xref: /netbsd-src/sys/arch/powerpc/ibm4xx/trap.c (revision 1b9578b8c2c1f848eeb16dabbfd7d1f0d9fdefbd)
1 /*	$NetBSD: trap.c,v 1.62 2011/06/21 06:38:50 matt 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 <sys/cdefs.h>
70 __KERNEL_RCSID(0, "$NetBSD: trap.c,v 1.62 2011/06/21 06:38:50 matt Exp $");
71 
72 #include "opt_altivec.h"
73 #include "opt_ddb.h"
74 #include "opt_kgdb.h"
75 
76 #include <sys/param.h>
77 #include <sys/proc.h>
78 #include <sys/reboot.h>
79 #include <sys/syscall.h>
80 #include <sys/systm.h>
81 #include <sys/sa.h>
82 #include <sys/savar.h>
83 #include <sys/userret.h>
84 #include <sys/kauth.h>
85 #include <sys/cpu.h>
86 
87 #if defined(KGDB)
88 #include <sys/kgdb.h>
89 #endif
90 
91 #include <uvm/uvm_extern.h>
92 
93 #include <dev/cons.h>
94 
95 #include <machine/fpu.h>
96 #include <machine/frame.h>
97 #include <machine/pcb.h>
98 #include <machine/psl.h>
99 #include <machine/trap.h>
100 
101 #include <powerpc/db_machdep.h>
102 #include <powerpc/spr.h>
103 #include <powerpc/ibm4xx/spr.h>
104 
105 #include <powerpc/ibm4xx/cpu.h>
106 #include <powerpc/ibm4xx/pmap.h>
107 #include <powerpc/ibm4xx/tlb.h>
108 
109 #include <powerpc/fpu/fpu_extern.h>
110 
111 /* These definitions should probably be somewhere else			XXX */
112 #define	FIRSTARG	3		/* first argument is in reg 3 */
113 #define	NARGREG		8		/* 8 args are in registers */
114 #define	MOREARGS(sp)	((void *)((int)(sp) + 8)) /* more args go here */
115 
116 static int fix_unaligned(struct lwp *l, struct trapframe *frame);
117 
118 void trap(struct trapframe *);	/* Called from locore / trap_subr */
119 /* Why are these not defined in a header? */
120 int badaddr(void *, size_t);
121 int badaddr_read(void *, size_t, int *);
122 int ctx_setup(int, int);
123 
124 #ifdef DEBUG
125 #define TDB_ALL	0x1
126 int trapdebug = /* TDB_ALL */ 0;
127 #define	DBPRINTF(x, y)	if (trapdebug & (x)) printf y
128 #else
129 #define DBPRINTF(x, y)
130 #endif
131 
132 void
133 trap(struct trapframe *tf)
134 {
135 	struct lwp *l = curlwp;
136 	struct proc *p = l->l_proc;
137 	struct pcb *pcb;
138 	int type = tf->tf_exc;
139 	int ftype, rv;
140 	ksiginfo_t ksi;
141 
142 	KASSERT(l->l_stat == LSONPROC);
143 
144 	if (tf->tf_srr1 & PSL_PR) {
145 		LWP_CACHE_CREDS(l, p);
146 		type |= EXC_USER;
147 	}
148 
149 	ftype = VM_PROT_READ;
150 
151 	DBPRINTF(TDB_ALL, ("trap(%x) at %lx from frame %p &frame %p\n",
152 	    type, tf->tf_srr0, tf, &tf));
153 
154 	switch (type) {
155 	case EXC_DEBUG|EXC_USER:
156 		{
157 			int srr2, srr3;
158 
159 			__asm volatile("mfspr %0,0x3f0" :
160 			    "=r" (rv), "=r" (srr2), "=r" (srr3) :);
161 			printf("debug reg is %x srr2 %x srr3 %x\n", rv, srr2,
162 			    srr3);
163 			/* XXX fall through or break here?! */
164 		}
165 		/*
166 		 * DEBUG intr -- probably single-step.
167 		 */
168 	case EXC_TRC|EXC_USER:
169 		tf->tf_srr1 &= ~PSL_SE;
170 		KSI_INIT_TRAP(&ksi);
171 		ksi.ksi_signo = SIGTRAP;
172 		ksi.ksi_trap = EXC_TRC;
173 		ksi.ksi_addr = (void *)tf->tf_srr0;
174 		trapsignal(l, &ksi);
175 		break;
176 
177 	/*
178 	 * If we could not find and install appropriate TLB entry, fall through.
