xref: /netbsd/sys/arch/powerpc/ibm4xx/trap.c (revision bf9ec67e)
1 /*	$NetBSD: trap.c,v 1.3 2002/02/14 07:08:13 chs Exp $	*/
2 
3 /*
4  * Copyright 2001 Wasabi Systems, Inc.
5  * All rights reserved.
6  *
7  * Written by Eduardo Horvath and Simon Burge for Wasabi Systems, Inc.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  * 3. All advertising materials mentioning features or use of this software
18  *    must display the following acknowledgement:
19  *      This product includes software developed for the NetBSD Project by
20  *      Wasabi Systems, Inc.
21  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
22  *    or promote products derived from this software without specific prior
23  *    written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35  * POSSIBILITY OF SUCH DAMAGE.
36  */
37 
38 /*
39  * Copyright (C) 1995, 1996 Wolfgang Solfrank.
40  * Copyright (C) 1995, 1996 TooLs GmbH.
41  * All rights reserved.
42  *
43  * Redistribution and use in source and binary forms, with or without
44  * modification, are permitted provided that the following conditions
45  * are met:
46  * 1. Redistributions of source code must retain the above copyright
47  *    notice, this list of conditions and the following disclaimer.
48  * 2. Redistributions in binary form must reproduce the above copyright
49  *    notice, this list of conditions and the following disclaimer in the
50  *    documentation and/or other materials provided with the distribution.
51  * 3. All advertising materials mentioning features or use of this software
52  *    must display the following acknowledgement:
53  *	This product includes software developed by TooLs GmbH.
54  * 4. The name of TooLs GmbH may not be used to endorse or promote products
55  *    derived from this software without specific prior written permission.
56  *
57  * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
58  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
59  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
60  * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
61  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
62  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
63  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
64  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
65  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
66  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
67  */
68 
69 #include "opt_altivec.h"
70 #include "opt_ddb.h"
71 #include "opt_ktrace.h"
72 #include "opt_syscall_debug.h"
73 
74 #include <sys/param.h>
75 #include <sys/proc.h>
76 #include <sys/reboot.h>
77 #include <sys/syscall.h>
78 #include <sys/systm.h>
79 #include <sys/user.h>
80 #include <sys/ktrace.h>
81 
82 #include <uvm/uvm_extern.h>
83 
84 #include <dev/cons.h>
85 
86 #include <machine/cpu.h>
87 #include <machine/db_machdep.h>
88 #include <machine/fpu.h>
89 #include <machine/frame.h>
90 #include <machine/pcb.h>
91 #include <machine/psl.h>
92 #include <machine/trap.h>
93 
94 #include <powerpc/spr.h>
95 #include <powerpc/ibm4xx/pmap.h>
96 #include <powerpc/ibm4xx/tlb.h>
97 #include <powerpc/fpu/fpu_extern.h>
98 
99 /* These definitions should probably be somewhere else			XXX */
100 #define	FIRSTARG	3		/* first argument is in reg 3 */
101 #define	NARGREG		8		/* 8 args are in registers */
102 #define	MOREARGS(sp)	((caddr_t)((int)(sp) + 8)) /* more args go here */
103 
104 #ifndef MULTIPROCESSOR
105 volatile int astpending;
106 volatile int want_resched;
107 #endif
108 
109 void *syscall = NULL;	/* XXX dummy symbol for emul_netbsd */
110 
111 static int fix_unaligned __P((struct proc *p, struct trapframe *frame));
112 
113 void trap __P((struct trapframe *));	/* Called from locore / trap_subr */
114 int setfault __P((faultbuf));	/* defined in locore.S */
115 /* Why are these not defined in a header? */
116 int badaddr __P((void *, size_t));
117 int badaddr_read __P((void *, size_t, int *));
118 int ctx_setup __P((int, int));
119 
120 #ifdef DEBUG
121 #define TDB_ALL	0x1
122 int trapdebug = /* TDB_ALL */ 0;
123 #define	DBPRINTF(x, y)	if (trapdebug & (x)) printf y
124 #else
125 #define DBPRINTF(x, y)
126 #endif
127 
128 void
129 trap(struct trapframe *frame)
130 {
131 	struct proc *p = curproc;
132 	int type = frame->exc;
133 	int ftype, rv;
134 
135 	KASSERT(p == 0 || (p->p_stat == SONPROC));
136 
137 	if (frame->srr1 & PSL_PR)
138 		type |= EXC_USER;
139 
140 	ftype = VM_PROT_READ;
141 
142 DBPRINTF(TDB_ALL, ("trap(%x) at %x from frame %p &frame %p\n",
143 	type, frame->srr0, frame, &frame));
144 
145 	switch (type) {
146 	case EXC_DEBUG|EXC_USER:
147 {
148 	int srr2, srr3;
149 __asm __volatile("mfspr %0,0x3f0" : "=r" (rv), "=r" (srr2), "=r" (srr3) :);
150 printf("debug reg is %x srr2 %x srr3 %x\n", rv, srr2, srr3);
151 }
152 		/*
153 		 * DEBUG intr -- probably single-step.
