xref: /netbsd-src/sys/arch/powerpc/ibm4xx/trap.c (revision 901e7e84758515fbf39dfc064cb0b45ab146d8b0)
1 /*	$NetBSD: trap.c,v 1.101 2022/10/05 08:18:00 rin 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 #define	__UFETCHSTORE_PRIVATE
70 
71 #include <sys/cdefs.h>
72 __KERNEL_RCSID(0, "$NetBSD: trap.c,v 1.101 2022/10/05 08:18:00 rin Exp $");
73 
74 #ifdef _KERNEL_OPT
75 #include "opt_ddb.h"
76 #include "opt_kgdb.h"
77 #include "opt_ppcarch.h"
78 #include "opt_ppcopts.h"
79 #endif
80 
81 #include <sys/param.h>
82 #include <sys/cpu.h>
83 #include <sys/kauth.h>
84 #include <sys/proc.h>
85 #include <sys/ptrace.h>
86 #include <sys/reboot.h>
87 #include <sys/syscall.h>
88 #include <sys/systm.h>
89 
90 #if defined(KGDB)
91 #include <sys/kgdb.h>
92 #endif
93 
94 #include <uvm/uvm_extern.h>
95 
96 #include <dev/cons.h>
97 
98 #include <machine/fpu.h>
99 #include <machine/frame.h>
100 #include <machine/pcb.h>
101 #include <machine/psl.h>
102 #include <machine/trap.h>
103 
104 #include <powerpc/db_machdep.h>
105 #include <powerpc/spr.h>
106 #include <powerpc/userret.h>
107 
108 #include <powerpc/ibm4xx/cpu.h>
109 #include <powerpc/ibm4xx/pmap.h>
110 #include <powerpc/ibm4xx/spr.h>
111 #include <powerpc/ibm4xx/tlb.h>
112 
113 #include <powerpc/fpu/fpu_extern.h>
114 
115 /* These definitions should probably be somewhere else			XXX */
116 #define	FIRSTARG	3		/* first argument is in reg 3 */
117 #define	NARGREG		8		/* 8 args are in registers */
118 #define	MOREARGS(sp)	((void *)((int)(sp) + 8)) /* more args go here */
119 
120 void trap(struct trapframe *);	/* Called from locore / trap_subr */
121 #if 0
122 /* Not currently used nor exposed externally in any header file */
123 int badaddr(void *, size_t);
124 int badaddr_read(void *, size_t, int *);
125 #endif
126 int ctx_setup(int, int);
127 
128 #ifndef PPC_NO_UNALIGNED
129 static bool fix_unaligned(struct trapframe *, ksiginfo_t *);
130 #endif
131 
132 #ifdef DEBUG
133 #define TDB_ALL	0x1
134 int trapdebug = /* TDB_ALL */ 0;
135 #define	DBPRINTF(x, y)	if (trapdebug & (x)) printf y
136 #else
137 #define DBPRINTF(x, y)
138 #endif
139 
140 void
141 trap(struct trapframe *tf)
142 {
143 	struct lwp *l = curlwp;
144 	struct proc *p = l->l_proc;
145 	struct pcb *pcb;
146 	int type = tf->tf_exc;
147 	int ftype, rv;
148 	ksiginfo_t ksi;
149 
150 	KASSERT(l->l_stat == LSONPROC);
