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metag: Traps
[linux-2.6-block.git] / arch / metag / kernel / traps.c
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ac919f08
JH		 1/*
2 * Meta exception handling.
3 *
4 * Copyright (C) 2005,2006,2007,2008,2009,2012 Imagination Technologies Ltd.
5 *
6 * This file is subject to the terms and conditions of the GNU General Public
7 * License. See the file COPYING in the main directory of this archive
8 * for more details.
9 */
10
11#include <linux/sched.h>
12#include <linux/signal.h>
13#include <linux/kernel.h>
14#include <linux/mm.h>
15#include <linux/types.h>
16#include <linux/init.h>
17#include <linux/interrupt.h>
18#include <linux/ptrace.h>
19#include <linux/module.h>
20#include <linux/kallsyms.h>
21#include <linux/kdebug.h>
22#include <linux/kexec.h>
23#include <linux/unistd.h>
24#include <linux/smp.h>
25#include <linux/slab.h>
26#include <linux/syscalls.h>
27
28#include <asm/bug.h>
29#include <asm/core_reg.h>
30#include <asm/irqflags.h>
31#include <asm/siginfo.h>
32#include <asm/traps.h>
33#include <asm/hwthread.h>
34#include <asm/switch.h>
35#include <asm/user_gateway.h>
36#include <asm/syscall.h>
37#include <asm/syscalls.h>
38
39/* Passing syscall arguments as long long is quicker. */
40typedef unsigned int (*LPSYSCALL) (unsigned long long,
41 unsigned long long,
42 unsigned long long);
43
44/*
45 * Users of LNKSET should compare the bus error bits obtained from DEFR
46 * against TXDEFR_LNKSET_SUCCESS only as the failure code will vary between
47 * different cores revisions.
48 */
49#define TXDEFR_LNKSET_SUCCESS 0x02000000
50#define TXDEFR_LNKSET_FAILURE 0x04000000
51
52/*
53 * Our global TBI handle. Initialised from setup.c/setup_arch.
54 */
55DECLARE_PER_CPU(PTBI, pTBI);
56
57#ifdef CONFIG_SMP
58static DEFINE_PER_CPU(unsigned int, trigger_mask);
59#else
60unsigned int global_trigger_mask;
61#endif
62
63unsigned long per_cpu__stack_save[NR_CPUS];
64
65static const char * const trap_names[] = {
66 [TBIXXF_SIGNUM_IIF] = "Illegal instruction fault",
67 [TBIXXF_SIGNUM_PGF] = "Privilege violation",
68 [TBIXXF_SIGNUM_DHF] = "Unaligned data access fault",
69 [TBIXXF_SIGNUM_IGF] = "Code fetch general read failure",
70 [TBIXXF_SIGNUM_DGF] = "Data access general read/write fault",
71 [TBIXXF_SIGNUM_IPF] = "Code fetch page fault",
72 [TBIXXF_SIGNUM_DPF] = "Data access page fault",
73 [TBIXXF_SIGNUM_IHF] = "Instruction breakpoint",
74 [TBIXXF_SIGNUM_DWF] = "Read-only data access fault",
75};
76
77const char *trap_name(int trapno)
78{
79 if (trapno >= 0 && trapno < ARRAY_SIZE(trap_names)
80 && trap_names[trapno])
81 return trap_names[trapno];
82 return "Unknown fault";
83}
84
85static DEFINE_SPINLOCK(die_lock);
86
87void die(const char *str, struct pt_regs *regs, long err,
88 unsigned long addr)
89{
90 static int die_counter;
91
92 oops_enter();
93
94 spin_lock_irq(&die_lock);
95 console_verbose();
96 bust_spinlocks(1);
97 pr_err("%s: err %04lx (%s) addr %08lx [#%d]\n", str, err & 0xffff,
98 trap_name(err & 0xffff), addr, ++die_counter);
99
100 print_modules();
101 show_regs(regs);
102
103 pr_err("Process: %s (pid: %d, stack limit = %p)\n", current->comm,
104 task_pid_nr(current), task_stack_page(current) + THREAD_SIZE);
105
106 bust_spinlocks(0);
107 add_taint(TAINT_DIE);
108 if (kexec_should_crash(current))
109 crash_kexec(regs);
110
111 if (in_interrupt())
112 panic("Fatal exception in interrupt");
113
114 if (panic_on_oops)
115 panic("Fatal exception");
116
117 spin_unlock_irq(&die_lock);
118 oops_exit();
119 do_exit(SIGSEGV);
120}
121
122#ifdef CONFIG_METAG_DSP
123/*
124 * The ECH encoding specifies the size of a DSPRAM as,
125 *
126 * "slots" / 4
127 *
128 * A "slot" is the size of two DSPRAM bank entries; an entry from
129 * DSPRAM bank A and an entry from DSPRAM bank B. One DSPRAM bank
130 * entry is 4 bytes.