179 	 */
180 
181 	case EXC_DSI:
182 		/* FALLTHROUGH */
183 	case EXC_DTMISS:
184 		{
185 			struct vm_map *map;
186 			vaddr_t va;
187 			struct faultbuf *fb = NULL;
188 
189 			va = tf->tf_dear;
190 			if (tf->tf_pid == KERNEL_PID) {
191 				map = kernel_map;
192 			} else {
193 				map = &p->p_vmspace->vm_map;
194 				if ((l->l_flag & LW_SA)
195 				    && (~l->l_pflag & LP_SA_NOBLOCK)) {
196 					l->l_savp->savp_faultaddr = va;
197 					l->l_pflag |= LP_SA_PAGEFAULT;
198 				}
199 			}
200 
201 			if (tf->tf_esr & (ESR_DST|ESR_DIZ))
202 				ftype = VM_PROT_WRITE;
203 
204 			DBPRINTF(TDB_ALL,
205 			    ("trap(EXC_DSI) at %lx %s fault on %p esr %x\n",
206 			    tf->tf_srr0,
207 			    (ftype & VM_PROT_WRITE) ? "write" : "read",
208 			    (void *)va, tf->tf_esr));
209 
210 			pcb = lwp_getpcb(l);
211 			fb = pcb->pcb_onfault;
212 			pcb->pcb_onfault = NULL;
213 			rv = uvm_fault(map, trunc_page(va), ftype);
214 			pcb->pcb_onfault = fb;
215 			if (map != kernel_map) {
216 				l->l_pflag &= ~LP_SA_PAGEFAULT;
217 			}
218 			if (rv == 0)
219 				goto done;
220 			if (fb != NULL) {
221 				tf->tf_pid = KERNEL_PID;
222 				tf->tf_srr0 = fb->fb_pc;
223 				tf->tf_srr1 |= PSL_IR; /* Re-enable IMMU */
224 				tf->tf_cr = fb->fb_cr;
225 				tf->tf_fixreg[1] = fb->fb_sp;
226 				tf->tf_fixreg[2] = fb->fb_r2;
227 				tf->tf_fixreg[3] = 1; /* Return TRUE */
228 				memcpy(&tf->tf_fixreg[13], fb->fb_fixreg,
229 				    sizeof(fb->fb_fixreg));
230 				goto done;
231 			}
232 		}
233 		goto brain_damage;
234 
235 	case EXC_DSI|EXC_USER:
236 		/* FALLTHROUGH */
237 	case EXC_DTMISS|EXC_USER:
238 		if (tf->tf_esr & (ESR_DST|ESR_DIZ))
239 			ftype = VM_PROT_WRITE;
240 
241 		DBPRINTF(TDB_ALL,
242 		    ("trap(EXC_DSI|EXC_USER) at %lx %s fault on %lx %x\n",
243 		    tf->tf_srr0, (ftype & VM_PROT_WRITE) ? "write" : "read",
244 		    tf->tf_dear, tf->tf_esr));
245 		KASSERT(l == curlwp && (l->l_stat == LSONPROC));
246 		if (l->l_flag & LW_SA) {
247 			l->l_savp->savp_faultaddr = (vaddr_t)tf->tf_dear;
248 			l->l_pflag |= LP_SA_PAGEFAULT;
249 		}
250 //		KASSERT(curpcb->pcb_onfault == NULL);
251 		rv = uvm_fault(&p->p_vmspace->vm_map, trunc_page(tf->tf_dear),
252 		    ftype);
253 		if (rv == 0) {
254 			l->l_pflag &= ~LP_SA_PAGEFAULT;
255 			break;
256 		}
257 		KSI_INIT_TRAP(&ksi);
258 		ksi.ksi_signo = SIGSEGV;
259 		ksi.ksi_trap = EXC_DSI;
260 		ksi.ksi_addr = (void *)tf->tf_dear;
261 		if (rv == ENOMEM) {
262 			printf("UVM: pid %d (%s) lid %d, uid %d killed: "
263 			    "out of swap\n",
264 			    p->p_pid, p->p_comm, l->l_lid,
265 			    l->l_cred ?