154 		 */
155 	case EXC_TRC|EXC_USER:
156 		KERNEL_PROC_LOCK(p);
157 		frame->srr1 &= ~PSL_SE;
158 		trapsignal(p, SIGTRAP, EXC_TRC);
159 		KERNEL_PROC_UNLOCK(p);
160 		break;
161 
162 	  /* If we could not find and install appropriate TLB entry, fall through */
163 
164 	case EXC_DSI:
165 		/* FALLTHROUGH */
166 	case EXC_DTMISS:
167 		{
168 			struct vm_map *map;
169 			vaddr_t va;
170 			faultbuf *fb = NULL;
171 
172 			KERNEL_LOCK(LK_CANRECURSE|LK_EXCLUSIVE);
173 			va = frame->dear;
174 			if (frame->pid == KERNEL_PID) {
175 				map = kernel_map;
176 			} else {
177 				map = &p->p_vmspace->vm_map;
178 			}
179 
180 			if (frame->esr & (ESR_DST|ESR_DIZ))
181 				ftype = VM_PROT_WRITE;
182 
183 DBPRINTF(TDB_ALL, ("trap(EXC_DSI) at %x %s fault on %p esr %x\n",
184 frame->srr0, (ftype&VM_PROT_WRITE) ? "write" : "read", (void *)va, frame->esr));
185 			rv = uvm_fault(map, trunc_page(va), 0, ftype);
186 			KERNEL_UNLOCK();
187 			if (rv == 0)
188 				goto done;
189 			if ((fb = p->p_addr->u_pcb.pcb_onfault) != NULL) {
190 				frame->pid = KERNEL_PID;
191 				frame->srr0 = (*fb)[0];
192 				frame->srr1 |= PSL_IR; /* Re-enable IMMU */
193 				frame->fixreg[1] = (*fb)[1];
194 				frame->fixreg[2] = (*fb)[2];
195 				frame->fixreg[3] = 1; /* Return TRUE */
196 				frame->cr = (*fb)[3];
197 				memcpy(&frame->fixreg[13], &(*fb)[4],
198 				      19 * sizeof(register_t));
199 				goto done;
200 			}
201 		}
202 		goto brain_damage;
203 
204 	case EXC_DSI|EXC_USER:
205 		/* FALLTHROUGH */
206 	case EXC_DTMISS|EXC_USER:
207 		KERNEL_PROC_LOCK(p);
208 
209 		if (frame->esr & (ESR_DST|ESR_DIZ))
210 			ftype = VM_PROT_WRITE;
211 
212 DBPRINTF(TDB_ALL, ("trap(EXC_DSI|EXC_USER) at %x %s fault on %x %x\n",
213 frame->srr0, (ftype&VM_PROT_WRITE) ? "write" : "read", frame->dear, frame->esr));
214 KASSERT(p == curproc && (p->p_stat == SONPROC));
215 		rv = uvm_fault(&p->p_vmspace->vm_map,
216 			       trunc_page(frame->dear), 0, ftype);
217 		if (rv == 0) {
218 		  KERNEL_PROC_UNLOCK(p);
219 		  break;
220 		}
221 		if (rv == ENOMEM) {
222 			printf("UVM: pid %d (%s), uid %d killed: "
223 			       "out of swap\n",
224 			       p->p_pid, p->p_comm,
225 			       p->p_cred && p->p_ucred ?
