xref: /netbsd-src/sys/arch/powerpc/ibm4xx/trap.c (revision 627f7eb200a4419d89b531d55fccd2ee3ffdcde0)
1 /*	$NetBSD: trap.c,v 1.86 2021/03/06 08:08:19 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 1.86 2021/03/06 08:08:19 rin Exp $");
73 
74 #ifdef _KERNEL_OPT
75 #include "opt_ddb.h"
76 #include "opt_kgdb.h"
77 #include "opt_ppcarch.h"
78 #endif
79 
80 #include <sys/param.h>
81 #include <sys/cpu.h>
82 #include <sys/kauth.h>
83 #include <sys/proc.h>
84 #include <sys/ptrace.h>
85 #include <sys/reboot.h>
86 #include <sys/syscall.h>
87 #include <sys/systm.h>
88 
89 #if defined(KGDB)
90 #include <sys/kgdb.h>
91 #endif
92 
93 #include <uvm/uvm_extern.h>
94 
95 #include <dev/cons.h>
96 
97 #include <machine/fpu.h>
98 #include <machine/frame.h>
99 #include <machine/pcb.h>
100 #include <machine/psl.h>
101 #include <machine/trap.h>
102 
103 #include <powerpc/db_machdep.h>
104 #include <powerpc/spr.h>
105 #include <powerpc/userret.h>
106 
107 #include <powerpc/ibm4xx/cpu.h>
108 #include <powerpc/ibm4xx/pmap.h>
109 #include <powerpc/ibm4xx/spr.h>
110 #include <powerpc/ibm4xx/tlb.h>
111 
112 #include <powerpc/fpu/fpu_extern.h>
113 
114 /* These definitions should probably be somewhere else			XXX */
115 #define	FIRSTARG	3		/* first argument is in reg 3 */
116 #define	NARGREG		8		/* 8 args are in registers */
117 #define	MOREARGS(sp)	((void *)((int)(sp) + 8)) /* more args go here */
118 
119 static int fix_unaligned(struct lwp *l, struct trapframe *tf);
120 
121 void trap(struct trapframe *);	/* Called from locore / trap_subr */
122 #if 0
123 /* Not currently used nor exposed externally in any header file */
124 int badaddr(void *, size_t);
125 int badaddr_read(void *, size_t, int *);
126 #endif
127 int ctx_setup(int, int);
128 
129 #ifdef DEBUG
130 #define TDB_ALL	0x1
131 int trapdebug = /* TDB_ALL */ 0;
132 #define	DBPRINTF(x, y)	if (trapdebug & (x)) printf y
133 #else
134 #define DBPRINTF(x, y)
135 #endif
136 
137 void
138 trap(struct trapframe *tf)
139 {
140 	struct lwp *l = curlwp;
141 	struct proc *p = l->l_proc;
142 	struct pcb *pcb;
143 	int type = tf->tf_exc;
144 	int ftype, rv;
145 	ksiginfo_t ksi;
146 
147 	KASSERT(l->l_stat == LSONPROC);
148 
149 	if (tf->tf_srr1 & PSL_PR) {
150 		LWP_CACHE_CREDS(l, p);
151 		type |= EXC_USER;
152 	}
153 
154 	ftype = VM_PROT_READ;
155 
156 	DBPRINTF(TDB_ALL, ("trap(%x) at %lx from frame %p &frame %p\n",
157 	    type, tf->tf_srr0, tf, &tf));
158 
159 	switch (type) {
160 	case EXC_DEBUG|EXC_USER:
161 		/* We don't use hardware breakpoints for userland. */
162 		goto brain_damage;
163 
164 	case EXC_TRC|EXC_USER:
165 		KSI_INIT_TRAP(&ksi);
166 		ksi.ksi_signo = SIGTRAP;
167 		ksi.ksi_trap = EXC_TRC;
168 		ksi.ksi_addr = (void *)tf->tf_srr0;
169 		trapsignal(l, &ksi);
170 		break;
171 
172 	case EXC_DSI:
173 		/* FALLTHROUGH */
174 	case EXC_DTMISS:
175 		{
176 			struct vm_map *map;
177 			vaddr_t va;
178 			struct faultbuf *fb;
179 
180 			pcb = lwp_getpcb(l);
181 			fb = pcb->pcb_onfault;
182 
183 			if (curcpu()->ci_idepth >= 0) {
184 				rv = EFAULT;
185 				goto out;
186 			}
187 
188 			va = tf->tf_dear;
189 			if (tf->tf_pid == KERNEL_PID) {
190 				map = kernel_map;
191 			} else {
192 				map = &p->p_vmspace->vm_map;
193 			}
194 
195 			if (tf->tf_esr & (ESR_DST|ESR_DIZ))
196 				ftype = VM_PROT_WRITE;
197 