266 			    kauth_cred_geteuid(l->l_cred) : -1);
267 			ksi.ksi_signo = SIGKILL;
268 		}
269 		trapsignal(l, &ksi);
270 		l->l_pflag &= ~LP_SA_PAGEFAULT;
271 		break;
272 
273 	case EXC_ITMISS|EXC_USER:
274 	case EXC_ISI|EXC_USER:
275 		if (l->l_flag & LW_SA) {
276 			l->l_savp->savp_faultaddr = (vaddr_t)tf->tf_srr0;
277 			l->l_pflag |= LP_SA_PAGEFAULT;
278 		}
279 		ftype = VM_PROT_EXECUTE;
280 		DBPRINTF(TDB_ALL,
281 		    ("trap(EXC_ISI|EXC_USER) at %lx execute fault tf %p\n",
282 		    tf->tf_srr0, tf));
283 //		KASSERT(curpcb->pcb_onfault == NULL);
284 		rv = uvm_fault(&p->p_vmspace->vm_map, trunc_page(tf->tf_srr0),
285 		    ftype);
286 		if (rv == 0) {
287 			l->l_pflag &= ~LP_SA_PAGEFAULT;
288 			break;
289 		}
290 		KSI_INIT_TRAP(&ksi);
291 		ksi.ksi_signo = SIGSEGV;
292 		ksi.ksi_trap = EXC_ISI;
293 		ksi.ksi_addr = (void *)tf->tf_srr0;
294 		ksi.ksi_code = (rv == EACCES ? SEGV_ACCERR : SEGV_MAPERR);
295 		trapsignal(l, &ksi);
296 		l->l_pflag &= ~LP_SA_PAGEFAULT;
297 		break;
298 
299 	case EXC_AST|EXC_USER:
300 		cpu_ast(l, curcpu());
301 		break;
302 
303 	case EXC_ALI|EXC_USER:
304 		if (fix_unaligned(l, tf) != 0) {
305 			KSI_INIT_TRAP(&ksi);
306 			ksi.ksi_signo = SIGBUS;
307 			ksi.ksi_trap = EXC_ALI;
308 			ksi.ksi_addr = (void *)tf->tf_dear;
309 			trapsignal(l, &ksi);
310 		} else
311 			tf->tf_srr0 += 4;
312 		break;
313 
314 	case EXC_PGM|EXC_USER:
315 		/*
316 		 * Illegal insn:
317 		 *
318 		 * let's try to see if it's FPU and can be emulated.
319 		 */
320 		curcpu()->ci_data.cpu_ntrap++;
321 		pcb = lwp_getpcb(l);
322 
323 		if (!(l->l_md.md_flags & MDLWP_USEDFPU)) {
324 			memset(&pcb->pcb_fpu, 0, sizeof(pcb->pcb_fpu));
325 			l->l_md.md_flags |= MDLWP_USEDFPU;
326 		}
327 
328 		if ((rv = fpu_emulate(tf, (struct fpreg *)&pcb->pcb_fpu))) {
329 			KSI_INIT_TRAP(&ksi);
330 			ksi.ksi_signo = rv;
331 			ksi.ksi_trap = EXC_PGM;
332 			ksi.ksi_addr = (void *)tf->tf_srr0;
333 			trapsignal(l, &ksi);
334 		}
335 		break;
336 
337 	case EXC_MCHK:
338 		{
339 			struct faultbuf *fb;
340 
341 			pcb = lwp_getpcb(l);
342 			if ((fb = pcb->pcb_onfault) != NULL) {
343 				tf->tf_pid = KERNEL_PID;
344 				tf->tf_srr0 = fb->fb_pc;
345 				tf->tf_srr1 |= PSL_IR; /* Re-enable IMMU */
346 				tf->tf_fixreg[1] = fb->fb_sp;
347 				tf->tf_fixreg[2] = fb->fb_r2;
348 				tf->tf_fixreg[3] = 1; /* Return TRUE */
349 				tf->tf_cr = fb->fb_cr;
350 				memcpy(&tf->tf_fixreg[13], fb->fb_fixreg,
351 				    sizeof(fb->fb_fixreg));
352 				goto done;
353 			}
354 		}
355 		goto brain_damage;
356 	default:
357  brain_damage:
358 		printf("trap type 0x%x at 0x%lx\n", type, tf->tf_srr0);
359 #if defined(DDB) || defined(KGDB)
360 		if (kdb_trap(type, tf))
361 			goto done;
362 #endif
363 #ifdef TRAP_PANICWAIT
364 		printf("Press a key to panic.\n");
365 		cngetc();
366 #endif
367 		panic("trap");
368 	}
369 
370 	/* Invoke MI userret code */
371 	mi_userret(l);
372  done:
373 	return;
374 }
375 
376 int
377 ctx_setup(int ctx, int srr1)
378 {
379 	volatile struct pmap *pm;
380 
381 	/* Update PID if we're returning to user mode. */
382 	if (srr1 & PSL_PR) {
383 		pm = curproc->p_vmspace->vm_map.pmap;
384 		if (!pm->pm_ctx) {
385 			ctx_alloc(__UNVOLATILE(pm));
386 		}
387 		ctx = pm->pm_ctx;
388 		if (srr1 & PSL_SE) {
389 			int dbreg, mask = 0x48000000;
390 				/*
391 				 * Set the Internal Debug and
392 				 * Instruction Completion bits of
393 				 * the DBCR0 register.