226 			       p->p_ucred->cr_uid : -1);
227 			trapsignal(p, SIGKILL, EXC_DSI);
228 		} else {
229 			trapsignal(p, SIGSEGV, EXC_DSI);
230 		}
231 		KERNEL_PROC_UNLOCK(p);
232 		break;
233 	case EXC_ITMISS|EXC_USER:
234 	case EXC_ISI|EXC_USER:
235 		KERNEL_PROC_LOCK(p);
236 		ftype = VM_PROT_READ | VM_PROT_EXECUTE;
237 DBPRINTF(TDB_ALL, ("trap(EXC_ISI|EXC_USER) at %x %s fault on %x tf %p\n",
238 frame->srr0, (ftype&VM_PROT_WRITE) ? "write" : "read", frame->srr0, frame));
239 		rv = uvm_fault(&p->p_vmspace->vm_map, trunc_page(frame->srr0), 0, ftype);
240 		if (rv == 0) {
241 		  KERNEL_PROC_UNLOCK(p);
242 		  break;
243 		}
244 		trapsignal(p, SIGSEGV, EXC_ISI);
245 		KERNEL_PROC_UNLOCK(p);
246 		break;
247 	case EXC_SC|EXC_USER:
248 		{
249 			const struct sysent *callp;
250 			size_t argsize;
251 			register_t code, error;
252 			register_t *params, rval[2];
253 			int n;
254 			register_t args[10];
255 
256 			KERNEL_PROC_LOCK(p);
257 
258 			uvmexp.syscalls++;
259 
260 			code = frame->fixreg[0];
261 			callp = p->p_emul->e_sysent;
262 			params = frame->fixreg + FIRSTARG;
263 			n = NARGREG;
264 
265 			switch (code) {
266 			case SYS_syscall:
267 				/*
268 				 * code is first argument,
269 				 * followed by actual args.
270 				 */
271 				code = *params++;
272 				n -= 1;
273 				break;
274 			case SYS___syscall:
275 				params++;
276 				code = *params++;
277 				n -= 2;
278 				break;
279 			default:
280 				break;
281 			}
282 
283 			code &= (SYS_NSYSENT - 1);
284 			callp += code;
285 			argsize = callp->sy_argsize;
286 
287 			if (argsize > n * sizeof(register_t)) {
288 				memcpy(args, params, n * sizeof(register_t));
289 				error = copyin(MOREARGS(frame->fixreg[1]),
290 					       args + n,
291 					       argsize - n * sizeof(register_t));
292 				if (error)
293 					goto syscall_bad;
294 				params = args;
295 			}
296 
297 #ifdef	KTRACE
298 			if (KTRPOINT(p, KTR_SYSCALL))
299 				ktrsyscall(p, code, argsize, params);
300 #endif
301 #ifdef SYSCALL_DEBUG
302 			if (trapdebug)
303 				scdebug_call(p, code, args);
304 #endif
305 			rval[0] = 0;
306 			rval[1] = 0;
307 
308 			error = (*callp->sy_call)(p, params, rval);
309 #ifdef SYSCALL_DEBUG
310 			if (trapdebug)
311 				scdebug_ret(p, code, error, rval);
312 #endif
313 			switch (error) {
314 			case 0:
315 				frame->fixreg[FIRSTARG] = rval[0];
316 				frame->fixreg[FIRSTARG + 1] = rval[1];
317 				frame->cr &= ~0x10000000;
318 				break;
319 			case ERESTART:
320 				/*
321 				 * Set user's pc back to redo the system call.
322 				 */
323 				frame->srr0 -= 4;
324 				break;
325 			case EJUSTRETURN:
326 				/* nothing to do */
327 				break;
328 			default:
329 syscall_bad:
330 				if (p->p_emul->e_errno)
331 					error = p->p_emul->e_errno[error];
332 				frame->fixreg[FIRSTARG] = error;
333 				frame->cr |= 0x10000000;
334 				break;
335 			}
336 
337 #ifdef	KTRACE
338 			if (KTRPOINT(p, KTR_SYSRET))
339 				ktrsysret(p, code, error, rval[0]);
340 #endif
341 		}
342 		KERNEL_PROC_UNLOCK(p);
343 		break;
344 
345 	case EXC_AST|EXC_USER:
346 		astpending = 0;		/* we are about to do it */
347 		KERNEL_PROC_LOCK(p);
348 		uvmexp.softs++;
349 		if (p->p_flag & P_OWEUPC) {
350 			p->p_flag &= ~P_OWEUPC;
351 			ADDUPROF(p);
352 		}
353 		/* Check whether we are being preempted. */
354 		if (want_resched)
355 			preempt(NULL);
356 		KERNEL_PROC_UNLOCK(p);
357 		break;
358 
359 
360 	case EXC_ALI|EXC_USER:
361 		KERNEL_PROC_LOCK(p);
362 		if (fix_unaligned(p, frame) != 0)
363 			trapsignal(p, SIGBUS, EXC_ALI);
364 		else
365 			frame->srr0 += 4;
366 		KERNEL_PROC_UNLOCK(p);
367 		break;
368 
369 	case EXC_PGM|EXC_USER:
370 		/*
371 		 * Illegal insn:
372 		 *
373 		 * let's try to see if it's FPU and can be emulated.