151 
152 	if (tf->tf_srr1 & PSL_PR) {
153 		LWP_CACHE_CREDS(l, p);
154 		type |= EXC_USER;
155 	}
156 
157 	ftype = VM_PROT_READ;
158 
159 	DBPRINTF(TDB_ALL, ("trap(%x) at %lx from frame %p &frame %p\n",
160 	    type, tf->tf_srr0, tf, &tf));
161 
162 	switch (type) {
163 	case EXC_DEBUG|EXC_USER:
164 		/* We don't use hardware breakpoints for userland. */
165 		goto brain_damage;
166 
167 	case EXC_TRC|EXC_USER:
168 		KSI_INIT_TRAP(&ksi);
169 		ksi.ksi_signo = SIGTRAP;
170 		ksi.ksi_trap = EXC_TRC;
171 		ksi.ksi_addr = (void *)tf->tf_srr0;
172 		trapsignal(l, &ksi);
173 		break;
174 
175 	case EXC_DSI:
176 		/* FALLTHROUGH */
177 	case EXC_DTMISS:
178 		{
179 			struct vm_map *map;
180 			vaddr_t va;
181 			struct faultbuf *fb;
182 
183 			pcb = lwp_getpcb(l);
184 			fb = pcb->pcb_onfault;
185 
186 			if (curcpu()->ci_idepth >= 0) {
187 				rv = EFAULT;
188 				goto out;
189 			}
190 
191 			va = tf->tf_dear;
192 			if (tf->tf_pid == KERNEL_PID) {
193 				map = kernel_map;
194 			} else {
195 				map = &p->p_vmspace->vm_map;
196 			}
197 
198 			if (tf->tf_esr & (ESR_DST|ESR_DIZ))
199 				ftype = VM_PROT_WRITE;
200 
201 			DBPRINTF(TDB_ALL,
202 			    ("trap(EXC_DSI) at %lx %s fault on %p esr %x\n",
203 			    tf->tf_srr0,
204 			    (ftype & VM_PROT_WRITE) ? "write" : "read",
205 			    (void *)va, tf->tf_esr));
206 
207 			pcb->pcb_onfault = NULL;
208 			rv = uvm_fault(map, trunc_page(va), ftype);
209 			pcb->pcb_onfault = fb;
210 			if (rv == 0)
211 				return;
212 out:
213 			if (fb != NULL) {
214 				tf->tf_pid = KERNEL_PID;
215 				tf->tf_srr0 = fb->fb_pc;
216 				tf->tf_srr1 |= PSL_IR; /* Re-enable IMMU */
217 				tf->tf_cr = fb->fb_cr;
218 				tf->tf_fixreg[1] = fb->fb_sp;
219 				tf->tf_fixreg[2] = fb->fb_r2;
220 				tf->tf_fixreg[3] = rv;
221 				memcpy(&tf->tf_fixreg[13], fb->fb_fixreg,
222 				    sizeof(fb->fb_fixreg));
223 				return;
224 			}
225 		}
226 		goto brain_damage;
227 
228 	case EXC_DSI|EXC_USER:
229 		/* FALLTHROUGH */
230 	case EXC_DTMISS|EXC_USER:
231 		if (tf->tf_esr & (ESR_DST|ESR_DIZ))
232 			ftype = VM_PROT_WRITE;
233 
234 		DBPRINTF(TDB_ALL,
235 		    ("trap(EXC_DSI|EXC_USER) at %lx %s fault on %lx %x\n",
236 		    tf->tf_srr0, (ftype & VM_PROT_WRITE) ? "write" : "read",
237 		    tf->tf_dear, tf->tf_esr));
238 		KASSERT(l == curlwp && (l->l_stat == LSONPROC));