198 			DBPRINTF(TDB_ALL,
199 			    ("trap(EXC_DSI) at %lx %s fault on %p esr %x\n",
200 			    tf->tf_srr0,
201 			    (ftype & VM_PROT_WRITE) ? "write" : "read",
202 			    (void *)va, tf->tf_esr));
203 
204 			pcb->pcb_onfault = NULL;
205 			rv = uvm_fault(map, trunc_page(va), ftype);
206 			pcb->pcb_onfault = fb;
207 			if (rv == 0)
208 				return;
209 out:
210 			if (fb != NULL) {
211 				tf->tf_pid = KERNEL_PID;
212 				tf->tf_srr0 = fb->fb_pc;
213 				tf->tf_srr1 |= PSL_IR; /* Re-enable IMMU */
214 				tf->tf_cr = fb->fb_cr;
215 				tf->tf_fixreg[1] = fb->fb_sp;
216 				tf->tf_fixreg[2] = fb->fb_r2;
217 				tf->tf_fixreg[3] = rv;
218 				memcpy(&tf->tf_fixreg[13], fb->fb_fixreg,
219 				    sizeof(fb->fb_fixreg));
220 				return;
221 			}
222 		}
223 		goto brain_damage;
224 
225 	case EXC_DSI|EXC_USER:
226 		/* FALLTHROUGH */
227 	case EXC_DTMISS|EXC_USER:
228 		if (tf->tf_esr & (ESR_DST|ESR_DIZ))
229 			ftype = VM_PROT_WRITE;
230 
231 		DBPRINTF(TDB_ALL,
232 		    ("trap(EXC_DSI|EXC_USER) at %lx %s fault on %lx %x\n",
233 		    tf->tf_srr0, (ftype & VM_PROT_WRITE) ? "write" : "read",
234 		    tf->tf_dear, tf->tf_esr));
235 		KASSERT(l == curlwp && (l->l_stat == LSONPROC));
236 //		KASSERT(curpcb->pcb_onfault == NULL);
237 		rv = uvm_fault(&p->p_vmspace->vm_map, trunc_page(tf->tf_dear),
238 		    ftype);
239 		if (rv == 0) {
240 			break;
241 		}
242 		KSI_INIT_TRAP(&ksi);
243 		ksi.ksi_trap = EXC_DSI;
244 		ksi.ksi_addr = (void *)tf->tf_dear;
245 vm_signal:
246 		switch (rv) {
247 		case EINVAL:
248 			ksi.ksi_signo = SIGBUS;
249 			ksi.ksi_code = BUS_ADRERR;
250 			break;
251 		case EACCES:
252 			ksi.ksi_signo = SIGSEGV;
253 			ksi.ksi_code = SEGV_ACCERR;
254 			break;
255 		case ENOMEM:
256 			ksi.ksi_signo = SIGKILL;
257 			printf("UVM: pid %d.%d (%s), uid %d killed: "
258 			       "out of swap\n", p->p_pid, l->l_lid, p->p_comm,
259 			       l->l_cred ? kauth_cred_geteuid(l->l_cred) : -1);
260 			break;
261 		default:
262 			ksi.ksi_signo = SIGSEGV;
263 			ksi.ksi_code = SEGV_MAPERR;
264 			break;
265 		}
266 		trapsignal(l, &ksi);
267 		break;
268 
269 	case EXC_ITMISS|EXC_USER:
270 	case EXC_ISI|EXC_USER:
271 		ftype = VM_PROT_EXECUTE;
272 		DBPRINTF(TDB_ALL,
273 		    ("trap(EXC_ISI|EXC_USER) at %lx execute fault tf %p\n",
274 		    tf->tf_srr0, tf));
275 //		KASSERT(curpcb->pcb_onfault == NULL);
276 		rv = uvm_fault(&p->p_vmspace->vm_map, trunc_page(tf->tf_srr0),
277 		    ftype);
278 		if (rv == 0) {
279 			break;
280 		}
281 isi:
282 		KSI_INIT_TRAP(&ksi);
283 		ksi.ksi_trap = EXC_ISI;
284 		ksi.ksi_addr = (void *)tf->tf_srr0;
285 		goto vm_signal;
286 		break;
287 
288 	case EXC_AST|EXC_USER:
289 		cpu_ast(l, curcpu());
290 		break;
291 
292 	case EXC_ALI|EXC_USER:
293 		if (fix_unaligned(l, tf) != 0) {
294 			KSI_INIT_TRAP(&ksi);
295 			ksi.ksi_signo = SIGBUS;
296 			ksi.ksi_trap = EXC_ALI;
297 			ksi.ksi_addr = (void *)tf->tf_dear;
298 			trapsignal(l, &ksi);
299 		} else
300 			tf->tf_srr0 += 4;
301 		break;
302 
303 	case EXC_PGM|EXC_USER:
304 		curcpu()->ci_data.cpu_ntrap++;
305 
306 		KSI_INIT_TRAP(&ksi);
307 		ksi.ksi_trap = EXC_PGM;
308 		ksi.ksi_addr = (void *)tf->tf_srr0;
309 
310 		if (tf->tf_esr & ESR_PTR) {
311 			vaddr_t va;
312 sigtrap:
313 			va = (vaddr_t)tf->tf_srr0;
314 			/*
315 		 	 * Restore original instruction and clear BP.