394 				 *
395 				 * XXX this is also used by jtag debuggers...
396 				 */
397 			__asm volatile("mfspr %0,0x3f2;"
398 			    "or %0,%0,%1;"
399 			    "mtspr 0x3f2,%0;" :
400 			    "=&r" (dbreg) : "r" (mask));
401 		}
402 	}
403 	else if (!ctx) {
404 		ctx = KERNEL_PID;
405 	}
406 	return (ctx);
407 }
408 
409 /*
410  * Used by copyin()/copyout()
411  */
412 extern vaddr_t vmaprange(struct proc *, vaddr_t, vsize_t, int);
413 extern void vunmaprange(vaddr_t, vsize_t);
414 static int bigcopyin(const void *, void *, size_t );
415 static int bigcopyout(const void *, void *, size_t );
416 
417 int
418 copyin(const void *udaddr, void *kaddr, size_t len)
419 {
420 	struct pmap *pm = curproc->p_vmspace->vm_map.pmap;
421 	int rv, msr, pid, tmp, ctx, count = 0;
422 	struct faultbuf env;
423 
424 	/* For bigger buffers use the faster copy */
425 	if (len > 1024)
426 		return (bigcopyin(udaddr, kaddr, len));
427 
428 	if ((rv = setfault(&env))) {
429 		curpcb->pcb_onfault = NULL;
430 		return rv;
431 	}
432 
433 	if (!(ctx = pm->pm_ctx)) {
434 		/* No context -- assign it one */
435 		ctx_alloc(pm);
436 		ctx = pm->pm_ctx;
437 	}
438 
439 	__asm volatile(
440 		"   mfmsr %[msr];"          /* Save MSR */
441 		"   li %[pid],0x20; "
442 		"   andc %[pid],%[msr],%[pid]; mtmsr %[pid];"   /* Disable IMMU */
443 		"   mfpid %[pid];"          /* Save old PID */
444 		"   sync; isync;"
445 
446 		"   srwi. %[count],%[len],0x2;"     /* How many words? */
447 		"   beq-  2f;"              /* No words. Go do bytes */
448 		"   mtctr %[count];"
449 		"1: mtpid %[ctx]; sync;"
450 		"   lswi %[tmp],%[udaddr],4;"       /* Load user word */
451 		"   addi %[udaddr],%[udaddr],0x4;"  /* next udaddr word */
452 		"   sync; isync;"
453 		"   mtpid %[pid];sync;"
454 		"   stswi %[tmp],%[kaddr],4;"        /* Store kernel word */
455 		"   dcbf 0,%[kaddr];"           /* flush cache */
456 		"   addi %[kaddr],%[kaddr],0x4;"    /* next udaddr word */
457 		"   sync; isync;"
458 		"   bdnz 1b;"               /* repeat */
459 
460 		"2: andi. %[count],%[len],0x3;"     /* How many remaining bytes? */
461 		"   addi %[count],%[count],0x1;"
462 		"   mtctr %[count];"
463 		"3: bdz 10f;"               /* while count */
464 		"   mtpid %[ctx];sync;"
465 		"   lbz %[tmp],0(%[udaddr]);"       /* Load user byte */
466 		"   addi %[udaddr],%[udaddr],0x1;"  /* next udaddr byte */
467 		"   sync; isync;"
468 		"   mtpid %[pid]; sync;"
469 		"   stb %[tmp],0(%[kaddr]);"        /* Store kernel byte */
470 		"   dcbf 0,%[kaddr];"           /* flush cache */
471 		"   addi %[kaddr],%[kaddr],0x1;"
472 		"   sync; isync;"
473 		"   b 3b;"
474 		"10:mtpid %[pid]; mtmsr %[msr]; sync; isync;" /* Restore PID and MSR */
475 		: [msr] "=&r" (msr), [pid] "=&r" (pid), [tmp] "=&r" (tmp)
476 		: [udaddr] "b" (udaddr), [ctx] "b" (ctx), [kaddr] "b" (kaddr), [len] "b" (len), [count] "b" (count));
477 
478 	curpcb->pcb_onfault = NULL;
479 	return 0;
480 }
481 
482 static int
