xref: /netbsd-src/sys/arch/powerpc/ibm4xx/trap.c (revision 466a16a118933bd295a8a104f095714fadf9cf68)
1 /*	$NetBSD: trap.c,v 1.49 2008/10/15 06:51:18 wrstuden 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 1.49 2008/10/15 06:51:18 wrstuden 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/user.h>
82 #include <sys/pool.h>
83 #include <sys/sa.h>
84 #include <sys/savar.h>
85 #include <sys/userret.h>
86 #include <sys/kauth.h>
87 
88 #if defined(KGDB)
89 #include <sys/kgdb.h>
90 #endif
91 
92 #include <uvm/uvm_extern.h>
93 
94 #include <dev/cons.h>
95 
96 #include <machine/cpu.h>
97 #include <machine/db_machdep.h>
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/spr.h>
105 #include <powerpc/ibm4xx/pmap.h>
106 #include <powerpc/ibm4xx/tlb.h>
107 #include <powerpc/fpu/fpu_extern.h>
108 
109 /* These definitions should probably be somewhere else			XXX */
110 #define	FIRSTARG	3		/* first argument is in reg 3 */
111 #define	NARGREG		8		/* 8 args are in registers */
112 #define	MOREARGS(sp)	((void *)((int)(sp) + 8)) /* more args go here */
113 
114 static int fix_unaligned __P((struct lwp *l, struct trapframe *frame));
115 
116 void trap __P((struct trapframe *));	/* Called from locore / trap_subr */
117 /* Why are these not defined in a header? */
118 int badaddr __P((void *, size_t));
119 int badaddr_read __P((void *, size_t, int *));
120 int ctx_setup __P((int, int));
121 
122 #ifdef DEBUG
123 #define TDB_ALL	0x1
124 int trapdebug = /* TDB_ALL */ 0;
125 #define	DBPRINTF(x, y)	if (trapdebug & (x)) printf y
126 #else
127 #define DBPRINTF(x, y)
128 #endif
129 
130 void
131 trap(struct trapframe *frame)
132 {
133 	struct lwp *l = curlwp;
134 	struct proc *p = l ? l->l_proc : NULL;
135 	int type = frame->exc;
136 	int ftype, rv;
137 	ksiginfo_t ksi;
138 
139 	KASSERT(l == 0 || (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 			if ((fb = l->l_addr->u_pcb.pcb_onfault) != NULL) {
213 				frame->tf_xtra[TF_PID] = KERNEL_PID;
214 				frame->srr0 = fb->fb_pc;
215 				frame->srr1 |= PSL_IR; /* Re-enable IMMU */
216 				frame->fixreg[1] = fb->fb_sp;
217 				frame->fixreg[2] = fb->fb_r2;
218 				frame->fixreg[3] = 1; /* Return TRUE */
219 				frame->cr = fb->fb_cr;
220 				memcpy(&frame->fixreg[13], fb->fb_fixreg,
221 				    sizeof(fb->fb_fixreg));
222 				goto done;
223 			}
224 		}
225 		goto brain_damage;
226 
227 	case EXC_DSI|EXC_USER:
228 		/* FALLTHROUGH */
229 	case EXC_DTMISS|EXC_USER:
230 		if (frame->tf_xtra[TF_ESR] & (ESR_DST|ESR_DIZ))
231 			ftype = VM_PROT_WRITE;
232 
233 		DBPRINTF(TDB_ALL,
234 		    ("trap(EXC_DSI|EXC_USER) at %lx %s fault on %lx %x\n",
235 		    frame->srr0, (ftype & VM_PROT_WRITE) ? "write" : "read",
236 		    frame->dar, frame->tf_xtra[TF_ESR]));
237 		KASSERT(l == curlwp && (l->l_stat == LSONPROC));
238 		if (l->l_flag & LW_SA) {
239 			l->l_savp->savp_faultaddr = (vaddr_t)frame->dar;
240 			l->l_pflag |= LP_SA_PAGEFAULT;
241 		}
242 		rv = uvm_fault(&p->p_vmspace->vm_map, trunc_page(frame->dar),
243 		    ftype);
244 		if (rv == 0) {
245 			l->l_pflag &= ~LP_SA_PAGEFAULT;
246 			break;
247 		}
248 		KSI_INIT_TRAP(&ksi);
249 		ksi.ksi_signo = SIGSEGV;
250 		ksi.ksi_trap = EXC_DSI;
251 		ksi.ksi_addr = (void *)frame->dar;
252 		if (rv == ENOMEM) {
253 			printf("UVM: pid %d (%s) lid %d, uid %d killed: "
254 			    "out of swap\n",
255 			    p->p_pid, p->p_comm, l->l_lid,
256 			    l->l_cred ?
