;
94
95 return tally;
96}
97
98/* Traverse the memory lists in the prom to see how much physical we
99 * have.
100 */
101unsigned long
102probe_memory(void)
103{
104 int total;
105
106 total = prom_probe_memory();
107
108 /* Oh man, much nicer, keep the dirt in promlib. */
109 return total;
110}
111
112extern void sun4c_complete_all_stores(void);
113
114/* Whee, a level 15 NMI interrupt memory error. Let's have fun... */
115asmlinkage void sparc_lvl15_nmi(struct pt_regs *regs, unsigned long serr,
116 unsigned long svaddr, unsigned long aerr,
117 unsigned long avaddr)
118{
119 sun4c_complete_all_stores();
120 printk("FAULT: NMI received\n");
121 printk("SREGS: Synchronous Error %08lx\n", serr);
122 printk(" Synchronous Vaddr %08lx\n", svaddr);
123 printk(" Asynchronous Error %08lx\n", aerr);
124 printk(" Asynchronous Vaddr %08lx\n", avaddr);
125 if (sun4c_memerr_reg)
126 printk(" Memory Parity Error %08lx\n", *sun4c_memerr_reg);
127 printk("REGISTER DUMP:\n");
128 show_regs(regs);
129 prom_halt();
130}
131
132static void unhandled_fault(unsigned long, struct task_struct *,
133 struct pt_regs *) __attribute__ ((noreturn));
134
135static void unhandled_fault(unsigned long address, struct task_struct *tsk,
136 struct pt_regs *regs)
137{
138 if((unsigned long) address < PAGE_SIZE) {
139 printk(KERN_ALERT
140 "Unable to handle kernel NULL pointer dereference\n");
141 } else {
142 printk(KERN_ALERT "Unable to handle kernel paging request "
143 "at virtual address %08lx\n", address);
144 }
145 printk(KERN_ALERT "tsk->{mm,active_mm}->context = %08lx\n",
146 (tsk->mm ? tsk->mm->context : tsk->active_mm->context));
147 printk(KERN_ALERT "tsk->{mm,active_mm}->pgd = %08lx\n",
148 (tsk->mm ? (unsigned long) tsk->mm->pgd :
149 (unsigned long) tsk->active_mm->pgd));
150 die_if_kernel("Oops", regs);
151}
152
153asmlinkage int lookup_fault(unsigned long pc, unsigned long ret_pc,
154 unsigned long address)
155{
156 struct pt_regs regs;
157 unsigned long g2;
158 unsigned int insn;
159 int i;
160
161 i = search_extables_range(ret_pc, &g2);
162 switch (i) {
163 case 3:
164 /* load & store will be handled by fixup */
165 return 3;
166
167 case 1:
168 /* store will be handled by fixup, load will bump out */
169 /* for _to_ macros */
170 insn = *((unsigned int *) pc);
171 if ((insn >> 21) & 1)
172 return 1;
173 break;
174
175 case 2:
176 /* load will be handled by fixup, store will bump out */
177 /* for _from_ macros */
178 insn = *((unsigned int *) pc);
179 if (!((insn >> 21) & 1) || ((insn>>19)&0x3f) == 15)
180 return 2;
181 break;
182
183 default:
184 break;
185 };
186
187 memset(&regs, 0, sizeof (regs));
188 regs.pc = pc;
189 regs.npc = pc + 4;
190 __asm__ __volatile__(
191 "rd %%psr, %0\n\t"
192 "nop\n\t"
193 "nop\n\t"
194 "nop\n" : "=r" (regs.psr));
195 unhandled_fault(address, current, &regs);
196
197 /* Not reached */
198 return 0;
199}
200
201extern unsigned long safe_compute_effective_address(struct pt_regs *,
202 unsigned int);
203
204static unsigned long compute_si_addr(struct pt_regs *regs, int text_fault)
205{
206 unsigned int insn;
207
208 if (text_fault)
209 return regs->pc;
210
211 if (regs->psr & PSR_PS) {
212 insn = *(unsigned int *) regs->pc;
213 } else {
214 __get_user(insn, (unsigned int *) regs->pc);
215 }
216
217 return safe_compute_effective_address(regs, insn);
218}
219
220asmlinkage void do_sparc_fault(struct pt_regs *regs, int text_fault, int write,
221 unsigned long address)
222{
223 struct vm_area_struct *vma;
224 struct task_struct *tsk = current;
225 struct mm_struct *mm = tsk->mm;
226 unsigned int fixup;
227 unsigned long g2;
228 siginfo_t info;
229 int from_user = !(regs->psr & PSR_PS);
230
231 if(text_fault)
232 address = regs->pc;
233
234 /*
235 * We fault-in kernel-space virtual memory on-demand. The
236 * 'reference' page table is init_mm.pgd.