131 */
132#define SLOT_SZ 8
133static inline unsigned int decode_dspram_size(unsigned int size)
134{
135 unsigned int _sz = size & 0x7f;
136
137 return _sz * SLOT_SZ * 4;
138}
139
140static void dspram_save(struct meta_ext_context *dsp_ctx,
141 unsigned int ramA_sz, unsigned int ramB_sz)
142{
143 unsigned int ram_sz[2];
144 int i;
145
146 ram_sz[0] = ramA_sz;
147 ram_sz[1] = ramB_sz;
148
149 for (i = 0; i < 2; i++) {
150 if (ram_sz[i] != 0) {
151 unsigned int sz;
152
153 if (i == 0)
154 sz = decode_dspram_size(ram_sz[i] >> 8);
155 else
156 sz = decode_dspram_size(ram_sz[i]);
157
158 if (dsp_ctx->ram[i] == NULL) {
159 dsp_ctx->ram[i] = kmalloc(sz, GFP_KERNEL);
160
161 if (dsp_ctx->ram[i] == NULL)
162 panic("couldn't save DSP context");
163 } else {
164 if (ram_sz[i] > dsp_ctx->ram_sz[i]) {
165 kfree(dsp_ctx->ram[i]);
166
167 dsp_ctx->ram[i] = kmalloc(sz,
168 GFP_KERNEL);
169
170 if (dsp_ctx->ram[i] == NULL)
171 panic("couldn't save DSP context");
172 }
173 }
174
175 if (i == 0)
176 __TBIDspramSaveA(ram_sz[i], dsp_ctx->ram[i]);
177 else
178 __TBIDspramSaveB(ram_sz[i], dsp_ctx->ram[i]);
179
180 dsp_ctx->ram_sz[i] = ram_sz[i];
181 }
182 }
183}
184#endif /* CONFIG_METAG_DSP */
185
186/*
187 * Allow interrupts to be nested and save any "extended" register
188 * context state, e.g. DSP regs and RAMs.
189 */
190static void nest_interrupts(TBIRES State, unsigned long mask)
191{
192#ifdef CONFIG_METAG_DSP
193 struct meta_ext_context *dsp_ctx;
194 unsigned int D0_8;
195
196 /*
197 * D0.8 may contain an ECH encoding. The upper 16 bits
198 * tell us what DSP resources the current process is
199 * using. OR the bits into the SaveMask so that
200 * __TBINestInts() knows what resources to save as
201 * part of this context.
202 *
203 * Don't save the context if we're nesting interrupts in the
204 * kernel because the kernel doesn't use DSP hardware.
205 */
206 D0_8 = __core_reg_get(D0.8);
207
208 if (D0_8 && (State.Sig.SaveMask & TBICTX_PRIV_BIT)) {
209 State.Sig.SaveMask |= (D0_8 >> 16);
210
211 dsp_ctx = current->thread.dsp_context;
212 if (dsp_ctx == NULL) {
213 dsp_ctx = kzalloc(sizeof(*dsp_ctx), GFP_KERNEL);
214 if (dsp_ctx == NULL)
215 panic("couldn't save DSP context: ENOMEM");
216
217 current->thread.dsp_context = dsp_ctx;
218 }
219
220 current->thread.user_flags |= (D0_8 & 0xffff0000);
221 __TBINestInts(State, &dsp_ctx->regs, mask);
222 dspram_save(dsp_ctx, D0_8 & 0x7f00, D0_8 & 0x007f);
223 } else
224 __TBINestInts(State, NULL, mask);
225#else
226 __TBINestInts(State, NULL, mask);
227#endif
228}
229
230void head_end(TBIRES State, unsigned long mask)
231{
232 unsigned int savemask = (unsigned short)State.Sig.SaveMask;
233 unsigned int ctx_savemask = (unsigned short)State.Sig.pCtx->SaveMask;
234
235 if (savemask & TBICTX_PRIV_BIT) {
236 ctx_savemask |= TBICTX_PRIV_BIT;
237 current->thread.user_flags = savemask;
238 }
239
240 /* Always undo the sleep bit */
241 ctx_savemask &= ~TBICTX_WAIT_BIT;
242
243 /* Always save the catch buffer and RD pipe if they are dirty */
244 savemask |= TBICTX_XCBF_BIT;
245
246 /* Only save the catch and RD if we have not already done so.