257 			    kauth_cred_geteuid(l->l_cred) : -1);
258 			ksi.ksi_signo = SIGKILL;
259 		}
260 		trapsignal(l, &ksi);
261 		l->l_pflag &= ~LP_SA_PAGEFAULT;
262 		break;
263 
264 	case EXC_ITMISS|EXC_USER:
265 	case EXC_ISI|EXC_USER:
266 		if (l->l_flag & LW_SA) {
267 			l->l_savp->savp_faultaddr = (vaddr_t)frame->srr0;
268 			l->l_pflag |= LP_SA_PAGEFAULT;
269 		}
270 		ftype = VM_PROT_EXECUTE;
271 		DBPRINTF(TDB_ALL,
272 		    ("trap(EXC_ISI|EXC_USER) at %lx execute fault tf %p\n",
273 		    frame->srr0, frame));
274 		rv = uvm_fault(&p->p_vmspace->vm_map, trunc_page(frame->srr0),
275 		    ftype);
276 		if (rv == 0) {
277 			l->l_pflag &= ~LP_SA_PAGEFAULT;
278 			break;
279 		}
280 		KSI_INIT_TRAP(&ksi);
281 		ksi.ksi_signo = SIGSEGV;
282 		ksi.ksi_trap = EXC_ISI;
283 		ksi.ksi_addr = (void *)frame->srr0;
284 		ksi.ksi_code = (rv == EACCES ? SEGV_ACCERR : SEGV_MAPERR);
285 		trapsignal(l, &ksi);
286 		l->l_pflag &= ~LP_SA_PAGEFAULT;
287 		break;
288 
289 	case EXC_AST|EXC_USER:
290 		curcpu()->ci_astpending = 0;	/* we are about to do it */
291 		uvmexp.softs++;
292 		if (l->l_pflag & LP_OWEUPC) {
293 			l->l_pflag &= ~LP_OWEUPC;
294 			ADDUPROF(l);
295 		}
296 		/* Check whether we are being preempted. */
297 		if (curcpu()->ci_want_resched)
298 			preempt();
299 		break;
300 
301 
302 	case EXC_ALI|EXC_USER:
303 		if (fix_unaligned(l, frame) != 0) {
304 			KSI_INIT_TRAP(&ksi);
305 			ksi.ksi_signo = SIGBUS;
306 			ksi.ksi_trap = EXC_ALI;
307 			ksi.ksi_addr = (void *)frame->dar;
308 			trapsignal(l, &ksi);
309 		} else
310 			frame->srr0 += 4;
311 		break;
312 
313 	case EXC_PGM|EXC_USER:
314 		/*
315 		 * Illegal insn:
316 		 *
317 		 * let's try to see if it's FPU and can be emulated.
