copyinstr.c revision 1.2 
1/*	$NetBSD: copyinstr.c,v 1.2 2002/07/11 01:38:48 simonb 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#include <sys/param.h>
39#include <uvm/uvm_extern.h>
40#include <machine/pcb.h>
41
42int setfault(faultbuf);		/* defined in locore.S */
43
44int
45copyinstr(const void *udaddr, void *kaddr, size_t len, size_t *done)
46{
47	struct pmap *pm = curproc->p_vmspace->vm_map.pmap;
48	int msr, pid, tmp, ctx;
49	faultbuf env;
50
51	if (setfault(env)) {
52		curpcb->pcb_onfault = 0;
53		/* XXXX -- len may be lost on a fault */
54		if (done)
55			*done = len;
56		return EFAULT;
57	}
58
59	if (!(ctx = pm->pm_ctx)) {
60		/* No context -- assign it one */
61		ctx_alloc(pm);
62		ctx = pm->pm_ctx;
63	}
64
65	if (len) {
66		asm volatile("mtctr %3;"		/* Set up counter */
67			"mfmsr %0;"			/* Save MSR */
68			"li %1,0x20; "
69			"andc %1,%0,%1; mtmsr %1;"	/* Disable IMMU */
70			"mfpid %1;"			/* Save old PID */
71			"sync; isync;"
72
73			"li %3,0;"			/* Clear len */
74
75			"1: "
76			"mtpid %4; sync;"		/* Load user ctx */
77			"lbz %2,0(%5); addi %5,%5,1;"	/* Load byte */
78			"sync; isync;"
79			"mtpid %1;sync;"
80			"stb %2,0(%6);  dcbf 0,%6; addi %6,%6,1;"	/* Store kernel byte */
81			"sync; isync;"
82			"addi %3,%3,1;"			/* Inc len */
83			"or. %2,%2,%2;"
84			"bdnzf 2,1b;"			/*
85							 * while(ctr-- && !zero)
86							 */
87
88			"2: mtpid %1; mtmsr %0;"	/* Restore PID, MSR */
89			"sync; isync;"
90			: "=&r" (msr), "=&r" (pid), "=&r" (tmp), "+r" (len)
91			: "r" (ctx), "r" (udaddr), "r" (kaddr));
92	}
93	curpcb->pcb_onfault = 0;
94	if (done)
95		*done = len;
96	return 0;
97}
98