247 * Note - the RD bits are in the pCtx only, and not in the
248 * State.SaveMask.
249 */
250 if ((savemask & TBICTX_CBUF_BIT) ||
251 (ctx_savemask & TBICTX_CBRP_BIT)) {
252 /* Have we already saved the buffers though?
253 * - See TestTrack 5071 */
254 if (ctx_savemask & TBICTX_XCBF_BIT) {
255 /* Strip off the bits so the call to __TBINestInts
256 * won't save the buffers again. */
257 savemask &= ~TBICTX_CBUF_BIT;
258 ctx_savemask &= ~TBICTX_CBRP_BIT;
259 }
260 }
261
262#ifdef CONFIG_METAG_META21
263 {
264 unsigned int depth, txdefr;
265
266 /*
267 * Save TXDEFR state.
268 *
269 * The process may have been interrupted after a LNKSET, but
270 * before it could read the DEFR state, so we mustn't lose that
271 * state or it could end up retrying an atomic operation that
272 * succeeded.
273 *
274 * All interrupts are disabled at this point so we
275 * don't need to perform any locking. We must do this
276 * dance before we use LNKGET or LNKSET.
277 */
278 BUG_ON(current->thread.int_depth > HARDIRQ_BITS);
279
280 depth = current->thread.int_depth++;
281
282 txdefr = __core_reg_get(TXDEFR);
283
284 txdefr &= TXDEFR_BUS_STATE_BITS;
285 if (txdefr & TXDEFR_LNKSET_SUCCESS)
286 current->thread.txdefr_failure &= ~(1 << depth);
287 else
288 current->thread.txdefr_failure |= (1 << depth);
289 }
290#endif
291
292 State.Sig.SaveMask = savemask;
293 State.Sig.pCtx->SaveMask = ctx_savemask;
294
295 nest_interrupts(State, mask);
296
297#ifdef CONFIG_METAG_POISON_CATCH_BUFFERS
298 /* Poison the catch registers. This shows up any mistakes we have
299 * made in their handling MUCH quicker.
300 */
301 __core_reg_set(TXCATCH0, 0x87650021);
302 __core_reg_set(TXCATCH1, 0x87654322);
303 __core_reg_set(TXCATCH2, 0x87654323);
304 __core_reg_set(TXCATCH3, 0x87654324);
305#endif /* CONFIG_METAG_POISON_CATCH_BUFFERS */
306}
307
308TBIRES tail_end_sys(TBIRES State, int syscall, int *restart)
309{
310 struct pt_regs *regs = (struct pt_regs *)State.Sig.pCtx;
311 unsigned long flags;
312
313 local_irq_disable();
314
315 if (user_mode(regs)) {
316 flags = current_thread_info()->flags;
317 if (flags & _TIF_WORK_MASK &&
318 do_work_pending(regs, flags, syscall)) {
319 *restart = 1;
320 return State;
321 }
322
323#ifdef CONFIG_METAG_FPU
324 if (current->thread.fpu_context &&
325 current->thread.fpu_context->needs_restore) {
326 __TBICtxFPURestore(State, current->thread.fpu_context);
327 /*
328 * Clearing this bit ensures the FP unit is not made
329 * active again unless it is used.
330 */
331 State.Sig.SaveMask &= ~TBICTX_FPAC_BIT;
332 current->thread.fpu_context->needs_restore = false;
333 }
334 State.Sig.TrigMask |= TBI_TRIG_BIT(TBID_SIGNUM_DFR);
335#endif
336 }
337
338 /* TBI will turn interrupts back on at some point. */
339 if (!irqs_disabled_flags((unsigned long)State.Sig.TrigMask))
340 trace_hardirqs_on();
341
342#ifdef CONFIG_METAG_DSP
343 /*
344 * If we previously saved an extended context then restore it
345 * now. Otherwise, clear D0.8 because this process is not
346 * using DSP hardware.
