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 *	@(#)kern_subr.c	8.3 (Berkeley) 1/21/94
36 */
37
38#include <sys/cdefs.h>
39__FBSDID("$FreeBSD$");
40
41#include <sys/param.h>
42#include <sys/systm.h>
43#include <sys/kernel.h>
44#include <sys/lock.h>
45#include <sys/mutex.h>
46#include <sys/proc.h>
47#include <sys/sf_buf.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#include <machine/cache.h>
55#include <machine/tlb.h>
56
57/*
58 * Implement uiomove(9) from physical memory using a combination
59 * of the direct mapping and sf_bufs to reduce the creation and
60 * destruction of ephemeral mappings.
61 */
62int
63uiomove_fromphys(vm_page_t ma[], vm_offset_t offset, int n, struct uio *uio)
64{
65	struct sf_buf *sf;
66	struct thread *td = curthread;
67	struct iovec *iov;
68	void *cp;
69	vm_offset_t page_offset;
70	vm_paddr_t pa;
71	vm_page_t m;
72	size_t cnt;
73	int error = 0;
74	int save = 0;
75
76	KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE,
77	    ("uiomove_fromphys: mode"));
78	KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread,
79	    ("uiomove_fromphys proc"));
80	save = td->td_pflags & TDP_DEADLKTREAT;
81	td->td_pflags |= TDP_DEADLKTREAT;
82	while (n > 0 && uio->uio_resid) {
83		iov = uio->uio_iov;
84		cnt = iov->iov_len;
85		if (cnt == 0) {
86			uio->uio_iov++;
87			uio->uio_iovcnt--;
88			continue;
89		}
90		if (cnt > n)
91			cnt = n;
92		page_offset = offset & PAGE_MASK;
93		cnt = ulmin(cnt, PAGE_SIZE - page_offset);
94		m = ma[offset >> PAGE_SHIFT];
95		pa = VM_PAGE_TO_PHYS(m);
96		if (dcache_color_ignore == 0 &&
97		    m->md.color != DCACHE_COLOR(pa)) {
98			sf = sf_buf_alloc(m, 0);
99			cp = (char *)sf_buf_kva(sf) + page_offset;
100		} else {
101			sf = NULL;
102			cp = (char *)TLB_PHYS_TO_DIRECT(pa) + page_offset;
103		}
104		switch (uio->uio_segflg) {
105		case UIO_USERSPACE:
106			maybe_yield();
107			if (uio->uio_rw == UIO_READ)
108				error = copyout(cp, iov->iov_base, cnt);
109			else
110				error = copyin(iov->iov_base, cp, cnt);
111			if (error) {
112				if (sf != NULL)
113					sf_buf_free(sf);
114				goto out;
115			}
116			break;
117		case UIO_SYSSPACE:
118			if (uio->uio_rw == UIO_READ)
119				bcopy(cp, iov->iov_base, cnt);
120			else
121				bcopy(iov->iov_base, cp, cnt);
122			break;
123		case UIO_NOCOPY:
124			break;
125		}
126		if (sf != NULL)
127			sf_buf_free(sf);
128		iov->iov_base = (char *)iov->iov_base + cnt;
129		iov->iov_len -= cnt;
130		uio->uio_resid -= cnt;
131		uio->uio_offset += cnt;
132		offset += cnt;
133		n -= cnt;
134	}
135out:
136	if (save == 0)
137		td->td_pflags &= ~TDP_DEADLKTREAT;
138	return (error);
139}
140