239 //		KASSERT(curpcb->pcb_onfault == NULL);
240 		rv = uvm_fault(&p->p_vmspace->vm_map, trunc_page(tf->tf_dear),
241 		    ftype);
242 		if (rv == 0) {
243 			break;
244 		}
245 		KSI_INIT_TRAP(&ksi);
246 		ksi.ksi_trap = EXC_DSI;
247 		ksi.ksi_addr = (void *)tf->tf_dear;
248 vm_signal:
249 		switch (rv) {
250 		case EINVAL:
251 			ksi.ksi_signo = SIGBUS;
252 			ksi.ksi_code = BUS_ADRERR;
253 			break;
254 		case EACCES:
255 			ksi.ksi_signo = SIGSEGV;
256 			ksi.ksi_code = SEGV_ACCERR;
257 			break;
258 		case ENOMEM:
259 			ksi.ksi_signo = SIGKILL;
260 			printf("UVM: pid %d.%d (%s), uid %d killed: "
261 			       "out of swap\n", p->p_pid, l->l_lid, p->p_comm,
262 			       l->l_cred ? kauth_cred_geteuid(l->l_cred) : -1);
263 			break;
264 		default:
265 			ksi.ksi_signo = SIGSEGV;
266 			ksi.ksi_code = SEGV_MAPERR;
267 			break;
268 		}
269 		trapsignal(l, &ksi);
270 		break;
271 
272 	case EXC_ITMISS|EXC_USER:
273 	case EXC_ISI|EXC_USER:
274 		ftype = VM_PROT_EXECUTE;
275 		DBPRINTF(TDB_ALL,
276 		    ("trap(EXC_ISI|EXC_USER) at %lx execute fault tf %p\n",
277 		    tf->tf_srr0, tf));
278 //		KASSERT(curpcb->pcb_onfault == NULL);
279 		rv = uvm_fault(&p->p_vmspace->vm_map, trunc_page(tf->tf_srr0),
280 		    ftype);
281 		if (rv == 0) {
282 			break;
283 		}
284 isi:
285 		KSI_INIT_TRAP(&ksi);
286 		ksi.ksi_trap = EXC_ISI;
287 		ksi.ksi_addr = (void *)tf->tf_srr0;
288 		goto vm_signal;
289 		break;
290 
291 	case EXC_AST|EXC_USER:
292 		cpu_ast(l, curcpu());
293 		break;
294 
295 	case EXC_ALI|EXC_USER:
296 		if (fix_unaligned(tf, &ksi))
297 			trapsignal(l, &ksi);
298 		break;
299 
300 	case EXC_PGM|EXC_USER:
301 		curcpu()->ci_data.cpu_ntrap++;
302 
303 		KSI_INIT_TRAP(&ksi);
304 		ksi.ksi_trap = EXC_PGM;
305 		ksi.ksi_addr = (void *)tf->tf_srr0;
306 
307 		if (tf->tf_esr & ESR_PTR) {
308 			vaddr_t va;
309 sigtrap:
310 			va = (vaddr_t)tf->tf_srr0;
311 			/*
312 		 	 * Restore original instruction and clear BP.
313 		 	 */
314 			if (p->p_md.md_ss_addr[0] == va ||
315 			    p->p_md.md_ss_addr[1] == va) {
316 				rv = ppc_sstep(l, 0);
317 				if (rv != 0)
318 					goto vm_signal;
319 				ksi.ksi_code = TRAP_TRACE;
320 			} else
321 				ksi.ksi_code = TRAP_BRKPT;
322 			if (p->p_raslist != NULL &&
323 			    ras_lookup(p, (void *)va) != (void *)-1) {
324 				tf->tf_srr0 += (ksi.ksi_code == TRAP_TRACE) ?