237 *
238 * NOTE! We MUST NOT take any locks for this case. We may
239 * be in an interrupt or a critical region, and should
240 * only copy the information from the master page table,
241 * nothing more.
242 */
243 if (!ARCH_SUN4C_SUN4 && address >= TASK_SIZE)
244 goto vmalloc_fault;
245
246 info.si_code = SEGV_MAPERR;
247
248 /*
249 * If we're in an interrupt or have no user
250 * context, we must not take the fault..
251 */
252 if (in_atomic() || !mm)
253 goto no_context;
254
255 down_read(&mm->mmap_sem);
256
257 /*
258 * The kernel referencing a bad kernel pointer can lock up
259 * a sun4c machine completely, so we must attempt recovery.
260 */
261 if(!from_user && address >= PAGE_OFFSET)
262 goto bad_area;
263
264 vma = find_vma(mm, address);
265 if(!vma)
266 goto bad_area;
267 if(vma->vm_start <= address)
268 goto good_area;
269 if(!(vma->vm_flags & VM_GROWSDOWN))
270 goto bad_area;
271 if(expand_stack(vma, address))
272 goto bad_area;
273 /*
274 * Ok, we have a good vm_area for this memory access, so
275 * we can handle it..
276 */
277good_area:
278 info.si_code = SEGV_ACCERR;
279 if(write) {
280 if(!(vma->vm_flags & VM_WRITE))
281 goto bad_area;
282 } else {
283 /* Allow reads even for write-only mappings */
284 if(!(vma->vm_flags & (VM_READ | VM_EXEC)))
285 goto bad_area;
286 }
287
288 /*
289 * If for any reason at all we couldn't handle the fault,
290 * make sure we exit gracefully rather than endlessly redo
291 * the fault.
292 */
293 switch (handle_mm_fault(mm, vma, address, write)) {
294 case VM_FAULT_SIGBUS:
295 goto do_sigbus;
296 case VM_FAULT_OOM:
297 goto out_of_memory;
298 case VM_FAULT_MAJOR:
299 current->maj_flt++;
300 break;
301 case VM_FAULT_MINOR:
302 default:
303 current->min_flt++;
304 break;
305 }
306 up_read(&mm->mmap_sem);
307 return;
308
309 /*
310 * Something tried to access memory that isn't in our memory map..
311 * Fix it, but check if it's kernel or user first..
312 */
313bad_area:
314 up_read(&mm->mmap_sem);
315
316bad_area_nosemaphore:
317 /* User mode accesses just cause a SIGSEGV */
318 if(from_user) {
319#if 0
320 printk("Fault whee %s [%d]: segfaults at %08lx pc=%08lx\n",
321 tsk->comm, tsk->pid, address, regs->pc);
322#endif
323 info.si_signo = SIGSEGV;
324 info.si_errno = 0;
325 /* info.si_code set above to make clear whether
326 this was a SEGV_MAPERR or SEGV_ACCERR fault. */
327 info.si_addr = (void __user *)compute_si_addr(regs, text_fault);
328 info.si_trapno = 0;
329 force_sig_info (SIGSEGV, &info, tsk);
330 return;
331 }
332
333 /* Is this in ex_table? */
334no_context:
335 g2 = regs->u_regs[UREG_G2];
336 if (!from_user && (fixup = search_extables_range(regs->pc, &g2))) {
337 if (fixup > 10) { /* Values below are reserved for other things */
338 extern const unsigned __memset_start[];
339 extern const unsigned __memset_end[];
340 extern const unsigned __csum_partial_copy_start[];
341 extern const unsigned __csum_partial_copy_end[];
342
343#ifdef DEBUG_EXCEPTIONS
344 printk("Exception: PC<%08lx> faddr<%08lx>\n", regs->pc, address);
345 printk("EX_TABLE: insn<%08lx> fixup<%08x> g2<%08lx>\n",
346 regs->pc, fixup, g2);
347#endif
348 if ((regs->pc >= (unsigned long)__memset_start &&
349 regs->pc < (unsigned long)__memset_end) ||
350 (regs->pc >= (unsigned long)__csum_partial_copy_start &&
351 regs->pc < (unsigned long)__csum_partial_copy_end)) {
352 regs->u_regs[UREG_I4] = address;
353 regs->u_regs[UREG_I5] = regs->pc;
354 }
355 regs->u_regs[UREG_G2] = g2;
356 regs->pc = fixup;
357 regs->npc = regs->pc + 4;
358 return;
359 }
360 }
361
362 unhandled_fault (address, tsk, regs);
363 do_exit(SIGKILL);
364
365/*
366 * We ran out of memory, or some other thing happened to us that made
367 * us unable to handle the page fault gracefully.