347 */
348 if (State.Sig.pCtx->SaveMask & TBICTX_XEXT_BIT) {
349 unsigned int D0_8;
350 struct meta_ext_context *dsp_ctx = current->thread.dsp_context;
351
352 /* Make sure we're going to return to userland. */
353 BUG_ON(current->thread.int_depth != 1);
354
355 if (dsp_ctx->ram_sz[0] > 0)
356 __TBIDspramRestoreA(dsp_ctx->ram_sz[0],
357 dsp_ctx->ram[0]);
358 if (dsp_ctx->ram_sz[1] > 0)
359 __TBIDspramRestoreB(dsp_ctx->ram_sz[1],
360 dsp_ctx->ram[1]);
361
362 State.Sig.SaveMask |= State.Sig.pCtx->SaveMask;
363 __TBICtxRestore(State, current->thread.dsp_context);
364 D0_8 = __core_reg_get(D0.8);
365 D0_8 |= current->thread.user_flags & 0xffff0000;
366 D0_8 |= (dsp_ctx->ram_sz[1] | dsp_ctx->ram_sz[0]) & 0xffff;
367 __core_reg_set(D0.8, D0_8);
368 } else
369 __core_reg_set(D0.8, 0);
370#endif /* CONFIG_METAG_DSP */
371
372#ifdef CONFIG_METAG_META21
373 {
374 unsigned int depth, txdefr;
375
376 /*
377 * If there hasn't been a LNKSET since the last LNKGET then the
378 * link flag will be set, causing the next LNKSET to succeed if
379 * the addresses match. The two LNK operations may not be a pair
380 * (e.g. see atomic_read()), so the LNKSET should fail.
381 * We use a conditional-never LNKSET to clear the link flag
382 * without side effects.
383 */
384 asm volatile("LNKSETDNV [D0Re0],D0Re0");
385
386 depth = --current->thread.int_depth;
387
388 BUG_ON(user_mode(regs) && depth);
389
390 txdefr = __core_reg_get(TXDEFR);
391
392 txdefr &= ~TXDEFR_BUS_STATE_BITS;
393
394 /* Do we need to restore a failure code into TXDEFR? */
395 if (current->thread.txdefr_failure & (1 << depth))
396 txdefr |= (TXDEFR_LNKSET_FAILURE | TXDEFR_BUS_TRIG_BIT);
397 else
398 txdefr |= (TXDEFR_LNKSET_SUCCESS | TXDEFR_BUS_TRIG_BIT);
399
400 __core_reg_set(TXDEFR, txdefr);
401 }
402#endif
403 return State;
404}
405
406#ifdef CONFIG_SMP
407/*
408 * If we took an interrupt in the middle of __kuser_get_tls then we need
409 * to rewind the PC to the start of the function in case the process
410 * gets migrated to another thread (SMP only) and it reads the wrong tls
411 * data.
412 */
413static inline void _restart_critical_section(TBIRES State)
414{
415 unsigned long get_tls_start;
416 unsigned long get_tls_end;
417
418 get_tls_start = (unsigned long)__kuser_get_tls -
419 (unsigned long)&__user_gateway_start;
420
421 get_tls_start += USER_GATEWAY_PAGE;
422
423 get_tls_end = (unsigned long)__kuser_get_tls_end -
424 (unsigned long)&__user_gateway_start;
425
426 get_tls_end += USER_GATEWAY_PAGE;
427
428 if ((State.Sig.pCtx->CurrPC >= get_tls_start) &&
429 (State.Sig.pCtx->CurrPC < get_tls_end))
430 State.Sig.pCtx->CurrPC = get_tls_start;
431}
432#else
433/*
434 * If we took an interrupt in the middle of
435 * __kuser_cmpxchg then we need to rewind the PC to the
436 * start of the function.
437 */
438static inline void _restart_critical_section(TBIRES State)
439{
440 unsigned long cmpxchg_start;
441 unsigned long cmpxchg_end;
442
443 cmpxchg_start = (unsigned long)__kuser_cmpxchg -
444 (unsigned long)&__user_gateway_start;
445
446 cmpxchg_start += USER_GATEWAY_PAGE;
447
448 cmpxchg_end = (unsigned long)__kuser_cmpxchg_end -
449 (unsigned long)&__user_gateway_start;
450
451 cmpxchg_end += USER_GATEWAY_PAGE;
452
453 if ((State.Sig.pCtx->CurrPC >= cmpxchg_start) &&
454 (State.Sig.pCtx->CurrPC < cmpxchg_end))
455 State.Sig.pCtx->CurrPC = cmpxchg_start;
456}
457#endif
458
459/* Used by kick_handler() */
460void restart_critical_section(TBIRES State)
461{
462 _restart_critical_section(State);
463}
464
465TBIRES trigger_handler(TBIRES State, int SigNum, int Triggers, int Inst,
466 PTBI pTBI)
467{
468 head_end(State, ~INTS_OFF_MASK);
469
470 /* If we interrupted user code handle any critical sections. */
471 if (State.Sig.SaveMask & TBICTX_PRIV_BIT)
472 _restart_critical_section(State);
473
474 trace_hardirqs_off();
475
476 do_IRQ(SigNum, (struct pt_regs *)State.Sig.pCtx);
477
478 return tail_end(State);
479}
480
481static unsigned int load_fault(PTBICTXEXTCB0 pbuf)
