xref: /netbsd-src/sys/arch/powerpc/ibm4xx/trap.c (revision 3816d47b2c42fcd6e549e3407f842a5b1a1d23ad)
1 /*	$NetBSD: trap.c,v 1.53 2009/11/21 17:40:29 rmind 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 1.53 2009/11/21 17:40:29 rmind 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/pool.h>
82 #include <sys/sa.h>
83 #include <sys/savar.h>
84 #include <sys/userret.h>
85 #include <sys/kauth.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/cpu.h>
96 #include <machine/db_machdep.h>
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/spr.h>
104 #include <powerpc/ibm4xx/pmap.h>
105 #include <powerpc/ibm4xx/tlb.h>
106 #include <powerpc/fpu/fpu_extern.h>
107 
108 /* These definitions should probably be somewhere else			XXX */
109 #define	FIRSTARG	3		/* first argument is in reg 3 */
110 #define	NARGREG		8		/* 8 args are in registers */
111 #define	MOREARGS(sp)	((void *)((int)(sp) + 8)) /* more args go here */
112 
113 static int fix_unaligned(struct lwp *l, struct trapframe *frame);
114 
115 void trap(struct trapframe *);	/* Called from locore / trap_subr */
116 /* Why are these not defined in a header? */
117 int badaddr(void *, size_t);
118 int badaddr_read(void *, size_t, int *);
119 int ctx_setup(int, int);
120 
121 #ifdef DEBUG
122 #define TDB_ALL	0x1
123 int trapdebug = /* TDB_ALL */ 0;
124 #define	DBPRINTF(x, y)	if (trapdebug & (x)) printf y
125 #else
126 #define DBPRINTF(x, y)
127 #endif
128 
129 void
130 trap(struct trapframe *frame)
131 {
132 	struct lwp *l = curlwp;
133 	struct proc *p = l ? l->l_proc : NULL;
134 	struct pcb *pcb;
135 	int type = frame->exc;
136 	int ftype, rv;
137 	ksiginfo_t ksi;
138 
139 	KASSERT(l == NULL || (l->l_stat == LSONPROC));
140 
141 	if (frame->srr1 & PSL_PR) {
142 		LWP_CACHE_CREDS(l, p);
143 		type |= EXC_USER;
144 	}
145 
146 	ftype = VM_PROT_READ;
147 
148 	DBPRINTF(TDB_ALL, ("trap(%x) at %lx from frame %p &frame %p\n",
149 	    type, frame->srr0, frame, &frame));
150 
151 	switch (type) {
152 	case EXC_DEBUG|EXC_USER:
153 		{
154 			int srr2, srr3;
155 
156 			__asm volatile("mfspr %0,0x3f0" :
157 			    "=r" (rv), "=r" (srr2), "=r" (srr3) :);
158 			printf("debug reg is %x srr2 %x srr3 %x\n", rv, srr2,
159 			    srr3);
160 			/* XXX fall through or break here?! */
161 		}
162 		/*
163 		 * DEBUG intr -- probably single-step.
164 		 */
165 	case EXC_TRC|EXC_USER:
166 		frame->srr1 &= ~PSL_SE;
167 		KSI_INIT_TRAP(&ksi);
168 		ksi.ksi_signo = SIGTRAP;
169 		ksi.ksi_trap = EXC_TRC;
170 		ksi.ksi_addr = (void *)frame->srr0;
171 		trapsignal(l, &ksi);
172 		break;
173 
174 	/*
175 	 * If we could not find and install appropriate TLB entry, fall through.