318 		 */
319 		uvmexp.traps++;
320 		if (!(l->l_addr->u_pcb.pcb_flags & PCB_FPU)) {
321 			memset(&l->l_addr->u_pcb.pcb_fpu, 0,
322 				sizeof l->l_addr->u_pcb.pcb_fpu);
323 			l->l_addr->u_pcb.pcb_flags |= PCB_FPU;
324 		}
325 
326 		if ((rv = fpu_emulate(frame,
327 			(struct fpreg *)&l->l_addr->u_pcb.pcb_fpu))) {
328 			KSI_INIT_TRAP(&ksi);
329 			ksi.ksi_signo = rv;
330 			ksi.ksi_trap = EXC_PGM;
331 			ksi.ksi_addr = (void *)frame->srr0;
332 			trapsignal(l, &ksi);
333 		}
334 		break;
335 
336 	case EXC_MCHK:
337 		{
338 			struct faultbuf *fb;
339 
340 			if ((fb = l->l_addr->u_pcb.pcb_onfault) != NULL) {
341 				frame->tf_xtra[TF_PID] = KERNEL_PID;
342 				frame->srr0 = fb->fb_pc;
343 				frame->srr1 |= PSL_IR; /* Re-enable IMMU */
344 				frame->fixreg[1] = fb->fb_sp;
345 				frame->fixreg[2] = fb->fb_r2;
346 				frame->fixreg[3] = 1; /* Return TRUE */
347 				frame->cr = fb->fb_cr;
348 				memcpy(&frame->fixreg[13], fb->fb_fixreg,
349 				    sizeof(fb->fb_fixreg));
350 				goto done;
351 			}
352 		}
353 		goto brain_damage;
354 	default:
355  brain_damage:
356 		printf("trap type 0x%x at 0x%lx\n", type, frame->srr0);
357 #if defined(DDB) || defined(KGDB)
358 		if (kdb_trap(type, frame))
359 			goto done;
360 #endif
361 #ifdef TRAP_PANICWAIT
362 		printf("Press a key to panic.\n");
363 		cngetc();
364 #endif
365 		panic("trap");
366 	}
367 
368 	/* Invoke MI userret code */
369 	mi_userret(l);
370  done:
371 	return;
372 }
373 
374 int
375 ctx_setup(int ctx, int srr1)
376 {
377 	volatile struct pmap *pm;
378 
379 	/* Update PID if we're returning to user mode. */
380 	if (srr1 & PSL_PR) {
381 		pm = curproc->p_vmspace->vm_map.pmap;
382 		if (!pm->pm_ctx) {
383 			ctx_alloc(__UNVOLATILE(pm));
384 		}
385 		ctx = pm->pm_ctx;
386 		if (srr1 & PSL_SE) {
387 			int dbreg, mask = 0x48000000;
388 				/*
389 				 * Set the Internal Debug and
390 				 * Instruction Completion bits of
391 				 * the DBCR0 register.
392 				 *
393 				 * XXX this is also used by jtag debuggers...
394 				 */
395 			__asm volatile("mfspr %0,0x3f2;"
396 			    "or %0,%0,%1;"
397 			    "mtspr 0x3f2,%0;" :
398 			    "=&r" (dbreg) : "r" (mask));
399 		}
400 	}
401 	else if (!ctx) {
402 		ctx = KERNEL_PID;
403 	}
404 	return (ctx);
405 }
406 
407 /*
408  * Used by copyin()/copyout()
409  */
410 extern vaddr_t vmaprange __P((struct proc *, vaddr_t, vsize_t, int));
411 extern void vunmaprange __P((vaddr_t, vsize_t));
412 static int bigcopyin __P((const void *, void *, size_t ));
413 static int bigcopyout __P((const void *, void *, size_t ));
414 
415 int
416 copyin(const void *udaddr, void *kaddr, size_t len)
417 {
418 	struct pmap *pm = curproc->p_vmspace->vm_map.pmap;
419 	int msr, pid, tmp, ctx, count=0;
420 	struct faultbuf env;
421 
422 	/* For bigger buffers use the faster copy */
423 	if (len > 1024)
424 		return (bigcopyin(udaddr, kaddr, len));
425 
426 	if (setfault(&env)) {
427 		curpcb->pcb_onfault = 0;
428 		return EFAULT;
429 	}
430 
431 	if (!(ctx = pm->pm_ctx)) {
432 		/* No context -- assign it one */
433 		ctx_alloc(pm);
434 		ctx = pm->pm_ctx;
435 	}
436 
437 	__asm volatile(
438 		"   mfmsr %[msr];"          /* Save MSR */
439 		"   li %[pid],0x20; "