482{
483 return pbuf->CBFlags & TXCATCH0_READ_BIT;
484}
485
486static unsigned long fault_address(PTBICTXEXTCB0 pbuf)
487{
488 return pbuf->CBAddr;
489}
490
491static void unhandled_fault(struct pt_regs *regs, unsigned long addr,
492 int signo, int code, int trapno)
493{
494 if (user_mode(regs)) {
495 siginfo_t info;
496
497 if (show_unhandled_signals && unhandled_signal(current, signo)
498 && printk_ratelimit()) {
499
500 pr_info("pid %d unhandled fault: pc 0x%08x, addr 0x%08lx, trap %d (%s)\n",
501 current->pid, regs->ctx.CurrPC, addr,
502 trapno, trap_name(trapno));
503 print_vma_addr(" in ", regs->ctx.CurrPC);
504 print_vma_addr(" rtp in ", regs->ctx.DX[4].U1);
505 printk("\n");
506 show_regs(regs);
507 }
508
509 info.si_signo = signo;
510 info.si_errno = 0;
511 info.si_code = code;
512 info.si_addr = (__force void __user *)addr;
513 info.si_trapno = trapno;
514 force_sig_info(signo, &info, current);
515 } else {
516 die("Oops", regs, trapno, addr);
517 }
518}
519
520static int handle_data_fault(PTBICTXEXTCB0 pcbuf, struct pt_regs *regs,
521 unsigned int data_address, int trapno)
522{
523 int ret;
524
525 ret = do_page_fault(regs, data_address, !load_fault(pcbuf), trapno);
526
527 return ret;
528}
529
530static unsigned long get_inst_fault_address(struct pt_regs *regs)
531{
532 return regs->ctx.CurrPC;
533}
534
535TBIRES fault_handler(TBIRES State, int SigNum, int Triggers,
536 int Inst, PTBI pTBI)
537{
538 struct pt_regs *regs = (struct pt_regs *)State.Sig.pCtx;
539 PTBICTXEXTCB0 pcbuf = (PTBICTXEXTCB0)&regs->extcb0;
540 unsigned long data_address;
541
542 head_end(State, ~INTS_OFF_MASK);
543
544 /* Hardware breakpoint or data watch */
545 if ((SigNum == TBIXXF_SIGNUM_IHF) ||
546 ((SigNum == TBIXXF_SIGNUM_DHF) &&
547 (pcbuf[0].CBFlags & (TXCATCH0_WATCH1_BIT |
548 TXCATCH0_WATCH0_BIT)))) {
549 State = __TBIUnExpXXX(State, SigNum, Triggers, Inst,
550 pTBI);
551 return tail_end(State);
552 }
553
554 local_irq_enable();
555
556 data_address = fault_address(pcbuf);
557
558 switch (SigNum) {
559 case TBIXXF_SIGNUM_IGF:
560 /* 1st-level entry invalid (instruction fetch) */
561 case TBIXXF_SIGNUM_IPF: {
562 /* 2nd-level entry invalid (instruction fetch) */
563 unsigned long addr = get_inst_fault_address(regs);
564 do_page_fault(regs, addr, 0, SigNum);
565 break;
566 }
567
568 case TBIXXF_SIGNUM_DGF:
569 /* 1st-level entry invalid (data access) */
570 case TBIXXF_SIGNUM_DPF:
571 /* 2nd-level entry invalid (data access) */
572 case TBIXXF_SIGNUM_DWF:
573 /* Write to read only page */
574 handle_data_fault(pcbuf, regs, data_address, SigNum);
575 break;
576
577 case TBIXXF_SIGNUM_IIF:
578 /* Illegal instruction */
579 unhandled_fault(regs, regs->ctx.CurrPC, SIGILL, ILL_ILLOPC,
580 SigNum);
581 break;
582
583 case TBIXXF_SIGNUM_DHF:
584 /* Unaligned access */
585 unhandled_fault(regs, data_address, SIGBUS, BUS_ADRALN,
586 SigNum);
587 break;
588 case TBIXXF_SIGNUM_PGF:
589 /* Privilege violation */
590 unhandled_fault(regs, data_address, SIGSEGV, SEGV_ACCERR,
591 SigNum);
592 break;
593 default:
594 BUG();
595 break;
596 }
597
598 return tail_end(State);
599}
600
601static bool switch_is_syscall(unsigned int inst)
602{
603 return inst == __METAG_SW_ENCODING(SYS);
604}
605
606static bool switch_is_legacy_syscall(unsigned int inst)
607{
608 return inst == __METAG_SW_ENCODING(SYS_LEGACY);
609}
610
611static inline void step_over_switch(struct pt_regs *regs, unsigned int inst)
612{
613 regs->ctx.CurrPC += 4;
614}
615
616static inline int test_syscall_work(void)
617{
618 return current_thread_info()->flags & _TIF_WORK_SYSCALL_MASK;
619}
620
621TBIRES switch1_handler(TBIRES State, int SigNum, int Triggers,
622 int Inst, PTBI pTBI)
623{
624 struct pt_regs *regs = (struct pt_regs *)State.Sig.pCtx;
625 unsigned int sysnumber;
626 unsigned long long a1_a2, a3_a4, a5_a6;
627 LPSYSCALL syscall_entry;
628 int restart;
629
630 head_end(State, ~INTS_OFF_MASK);
631
632 /*
633 * If this is not a syscall SWITCH it could be a breakpoint.