316 		 	 */
317 			if (p->p_md.md_ss_addr[0] == va ||
318 			    p->p_md.md_ss_addr[1] == va) {
319 				rv = ppc_sstep(l, 0);
320 				if (rv != 0)
321 					goto vm_signal;
322 				ksi.ksi_code = TRAP_TRACE;
323 			} else
324 				ksi.ksi_code = TRAP_BRKPT;
325 			if (p->p_raslist != NULL &&
326 			    ras_lookup(p, (void *)va) != (void *)-1) {
327 				tf->tf_srr0 += (ksi.ksi_code == TRAP_TRACE) ?
328 				    0 : 4;
329 				break;
330 			}
331 			ksi.ksi_signo = SIGTRAP;
332 		} else if (tf->tf_esr & ESR_PPR) {
333 			uint32_t opcode;
334 
335 			rv = copyin((void *)tf->tf_srr0, &opcode,
336 			    sizeof(opcode));
337 			if (rv)
338 				goto isi;
339 			if (emulate_mxmsr(l, tf, opcode)) {
340 				tf->tf_srr0 += 4;
341 				break;
342 			}
343 
344 			ksi.ksi_code = ILL_PRVOPC;
345 			ksi.ksi_signo = SIGILL;
346 		} else {
347 			pcb = lwp_getpcb(l);
348 
349 			if (__predict_false(!fpu_used_p(l))) {
350 				memset(&pcb->pcb_fpu, 0, sizeof(pcb->pcb_fpu));
351 				fpu_mark_used(l);
352 			}
353 
354 			if (fpu_emulate(tf, &pcb->pcb_fpu, &ksi)) {
355 				if (ksi.ksi_signo == 0)	/* was emulated */
356 					break;
357 				else if (ksi.ksi_signo == SIGTRAP)
358 					goto sigtrap;	/* XXX H/W bug? */
359 			} else {
360 				ksi.ksi_code = ILL_ILLOPC;
361 				ksi.ksi_signo = SIGILL;
362 			}
363 		}
364 
365 		trapsignal(l, &ksi);
366 		break;
367 
368 	case EXC_MCHK:
369 		{
370 			struct faultbuf *fb;
371 
372 			pcb = lwp_getpcb(l);
373 			if ((fb = pcb->pcb_onfault) != NULL) {
374 				tf->tf_pid = KERNEL_PID;
375 				tf->tf_srr0 = fb->fb_pc;
376 				tf->tf_srr1 |= PSL_IR; /* Re-enable IMMU */
377 				tf->tf_fixreg[1] = fb->fb_sp;
378 				tf->tf_fixreg[2] = fb->fb_r2;
379 				tf->tf_fixreg[3] = 1; /* Return TRUE */
380 				tf->tf_cr = fb->fb_cr;
381 				memcpy(&tf->tf_fixreg[13], fb->fb_fixreg,
382 				    sizeof(fb->fb_fixreg));
383 				return;
384 			}
385 		}
386 		goto brain_damage;
387 
388 	default:
389 brain_damage:
390 		printf("trap type 0x%x at 0x%lx\n", type, tf->tf_srr0);
391 #if defined(DDB) || defined(KGDB)
392 		if (kdb_trap(type, tf))
393 			return;
394 #endif
395 #ifdef TRAP_PANICWAIT
396 		printf("Press a key to panic.\n");
397 		cngetc();
398 #endif
399 		panic("trap");
400 	}
401 
402 	/* Invoke powerpc userret code */
403 	userret(l, tf);
404 }
405 
406 int
407 ctx_setup(int ctx, int srr1)
408 {
409 	volatile struct pmap *pm;
410 
411 	/* Update PID if we're returning to user mode. */
412 	if (srr1 & PSL_PR) {
413 		pm = curproc->p_vmspace->vm_map.pmap;
414 		if (!pm->pm_ctx) {
415 			ctx_alloc(__UNVOLATILE(pm));
416 		}
417 		ctx = pm->pm_ctx;
418 	}
419 	else if (!ctx) {
420 		ctx = KERNEL_PID;
421 	}
422 	return (ctx);
423 }
424 
425 /*
426  * Used by copyin()/copyout()
427  */
428 extern vaddr_t vmaprange(struct proc *, vaddr_t, vsize_t, int);
429 extern void vunmaprange(vaddr_t, vsize_t);
430 static int bigcopyin(const void *, void *, size_t );
431 static int bigcopyout(const void *, void *, size_t );
432 
433 int
434 copyin(const void *udaddr, void *kaddr, size_t len)