176 	 */
177 
178 	case EXC_DSI:
179 		/* FALLTHROUGH */
180 	case EXC_DTMISS:
181 		{
182 			struct vm_map *map;
183 			vaddr_t va;
184 			struct faultbuf *fb = NULL;
185 
186 			va = frame->dar;
187 			if (frame->tf_xtra[TF_PID] == KERNEL_PID) {
188 				map = kernel_map;
189 			} else {
190 				map = &p->p_vmspace->vm_map;
191 				if ((l->l_flag & LW_SA)
192 				    && (~l->l_pflag & LP_SA_NOBLOCK)) {
193 					l->l_savp->savp_faultaddr = va;
194 					l->l_pflag |= LP_SA_PAGEFAULT;
195 				}
196 			}
197 
198 			if (frame->tf_xtra[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 			    frame->srr0,
204 			    (ftype & VM_PROT_WRITE) ? "write" : "read",
205 			    (void *)va, frame->tf_xtra[TF_ESR]));
206 			rv = uvm_fault(map, trunc_page(va), ftype);
207 			if (map != kernel_map) {
208 				l->l_pflag &= ~LP_SA_PAGEFAULT;
209 			}
210 			if (rv == 0)
211 				goto done;
212 			pcb = lwp_getpcb(l);
213 			if ((fb = pcb->pcb_onfault) != NULL) {
214 				frame->tf_xtra[TF_PID] = KERNEL_PID;
215 				frame->srr0 = fb->fb_pc;
216 				frame->srr1 |= PSL_IR; /* Re-enable IMMU */
217 				frame->fixreg[1] = fb->fb_sp;
218 				frame->fixreg[2] = fb->fb_r2;
219 				frame->fixreg[3] = 1; /* Return TRUE */
220 				frame->cr = fb->fb_cr;
221 				memcpy(&frame->fixreg[13], fb->fb_fixreg,
222 				    sizeof(fb->fb_fixreg));
223 				goto done;
224 			}
225 		}
226 		goto brain_damage;
227 
228 	case EXC_DSI|EXC_USER:
229 		/* FALLTHROUGH */
230 	case EXC_DTMISS|EXC_USER:
231 		if (frame->tf_xtra[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 		    frame->srr0, (ftype & VM_PROT_WRITE) ? "write" : "read",
237 		    frame->dar, frame->tf_xtra[TF_ESR]));
238 		KASSERT(l == curlwp && (l->l_stat == LSONPROC));
239 		if (l->l_flag & LW_SA) {
240 			l->l_savp->savp_faultaddr = (vaddr_t)frame->dar;
241 			l->l_pflag |= LP_SA_PAGEFAULT;
242 		}
243 		rv = uvm_fault(&p->p_vmspace->vm_map, trunc_page(frame->dar),
244 		    ftype);
245 		if (rv == 0) {
246 			l->l_pflag &= ~LP_SA_PAGEFAULT;
247 			break;
248 		}
249 		KSI_INIT_TRAP(&ksi);
250 		ksi.ksi_signo = SIGSEGV;
251 		ksi.ksi_trap = EXC_DSI;
252 		ksi.ksi_addr = (void *)frame->dar;
253 		if (rv == ENOMEM) {
254 			printf("UVM: pid %d (%s) lid %d, uid %d killed: "
255 			    "out of swap\n",
256 			    p->p_pid, p->p_comm, l->l_lid,
257 			    l->l_cred ?
258 			    kauth_cred_geteuid(l->l_cred) : -1);
259 			ksi.ksi_signo = SIGKILL;
260 		}
261 		trapsignal(l, &ksi);
262 		l->l_pflag &= ~LP_SA_PAGEFAULT;
263 		break;
264 
265 	case EXC_ITMISS|EXC_USER:
266 	case EXC_ISI|EXC_USER:
267 		if (l->l_flag & LW_SA) {
268 			l->l_savp->savp_faultaddr = (vaddr_t)frame->srr0;
269 			l->l_pflag |= LP_SA_PAGEFAULT;
270 		}
271 		ftype = VM_PROT_EXECUTE;
272 		DBPRINTF(TDB_ALL,
273 		    ("trap(EXC_ISI|EXC_USER) at %lx execute fault tf %p\n",
274 		    frame->srr0, frame));
275 		rv = uvm_fault(&p->p_vmspace->vm_map, trunc_page(frame->srr0),
276 		    ftype);
277 		if (rv == 0) {
278 			l->l_pflag &= ~LP_SA_PAGEFAULT;
279 			break;
280 		}
281 		KSI_INIT_TRAP(&ksi);
282 		ksi.ksi_signo = SIGSEGV;
283 		ksi.ksi_trap = EXC_ISI;
284 		ksi.ksi_addr = (void *)frame->srr0;
285 		ksi.ksi_code = (rv == EACCES ? SEGV_ACCERR : SEGV_MAPERR);
286 		trapsignal(l, &ksi);
287 		l->l_pflag &= ~LP_SA_PAGEFAULT;
288 		break;
289 
290 	case EXC_AST|EXC_USER:
291 		curcpu()->ci_astpending = 0;	/* we are about to do it */
292 		uvmexp.softs++;
293 		if (l->l_pflag & LP_OWEUPC) {
294 			l->l_pflag &= ~LP_OWEUPC;
295 			ADDUPROF(l);
296 		}
297 		/* Check whether we are being preempted. */
298 		if (curcpu()->ci_want_resched)
299 			preempt();
300 		break;
301 
302 
303 	case EXC_ALI|EXC_USER:
304 		if (fix_unaligned(l, frame) != 0) {
305 			KSI_INIT_TRAP(&ksi);