483 bigcopyin(const void *udaddr, void *kaddr, size_t len)
484 {
485 	const char *up;
486 	char *kp = kaddr;
487 	struct lwp *l = curlwp;
488 	struct proc *p;
489 	struct faultbuf env;
490 	int error;
491 
492 	p = l->l_proc;
493 
494 	/*
495 	 * Stolen from physio():
496 	 */
497 	error = uvm_vslock(p->p_vmspace, __UNCONST(udaddr), len, VM_PROT_READ);
498 	if (error) {
499 		return error;
500 	}
501 	up = (char *)vmaprange(p, (vaddr_t)udaddr, len, VM_PROT_READ);
502 
503 	if ((error = setfault(&env)) == 0) {
504 		memcpy(kp, up, len);
505 	}
506 
507 	curpcb->pcb_onfault = NULL;
508 	vunmaprange((vaddr_t)up, len);
509 	uvm_vsunlock(p->p_vmspace, __UNCONST(udaddr), len);
510 
511 	return error;
512 }
513 
514 int
515 copyout(const void *kaddr, void *udaddr, size_t len)
516 {
517 	struct pmap *pm = curproc->p_vmspace->vm_map.pmap;
518 	int rv, msr, pid, tmp, ctx, count = 0;
519 	struct faultbuf env;
520 
521 	/* For big copies use more efficient routine */
522 	if (len > 1024)
523 		return (bigcopyout(kaddr, udaddr, len));
524 
525 	if ((rv = setfault(&env))) {
526 		curpcb->pcb_onfault = NULL;
527 		return rv;
528 	}
529 
530 	if (!(ctx = pm->pm_ctx)) {
531 		/* No context -- assign it one */
532 		ctx_alloc(pm);
533 		ctx = pm->pm_ctx;
534 	}
535 
536 	__asm volatile(
537 		"   mfmsr %[msr];"          /* Save MSR */ \
538 		"   li %[pid],0x20; " \
539 		"   andc %[pid],%[msr],%[pid]; mtmsr %[pid];"   /* Disable IMMU */ \
540 		"   mfpid %[pid];"          /* Save old PID */ \
541 		"   sync; isync;"
542 
543 		"   srwi. %[count],%[len],0x2;"     /* How many words? */
544 		"   beq-  2f;"              /* No words. Go do bytes */
545 		"   mtctr %[count];"
546 		"1: mtpid %[pid];sync;"
547 		"   lswi %[tmp],%[kaddr],4;"        /* Load kernel word */
548 		"   addi %[kaddr],%[kaddr],0x4;"    /* next kaddr word */
549 		"   sync; isync;"
550 		"   mtpid %[ctx]; sync;"
551 		"   stswi %[tmp],%[udaddr],4;"       /* Store user word */
552 		"   dcbf 0,%[udaddr];"          /* flush cache */
553 		"   addi %[udaddr],%[udaddr],0x4;"  /* next udaddr word */
554 		"   sync; isync;"
555 		"   bdnz 1b;"               /* repeat */
556 
557 		"2: andi. %[count],%[len],0x3;"     /* How many remaining bytes? */
558 		"   addi %[count],%[count],0x1;"
559 		"   mtctr %[count];"
560 		"3: bdz  10f;"              /* while count */
561 		"   mtpid %[pid];sync;"
562 		"   lbz %[tmp],0(%[kaddr]);"        /* Load kernel byte */
563 		"   addi %[kaddr],%[kaddr],0x1;"    /* next kaddr byte */
564 		"   sync; isync;"
565 		"   mtpid %[ctx]; sync;"
566 		"   stb %[tmp],0(%[udaddr]);"       /* Store user byte */
567 		"   dcbf 0,%[udaddr];"          /* flush cache */
568 		"   addi %[udaddr],%[udaddr],0x1;"
569 		"   sync; isync;"
570 		"   b 3b;"
571 		"10:mtpid %[pid]; mtmsr %[msr]; sync; isync;" /* Restore PID and MSR */
572 		: [msr] "=&r" (msr), [pid] "=&r" (pid), [tmp] "=&r" (tmp)
573 		: [udaddr] "b" (udaddr), [ctx] "b" (ctx), [kaddr] "b" (kaddr), [len] "b" (len), [count] "b" (count));
