uio_machdep.c revision 206714 
1272343Sngie/*-
2 * Copyright (c) 2004 Alan L. Cox <alc@cs.rice.edu>
3 * Copyright (c) 1982, 1986, 1991, 1993
4 *	The Regents of the University of California.  All rights reserved.
5 * (c) UNIX System Laboratories, Inc.
6 * All or some portions of this file are derived from material licensed
7 * to the University of California by American Telephone and Telegraph
8 * Co. or Unix System Laboratories, Inc. and are reproduced herein with
9 * the permission of UNIX System Laboratories, Inc.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in the
18 *    documentation and/or other materials provided with the distribution.
19 * 4. Neither the name of the University nor the names of its contributors
20 *    may be used to endorse or promote products derived from this software
21 *    without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 *
35 *	@(#)kern_subr.c	8.3 (Berkeley) 1/21/94
36 */
37
38#include <sys/cdefs.h>
39__FBSDID("$FreeBSD: head/sys/mips/mips/uio_machdep.c 206714 2010-04-16 23:48:28Z jmallett $");
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/sf_buf.h>
47#include <sys/systm.h>
48#include <sys/uio.h>
49
50#include <vm/vm.h>
51#include <vm/vm_page.h>
52#include <vm/vm_param.h>
53
54/*
55 * Implement uiomove(9) from physical memory using a combination
56 * of the direct mapping and sf_bufs to reduce the creation and
57 * destruction of ephemeral mappings.
58 */
59int
60uiomove_fromphys(vm_page_t ma[], vm_offset_t offset, int n, struct uio *uio)
61{
62	struct sf_buf *sf;
63	struct thread *td = curthread;
64	struct iovec *iov;
65	void *cp;
66	vm_offset_t page_offset;
67	vm_paddr_t pa;
68	vm_page_t m;
69	size_t cnt;
70	int error = 0;
71	int save = 0;
72
73	KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE,
74	    ("uiomove_fromphys: mode"));
75	KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread,
76	    ("uiomove_fromphys proc"));
77	save = td->td_pflags & TDP_DEADLKTREAT;
78	td->td_pflags |= TDP_DEADLKTREAT;
79	while (n > 0 && uio->uio_resid) {
80		iov = uio->uio_iov;
81		cnt = iov->iov_len;
82		if (cnt == 0) {
83			uio->uio_iov++;
84			uio->uio_iovcnt--;
85			continue;
86		}
87		if (cnt > n)
88			cnt = n;
89		page_offset = offset & PAGE_MASK;
90		cnt = ulmin(cnt, PAGE_SIZE - page_offset);
91		m = ma[offset >> PAGE_SHIFT];
92		pa = VM_PAGE_TO_PHYS(m);
93		if (pa < MIPS_KSEG0_LARGEST_PHYS) {
94			cp = (char *)MIPS_PHYS_TO_KSEG0(pa);
95			sf = NULL;
96		} else {
97			sf = sf_buf_alloc(m, 0);
98			cp = (char *)sf_buf_kva(sf) + page_offset;
99		}
100		switch (uio->uio_segflg) {
101		case UIO_USERSPACE:
102			if (ticks - PCPU_GET(switchticks) >= hogticks)
103				uio_yield();
104			if (uio->uio_rw == UIO_READ)
105				error = copyout(cp, iov->iov_base, cnt);
106			else
107				error = copyin(iov->iov_base, cp, cnt);
108			if (error) {
109				if (sf != NULL)
110					sf_buf_free(sf);
111				goto out;
112			}
113			break;
114		case UIO_SYSSPACE:
115			if (uio->uio_rw == UIO_READ)
116				bcopy(cp, iov->iov_base, cnt);
117			else
118				bcopy(iov->iov_base, cp, cnt);
119			break;
120		case UIO_NOCOPY:
121			break;
122		}
123		if (sf != NULL)
124			sf_buf_free(sf);
125		iov->iov_base = (char *)iov->iov_base + cnt;
126		iov->iov_len -= cnt;
127		uio->uio_resid -= cnt;
128		uio->uio_offset += cnt;
129		offset += cnt;
130		n -= cnt;
131	}
132out:
133	if (save == 0)
134		td->td_pflags &= ~TDP_DEADLKTREAT;
135	return (error);
136}
137