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trap.c revision 1.87
      1 /*	$NetBSD: trap.c,v 1.87 2022/05/30 14:09:01 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 1.87 2022/05/30 14:09:01 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 int
    431 copyin(const void *udaddr, void *kaddr, size_t len)
    432 {
    433 	struct pmap *pm = curproc->p_vmspace->vm_map.pmap;
    434 	int rv, msr, pid, tmp, ctx, count = 0;
    435 	struct faultbuf env;
    436 
    437 	/* For bigger buffers use the faster copy */
    438 	if (len > 1024)
    439 		return (bigcopyin(udaddr, kaddr, len));
    440 
    441 	if ((rv = setfault(&env))) {
    442 		curpcb->pcb_onfault = NULL;
    443 		return rv;
    444 	}
    445 
    446 	if (!(ctx = pm->pm_ctx)) {
    447 		/* No context -- assign it one */
    448 		ctx_alloc(pm);
    449 		ctx = pm->pm_ctx;
    450 	}
    451 
    452 	__asm volatile(
    453 		"   mfmsr %[msr];"		/* Save MSR */
    454 		"   li %[pid],0x20;"
    455 		"   andc %[pid],%[msr],%[pid]; mtmsr %[pid];" /* Disable IMMU */
    456 		"   isync;"
    457 		"   mfpid %[pid];"		/* Save old PID */
    458 
    459 		"   srwi. %[count],%[len],0x2;"	/* How many words? */
    460 		"   beq- 2f;"			/* No words. Go do bytes */
    461 		"   mtctr %[count];"
    462 		"1: mtpid %[ctx]; isync;"
    463 #ifdef PPC_IBM403
    464 		"   lswi %[tmp],%[udaddr],4;"	/* Load user word */
    465 #else
    466 		"   lwz %[tmp],0(%[udaddr]);"
    467 #endif
    468 		"   addi %[udaddr],%[udaddr],0x4;" /* next udaddr word */
    469 		"   sync;"
    470 		"   mtpid %[pid]; isync;"
    471 #ifdef PPC_IBM403
    472 		"   stswi %[tmp],%[kaddr],4;"	/* Store kernel word */
    473 #else
    474 		"   stw %[tmp],0(%[kaddr]);"
    475 #endif
    476 		"   dcbst 0,%[kaddr];"		/* flush cache */
    477 		"   addi %[kaddr],%[kaddr],0x4;" /* next udaddr word */
    478 		"   sync;"
    479 		"   bdnz 1b;"			/* repeat */
    480 
    481 		"2: andi. %[count],%[len],0x3;"	/* How many remaining bytes? */
    482 		"   addi %[count],%[count],0x1;"
    483 		"   mtctr %[count];"
    484 		"3: bdz 10f;"			/* while count */
    485 		"   mtpid %[ctx]; isync;"
    486 		"   lbz %[tmp],0(%[udaddr]);"	/* Load user byte */
    487 		"   addi %[udaddr],%[udaddr],0x1;" /* next udaddr byte */
    488 		"   sync;"
    489 		"   mtpid %[pid]; isync;"
    490 		"   stb %[tmp],0(%[kaddr]);"	/* Store kernel byte */
    491 		"   dcbst 0,%[kaddr];"		/* flush cache */
    492 		"   addi %[kaddr],%[kaddr],0x1;"
    493 		"   sync;"
    494 		"   b 3b;"
    495 		"10:mtpid %[pid]; mtmsr %[msr]; isync;"
    496 						/* Restore PID and MSR */
    497 		: [msr] "=&r" (msr), [pid] "=&r" (pid), [tmp] "=&r" (tmp)
    498 		: [udaddr] "b" (udaddr), [ctx] "b" (ctx), [kaddr] "b" (kaddr),
    499 		  [len] "b" (len), [count] "b" (count));
    500 
    501 	curpcb->pcb_onfault = NULL;
    502 	return 0;
    503 }
    504 
    505 static int
    506 bigcopyin(const void *udaddr, void *kaddr, size_t len)
    507 {
    508 	const char *up;
    509 	char *kp = kaddr;
    510 	struct lwp *l = curlwp;
    511 	struct proc *p;
    512 	struct faultbuf env;
    513 	int error;
    514 
    515 	p = l->l_proc;
    516 
    517 	/*
    518 	 * Stolen from physio():
    519 	 */
    520 	error = uvm_vslock(p->p_vmspace, __UNCONST(udaddr), len, VM_PROT_READ);
    521 	if (error) {
    522 		return error;
    523 	}
    524 	up = (char *)vmaprange(p, (vaddr_t)udaddr, len, VM_PROT_READ);
    525 
    526 	if ((error = setfault(&env)) == 0) {
    527 		memcpy(kp, up, len);
    528 	}
    529 
    530 	curpcb->pcb_onfault = NULL;
    531 	vunmaprange((vaddr_t)up, len);
    532 	uvm_vsunlock(p->p_vmspace, __UNCONST(udaddr), len);
    533 
    534 	return error;