325 				    0 : 4;
326 				break;
327 			}
328 			ksi.ksi_signo = SIGTRAP;
329 		} else if (tf->tf_esr & ESR_PPR) {
330 			uint32_t opcode;
331 
332 			rv = copyin((void *)tf->tf_srr0, &opcode,
333 			    sizeof(opcode));
334 			if (rv)
335 				goto isi;
336 			if (emulate_mxmsr(l, tf, opcode)) {
337 				tf->tf_srr0 += 4;
338 				break;
339 			}
340 
341 			ksi.ksi_code = ILL_PRVOPC;
342 			ksi.ksi_signo = SIGILL;
343 		} else {
344 			pcb = lwp_getpcb(l);
345 
346 			if (__predict_false(!fpu_used_p(l))) {
347 				memset(&pcb->pcb_fpu, 0, sizeof(pcb->pcb_fpu));
348 				fpu_mark_used(l);
349 			}
350 
351 			if (fpu_emulate(tf, &pcb->pcb_fpu, &ksi)) {
352 				if (ksi.ksi_signo == 0)	/* was emulated */
353 					break;
354 				else if (ksi.ksi_signo == SIGTRAP)
355 					goto sigtrap;	/* XXX H/W bug? */
356 			} else {
357 				ksi.ksi_code = ILL_ILLOPC;
358 				ksi.ksi_signo = SIGILL;
359 			}
360 		}
361 
362 		trapsignal(l, &ksi);
363 		break;
364 
365 	case EXC_MCHK:
366 		{
367 			struct faultbuf *fb;
368 
369 			pcb = lwp_getpcb(l);
370 			if ((fb = pcb->pcb_onfault) != NULL) {
371 				tf->tf_pid = KERNEL_PID;
372 				tf->tf_srr0 = fb->fb_pc;
373 				tf->tf_srr1 |= PSL_IR; /* Re-enable IMMU */
374 				tf->tf_fixreg[1] = fb->fb_sp;
375 				tf->tf_fixreg[2] = fb->fb_r2;
376 				tf->tf_fixreg[3] = 1; /* Return TRUE */
377 				tf->tf_cr = fb->fb_cr;
378 				memcpy(&tf->tf_fixreg[13], fb->fb_fixreg,
379 				    sizeof(fb->fb_fixreg));
380 				return;
381 			}
382 		}
383 		goto brain_damage;
384 
385 	default:
386 brain_damage:
387 		printf("trap type 0x%x at 0x%lx\n", type, tf->tf_srr0);
388 #if defined(DDB) || defined(KGDB)
389 		if (kdb_trap(type, tf))
390 			return;
391 #endif
392 #ifdef TRAP_PANICWAIT
393 		printf("Press a key to panic.\n");
394 		cngetc();
395 #endif
396 		panic("trap");
397 	}
398 
399 	/* Invoke powerpc userret code */
400 	userret(l, tf);
401 }
402 
403 int
404 ctx_setup(int ctx, int srr1)
405 {
406 	volatile struct pmap *pm;
407 
408 	/* Update PID if we're returning to user mode. */
409 	if (srr1 & PSL_PR) {
410 		pm = curproc->p_vmspace->vm_map.pmap;
411 		if (!pm->pm_ctx) {
412 			ctx_alloc(__UNVOLATILE(pm));
413 		}
414 		ctx = pm->pm_ctx;
415 	}
416 	else if (!ctx) {
417 		ctx = KERNEL_PID;
418 	}
419 	return (ctx);
420 }
421 
422 /*
423  * Used by copyin()/copyout()
424  */
425 extern vaddr_t vmaprange(struct proc *, vaddr_t, vsize_t, int);
426 extern void vunmaprange(vaddr_t, vsize_t);
427 static int bigcopyin(const void *, void *, size_t );
428 static int bigcopyout(const void *, void *, size_t );
429 
430 #ifdef __clang__
431 #pragma clang optimize off
432 #endif
433 int
434 copyin(const void *uaddr, void *kaddr, size_t len)
435 {
436 	struct pmap *pm = curproc->p_vmspace->vm_map.pmap;
437 	int rv, msr, pid, tmp, ctx;
438 	struct faultbuf env;
439 
440 	/* For bigger buffers use the faster copy */
