uio_machdep.c revision 127297 
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. All advertising materials mentioning features or use of this software
20 *    must display the following acknowledgement:
21 *	This product includes software developed by the University of
22 *	California, Berkeley and its contributors.
23 * 4. Neither the name of the University nor the names of its contributors
24 *    may be used to endorse or promote products derived from this software
25 *    without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 * SUCH DAMAGE.
38 *
39 *	@(#)kern_subr.c	8.3 (Berkeley) 1/21/94
40 */
41
42#include <sys/cdefs.h>
43__FBSDID("$FreeBSD: head/sys/sparc64/sparc64/uio_machdep.c 127297 2004-03-22 08:08:25Z alc $");
44
45#include <sys/param.h>
46#include <sys/kernel.h>
47#include <sys/lock.h>
48#include <sys/mutex.h>
49#include <sys/proc.h>
50#include <sys/sf_buf.h>
51#include <sys/systm.h>
52#include <sys/uio.h>
53
54#include <vm/vm.h>
55#include <vm/vm_page.h>
56#include <vm/vm_param.h>
57
58#include <machine/tlb.h>
59
60/*
61 * Implement uiomove(9) from physical memory using a combination
62 * of the direct mapping and sf_bufs to reduce the creation and
63 * destruction of ephemeral mappings.
64 */
65int
66uiomove_fromphys(vm_page_t ma[], vm_offset_t offset, int n, struct uio *uio)
67{
68	struct sf_buf *sf;
69	struct thread *td = curthread;
70	struct iovec *iov;
71	void *cp;
72	vm_offset_t page_offset;
73	vm_paddr_t pa;
74	vm_page_t m;
75	size_t cnt;
76	int error = 0;
77	int save = 0;
78
79	KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE,
80	    ("uiomove_fromphys: mode"));
81	KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread,
82	    ("uiomove_fromphys proc"));
83	if (td != NULL) {
84		mtx_lock_spin(&sched_lock);
85		save = td->td_flags & TDF_DEADLKTREAT;
86		td->td_flags |= TDF_DEADLKTREAT;
87		mtx_unlock_spin(&sched_lock);
88	}
89	while (n > 0 && uio->uio_resid) {
90		iov = uio->uio_iov;
91		cnt = iov->iov_len;
92		if (cnt == 0) {
93			uio->uio_iov++;
94			uio->uio_iovcnt--;
95			continue;
96		}
97		if (cnt > n)
98			cnt = n;
99		page_offset = offset & PAGE_MASK;
100		cnt = min(cnt, PAGE_SIZE - page_offset);
101		m = ma[offset >> PAGE_SHIFT];
102		pa = VM_PAGE_TO_PHYS(m);
103		if (m->md.color != DCACHE_COLOR(pa)) {
104			sf = sf_buf_alloc(m);
105			cp = (char *)sf_buf_kva(sf) + page_offset;
106		} else {
107			sf = NULL;
108			cp = (char *)TLB_PHYS_TO_DIRECT(pa) + page_offset;
109		}
110		switch (uio->uio_segflg) {
111		case UIO_USERSPACE:
112			if (ticks - PCPU_GET(switchticks) >= hogticks)
113				uio_yield();
114			if (uio->uio_rw == UIO_READ)
115				error = copyout(cp, iov->iov_base, cnt);
116			else
117				error = copyin(iov->iov_base, cp, cnt);
118			if (error)
119				goto out;
120			break;
121		case UIO_SYSSPACE:
122			if (uio->uio_rw == UIO_READ)
123				bcopy(cp, iov->iov_base, cnt);
124			else
125				bcopy(iov->iov_base, cp, cnt);
126			break;
127		case UIO_NOCOPY:
128			break;
129		}
130		if (sf != NULL)
131			sf_buf_free(sf);
132		iov->iov_base = (char *)iov->iov_base + cnt;
133		iov->iov_len -= cnt;
134		uio->uio_resid -= cnt;
135		uio->uio_offset += cnt;
136		offset += cnt;
137		n -= cnt;
138	}
139out:
140	if (td != NULL && save == 0) {
141		mtx_lock_spin(&sched_lock);
142		td->td_flags &= ~TDF_DEADLKTREAT;
143		mtx_unlock_spin(&sched_lock);
144	}
145	return (error);
146}
147