copyinstr.c revision 1.3 
1/*	$NetBSD: copyinstr.c,v 1.3 2003/02/02 20:43:22 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#include <sys/param.h>
39#include <uvm/uvm_extern.h>
40#include <machine/pcb.h>
41
42int
43copyinstr(const void *udaddr, void *kaddr, size_t len, size_t *done)
44{
45	struct pmap *pm = curproc->p_vmspace->vm_map.pmap;
46	int msr, pid, tmp, ctx;
47	struct faultbuf env;
48
49	if (setfault(&env)) {
50		curpcb->pcb_onfault = 0;
51		/* XXXX -- len may be lost on a fault */
52		if (done)
53			*done = len;
54		return EFAULT;
55	}
56
57	if (!(ctx = pm->pm_ctx)) {
58		/* No context -- assign it one */
59		ctx_alloc(pm);
60		ctx = pm->pm_ctx;
61	}
62
63	if (len) {
64		asm volatile("mtctr %3;"		/* Set up counter */
65			"mfmsr %0;"			/* Save MSR */
66			"li %1,0x20; "
67			"andc %1,%0,%1; mtmsr %1;"	/* Disable IMMU */
68			"mfpid %1;"			/* Save old PID */
69			"sync; isync;"
70
71			"li %3,0;"			/* Clear len */
72
73			"1: "
74			"mtpid %4; sync;"		/* Load user ctx */
75			"lbz %2,0(%5); addi %5,%5,1;"	/* Load byte */
76			"sync; isync;"
77			"mtpid %1;sync;"
78			"stb %2,0(%6);  dcbf 0,%6; addi %6,%6,1;"	/* Store kernel byte */
79			"sync; isync;"
80			"addi %3,%3,1;"			/* Inc len */
81			"or. %2,%2,%2;"
82			"bdnzf 2,1b;"			/*
83							 * while(ctr-- && !zero)
84							 */
85
86			"2: mtpid %1; mtmsr %0;"	/* Restore PID, MSR */
87			"sync; isync;"
88			: "=&r" (msr), "=&r" (pid), "=&r" (tmp), "+r" (len)
89			: "r" (ctx), "r" (udaddr), "r" (kaddr));
90	}
91	curpcb->pcb_onfault = 0;
92	if (done)
93		*done = len;
94	return 0;
95}
96