634 */
635 if (!switch_is_syscall(Inst)) {
636 /*
637 * Alert the user if they're trying to use legacy system
638 * calls. This suggests they need to update their C
639 * library and build against up to date kernel headers.
640 */
641 if (switch_is_legacy_syscall(Inst))
642 pr_warn_once("WARNING: A legacy syscall was made. Your userland needs updating.\n");
643 /*
644 * We don't know how to handle the SWITCH and cannot
645 * safely ignore it, so treat all unknown switches
646 * (including breakpoints) as traps.
647 */
648 force_sig(SIGTRAP, current);
649 return tail_end(State);
650 }
651
652 local_irq_enable();
653
654restart_syscall:
655 restart = 0;
656 sysnumber = regs->ctx.DX[0].U1;
657
658 if (test_syscall_work())
659 sysnumber = syscall_trace_enter(regs);
660
661 /* Skip over the SWITCH instruction - or you just get 'stuck' on it! */
662 step_over_switch(regs, Inst);
663
664 if (sysnumber >= __NR_syscalls) {
665 pr_debug("unknown syscall number: %d\n", sysnumber);
666 syscall_entry = (LPSYSCALL) sys_ni_syscall;
667 } else {
668 syscall_entry = (LPSYSCALL) sys_call_table[sysnumber];
669 }
670
671 /* Use 64bit loads for speed. */
672 a5_a6 = *(unsigned long long *)&regs->ctx.DX[1];
673 a3_a4 = *(unsigned long long *)&regs->ctx.DX[2];
674 a1_a2 = *(unsigned long long *)&regs->ctx.DX[3];
675
676 /* here is the actual call to the syscall handler functions */
677 regs->ctx.DX[0].U0 = syscall_entry(a1_a2, a3_a4, a5_a6);
678
679 if (test_syscall_work())
680 syscall_trace_leave(regs);
681
682 State = tail_end_sys(State, sysnumber, &restart);
683 /* Handlerless restarts shouldn't go via userland */
684 if (restart)
685 goto restart_syscall;
686 return State;
687}
688
689TBIRES switchx_handler(TBIRES State, int SigNum, int Triggers,
690 int Inst, PTBI pTBI)
691{
692 struct pt_regs *regs = (struct pt_regs *)State.Sig.pCtx;
693
694 /*
695 * This can be caused by any user process simply executing an unusual
696 * SWITCH instruction. If there's no DA, __TBIUnExpXXX will cause the
697 * thread to stop, so signal a SIGTRAP instead.