441 	if (len > 1024)
442 		return (bigcopyin(uaddr, kaddr, len));
443 
444 	if ((rv = setfault(&env))) {
445 		curpcb->pcb_onfault = NULL;
446 		return rv;
447 	}
448 
449 	if (!(ctx = pm->pm_ctx)) {
450 		/* No context -- assign it one */
451 		ctx_alloc(pm);
452 		ctx = pm->pm_ctx;
453 	}
454 
455 	__asm volatile (
456 		"mfmsr	%[msr];"		/* Save MSR */
457 		"li	%[tmp],0x20;"		/* Disable IMMU */
458 		"andc	%[tmp],%[msr],%[tmp];"
459 		"mtmsr	%[tmp];"
460 		"isync;"
461 		MFPID(%[pid])			/* Save old PID */
462 
463 		"srwi.	%[tmp],%[len],0x2;"	/* How many words? */
464 		"beq-	2f;"			/* No words. Go do bytes */
465 		"mtctr	%[tmp];"
466 
467 	"1:"	MTPID(%[ctx])
468 		"isync;"
469 #ifdef PPC_IBM403
470 		"lswi	%[tmp],%[uaddr],4;"	/* Load user word */
471 #else
472 		"lwz	%[tmp],0(%[uaddr]);"
473 #endif
474 		"addi	%[uaddr],%[uaddr],0x4;"	/* next uaddr word */
475 		"sync;"
476 
477 		MTPID(%[pid])
478 		"isync;"
479 #ifdef PPC_IBM403
480 		"stswi	%[tmp],%[kaddr],4;"	/* Store kernel word */
481 #else
482 		"stw	%[tmp],0(%[kaddr]);"
483 #endif
484 		"addi	%[kaddr],%[kaddr],0x4;"	/* next kaddr word */
485 		"sync;"
486 		"bdnz	1b;"			/* repeat */
487 
488 	"2:"	"andi.	%[tmp],%[len],0x3;"	/* How many remaining bytes? */
489 		"beq	10f;"
490 		"mtxer	%[tmp];"
491 
492 		MTPID(%[ctx])
493 		"isync;"
494 		"lswx	%[tmp],0,%[uaddr];"	/* Load user bytes */
495 		"sync;"
496 
497 		MTPID(%[pid])
498 		"isync;"
499 		"stswx	%[tmp],0,%[kaddr];"	/* Store kernel bytes */
500 		"sync;"
501 
502 	"10:"	"mtmsr	%[msr];"		/* Restore MSR */
503 		"isync;"
504 
505 		: [msr] "=&r" (msr), [pid] "=&r" (pid), [tmp] "=&r" (tmp)
506 		: [uaddr] "b" (uaddr), [kaddr] "b" (kaddr),
507 		  [ctx] "r" (ctx), [len] "r" (len)
508 		: "cr0", "ctr", "xer");
509 
510 	curpcb->pcb_onfault = NULL;
511 	return 0;
512 }
513 #ifdef __clang__
514 #pragma clang optimize on
515 #endif
516 
517 static int
518 bigcopyin(const void *uaddr, void *kaddr, size_t len)
519 {
520 	const char *up;
521 	char *kp = kaddr;
522 	struct lwp *l = curlwp;
523 	struct proc *p;
524 	struct faultbuf env;
525 	int error;
526 
527 	p = l->l_proc;
528 
529 	/*
530 	 * Stolen from physio():
531 	 */
532 	error = uvm_vslock(p->p_vmspace, __UNCONST(uaddr), len, VM_PROT_READ);
533 	if (error) {
534 		return error;
535 	}
536 	up = (char *)vmaprange(p, (vaddr_t)uaddr, len, VM_PROT_READ);
537 
538 	if ((error = setfault(&env)) == 0) {
539 		memcpy(kp, up, len);
540 	}
541 
542 	curpcb->pcb_onfault = NULL;
543 	vunmaprange((vaddr_t)up, len);
544 	uvm_vsunlock(p->p_vmspace, __UNCONST(uaddr), len);
545 
546 	return error;
547 }
548 
549 #ifdef __clang__
550 #pragma clang optimize off
551 #endif
552 int
553 copyout(const void *kaddr, void *uaddr, size_t len)
554 {
555 	struct pmap *pm = curproc->p_vmspace->vm_map.pmap;
556 	int rv, msr, pid, tmp, ctx;