440 		"   andc %[pid],%[msr],%[pid]; mtmsr %[pid];"   /* Disable IMMU */
441 		"   mfpid %[pid];"          /* Save old PID */
442 		"   sync; isync;"
443 
444 		"   srwi. %[count],%[len],0x2;"     /* How many words? */
445 		"   beq-  2f;"              /* No words. Go do bytes */
446 		"   mtctr %[count];"
447 		"1: mtpid %[ctx]; sync;"
448 		"   lswi %[tmp],%[udaddr],4;"       /* Load user word */
449 		"   addi %[udaddr],%[udaddr],0x4;"  /* next udaddr word */
450 		"   sync; isync;"
451 		"   mtpid %[pid];sync;"
452 		"   stswi %[tmp],%[kaddr],4;"        /* Store kernel word */
453 		"   dcbf 0,%[kaddr];"           /* flush cache */
454 		"   addi %[kaddr],%[kaddr],0x4;"    /* next udaddr word */
455 		"   sync; isync;"
456 		"   bdnz 1b;"               /* repeat */
457 
458 		"2: andi. %[count],%[len],0x3;"     /* How many remaining bytes? */
459 		"   addi %[count],%[count],0x1;"
460 		"   mtctr %[count];"
461 		"3: bdz 10f;"               /* while count */
462 		"   mtpid %[ctx];sync;"
463 		"   lbz %[tmp],0(%[udaddr]);"       /* Load user byte */
464 		"   addi %[udaddr],%[udaddr],0x1;"  /* next udaddr byte */
465 		"   sync; isync;"
466 		"   mtpid %[pid]; sync;"
467 		"   stb %[tmp],0(%[kaddr]);"        /* Store kernel byte */
468 		"   dcbf 0,%[kaddr];"           /* flush cache */
469 		"   addi %[kaddr],%[kaddr],0x1;"
470 		"   sync; isync;"
471 		"   b 3b;"
472 		"10:mtpid %[pid]; mtmsr %[msr]; sync; isync;" /* Restore PID and MSR */
473 		: [msr] "=&r" (msr), [pid] "=&r" (pid), [tmp] "=&r" (tmp)
474 		: [udaddr] "b" (udaddr), [ctx] "b" (ctx), [kaddr] "b" (kaddr), [len] "b" (len), [count] "b" (count));
475 
476 	curpcb->pcb_onfault = 0;
477 	return 0;
478 }
479 
480 static int
481 bigcopyin(const void *udaddr, void *kaddr, size_t len)
482 {
483 	const char *up;
484 	char *kp = kaddr;
485 	struct lwp *l = curlwp;
486 	struct proc *p;
487 	int error;
488 
489 	if (!l) {
490 		return EFAULT;
491 	}
492 
493 	p = l->l_proc;
494 
495 	/*
496 	 * Stolen from physio():
497 	 */
498 	uvm_lwp_hold(l);
499 	error = uvm_vslock(p->p_vmspace, __UNCONST(udaddr), len, VM_PROT_READ);
500 	if (error) {
501 		uvm_lwp_rele(l);
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 	uvm_lwp_rele(l);
510 
511 	return 0;
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 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 (setfault(&env)) {
526 		curpcb->pcb_onfault = 0;
527 		return EFAULT;
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 = 0;
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 	int error;
587 
588 	if (!l) {
589 		return EFAULT;
590 	}
591 
592 	p = l->l_proc;
593 
594 	/*
595 	 * Stolen from physio():
596 	 */
597 	uvm_lwp_hold(l);
598 	error = uvm_vslock(p->p_vmspace, udaddr, len, VM_PROT_WRITE);
599 	if (error) {
600 		uvm_lwp_rele(l);
601 		return EFAULT;
602 	}
603 	up = (char *)vmaprange(p, (vaddr_t)udaddr, len,
604 	    VM_PROT_READ | VM_PROT_WRITE);
605 
606 	memcpy(up, kp, len);
607 	vunmaprange((vaddr_t)up, len);
608 	uvm_vsunlock(p->p_vmspace, udaddr, len);
609 	uvm_lwp_rele(l);
610 
611 	return 0;
612 }
613 
614 /*
615  * kcopy(const void *src, void *dst, size_t len);
616  *
617  * Copy len bytes from src to dst, aborting if we encounter a fatal
618  * page fault.