435 {
436 	struct pmap *pm = curproc->p_vmspace->vm_map.pmap;
437 	int rv, msr, pid, tmp, ctx, count = 0;
438 	struct faultbuf env;
439 
440 	/* For bigger buffers use the faster copy */
441 	if (len > 1024)
442 		return (bigcopyin(udaddr, 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 %[pid],0x20;"
458 		"   andc %[pid],%[msr],%[pid]; mtmsr %[pid];" /* Disable IMMU */
459 		"   isync;"
460 		"   mfpid %[pid];"		/* Save old PID */
461 
462 		"   srwi. %[count],%[len],0x2;"	/* How many words? */
463 		"   beq- 2f;"			/* No words. Go do bytes */
464 		"   mtctr %[count];"
465 		"1: mtpid %[ctx]; isync;"
466 #ifdef PPC_IBM403
467 		"   lswi %[tmp],%[udaddr],4;"	/* Load user word */
468 #else
469 		"   lwz %[tmp],0(%[udaddr]);"
470 #endif
471 		"   addi %[udaddr],%[udaddr],0x4;" /* next udaddr word */
472 		"   sync;"
473 		"   mtpid %[pid]; isync;"
474 #ifdef PPC_IBM403
475 		"   stswi %[tmp],%[kaddr],4;"	/* Store kernel word */
476 #else
477 		"   stw %[tmp],0(%[kaddr]);"
478 #endif
479 		"   dcbst 0,%[kaddr];"		/* flush cache */
480 		"   addi %[kaddr],%[kaddr],0x4;" /* next udaddr word */
481 		"   sync;"
482 		"   bdnz 1b;"			/* repeat */
483 
484 		"2: andi. %[count],%[len],0x3;"	/* How many remaining bytes? */
485 		"   addi %[count],%[count],0x1;"
486 		"   mtctr %[count];"
487 		"3: bdz 10f;"			/* while count */
488 		"   mtpid %[ctx]; isync;"
489 		"   lbz %[tmp],0(%[udaddr]);"	/* Load user byte */
490 		"   addi %[udaddr],%[udaddr],0x1;" /* next udaddr byte */
491 		"   sync;"
492 		"   mtpid %[pid]; isync;"
493 		"   stb %[tmp],0(%[kaddr]);"	/* Store kernel byte */
494 		"   dcbst 0,%[kaddr];"		/* flush cache */
495 		"   addi %[kaddr],%[kaddr],0x1;"
496 		"   sync;"
497 		"   b 3b;"
498 		"10:mtpid %[pid]; mtmsr %[msr]; isync;"
499 						/* Restore PID and MSR */
500 		: [msr] "=&r" (msr), [pid] "=&r" (pid), [tmp] "=&r" (tmp)
501 		: [udaddr] "b" (udaddr), [ctx] "b" (ctx), [kaddr] "b" (kaddr),
502 		  [len] "b" (len), [count] "b" (count));
503 
504 	curpcb->pcb_onfault = NULL;
505 	return 0;
506 }
507 
508 static int
509 bigcopyin(const void *udaddr, void *kaddr, size_t len)
510 {
511 	const char *up;
512 	char *kp = kaddr;
513 	struct lwp *l = curlwp;
514 	struct proc *p;
515 	struct faultbuf env;
516 	int error;
517 
518 	p = l->l_proc;
519 
520 	/*
521 	 * Stolen from physio():
522 	 */
523 	error = uvm_vslock(p->p_vmspace, __UNCONST(udaddr), len, VM_PROT_READ);
524 	if (error) {
525 		return error;
526 	}
527 	up = (char *)vmaprange(p, (vaddr_t)udaddr, len, VM_PROT_READ);
528 
529 	if ((error = setfault(&env)) == 0) {
530 		memcpy(kp, up, len);
531 	}
532 
533 	curpcb->pcb_onfault = NULL;
534 	vunmaprange((vaddr_t)up, len);
535 	uvm_vsunlock(p->p_vmspace, __UNCONST(udaddr), len);
536 
537 	return error;
538 }
539 
540 int
541 copyout(const void *kaddr, void *udaddr, size_t len)
542 {
543 	struct pmap *pm = curproc->p_vmspace->vm_map.pmap;
544 	int rv, msr, pid, tmp, ctx, count = 0;
545 	struct faultbuf env;
546 
547 	/* For big copies use more efficient routine */