368 */
369out_of_memory:
370 up_read(&mm->mmap_sem);
371 printk("VM: killing process %s\n", tsk->comm);
372 if (from_user)
373 do_exit(SIGKILL);
374 goto no_context;
375
376do_sigbus:
377 up_read(&mm->mmap_sem);
378 info.si_signo = SIGBUS;
379 info.si_errno = 0;
380 info.si_code = BUS_ADRERR;
381 info.si_addr = (void __user *) compute_si_addr(regs, text_fault);
382 info.si_trapno = 0;
383 force_sig_info (SIGBUS, &info, tsk);
384 if (!from_user)
385 goto no_context;
386
387vmalloc_fault:
388 {
389 /*
390 * Synchronize this task's top level page-table
391 * with the 'reference' page table.
392 */
393 int offset = pgd_index(address);
394 pgd_t *pgd, *pgd_k;
395 pmd_t *pmd, *pmd_k;
396
397 pgd = tsk->active_mm->pgd + offset;
398 pgd_k = init_mm.pgd + offset;
399
400 if (!pgd_present(*pgd)) {
401 if (!pgd_present(*pgd_k))
402 goto bad_area_nosemaphore;
403 pgd_val(*pgd) = pgd_val(*pgd_k);
404 return;
405 }
406
407 pmd = pmd_offset(pgd, address);
408 pmd_k = pmd_offset(pgd_k, address);
409
410 if (pmd_present(*pmd) || !pmd_present(*pmd_k))
411 goto bad_area_nosemaphore;
412 *pmd = *pmd_k;
413 return;
414 }
415}
416
417asmlinkage void do_sun4c_fault(struct pt_regs *regs, int text_fault, int write,
418 unsigned long address)
419{
420 extern void sun4c_update_mmu_cache(struct vm_area_struct *,
421 unsigned long,pte_t);
422 extern pte_t *sun4c_pte_offset_kernel(pmd_t *,unsigned long);
423 struct task_struct *tsk = current;
424 struct mm_struct *mm = tsk->mm;
425 pgd_t *pgdp;
426 pte_t *ptep;
427
428 if (text_fault) {
429 address = regs->pc;
430 } else if (!write &&
431 !(regs->psr & PSR_PS)) {
432 unsigned int insn, __user *ip;
433
434 ip = (unsigned int __user *)regs->pc;
435 if (!get_user(insn, ip)) {
436 if ((insn & 0xc1680000) == 0xc0680000)
437 write = 1;
438 }
439 }
440
441 if (!mm) {
442 /* We are oopsing. */
443 do_sparc_fault(regs, text_fault, write, address);
444 BUG(); /* P3 Oops already, you bitch */
445 }
446
447 pgdp = pgd_offset(mm, address);
448 ptep = sun4c_pte_offset_kernel((pmd_t *) pgdp, address);
449
450 if (pgd_val(*pgdp)) {
451 if (write) {
452 if ((pte_val(*ptep) & (_SUN4C_PAGE_WRITE|_SUN4C_PAGE_PRESENT))
453 == (_SUN4C_PAGE_WRITE|_SUN4C_PAGE_PRESENT)) {
454 unsigned long flags;
455
456 *ptep = __pte(pte_val(*ptep) | _SUN4C_PAGE_ACCESSED |
457 _SUN4C_PAGE_MODIFIED |
458 _SUN4C_PAGE_VALID |
459 _SUN4C_PAGE_DIRTY);
460
461 local_irq_save(flags);
462 if (sun4c_get_segmap(address) != invalid_segment) {
463 sun4c_put_pte(address, pte_val(*ptep));
464 local_irq_restore(flags);
465 return;
466 }
467 local_irq_restore(flags);
468 }
469 } else {
470 if ((pte_val(*ptep) & (_SUN4C_PAGE_READ|_SUN4C_PAGE_PRESENT))
471 == (_SUN4C_PAGE_READ|_SUN4C_PAGE_PRESENT)) {
472 unsigned long flags;
473
474 *ptep = __pte(pte_val(*ptep) | _SUN4C_PAGE_ACCESSED |
475 _SUN4C_PAGE_VALID);
476
477 local_irq_save(flags);
478 if (sun4c_get_segmap(address) != invalid_segment) {
479 sun4c_put_pte(address, pte_val(*ptep));
480 local_irq_restore(flags);
481 return;
482 }
483 local_irq_restore(flags);
484 }
485 }
486 }
487
488 /* This conditional is 'interesting'. */
489 if (pgd_val(*pgdp) && !(write && !(pte_val(*ptep) & _SUN4C_PAGE_WRITE))
490 && (pte_val(*ptep) & _SUN4C_PAGE_VALID))
491 /* Note: It is safe to not grab the MMAP semaphore here because
492 * we know that update_mmu_cache() will not sleep for
493 * any reason (at least not in the current implementation)
494 * and therefore there is no danger of another thread getting
495 * on the CPU and doing a shrink_mmap() on this vma.
