1/*-
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 * 3. 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
36#include <sys/param.h>
37#include <sys/kernel.h>
38#include <sys/lock.h>
39#include <sys/mutex.h>
40#include <sys/proc.h>
41#include <sys/systm.h>
42#include <sys/uio.h>
43
44#include <vm/vm.h>
45#include <vm/vm_page.h>
46
47#include <machine/vmparam.h>
48
49/*
50 * Implement uiomove(9) from physical memory using the direct map to
51 * avoid the creation and destruction of ephemeral mappings.
52 */
53int
54uiomove_fromphys(vm_page_t ma[], vm_offset_t offset, int n, struct uio *uio)
55{
56	struct thread *td = curthread;
57	struct iovec *iov;
58	void *cp;
59	vm_offset_t page_offset, vaddr;
60	size_t cnt;
61	int error = 0;
62	int save = 0;
63	bool mapped;
64
65	KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE,
66	    ("uiomove_fromphys: mode"));
67	KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread,
68	    ("uiomove_fromphys proc"));
69	KASSERT(uio->uio_resid >= 0,
70	    ("%s: uio %p resid underflow", __func__, uio));
71
72	save = td->td_pflags & TDP_DEADLKTREAT;
73	td->td_pflags |= TDP_DEADLKTREAT;
74	mapped = false;
75	while (n > 0 && uio->uio_resid) {
76		KASSERT(uio->uio_iovcnt > 0,
77		    ("%s: uio %p iovcnt underflow", __func__, uio));
78
79		iov = uio->uio_iov;
80		cnt = iov->iov_len;
81		if (cnt == 0) {
82			uio->uio_iov++;
83			uio->uio_iovcnt--;
84			continue;
85		}
86		if (cnt > n)
87			cnt = n;
88		page_offset = offset & PAGE_MASK;
89		cnt = min(cnt, PAGE_SIZE - page_offset);
90		if (uio->uio_segflg != UIO_NOCOPY) {
91			mapped = pmap_map_io_transient(
92			    &ma[offset >> PAGE_SHIFT], &vaddr, 1, true);
93			cp = (char *)vaddr + page_offset;
94		}
95		switch (uio->uio_segflg) {
96		case UIO_USERSPACE:
97			maybe_yield();
98			switch (uio->uio_rw) {
99			case UIO_READ:
100				error = copyout(cp, iov->iov_base, cnt);
101				break;
102			case UIO_WRITE:
103				error = copyin(iov->iov_base, cp, cnt);
104				break;
105			}
106			if (error)
107				goto out;
108			break;
109		case UIO_SYSSPACE:
110			switch (uio->uio_rw) {
111			case UIO_READ:
112				bcopy(cp, iov->iov_base, cnt);
113				break;
114			case UIO_WRITE:
115				bcopy(iov->iov_base, cp, cnt);
116				break;
117			}
118			break;
119		case UIO_NOCOPY:
120			break;
121		}
122		if (__predict_false(mapped)) {
123			pmap_unmap_io_transient(&ma[offset >> PAGE_SHIFT],
124			    &vaddr, 1, true);
125			mapped = false;
126		}
127		iov->iov_base = (char *)iov->iov_base + cnt;
128		iov->iov_len -= cnt;
129		uio->uio_resid -= cnt;
130		uio->uio_offset += cnt;
131		offset += cnt;
132		n -= cnt;
133	}
134out:
135	if (__predict_false(mapped)) {
136		panic("TODO 3");
137		pmap_unmap_io_transient(&ma[offset >> PAGE_SHIFT], &vaddr, 1,
138		    true);
139	}
140	if (save == 0)
141		td->td_pflags &= ~TDP_DEADLKTREAT;
142	return (error);
143}
144