    535 }
    536 
    537 int
    538 copyout(const void *kaddr, void *udaddr, size_t len)
    539 {
    540 	struct pmap *pm = curproc->p_vmspace->vm_map.pmap;
    541 	int rv, msr, pid, tmp, ctx, count = 0;
    542 	struct faultbuf env;
    543 
    544 	/* For big copies use more efficient routine */
    545 	if (len > 1024)
    546 		return (bigcopyout(kaddr, udaddr, len));
    547 
    548 	if ((rv = setfault(&env))) {
    549 		curpcb->pcb_onfault = NULL;
    550 		return rv;
    551 	}
    552 
    553 	if (!(ctx = pm->pm_ctx)) {
    554 		/* No context -- assign it one */
    555 		ctx_alloc(pm);
    556 		ctx = pm->pm_ctx;
    557 	}
    558 
    559 	__asm volatile(
    560 		"   mfmsr %[msr];"		/* Save MSR */
    561 		"   li %[pid],0x20;"
    562 		"   andc %[pid],%[msr],%[pid]; mtmsr %[pid];" /* Disable IMMU */
    563 		"   isync;"
    564 		"   mfpid %[pid];"		/* Save old PID */
    565 
    566 		"   srwi. %[count],%[len],0x2;"	/* How many words? */
    567 		"   beq- 2f;"			/* No words. Go do bytes */
    568 		"   mtctr %[count];"
    569 		"1: mtpid %[pid]; isync;"
    570 #ifdef PPC_IBM403
    571 		"   lswi %[tmp],%[kaddr],4;"	/* Load kernel word */
    572 #else
    573 		"   lwz %[tmp],0(%[kaddr]);"
    574 #endif
    575 		"   addi %[kaddr],%[kaddr],0x4;" /* next kaddr word */
    576 		"   sync;"
    577 		"   mtpid %[ctx]; isync;"
    578 #ifdef PPC_IBM403
    579 		"   stswi %[tmp],%[udaddr],4;"	/* Store user word */
    580 #else
    581 		"   stw %[tmp],0(%[udaddr]);"
    582 #endif
    583 		"   dcbst 0,%[udaddr];"		/* flush cache */
    584 		"   addi %[udaddr],%[udaddr],0x4;" /* next udaddr word */
    585 		"   sync;"
    586 		"   bdnz 1b;"			/* repeat */
    587 
    588 		"2: andi. %[count],%[len],0x3;"	/* How many remaining bytes? */
    589 		"   addi %[count],%[count],0x1;"
    590 		"   mtctr %[count];"
    591 		"3: bdz  10f;"			/* while count */
    592 		"   mtpid %[pid]; isync;"
    593 		"   lbz %[tmp],0(%[kaddr]);"	/* Load kernel byte */
    594 		"   addi %[kaddr],%[kaddr],0x1;" /* next kaddr byte */
    595 		"   sync;"
    596 		"   mtpid %[ctx]; isync;"
    597 		"   stb %[tmp],0(%[udaddr]);"	/* Store user byte */
    598 		"   dcbst 0,%[udaddr];"		/* flush cache */
    599 		"   addi %[udaddr],%[udaddr],0x1;"
    600 		"   sync;"
    601 		"   b 3b;"
    602 		"10:mtpid %[pid]; mtmsr %[msr]; isync;"
    603 						/* Restore PID and MSR */
    604 		: [msr] "=&r" (msr), [pid] "=&r" (pid), [tmp] "=&r" (tmp)
    605 		: [udaddr] "b" (udaddr), [ctx] "b" (ctx), [kaddr] "b" (kaddr),
    606 		  [len] "b" (len), [count] "b" (count));
    607 
    608 	curpcb->pcb_onfault = NULL;
    609 	return 0;
    610 }
    611 
    612 static int
    613 bigcopyout(const void *kaddr, void *udaddr, size_t len)
    614 {
    615 	char *up;
    616 	const char *kp = (const char *)kaddr;
    617 	struct lwp *l = curlwp;
    618 	struct proc *p;
    619 	struct faultbuf env;
    620 	int error;
    621 
    622 	p = l->l_proc;
    623 
    624 	/*
    625 	 * Stolen from physio():
    626 	 */
    627 	error = uvm_vslock(p->p_vmspace, udaddr, len, VM_PROT_WRITE);
    628 	if (error) {
    629 		return error;
    630 	}
    631 	up = (char *)vmaprange(p, (vaddr_t)udaddr, len,
    632 	    VM_PROT_READ | VM_PROT_WRITE);
    633 
    634 	if ((error = setfault(&env)) == 0) {
    635 		memcpy(up, kp, len);
    636 	}
    637 
    638 	curpcb->pcb_onfault = NULL;
    639 	vunmaprange((vaddr_t)up, len);
    640 	uvm_vsunlock(p->p_vmspace, udaddr, len);
    641 
    642 	return error;
    643 }
    644 
    645 /*
    646  * kcopy(const void *src, void *dst, size_t len);
    647  *
    648  * Copy len bytes from src to dst, aborting if we encounter a fatal
    649  * page fault.