374 		 */
375 		uvmexp.traps ++;
376 		if (!(p->p_addr->u_pcb.pcb_flags & PCB_FPU)) {
377 			memset(&p->p_addr->u_pcb.pcb_fpu, 0,
378 				sizeof p->p_addr->u_pcb.pcb_fpu);
379 			p->p_addr->u_pcb.pcb_flags |= PCB_FPU;
380 		}
381 
382 		if ((rv = fpu_emulate(frame,
383 			(struct fpreg *)&p->p_addr->u_pcb.pcb_fpu))) {
384 			KERNEL_PROC_LOCK(p);
385 			trapsignal(p, rv, EXC_PGM);
386 			KERNEL_PROC_UNLOCK(p);
387 		}
388 		break;
389 
390 	case EXC_MCHK:
391 		{
392 			faultbuf *fb;
393 
394 			if ((fb = p->p_addr->u_pcb.pcb_onfault) != NULL) {
395 				frame->pid = KERNEL_PID;
396 				frame->srr0 = (*fb)[0];
397 				frame->srr1 |= PSL_IR; /* Re-enable IMMU */
398 				frame->fixreg[1] = (*fb)[1];
399 				frame->fixreg[2] = (*fb)[2];
400 				frame->fixreg[3] = 1; /* Return TRUE */
401 				frame->cr = (*fb)[3];
402 				memcpy(&frame->fixreg[13], &(*fb)[4],
403 				      19 * sizeof(register_t));
404 				goto done;
405 			}
406 		}
407 		goto brain_damage;
408 	default:
409 brain_damage:
410 		printf("trap type 0x%x at 0x%x\n", type, frame->srr0);
411 #ifdef DDB
412 		if (kdb_trap(type, frame))
413 			goto done;
414 #endif
415 #ifdef TRAP_PANICWAIT
416 		printf("Press a key to panic.\n");
417 		cngetc();
418 #endif
419 		panic("trap");
420 	}
421 
422 	/* Take pending signals. */
423 	{
424 		int sig;
425 
426 		while ((sig = CURSIG(p)) != 0)
427 			postsig(sig);
428 	}
429 
430 	curcpu()->ci_schedstate.spc_curpriority = p->p_priority = p->p_usrpri;
431   done:
432 }
433 
434 int
435 ctx_setup(int ctx, int srr1)
436 {
437 	volatile struct pmap *pm;
438 
439 	/* Update PID if we're returning to user mode. */
440 	if (srr1 & PSL_PR) {
441 		pm = curproc->p_vmspace->vm_map.pmap;
442 		if (!pm->pm_ctx) {
443 			ctx_alloc((struct pmap *)pm);
444 		}
445 		ctx = pm->pm_ctx;
446 		if (srr1 & PSL_SE) {
447 			int dbreg, mask = 0x48000000;
448 				/*
449 				 * Set the Internal Debug and
450 				 * Instruction Completion bits of
451 				 * the DBCR0 register.
452 				 *
453 				 * XXX this is also used by jtag debuggers...