698 */
699 head_end(State, ~INTS_OFF_MASK);
700 if (user_mode(regs))
701 force_sig(SIGTRAP, current);
702 else
703 State = __TBIUnExpXXX(State, SigNum, Triggers, Inst, pTBI);
704 return tail_end(State);
705}
706
707#ifdef CONFIG_METAG_META21
708TBIRES fpe_handler(TBIRES State, int SigNum, int Triggers, int Inst, PTBI pTBI)
709{
710 struct pt_regs *regs = (struct pt_regs *)State.Sig.pCtx;
711 unsigned int error_state = Triggers;
712 siginfo_t info;
713
714 head_end(State, ~INTS_OFF_MASK);
715
716 local_irq_enable();
717
718 info.si_signo = SIGFPE;
719
720 if (error_state & TXSTAT_FPE_INVALID_BIT)
721 info.si_code = FPE_FLTINV;
722 else if (error_state & TXSTAT_FPE_DIVBYZERO_BIT)
723 info.si_code = FPE_FLTDIV;
724 else if (error_state & TXSTAT_FPE_OVERFLOW_BIT)
725 info.si_code = FPE_FLTOVF;
726 else if (error_state & TXSTAT_FPE_UNDERFLOW_BIT)
727 info.si_code = FPE_FLTUND;
728 else if (error_state & TXSTAT_FPE_INEXACT_BIT)
729 info.si_code = FPE_FLTRES;
730 else
731 info.si_code = 0;
732 info.si_errno = 0;
733 info.si_addr = (__force void __user *)regs->ctx.CurrPC;
734 force_sig_info(SIGFPE, &info, current);
735
736 return tail_end(State);
737}
738#endif
739
740#ifdef CONFIG_METAG_SUSPEND_MEM
741struct traps_context {
742 PTBIAPIFN fnSigs[TBID_SIGNUM_MAX + 1];
743};
744
745static struct traps_context *metag_traps_context;
746
747int traps_save_context(void)
748{
749 unsigned long cpu = smp_processor_id();
750 PTBI _pTBI = per_cpu(pTBI, cpu);
751 struct traps_context *context;
752
753 context = kzalloc(sizeof(*context), GFP_ATOMIC);
754 if (!context)
755 return -ENOMEM;
756
757 memcpy(context->fnSigs, (void *)_pTBI->fnSigs, sizeof(context->fnSigs));
758
759 metag_traps_context = context;
760 return 0;
761}
762
763int traps_restore_context(void)
764{
765 unsigned long cpu = smp_processor_id();
766 PTBI _pTBI = per_cpu(pTBI, cpu);
767 struct traps_context *context = metag_traps_context;
768
769 metag_traps_context = NULL;
770
771 memcpy((void *)_pTBI->fnSigs, context->fnSigs, sizeof(context->fnSigs));
772
773 kfree(context);
774 return 0;
775}
776#endif
777
778#ifdef CONFIG_SMP
779unsigned int get_trigger_mask(void)
780{
781 unsigned long cpu = smp_processor_id();
782 return per_cpu(trigger_mask, cpu);
783}
784
785static void set_trigger_mask(unsigned int mask)
786{
787 unsigned long cpu = smp_processor_id();
788 per_cpu(trigger_mask, cpu) = mask;
789}
790#else
791static void set_trigger_mask(unsigned int mask)
792{
793 global_trigger_mask = mask;
794}
795#endif
796
797void __cpuinit per_cpu_trap_init(unsigned long cpu)
798{
799 TBIRES int_context;
800 unsigned int thread = cpu_2_hwthread_id[cpu];
801
802 set_trigger_mask(TBI_INTS_INIT(thread) | /* interrupts */
803 TBI_TRIG_BIT(TBID_SIGNUM_LWK) | /* low level kick */
804 TBI_TRIG_BIT(TBID_SIGNUM_SW1) |
805 TBI_TRIG_BIT(TBID_SIGNUM_SWS));
806
807 /* non-priv - use current stack */
808 int_context.Sig.pCtx = NULL;
809 /* Start with interrupts off */
810 int_context.Sig.TrigMask = INTS_OFF_MASK;
811 int_context.Sig.SaveMask = 0;
812
813 /* And call __TBIASyncTrigger() */
814 __TBIASyncTrigger(int_context);
815}
816
817void __init trap_init(void)
818{
819 unsigned long cpu = smp_processor_id();
820 PTBI _pTBI = per_cpu(pTBI, cpu);
821
822 _pTBI->fnSigs[TBID_SIGNUM_XXF] = fault_handler;
823 _pTBI->fnSigs[TBID_SIGNUM_SW0] = switchx_handler;
824 _pTBI->fnSigs[TBID_SIGNUM_SW1] = switch1_handler;
825 _pTBI->fnSigs[TBID_SIGNUM_SW2] = switchx_handler;
826 _pTBI->fnSigs[TBID_SIGNUM_SW3] = switchx_handler;
827 _pTBI->fnSigs[TBID_SIGNUM_SWK] = kick_handler;
828
829#ifdef CONFIG_METAG_META21