557 	struct faultbuf env;
558 
559 	/* For big copies use more efficient routine */
560 	if (len > 1024)
561 		return (bigcopyout(kaddr, uaddr, len));
562 
563 	if ((rv = setfault(&env))) {
564 		curpcb->pcb_onfault = NULL;
565 		return rv;
566 	}
567 
568 	if (!(ctx = pm->pm_ctx)) {
569 		/* No context -- assign it one */
570 		ctx_alloc(pm);
571 		ctx = pm->pm_ctx;
572 	}
573 
574 	__asm volatile (
575 		"mfmsr	%[msr];"		/* Save MSR */
576 		"li	%[tmp],0x20;"		/* Disable IMMU */
577 		"andc	%[tmp],%[msr],%[tmp];"
578 		"mtmsr	%[tmp];"
579 		"isync;"
580 		MFPID(%[pid])			/* Save old PID */
581 
582 		"srwi.	%[tmp],%[len],0x2;"	/* How many words? */
583 		"beq-	2f;"			/* No words. Go do bytes */
584 		"mtctr	%[tmp];"
585 
586 	"1:"
587 #ifdef PPC_IBM403
588 		"lswi	%[tmp],%[kaddr],4;"	/* Load kernel word */
589 #else
590 		"lwz	%[tmp],0(%[kaddr]);"
591 #endif
592 		"addi	%[kaddr],%[kaddr],0x4;"	/* next kaddr word */
593 		"sync;"
594 
595 		MTPID(%[ctx])
596 		"isync;"
597 #ifdef PPC_IBM403
598 		"stswi	%[tmp],%[uaddr],4;"	/* Store user word */
599 #else
600 		"stw	%[tmp],0(%[uaddr]);"
601 #endif
602 		"addi	%[uaddr],%[uaddr],0x4;"	/* next uaddr word */
603 		"sync;"
604 
605 		MTPID(%[pid])
606 		"isync;"
607 		"bdnz	1b;"			/* repeat */
608 
609 	"2:"	"andi.	%[tmp],%[len],0x3;"	/* How many remaining bytes? */
610 		"beq	10f;"
611 		"mtxer	%[tmp];"
612 
613 		"lswx	%[tmp],0,%[kaddr];"	/* Load kernel bytes */
614 		"sync;"
615 
616 		MTPID(%[ctx])
617 		"isync;"
618 		"stswx	%[tmp],0,%[uaddr];"	/* Store user bytes */
619 		"sync;"
620 
621 		MTPID(%[pid])			/* Restore PID and MSR */
622 	"10:"	"mtmsr	%[msr];"
623 		"isync;"
624 
625 		: [msr] "=&r" (msr), [pid] "=&r" (pid), [tmp] "=&r" (tmp)
626 		: [uaddr] "b" (uaddr), [kaddr] "b" (kaddr),
627 		  [ctx] "r" (ctx), [len] "r" (len)
628 		: "cr0", "ctr", "xer");
629 
630 	curpcb->pcb_onfault = NULL;
631 	return 0;
632 }
633 #ifdef __clang__
634 #pragma clang optimize on
635 #endif
636 
637 static int
638 bigcopyout(const void *kaddr, void *uaddr, size_t len)
639 {
640 	char *up;
641 	const char *kp = (const char *)kaddr;
642 	struct lwp *l = curlwp;
643 	struct proc *p;
644 	struct faultbuf env;
645 	int error;
646 
647 	p = l->l_proc;
648 
649 	/*
650 	 * Stolen from physio():
651 	 */
652 	error = uvm_vslock(p->p_vmspace, uaddr, len, VM_PROT_WRITE);
653 	if (error) {
654 		return error;
655 	}
656 	up = (char *)vmaprange(p, (vaddr_t)uaddr, len,
657 	    VM_PROT_READ | VM_PROT_WRITE);
658 
659 	if ((error = setfault(&env)) == 0) {
660 		memcpy(up, kp, len);
661 	}
662 
663 	curpcb->pcb_onfault = NULL;
664 	vunmaprange((vaddr_t)up, len);
665 	uvm_vsunlock(p->p_vmspace, uaddr, len);
666 
667 	return error;
668 }
669 
670 /*
671  * kcopy(const void *src, void *dst, size_t len);
672  *
673  * Copy len bytes from src to dst, aborting if we encounter a fatal
674  * page fault.