454 				 */
455 			__asm __volatile("mfspr %0,0x3f2;"
456 				"or %0,%0,%1;"
457 				"mtspr 0x3f2,%0;" :
458 				"=&r" (dbreg) : "r" (mask));
459 		}
460 	}
461 	else if (!ctx) {
462 		ctx = KERNEL_PID;
463 	}
464 	return (ctx);
465 }
466 
467 void
468 child_return(void *arg)
469 {
470 	struct proc *p = arg;
471 	struct trapframe *tf = trapframe(p);
472 
473 	KERNEL_PROC_UNLOCK(p);
474 
475 	tf->fixreg[FIRSTARG] = 0;
476 	tf->fixreg[FIRSTARG + 1] = 1;
477 	tf->cr &= ~0x10000000;
478 	tf->srr1 &= ~(PSL_FP|PSL_VEC);	/* Disable FP & AltiVec, as we can't be them */
479 #ifdef	KTRACE
480 	if (KTRPOINT(p, KTR_SYSRET)) {
481 		KERNEL_PROC_LOCK(p);
482 		ktrsysret(p, SYS_fork, 0, 0);
483 		KERNEL_PROC_UNLOCK(p);
484 	}
485 #endif
486 	/* Profiling?							XXX */
487 	curcpu()->ci_schedstate.spc_curpriority = p->p_priority;
488 }
489 
490 /*
491  * Used by copyin()/copyout()
492  */
493 extern vaddr_t vmaprange __P((struct proc *, vaddr_t, vsize_t, int));
494 extern void vunmaprange __P((vaddr_t, vsize_t));
495 static int bigcopyin __P((const void *,	void *,	size_t ));
496 static int bigcopyout __P((const void *, void *, size_t ));
497 
498 int
499 copyin(const void *udaddr, void *kaddr, size_t len)
500 {
501 	struct pmap *pm = curproc->p_vmspace->vm_map.pmap;
502 	int msr, pid, tmp, ctx;
503 	faultbuf env;
504 
505 	/* For bigger buffers use the faster copy */
506 	if (len > 256) return (bigcopyin(udaddr, kaddr, len));
507 
508 	if (setfault(env)) {
509 		curpcb->pcb_onfault = 0;
510 		return EFAULT;
511 	}
512 
513 	if (!(ctx = pm->pm_ctx)) {
514 		/* No context -- assign it one */
515 		ctx_alloc(pm);
516 		ctx = pm->pm_ctx;
517 	}
518 
519 	asm volatile("addi %6,%6,1; mtctr %6;"	/* Set up counter */
520 		"mfmsr %0;"			/* Save MSR */
521 		"li %1,0x20; "
522 		"andc %1,%0,%1; mtmsr %1;"	/* Disable IMMU */
523 		"mfpid %1;"			/* Save old PID */
524 		"sync; isync;"
525 
526 		"1: bdz 2f;"			/* while len */
527 		"mtpid %3; sync;"		/* Load user ctx */
528 		"lbz %2,0(%4); addi %4,%4,1;"	/* Load byte */
529 		"sync; isync;"
530 		"mtpid %1;sync;"
531 		"stb %2,0(%5); dcbf 0,%5; addi %5,%5,1;"	/* Store kernel byte */
532 		"sync; isync;"
533 		"b 1b;"				/* repeat */
534 
535 		"2: mtpid %1; mtmsr %0;"	/* Restore PID and MSR */
536 		"sync; isync;"
537 		: "=&r" (msr), "=&r" (pid), "=&r" (tmp)
538 		: "r" (ctx), "r" (udaddr), "r" (kaddr), "r" (len));
539 
540 	curpcb->pcb_onfault = 0;
541 	return 0;
542 }
543 
544 static int
545 bigcopyin(const void *udaddr, void *kaddr, size_t len)
546 {
547 	const char *up;
548 	char *kp = kaddr;
549 	struct proc *p = curproc;
550 	int error;
551 
552 	if (!p) {
553 		return EFAULT;
554 	}
555 
556 	/*
557 	 * Stolen from physio():
558 	 */
559 	PHOLD(p);
560 	error = uvm_vslock(p, (caddr_t)udaddr, len, VM_PROT_READ);
561 	if (error) {
562 		PRELE(p);
563 		return EFAULT;
564 	}
565 	up = (char *)vmaprange(p, (vaddr_t)udaddr, len, VM_PROT_READ);
566 
567 	memcpy(kp, up, len);
568 	vunmaprange((vaddr_t)up, len);
569 	uvm_vsunlock(p, (caddr_t)udaddr, len);
570 	PRELE(p);
571 
572 	return 0;
573 }
574 
575 int
576 copyout(const void *kaddr, void *udaddr, size_t len)
577 {
578 	struct pmap *pm = curproc->p_vmspace->vm_map.pmap;
579 	int msr, pid, tmp, ctx;
580 	faultbuf env;
581 
582 	/* For big copies use more efficient routine */
583 	if (len > 256) return (bigcopyout(kaddr, udaddr, len));
584 
585 	if (setfault(env)) {
586 		curpcb->pcb_onfault = 0;
587 		return EFAULT;
588 	}
589 
590 	if (!(ctx = pm->pm_ctx)) {
591 		/* No context -- assign it one */
592 		ctx_alloc(pm);
