xref: /netbsd-src/sys/arch/powerpc/ibm4xx/copyoutstr.c (revision 001c68bd94f75ce9270b69227c4199fbf34ee396)
1 /*	$NetBSD: copyoutstr.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 
42 int
43 copyoutstr(const void *kaddr, void *udaddr, 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 %1;sync;"
75 			"lbz %2,0(%6); addi %6,%6,1;"	/* Store kernel byte */
76 			"sync; isync;"
77 			"mtpid %4; sync;"		/* Load user ctx */
78 			"stb %2,0(%5);  dcbf 0,%5; addi %5,%5,1;"	/* Load 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