548 	if (len > 1024)
549 		return (bigcopyout(kaddr, udaddr, len));
550 
551 	if ((rv = setfault(&env))) {
552 		curpcb->pcb_onfault = NULL;
553 		return rv;
554 	}
555 
556 	if (!(ctx = pm->pm_ctx)) {
557 		/* No context -- assign it one */
558 		ctx_alloc(pm);
559 		ctx = pm->pm_ctx;
560 	}
561 
562 	__asm volatile(
563 		"   mfmsr %[msr];"		/* Save MSR */
564 		"   li %[pid],0x20;"
565 		"   andc %[pid],%[msr],%[pid]; mtmsr %[pid];" /* Disable IMMU */
566 		"   isync;"
567 		"   mfpid %[pid];"		/* Save old PID */
568 
569 		"   srwi. %[count],%[len],0x2;"	/* How many words? */
570 		"   beq- 2f;"			/* No words. Go do bytes */
571 		"   mtctr %[count];"
572 		"1: mtpid %[pid]; isync;"
573 #ifdef PPC_IBM403
574 		"   lswi %[tmp],%[kaddr],4;"	/* Load kernel word */
575 #else
576 		"   lwz %[tmp],0(%[kaddr]);"
577 #endif
578 		"   addi %[kaddr],%[kaddr],0x4;" /* next kaddr word */
579 		"   sync;"
580 		"   mtpid %[ctx]; isync;"
581 #ifdef PPC_IBM403
582 		"   stswi %[tmp],%[udaddr],4;"	/* Store user word */
583 #else
584 		"   stw %[tmp],0(%[udaddr]);"
585 #endif
586 		"   dcbst 0,%[udaddr];"		/* flush cache */
587 		"   addi %[udaddr],%[udaddr],0x4;" /* next udaddr word */
588 		"   sync;"
589 		"   bdnz 1b;"			/* repeat */
590 
591 		"2: andi. %[count],%[len],0x3;"	/* How many remaining bytes? */
592 		"   addi %[count],%[count],0x1;"
593 		"   mtctr %[count];"
594 		"3: bdz  10f;"			/* while count */
595 		"   mtpid %[pid]; isync;"
596 		"   lbz %[tmp],0(%[kaddr]);"	/* Load kernel byte */
597 		"   addi %[kaddr],%[kaddr],0x1;" /* next kaddr byte */
598 		"   sync;"
599 		"   mtpid %[ctx]; isync;"
600 		"   stb %[tmp],0(%[udaddr]);"	/* Store user byte */
601 		"   dcbst 0,%[udaddr];"		/* flush cache */
602 		"   addi %[udaddr],%[udaddr],0x1;"
603 		"   sync;"
604 		"   b 3b;"
605 		"10:mtpid %[pid]; mtmsr %[msr]; isync;"
606 						/* Restore PID and MSR */
607 		: [msr] "=&r" (msr), [pid] "=&r" (pid), [tmp] "=&r" (tmp)
608 		: [udaddr] "b" (udaddr), [ctx] "b" (ctx), [kaddr] "b" (kaddr),
609 		  [len] "b" (len), [count] "b" (count));
610 
611 	curpcb->pcb_onfault = NULL;
612 	return 0;
613 }
614 
615 static int
616 bigcopyout(const void *kaddr, void *udaddr, size_t len)
617 {
618 	char *up;
619 	const char *kp = (const char *)kaddr;
620 	struct lwp *l = curlwp;
621 	struct proc *p;
622 	struct faultbuf env;
623 	int error;
624 
625 	p = l->l_proc;
626 
627 	/*
628 	 * Stolen from physio():
629 	 */
630 	error = uvm_vslock(p->p_vmspace, udaddr, len, VM_PROT_WRITE);
631 	if (error) {
632 		return error;
633 	}
634 	up = (char *)vmaprange(p, (vaddr_t)udaddr, len,
635 	    VM_PROT_READ | VM_PROT_WRITE);
636 
637 	if ((error = setfault(&env)) == 0) {
638 		memcpy(up, kp, len);
639 	}
640 
641 	curpcb->pcb_onfault = NULL;
642 	vunmaprange((vaddr_t)up, len);
643 	uvm_vsunlock(p->p_vmspace, udaddr, len);
644 
645 	return error;
646 }
647 
648 /*
649  * kcopy(const void *src, void *dst, size_t len);
650  *
651  * Copy len bytes from src to dst, aborting if we encounter a fatal
652  * page fault.
