uio_machdep.c revision 266312 
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: stable/10/sys/mips/mips/uio_machdep.c 266312 2014-05-17 13:59:11Z ian $");
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
56/*
57 * Implement uiomove(9) from physical memory using a combination
58 * of the direct mapping and sf_bufs to reduce the creation and
59 * destruction of ephemeral mappings.
60 */
61int
62uiomove_fromphys(vm_page_t ma[], vm_offset_t offset, int n, struct uio *uio)
63{
64	struct sf_buf *sf;
65	struct thread *td = curthread;
66	struct iovec *iov;
67	void *cp;
68	vm_offset_t page_offset;
69	vm_paddr_t pa;
70	vm_page_t m;
71	size_t cnt;
72	int error = 0;
73	int save = 0;
74
75	KASSERT(uio->uio_rw == UIO_READ || uio->uio_rw == UIO_WRITE,
76	    ("uiomove_fromphys: mode"));
77	KASSERT(uio->uio_segflg != UIO_USERSPACE || uio->uio_td == curthread,
78	    ("uiomove_fromphys proc"));
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 = ulmin(cnt, PAGE_SIZE - page_offset);
93		m = ma[offset >> PAGE_SHIFT];
94		pa = VM_PAGE_TO_PHYS(m);
95		if (MIPS_DIRECT_MAPPABLE(pa)) {
96			sf = NULL;
97			cp = (char *)MIPS_PHYS_TO_DIRECT(pa) + page_offset;
98			/*
99			 * flush all mappings to this page, KSEG0 address first
100			 * in order to get it overwritten by correct data
101			 */
102			mips_dcache_wbinv_range((vm_offset_t)cp, cnt);
103			pmap_flush_pvcache(m);
104		} else {
105			sf = sf_buf_alloc(m, 0);
106			cp = (char *)sf_buf_kva(sf) + page_offset;
107		}
108		switch (uio->uio_segflg) {
109		case UIO_USERSPACE:
110			maybe_yield();
111			if (uio->uio_rw == UIO_READ)
112				error = copyout(cp, iov->iov_base, cnt);
113			else
114				error = copyin(iov->iov_base, cp, cnt);
115			if (error) {
116				if (sf != NULL)
117					sf_buf_free(sf);
118				goto out;
119			}
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		else
133			mips_dcache_wbinv_range((vm_offset_t)cp, cnt);
134		iov->iov_base = (char *)iov->iov_base + cnt;
135		iov->iov_len -= cnt;
136		uio->uio_resid -= cnt;
137		uio->uio_offset += cnt;
138		offset += cnt;
139		n -= cnt;
140	}
141out:
142	if (save == 0)
143		td->td_pflags &= ~TDP_DEADLKTREAT;
144	return (error);
145}
146