306 			ksi.ksi_signo = SIGBUS;
307 			ksi.ksi_trap = EXC_ALI;
308 			ksi.ksi_addr = (void *)frame->dar;
309 			trapsignal(l, &ksi);
310 		} else
311 			frame->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 		uvmexp.traps++;
321 		pcb = lwp_getpcb(l);
322 
323 		if (!(pcb->pcb_flags & PCB_FPU)) {
324 			memset(&pcb->pcb_fpu, 0, sizeof(pcb->pcb_fpu));
325 			pcb->pcb_flags |= PCB_FPU;
326 		}
327 
328 		if ((rv = fpu_emulate(frame, (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 *)frame->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 				frame->tf_xtra[TF_PID] = KERNEL_PID;
344 				frame->srr0 = fb->fb_pc;
345 				frame->srr1 |= PSL_IR; /* Re-enable IMMU */
346 				frame->fixreg[1] = fb->fb_sp;
347 				frame->fixreg[2] = fb->fb_r2;
348 				frame->fixreg[3] = 1; /* Return TRUE */
349 				frame->cr = fb->fb_cr;
350 				memcpy(&frame->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, frame->srr0);
359 #if defined(DDB) || defined(KGDB)
360 		if (kdb_trap(type, frame))
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 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 (setfault(&env)) {
429 		curpcb->pcb_onfault = 0;
430 		return EFAULT;
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 = 0;
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 	int error;
490 
491 	if (!l) {
492 		return EFAULT;
493 	}
494 
495 	p = l->l_proc;
496 
497 	/*
498 	 * Stolen from physio():
499 	 */
500 	error = uvm_vslock(p->p_vmspace, __UNCONST(udaddr), len, VM_PROT_READ);
501 	if (error) {
502 		return EFAULT;
503 	}
504 	up = (char *)vmaprange(p, (vaddr_t)udaddr, len, VM_PROT_READ);
505 
506 	memcpy(kp, up, len);
507 	vunmaprange((vaddr_t)up, len);
508 	uvm_vsunlock(p->p_vmspace, __UNCONST(udaddr), len);
509 
510 	return 0;
511 }
512 
513 int
514 copyout(const void *kaddr, void *udaddr, size_t len)
515 {
516 	struct pmap *pm = curproc->p_vmspace->vm_map.pmap;
517 	int msr, pid, tmp, ctx, count=0;
518 	struct faultbuf env;
519 
520 	/* For big copies use more efficient routine */
521 	if (len > 1024)
522 		return (bigcopyout(kaddr, udaddr, len));
523 
524 	if (setfault(&env)) {
525 		curpcb->pcb_onfault = 0;
526 		return EFAULT;
527 	}
528 
529 	if (!(ctx = pm->pm_ctx)) {
530 		/* No context -- assign it one */
531 		ctx_alloc(pm);
532 		ctx = pm->pm_ctx;
533 	}
534 
535 	__asm volatile(
536 		"   mfmsr %[msr];"          /* Save MSR */ \
537 		"   li %[pid],0x20; " \
538 		"   andc %[pid],%[msr],%[pid]; mtmsr %[pid];"   /* Disable IMMU */ \
539 		"   mfpid %[pid];"          /* Save old PID */ \
540 		"   sync; isync;"
541 
542 		"   srwi. %[count],%[len],0x2;"     /* How many words? */
543 		"   beq-  2f;"              /* No words. Go do bytes */
544 		"   mtctr %[count];"
545 		"1: mtpid %[pid];sync;"
546 		"   lswi %[tmp],%[kaddr],4;"        /* Load kernel word */
547 		"   addi %[kaddr],%[kaddr],0x4;"    /* next kaddr word */
548 		"   sync; isync;"
549 		"   mtpid %[ctx]; sync;"
550 		"   stswi %[tmp],%[udaddr],4;"       /* Store user word */
551 		"   dcbf 0,%[udaddr];"          /* flush cache */
552 		"   addi %[udaddr],%[udaddr],0x4;"  /* next udaddr word */
553 		"   sync; isync;"
554 		"   bdnz 1b;"               /* repeat */
555 
556 		"2: andi. %[count],%[len],0x3;"     /* How many remaining bytes? */
557 		"   addi %[count],%[count],0x1;"
558 		"   mtctr %[count];"
559 		"3: bdz  10f;"              /* while count */
560 		"   mtpid %[pid];sync;"
561 		"   lbz %[tmp],0(%[kaddr]);"        /* Load kernel byte */
562 		"   addi %[kaddr],%[kaddr],0x1;"    /* next kaddr byte */
563 		"   sync; isync;"
564 		"   mtpid %[ctx]; sync;"
565 		"   stb %[tmp],0(%[udaddr]);"       /* Store user byte */
566 		"   dcbf 0,%[udaddr];"          /* flush cache */