    650  *
    651  * kcopy() _must_ save and restore the old fault handler since it is
    652  * called by uiomove(), which may be in the path of servicing a non-fatal
    653  * page fault.
    654  */
    655 int
    656 kcopy(const void *src, void *dst, size_t len)
    657 {
    658 	struct faultbuf env, *oldfault;
    659 	int rv;
    660 
    661 	oldfault = curpcb->pcb_onfault;
    662 	if ((rv = setfault(&env))) {
    663 		curpcb->pcb_onfault = oldfault;
    664 		return rv;
    665 	}
    666 
    667 	memcpy(dst, src, len);
    668 
    669 	curpcb->pcb_onfault = oldfault;
    670 	return 0;
    671 }
    672 
    673 #if 0
    674 int
    675 badaddr(void *addr, size_t size)
    676 {
    677 
    678 	return badaddr_read(addr, size, NULL);
    679 }
    680 
    681 int
    682 badaddr_read(void *addr, size_t size, int *rptr)
    683 {
    684 	struct faultbuf env;
    685 	int x;
    686 
    687 	/* Get rid of any stale machine checks that have been waiting.  */
    688 	__asm volatile ("sync; isync");
    689 
    690 	if (setfault(&env)) {
    691 		curpcb->pcb_onfault = NULL;
    692 		__asm volatile ("sync");
    693 		return 1;
    694 	}
    695 
    696 	__asm volatile ("sync");
    697 
    698 	switch (size) {
    699 	case 1:
    700 		x = *(volatile int8_t *)addr;
    701 		break;
    702 	case 2:
    703 		x = *(volatile int16_t *)addr;
    704 		break;
    705 	case 4:
    706 		x = *(volatile int32_t *)addr;
    707 		break;
    708 	default:
    709 		panic("badaddr: invalid size (%d)", size);
    710 	}
    711 
    712 	/* Make sure we took the machine check, if we caused one. */
    713 	__asm volatile ("sync; isync");
    714 
    715 	curpcb->pcb_onfault = NULL;
    716 	__asm volatile ("sync");	/* To be sure. */
    717 
    718 	/* Use the value to avoid reorder. */
    719 	if (rptr)
    720 		*rptr = x;
    721 
    722 	return 0;
    723 }
    724 #endif
    725 
    726 #ifndef PPC_NO_UNALIGNED
    727 static bool
    728 fix_unaligned(struct trapframe *tf, ksiginfo_t *ksi)
    729 {
    730 
    731 	KSI_INIT_TRAP(ksi);
    732 	ksi->ksi_signo = SIGBUS;
    733 	ksi->ksi_trap = EXC_ALI;
    734 	ksi->ksi_addr = (void *)tf->tf_dear;
    735 	return true;
    736 }
    737 #endif
    738 
    739 /*
    740  * XXX Extremely lame implementations of _ufetch_* / _ustore_*.  IBM 4xx
    741  * experts should make versions that are good.
    742  */
    743 
    744 #define UFETCH(sz)							\
    745 int									\
    746 _ufetch_ ## sz(const uint ## sz ## _t *uaddr, uint ## sz ## _t *valp)	\
    747 {									\
    748 	return copyin(uaddr, valp, sizeof(*valp));			\
    749 }
    750 
    751 UFETCH(8)
    752 UFETCH(16)
    753 UFETCH(32)
    754 
    755 #define USTORE(sz)							\
    756 int									\
    757 _ustore_ ## sz(uint ## sz ## _t *uaddr, uint ## sz ## _t val)		\
    758 {									\
    759 	return copyout(&val, uaddr, sizeof(val));			\
    760 }
    761 
    762 USTORE(8)
    763 USTORE(16)
    764 USTORE(32)
    765