830 _pTBI->fnSigs[TBID_SIGNUM_DFR] = __TBIHandleDFR;
831 _pTBI->fnSigs[TBID_SIGNUM_FPE] = fpe_handler;
832#endif
833
834 per_cpu_trap_init(cpu);
835}
836
837void tbi_startup_interrupt(int irq)
838{
839 unsigned long cpu = smp_processor_id();
840 PTBI _pTBI = per_cpu(pTBI, cpu);
841
842 BUG_ON(irq > TBID_SIGNUM_MAX);
843
844 /* For TR1 and TR2, the thread id is encoded in the irq number */
845 if (irq >= TBID_SIGNUM_T10 && irq < TBID_SIGNUM_TR3)
846 cpu = hwthread_id_2_cpu[(irq - TBID_SIGNUM_T10) % 4];
847
848 set_trigger_mask(get_trigger_mask() | TBI_TRIG_BIT(irq));
849
850 _pTBI->fnSigs[irq] = trigger_handler;
851}
852
853void tbi_shutdown_interrupt(int irq)
854{
855 unsigned long cpu = smp_processor_id();
856 PTBI _pTBI = per_cpu(pTBI, cpu);
857
858 BUG_ON(irq > TBID_SIGNUM_MAX);
859
860 set_trigger_mask(get_trigger_mask() & ~TBI_TRIG_BIT(irq));
861
862 _pTBI->fnSigs[irq] = __TBIUnExpXXX;
863}
864
865int ret_from_fork(TBIRES arg)
866{
867 struct task_struct *prev = arg.Switch.pPara;
868 struct task_struct *tsk = current;
869 struct pt_regs *regs = task_pt_regs(tsk);
870 int (*fn)(void *);
871 TBIRES Next;
872
873 schedule_tail(prev);
874
875 if (tsk->flags & PF_KTHREAD) {
876 fn = (void *)regs->ctx.DX[4].U1;
877 BUG_ON(!fn);
878
879 fn((void *)regs->ctx.DX[3].U1);
880 }
881
882 if (test_syscall_work())
883 syscall_trace_leave(regs);
884
885 preempt_disable();
886
887 Next.Sig.TrigMask = get_trigger_mask();
888 Next.Sig.SaveMask = 0;
889 Next.Sig.pCtx = &regs->ctx;
890
891 set_gateway_tls(current->thread.tls_ptr);
892
893 preempt_enable_no_resched();
894
895 /* And interrupts should come back on when we resume the real usermode
896 * code. Call __TBIASyncResume()
897 */
898 __TBIASyncResume(tail_end(Next));
899 /* ASyncResume should NEVER return */
900 BUG();
901 return 0;
902}
903
904void show_trace(struct task_struct *tsk, unsigned long *sp,
905 struct pt_regs *regs)
906{
907 unsigned long addr;
908#ifdef CONFIG_FRAME_POINTER
909 unsigned long fp, fpnew;
910 unsigned long stack;
911#endif
912
913 if (regs && user_mode(regs))
914 return;
915
916 printk("\nCall trace: ");
917#ifdef CONFIG_KALLSYMS
918 printk("\n");
919#endif
920
921 if (!tsk)
922 tsk = current;
923
924#ifdef CONFIG_FRAME_POINTER
925 if (regs) {
926 print_ip_sym(regs->ctx.CurrPC);
927 fp = regs->ctx.AX[1].U0;
928 } else {
929 fp = __core_reg_get(A0FrP);
930 }
931
932 /* detect when the frame pointer has been used for other purposes and
933 * doesn't point to the stack (it may point completely elsewhere which
934 * kstack_end may not detect).
935 */
936 stack = (unsigned long)task_stack_page(tsk);
937 while (fp >= stack && fp + 8 <= stack + THREAD_SIZE) {
938 addr = __raw_readl((unsigned long *)(fp + 4)) - 4;
939 if (kernel_text_address(addr))
940 print_ip_sym(addr);
941 else
942 break;
943 /* stack grows up, so frame pointers must decrease */
944 fpnew = __raw_readl((unsigned long *)(fp + 0));
945 if (fpnew >= fp)
946 break;
947 fp = fpnew;
948 }
949#else
950 while (!kstack_end(sp)) {
951 addr = (*sp--) - 4;
952 if (kernel_text_address(addr))
953 print_ip_sym(addr);
954 }
955#endif
956
957 printk("\n");
958
959 debug_show_held_locks(tsk);
960}
961
962void show_stack(struct task_struct *tsk, unsigned long *sp)
963{
964 if (!tsk)
965 tsk = current;
966 if (tsk == current)
967 sp = (unsigned long *)current_stack_pointer;
968 else
969 sp = (unsigned long *)tsk->thread.kernel_context->AX[0].U0;
970
971 show_trace(tsk, sp, NULL);
972}
973
974void dump_stack(void)
975{
976 show_stack(NULL, NULL);
977}
978EXPORT_SYMBOL(dump_stack);
Linux 6.x block layer and io_uring tree(s)