uio_machdep.c revision 218195 
188794Sjake/*-
288794Sjake * Copyright (c) 2004 Alan L. Cox <alc@cs.rice.edu>
388794Sjake * Copyright (c) 1982, 1986, 1991, 1993
488794Sjake *	The Regents of the University of California.  All rights reserved.
588794Sjake * (c) UNIX System Laboratories, Inc.
688794Sjake * All or some portions of this file are derived from material licensed
788794Sjake * to the University of California by American Telephone and Telegraph
888794Sjake * Co. or Unix System Laboratories, Inc. and are reproduced herein with
988794Sjake * the permission of UNIX System Laboratories, Inc.
1088794Sjake *
1188794Sjake * Redistribution and use in source and binary forms, with or without
1288794Sjake * modification, are permitted provided that the following conditions
1388794Sjake * are met:
1488794Sjake * 1. Redistributions of source code must retain the above copyright
1588794Sjake *    notice, this list of conditions and the following disclaimer.
1688794Sjake * 2. Redistributions in binary form must reproduce the above copyright
1788794Sjake *    notice, this list of conditions and the following disclaimer in the
1888794Sjake *    documentation and/or other materials provided with the distribution.
1988794Sjake * 4. Neither the name of the University nor the names of its contributors
2088794Sjake *    may be used to endorse or promote products derived from this software
2188794Sjake *    without specific prior written permission.
2288794Sjake *
2388794Sjake * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
2488794Sjake * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
2588794Sjake * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
2688794Sjake * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
2799116Sobrien * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
2899116Sobrien * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
2988794Sjake * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
3088794Sjake * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
3188794Sjake * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
3288794Sjake * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
3388794Sjake * SUCH DAMAGE.
3488794Sjake *
3588794Sjake *	@(#)kern_subr.c	8.3 (Berkeley) 1/21/94
3688794Sjake */
37
38#include <sys/cdefs.h>
39__FBSDID("$FreeBSD: head/sys/powerpc/powerpc/uio_machdep.c 218195 2011-02-02 16:35:10Z mdf $");
40
41#include <sys/param.h>
42#include <sys/kernel.h>
43#include <sys/lock.h>
44#include <sys/mutex.h>
45#include <sys/proc.h>
46#include <sys/systm.h>
47#include <sys/uio.h>
48#include <sys/sf_buf.h>
49
50#include <vm/vm.h>
51#include <vm/vm_page.h>
52
53#include <machine/cpu.h>
54#include <machine/vmparam.h>
55#include <machine/md_var.h>
56
57/*
58 * Implement uiomove(9) from physical memory using sf_bufs to
59 * avoid the creation and destruction of ephemeral mappings.
60 */
61int
62uiomove_fromphys(vm_page_t ma[], vm_offset_t offset, int n, struct uio *uio)
63{
64	struct thread *td = curthread;
65	struct iovec *iov;
66	void *cp;
67	vm_offset_t page_offset;
68	vm_page_t m;
69	size_t cnt;
70	int error = 0;
71	int save = 0;
72	struct sf_buf *sf;
73
74	KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE,
75	    ("uiomove_fromphys: mode"));
76	KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread,
77	    ("uiomove_fromphys proc"));
78
79	save = td->td_pflags & TDP_DEADLKTREAT;
80	td->td_pflags |= TDP_DEADLKTREAT;
81	while (n > 0 && uio->uio_resid) {
82		iov = uio->uio_iov;
83		cnt = iov->iov_len;
84		if (cnt == 0) {
85			uio->uio_iov++;
86			uio->uio_iovcnt--;
87			continue;
88		}
89		if (cnt > n)
90			cnt = n;
91		page_offset = offset & PAGE_MASK;
92		cnt = min(cnt, PAGE_SIZE - page_offset);
93
94		m = ma[offset >> PAGE_SHIFT];
95		sf = sf_buf_alloc(m, 0);
96		cp = (char*)sf_buf_kva(sf) + page_offset;
97
98		switch (uio->uio_segflg) {
99			case UIO_USERSPACE:
100				maybe_yield();
101				if (uio->uio_rw == UIO_READ)
102					error = copyout(cp, iov->iov_base, cnt);
103				else
104					error = copyin(iov->iov_base, cp, cnt);
105				if (error) {
106					sf_buf_free(sf);
107					goto out;
108				}
109				break;
110			case UIO_SYSSPACE:
111				if (uio->uio_rw == UIO_READ)
112					bcopy(cp, iov->iov_base, cnt);
113				else
114					bcopy(iov->iov_base, cp, cnt);
115				break;
116			case UIO_NOCOPY:
117				break;
118		}
119		sf_buf_free(sf);
120		iov->iov_base = (char *)iov->iov_base + cnt;
121		iov->iov_len -= cnt;
122		uio->uio_resid -= cnt;
123		uio->uio_offset += cnt;
124		offset += cnt;
125		n -= cnt;
126	}
127out:
128	if (save == 0)
129		td->td_pflags &= ~TDP_DEADLKTREAT;
130	return (error);
131}
132