496 */
497 sun4c_update_mmu_cache (find_vma(current->mm, address), address,
498 *ptep);
499 else
500 do_sparc_fault(regs, text_fault, write, address);
501}
502
503/* This always deals with user addresses. */
504inline void force_user_fault(unsigned long address, int write)
505{
506 struct vm_area_struct *vma;
507 struct task_struct *tsk = current;
508 struct mm_struct *mm = tsk->mm;
509 siginfo_t info;
510
511 info.si_code = SEGV_MAPERR;
512
513#if 0
514 printk("wf<pid=%d,wr=%d,addr=%08lx>\n",
515 tsk->pid, write, address);
516#endif
517 down_read(&mm->mmap_sem);
518 vma = find_vma(mm, address);
519 if(!vma)
520 goto bad_area;
521 if(vma->vm_start <= address)
522 goto good_area;
523 if(!(vma->vm_flags & VM_GROWSDOWN))
524 goto bad_area;
525 if(expand_stack(vma, address))
526 goto bad_area;
527good_area:
528 info.si_code = SEGV_ACCERR;
529 if(write) {
530 if(!(vma->vm_flags & VM_WRITE))
531 goto bad_area;
532 } else {
533 if(!(vma->vm_flags & (VM_READ | VM_EXEC)))
534 goto bad_area;
535 }
536 switch (handle_mm_fault(mm, vma, address, write)) {
537 case VM_FAULT_SIGBUS:
538 case VM_FAULT_OOM:
539 goto do_sigbus;
540 }
541 up_read(&mm->mmap_sem);
542 return;
543bad_area:
544 up_read(&mm->mmap_sem);
545#if 0
546 printk("Window whee %s [%d]: segfaults at %08lx\n",
547 tsk->comm, tsk->pid, address);
548#endif
549 info.si_signo = SIGSEGV;
550 info.si_errno = 0;
551 /* info.si_code set above to make clear whether
552 this was a SEGV_MAPERR or SEGV_ACCERR fault. */
553 info.si_addr = (void __user *) address;
554 info.si_trapno = 0;
555 force_sig_info (SIGSEGV, &info, tsk);
556 return;
557
558do_sigbus:
559 up_read(&mm->mmap_sem);
560 info.si_signo = SIGBUS;
561 info.si_errno = 0;
562 info.si_code = BUS_ADRERR;
563 info.si_addr = (void __user *) address;
564 info.si_trapno = 0;
565 force_sig_info (SIGBUS, &info, tsk);
566}
567
568void window_overflow_fault(void)
569{
570 unsigned long sp;
571
572 sp = current_thread_info()->rwbuf_stkptrs[0];
573 if(((sp + 0x38) & PAGE_MASK) != (sp & PAGE_MASK))
574 force_user_fault(sp + 0x38, 1);
575 force_user_fault(sp, 1);
576}
577
578void window_underflow_fault(unsigned long sp)
579{
580 if(((sp + 0x38) & PAGE_MASK) != (sp & PAGE_MASK))
581 force_user_fault(sp + 0x38, 0);
582 force_user_fault(sp, 0);
583}
584
585void window_ret_fault(struct pt_regs *regs)
586{
587 unsigned long sp;
588
589 sp = regs->u_regs[UREG_FP];
590 if(((sp + 0x38) & PAGE_MASK) != (sp & PAGE_MASK))
591 force_user_fault(sp + 0x38, 0);
592 force_user_fault(sp, 0);
593}
kernel source for telekom puls (alcatel/mediatek)