653  *
654  * kcopy() _must_ save and restore the old fault handler since it is
655  * called by uiomove(), which may be in the path of servicing a non-fatal
656  * page fault.
657  */
658 int
659 kcopy(const void *src, void *dst, size_t len)
660 {
661 	struct faultbuf env, *oldfault;
662 	int rv;
663 
664 	oldfault = curpcb->pcb_onfault;
665 	if ((rv = setfault(&env))) {
666 		curpcb->pcb_onfault = oldfault;
667 		return rv;
668 	}
669 
670 	memcpy(dst, src, len);
671 
672 	curpcb->pcb_onfault = oldfault;
673 	return 0;
674 }
675 
676 #if 0
677 int
678 badaddr(void *addr, size_t size)
679 {
680 
681 	return badaddr_read(addr, size, NULL);
682 }
683 
684 int
685 badaddr_read(void *addr, size_t size, int *rptr)
686 {
687 	struct faultbuf env;
688 	int x;
689 
690 	/* Get rid of any stale machine checks that have been waiting.  */
691 	__asm volatile ("sync; isync");
692 
693 	if (setfault(&env)) {
694 		curpcb->pcb_onfault = NULL;
695 		__asm volatile ("sync");
696 		return 1;
697 	}
698 
699 	__asm volatile ("sync");
700 
701 	switch (size) {
702 	case 1:
703 		x = *(volatile int8_t *)addr;
704 		break;
705 	case 2:
706 		x = *(volatile int16_t *)addr;
707 		break;
708 	case 4:
709 		x = *(volatile int32_t *)addr;
710 		break;
711 	default:
712 		panic("badaddr: invalid size (%d)", size);
713 	}
714 
715 	/* Make sure we took the machine check, if we caused one. */
716 	__asm volatile ("sync; isync");
717 
718 	curpcb->pcb_onfault = NULL;
719 	__asm volatile ("sync");	/* To be sure. */
720 
721 	/* Use the value to avoid reorder. */
722 	if (rptr)
723 		*rptr = x;
724 
725 	return 0;
726 }
727 #endif
728 
729 /*
730  * For now, this only deals with the particular unaligned access case
731  * that gcc tends to generate.  Eventually it should handle all of the
732  * possibilities that can happen on a 32-bit PowerPC in big-endian mode.
733  */
734 
735 static int
736 fix_unaligned(struct lwp *l, struct trapframe *tf)
737 {
738 
739 	return -1;
740 }
741 
742 /*
743  * XXX Extremely lame implementations of _ufetch_* / _ustore_*.  IBM 4xx
744  * experts should make versions that are good.
745  */
746 
747 #define UFETCH(sz)							\
748 int									\
749 _ufetch_ ## sz(const uint ## sz ## _t *uaddr, uint ## sz ## _t *valp)	\
750 {									\
751 	return copyin(uaddr, valp, sizeof(*valp));			\
752 }
753 
754 UFETCH(8)
755 UFETCH(16)
756 UFETCH(32)
757 
758 #define USTORE(sz)							\
759 int									\
760 _ustore_ ## sz(uint ## sz ## _t *uaddr, uint ## sz ## _t val)		\
761 {									\
762 	return copyout(&val, uaddr, sizeof(val));			\
763 }
764 
765 USTORE(8)
766 USTORE(16)
767 USTORE(32)
768