567 		"   addi %[udaddr],%[udaddr],0x1;"
568 		"   sync; isync;"
569 		"   b 3b;"
570 		"10:mtpid %[pid]; mtmsr %[msr]; sync; isync;" /* Restore PID and MSR */
571 		: [msr] "=&r" (msr), [pid] "=&r" (pid), [tmp] "=&r" (tmp)
572 		: [udaddr] "b" (udaddr), [ctx] "b" (ctx), [kaddr] "b" (kaddr), [len] "b" (len), [count] "b" (count));
573 
574 	curpcb->pcb_onfault = 0;
575 	return 0;
576 }
577 
578 static int
579 bigcopyout(const void *kaddr, void *udaddr, size_t len)
580 {
581 	char *up;
582 	const char *kp = (const char *)kaddr;
583 	struct lwp *l = curlwp;
584 	struct proc *p;
585 	int error;
586 
587 	if (!l) {
588 		return EFAULT;
589 	}
590 
591 	p = l->l_proc;
592 
593 	/*
594 	 * Stolen from physio():
595 	 */
596 	error = uvm_vslock(p->p_vmspace, udaddr, len, VM_PROT_WRITE);
597 	if (error) {
598 		return EFAULT;
599 	}
600 	up = (char *)vmaprange(p, (vaddr_t)udaddr, len,
601 	    VM_PROT_READ | VM_PROT_WRITE);
602 
603 	memcpy(up, kp, len);
604 	vunmaprange((vaddr_t)up, len);
605 	uvm_vsunlock(p->p_vmspace, udaddr, len);
606 
607 	return 0;
608 }
609 
610 /*
611  * kcopy(const void *src, void *dst, size_t len);
612  *
613  * Copy len bytes from src to dst, aborting if we encounter a fatal
614  * page fault.
615  *
616  * kcopy() _must_ save and restore the old fault handler since it is
617  * called by uiomove(), which may be in the path of servicing a non-fatal
618  * page fault.
619  */
620 int
621 kcopy(const void *src, void *dst, size_t len)
622 {
623 	struct faultbuf env, *oldfault;
624 
625 	oldfault = curpcb->pcb_onfault;
626 	if (setfault(&env)) {
627 		curpcb->pcb_onfault = oldfault;
628 		return EFAULT;
629 	}
630 
631 	memcpy(dst, src, len);
632 
633 	curpcb->pcb_onfault = oldfault;
634 	return 0;
635 }
636 
637 int
638 badaddr(void *addr, size_t size)
639 {
640 
641 	return badaddr_read(addr, size, NULL);
642 }
643 
644 int
645 badaddr_read(void *addr, size_t size, int *rptr)
646 {
647 	struct faultbuf env;
648 	int x;
649 
650 	/* Get rid of any stale machine checks that have been waiting.  */
651 	__asm volatile ("sync; isync");
652 
653 	if (setfault(&env)) {
654 		curpcb->pcb_onfault = 0;
655 		__asm volatile ("sync");
656 		return 1;
657 	}
658 
659 	__asm volatile ("sync");
660 
661 	switch (size) {
662 	case 1:
663 		x = *(volatile int8_t *)addr;
664 		break;
665 	case 2:
666 		x = *(volatile int16_t *)addr;
667 		break;
668 	case 4:
669 		x = *(volatile int32_t *)addr;
670 		break;
671 	default:
672 		panic("badaddr: invalid size (%d)", size);
673 	}
674 
675 	/* Make sure we took the machine check, if we caused one. */
676 	__asm volatile ("sync; isync");
677 
678 	curpcb->pcb_onfault = 0;
679 	__asm volatile ("sync");	/* To be sure. */
680 
681 	/* Use the value to avoid reorder. */
682 	if (rptr)
683 		*rptr = x;
684 
685 	return 0;
686 }
687 
688 /*
689  * For now, this only deals with the particular unaligned access case
690  * that gcc tends to generate.  Eventually it should handle all of the
691  * possibilities that can happen on a 32-bit PowerPC in big-endian mode.
692  */
693 
694 static int
695 fix_unaligned(struct lwp *l, struct trapframe *frame)
696 {
697 
698 	return -1;
699 }
700 
701 /*
702  * Start a new LWP
703  */
704 void
705 startlwp(void *arg)
706 {
707 	int err;
708 	ucontext_t *uc = arg;
709 	struct lwp *l = curlwp;
710 
711 	err = cpu_setmcontext(l, &uc->uc_mcontext, uc->uc_flags);
712 #if DIAGNOSTIC
713 	if (err) {
714 		printf("Error %d from cpu_setmcontext.", err);
715 	}
716 #endif
717 	pool_put(&lwp_uc_pool, uc);
718 
719 	upcallret(l);
720 }
721 
722 /*
723  * XXX This is a terrible name.
724  */
725 void
726 upcallret(struct lwp *l)
727 {
728 
729 	/* Invoke MI userret code */
730 	mi_userret(l);
731 }
732