675  *
676  * kcopy() _must_ save and restore the old fault handler since it is
677  * called by uiomove(), which may be in the path of servicing a non-fatal
678  * page fault.
679  */
680 int
681 kcopy(const void *src, void *dst, size_t len)
682 {
683 	struct faultbuf env, *oldfault;
684 	int rv;
685 
686 	oldfault = curpcb->pcb_onfault;
687 	if ((rv = setfault(&env))) {
688 		curpcb->pcb_onfault = oldfault;
689 		return rv;
690 	}
691 
692 	memcpy(dst, src, len);
693 
694 	curpcb->pcb_onfault = oldfault;
695 	return 0;
696 }
697 
698 #if 0
699 int
700 badaddr(void *addr, size_t size)
701 {
702 
703 	return badaddr_read(addr, size, NULL);
704 }
705 
706 int
707 badaddr_read(void *addr, size_t size, int *rptr)
708 {
709 	struct faultbuf env;
710 	int x;
711 
712 	/* Get rid of any stale machine checks that have been waiting.  */
713 	__asm volatile ("sync; isync");
714 
715 	if (setfault(&env)) {
716 		curpcb->pcb_onfault = NULL;
717 		__asm volatile ("sync");
718 		return 1;
719 	}
720 
721 	__asm volatile ("sync");
722 
723 	switch (size) {
724 	case 1:
725 		x = *(volatile int8_t *)addr;
726 		break;
727 	case 2:
728 		x = *(volatile int16_t *)addr;
729 		break;
730 	case 4:
731 		x = *(volatile int32_t *)addr;
732 		break;
733 	default:
734 		panic("badaddr: invalid size (%d)", size);
735 	}
736 
737 	/* Make sure we took the machine check, if we caused one. */
738 	__asm volatile ("sync; isync");
739 
740 	curpcb->pcb_onfault = NULL;
741 	__asm volatile ("sync");	/* To be sure. */
742 
743 	/* Use the value to avoid reorder. */
744 	if (rptr)
745 		*rptr = x;
746 
747 	return 0;
748 }
749 #endif
750 
751 #ifndef PPC_NO_UNALIGNED
752 static bool
753 fix_unaligned(struct trapframe *tf, ksiginfo_t *ksi)
754 {
755 
756 	KSI_INIT_TRAP(ksi);
757 	ksi->ksi_signo = SIGBUS;
758 	ksi->ksi_trap = EXC_ALI;
759 	ksi->ksi_addr = (void *)tf->tf_dear;
760 	return true;
761 }
762 #endif
763 
764 /*
765  * XXX Extremely lame implementations of _ufetch_* / _ustore_*.  IBM 4xx
766  * experts should make versions that are good.
767  */
768 
769 #define UFETCH(sz)							\
770 int									\
771 _ufetch_ ## sz(const uint ## sz ## _t *uaddr, uint ## sz ## _t *valp)	\
772 {									\
773 	return copyin(uaddr, valp, sizeof(*valp));			\
774 }
775 
776 UFETCH(8)
777 UFETCH(16)
778 UFETCH(32)
779 
780 #define USTORE(sz)							\
781 int									\
782 _ustore_ ## sz(uint ## sz ## _t *uaddr, uint ## sz ## _t val)		\
783 {									\
784 	return copyout(&val, uaddr, sizeof(val));			\
785 }
786 
787 USTORE(8)
788 USTORE(16)
789 USTORE(32)
790