593 		ctx = pm->pm_ctx;
594 	}
595 
596 	asm volatile("addi %6,%6,1; mtctr %6;"	/* Set up counter */
597 		"mfmsr %0;"			/* Save MSR */
598 		"li %1,0x20; "
599 		"andc %1,%0,%1; mtmsr %1;"	/* Disable IMMU */
600 		"mfpid %1;"			/* Save old PID */
601 		"sync; isync;"
602 
603 		"1: bdz 2f;"			/* while len */
604 		"mtpid %1;sync;"
605 		"lbz %2,0(%5); addi %5,%5,1;"	/* Load kernel byte */
606 		"sync; isync;"
607 		"mtpid %3; sync;"		/* Load user ctx */
608 		"stb %2,0(%4);  dcbf 0,%4; addi %4,%4,1;"	/* Store user byte */
609 		"sync; isync;"
610 		"b 1b;"				/* repeat */
611 
612 		"2: mtpid %1; mtmsr %0;"	/* Restore PID and MSR */
613 		"sync; isync;"
614 		: "=&r" (msr), "=&r" (pid), "=&r" (tmp)
615 		: "r" (ctx), "r" (udaddr), "r" (kaddr), "r" (len));
616 
617 	curpcb->pcb_onfault = 0;
618 	return 0;
619 }
620 
621 static int
622 bigcopyout(const void *kaddr, void *udaddr, size_t len)
623 {
624 	char *up;
625 	const char *kp = (char *)kaddr;
626 	struct proc *p = curproc;
627 	int error;
628 
629 	if (!p) {
630 		return EFAULT;
631 	}
632 
633 	/*
634 	 * Stolen from physio():
635 	 */
636 	PHOLD(p);
637 	error = uvm_vslock(p, udaddr, len, VM_PROT_WRITE);
638 	if (error) {
639 		PRELE(p);
640 		return EFAULT;
641 	}
642 	up = (char *)vmaprange(p, (vaddr_t)udaddr, len,
643 		VM_PROT_READ|VM_PROT_WRITE);
644 
645 	memcpy(up, kp, len);
646 	vunmaprange((vaddr_t)up, len);
647 	uvm_vsunlock(p, udaddr, len);
648 	PRELE(p);
649 
650 	return 0;
651 }
652 
653 /*
654  * kcopy(const void *src, void *dst, size_t len);
655  *
656  * Copy len bytes from src to dst, aborting if we encounter a fatal
657  * page fault.
658  *
659  * kcopy() _must_ save and restore the old fault handler since it is
660  * called by uiomove(), which may be in the path of servicing a non-fatal
661  * page fault.
662  */
663 int
664 kcopy(const void *src, void *dst, size_t len)
665 {
666 	faultbuf env, *oldfault;
667 
668 	oldfault = curpcb->pcb_onfault;
669 	if (setfault(env)) {
670 		curpcb->pcb_onfault = oldfault;
671 		return EFAULT;
672 	}
673 
674 	memcpy(dst, src, len);
675 
676 	curpcb->pcb_onfault = oldfault;
677 	return 0;
678 }
679 
680 int
681 badaddr(void *addr, size_t size)
682 {
683 
684 	return badaddr_read(addr, size, NULL);
685 }
686 
687 int
688 badaddr_read(void *addr, size_t size, int *rptr)
689 {
690 	faultbuf env;
691 	int x;
692 
693 	/* Get rid of any stale machine checks that have been waiting.  */
694 	__asm __volatile ("sync; isync");
695 
696 	if (setfault(env)) {
697 		curpcb->pcb_onfault = 0;
698 		__asm __volatile ("sync");
699 		return 1;
700 	}
701 
702 	__asm __volatile ("sync");
703 
704 	switch (size) {
705 	case 1:
706 		x = *(volatile int8_t *)addr;
707 		break;
708 	case 2:
709 		x = *(volatile int16_t *)addr;
710 		break;
711 	case 4:
712 		x = *(volatile int32_t *)addr;
713 		break;
714 	default:
715 		panic("badaddr: invalid size (%d)", size);
716 	}
717 
718 	/* Make sure we took the machine check, if we caused one. */
719 	__asm __volatile ("sync; isync");
720 
721 	curpcb->pcb_onfault = 0;
722 	__asm __volatile ("sync");	/* To be sure. */
723 
724 	/* Use the value to avoid reorder. */
725 	if (rptr)
726 		*rptr = x;
727 
728 	return 0;
729 }
730 
731 /*
732  * For now, this only deals with the particular unaligned access case
733  * that gcc tends to generate.  Eventually it should handle all of the
734  * possibilities that can happen on a 32-bit PowerPC in big-endian mode.
735  */
736 
737 static int
738 fix_unaligned(struct proc *p, struct trapframe *frame)
739 {
740 
741 	return -1;
742 }
743