619  *
620  * kcopy() _must_ save and restore the old fault handler since it is
621  * called by uiomove(), which may be in the path of servicing a non-fatal
622  * page fault.
623  */
624 int
625 kcopy(const void *src, void *dst, size_t len)
626 {
627 	struct faultbuf env, *oldfault;
628 
629 	oldfault = curpcb->pcb_onfault;
630 	if (setfault(&env)) {
631 		curpcb->pcb_onfault = oldfault;
632 		return EFAULT;
633 	}
634 
635 	memcpy(dst, src, len);
636 
637 	curpcb->pcb_onfault = oldfault;
638 	return 0;
639 }
640 
641 int
642 badaddr(void *addr, size_t size)
643 {
644 
645 	return badaddr_read(addr, size, NULL);
646 }
647 
648 int
649 badaddr_read(void *addr, size_t size, int *rptr)
650 {
651 	struct faultbuf env;
652 	int x;
653 
654 	/* Get rid of any stale machine checks that have been waiting.  */
655 	__asm volatile ("sync; isync");
656 
657 	if (setfault(&env)) {
658 		curpcb->pcb_onfault = 0;
659 		__asm volatile ("sync");
660 		return 1;
661 	}
662 
663 	__asm volatile ("sync");
664 
665 	switch (size) {
666 	case 1:
667 		x = *(volatile int8_t *)addr;
668 		break;
669 	case 2:
670 		x = *(volatile int16_t *)addr;
671 		break;
672 	case 4:
673 		x = *(volatile int32_t *)addr;
674 		break;
675 	default:
676 		panic("badaddr: invalid size (%d)", size);
677 	}
678 
679 	/* Make sure we took the machine check, if we caused one. */
680 	__asm volatile ("sync; isync");
681 
682 	curpcb->pcb_onfault = 0;
683 	__asm volatile ("sync");	/* To be sure. */
684 
685 	/* Use the value to avoid reorder. */
686 	if (rptr)
687 		*rptr = x;
688 
689 	return 0;
690 }
691 
692 /*
693  * For now, this only deals with the particular unaligned access case
694  * that gcc tends to generate.  Eventually it should handle all of the
695  * possibilities that can happen on a 32-bit PowerPC in big-endian mode.
696  */
697 
698 static int
699 fix_unaligned(struct lwp *l, struct trapframe *frame)
700 {
701 
702 	return -1;
703 }
704 
705 /*
706  * Start a new LWP
707  */
708 void
709 startlwp(arg)
710 	void *arg;
711 {
712 	int err;
713 	ucontext_t *uc = arg;
714 	struct lwp *l = curlwp;
715 
716 	err = cpu_setmcontext(l, &uc->uc_mcontext, uc->uc_flags);
717 #if DIAGNOSTIC
718 	if (err) {
719 		printf("Error %d from cpu_setmcontext.", err);
720 	}
721 #endif
722 	pool_put(&lwp_uc_pool, uc);
723 
724 	upcallret(l);
725 }
726 
727 /*
728  * XXX This is a terrible name.
729  */
730 void
731 upcallret(l)
732 	struct lwp *l;
733 {
734 
735 	/* Invoke MI userret code */
736 	mi_userret(l);
737 }
738