574 
575 	curpcb->pcb_onfault = NULL;
576 	return 0;
577 }
578 
579 static int
580 bigcopyout(const void *kaddr, void *udaddr, size_t len)
581 {
582 	char *up;
583 	const char *kp = (const char *)kaddr;
584 	struct lwp *l = curlwp;
585 	struct proc *p;
586 	struct faultbuf env;
587 	int error;
588 
589 	p = l->l_proc;
590 
591 	/*
592 	 * Stolen from physio():
593 	 */
594 	error = uvm_vslock(p->p_vmspace, udaddr, len, VM_PROT_WRITE);
595 	if (error) {
596 		return error;
597 	}
598 	up = (char *)vmaprange(p, (vaddr_t)udaddr, len,
599 	    VM_PROT_READ | VM_PROT_WRITE);
600 
601 	if ((error = setfault(&env)) == 0) {
602 		memcpy(up, kp, len);
603 	}
604 
605 	curpcb->pcb_onfault = NULL;
606 	vunmaprange((vaddr_t)up, len);
607 	uvm_vsunlock(p->p_vmspace, udaddr, len);
608 
609 	return error;
610 }
611 
612 /*
613  * kcopy(const void *src, void *dst, size_t len);
614  *
615  * Copy len bytes from src to dst, aborting if we encounter a fatal
616  * page fault.
617  *
618  * kcopy() _must_ save and restore the old fault handler since it is
619  * called by uiomove(), which may be in the path of servicing a non-fatal
620  * page fault.
621  */
622 int
623 kcopy(const void *src, void *dst, size_t len)
624 {
625 	struct faultbuf env, *oldfault;
626 	int rv;
627 
628 	oldfault = curpcb->pcb_onfault;
629 	if ((rv = setfault(&env))) {
630 		curpcb->pcb_onfault = oldfault;
631 		return rv;
632 	}
633 
634 	memcpy(dst, src, len);
635 
636 	curpcb->pcb_onfault = oldfault;
637 	return 0;
638 }
639 
640 int
641 badaddr(void *addr, size_t size)
642 {
643 
644 	return badaddr_read(addr, size, NULL);
645 }
646 
647 int
648 badaddr_read(void *addr, size_t size, int *rptr)
649 {
650 	struct faultbuf env;
651 	int x;
652 
653 	/* Get rid of any stale machine checks that have been waiting.  */
654 	__asm volatile ("sync; isync");
655 
656 	if (setfault(&env)) {
657 		curpcb->pcb_onfault = NULL;
658 		__asm volatile ("sync");
659 		return 1;
660 	}
661 
662 	__asm volatile ("sync");
663 
664 	switch (size) {
665 	case 1:
666 		x = *(volatile int8_t *)addr;
667 		break;
668 	case 2:
669 		x = *(volatile int16_t *)addr;
670 		break;
671 	case 4:
672 		x = *(volatile int32_t *)addr;
673 		break;
674 	default:
675 		panic("badaddr: invalid size (%d)", size);
676 	}
677 
678 	/* Make sure we took the machine check, if we caused one. */
679 	__asm volatile ("sync; isync");
680 
681 	curpcb->pcb_onfault = NULL;
682 	__asm volatile ("sync");	/* To be sure. */
683 
684 	/* Use the value to avoid reorder. */
685 	if (rptr)
686 		*rptr = x;
687 
688 	return 0;
689 }
690 
691 /*
692  * For now, this only deals with the particular unaligned access case
693  * that gcc tends to generate.  Eventually it should handle all of the
694  * possibilities that can happen on a 32-bit PowerPC in big-endian mode.
695  */
696 
697 static int
698 fix_unaligned(struct lwp *l, struct trapframe *tf)
699 {
700 
701 	return -1;
702 }
703