source: mainline/uspace/lib/c/generic/as.c@ 6aae539d

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since 6aae539d was fbcdeb8, checked in by Martin Decky <martin@…>, 14 years ago

Remove the two-phase way of creating virtual memory areas (first asking for a mappable address and then mapping it) which was prone to race conditions when two or more calls to as_get_mappable_page() and as_area_create() were interleaved. This for example caused the e1k driver to randomly fail.

The memory area related syscalls and IPC calls have all been altered to accept a special value (void *) -1, representing a demand to atomically search for a mappable address space "hole" and map to it.

Individual changes:

  • IPC_M_SHARE_OUT: the destination address space area is supplied by the kernel, the callee only specifies the lower bound

(the address is returned to the callee via a pointer in an IPC reply argument)

  • IPC_M_SHARE_IN: the destination address space ares is supplied by the kernel, the callee only specifies the lower bound

(the address is returned to the caller as usual via an IPC argument)

  • SYS_AS_GET_UNMAPPED_AREA was removed
  • dummy implementations of SYS_PHYSMEM_UNMAP and SYS_IOSPACE_DISABLE were added for the sake of symmetry (they do nothing yet)
  • SYS_PHYSMEM_MAP and SYS_DMAMEM_MAP were altered to accept (void *) -1 as address space area base and a lower bound
  • kernel as_area_create() and as_area_share() were altered to accept (void *) -1 as address space area base and a lower bound
  • uspace libraries and programs were altered to reflect the new API
  • Property mode set to 100644
File size: 3.8 KB
Line 
1/*
2 * Copyright (c) 2006 Jakub Jermar
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * - The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29/** @addtogroup libc
30 * @{
31 */
32/** @file
33 */
34
35#include <as.h>
36#include <libc.h>
37#include <errno.h>
38#include <unistd.h>
39#include <align.h>
40#include <sys/types.h>
41#include <bitops.h>
42#include <malloc.h>
43#include "private/libc.h"
44
45/** Create address space area.
46 *
47 * @param base Starting virtual address of the area.
48 * If set to (void *) -1, the kernel finds
49 * a mappable area.
50 * @param size Size of the area.
51 * @param flags Flags describing type of the area.
52 *
53 * @return Starting virtual address of the created area on success.
54 * @return (void *) -1 otherwise.
55 *
56 */
57void *as_area_create(void *base, size_t size, unsigned int flags)
58{
59 return (void *) __SYSCALL4(SYS_AS_AREA_CREATE, (sysarg_t) base,
60 (sysarg_t) size, (sysarg_t) flags, (sysarg_t) __entry);
61}
62
63/** Resize address space area.
64 *
65 * @param address Virtual address pointing into already existing address space
66 * area.
67 * @param size New requested size of the area.
68 * @param flags Currently unused.
69 *
70 * @return zero on success or a code from @ref errno.h on failure.
71 *
72 */
73int as_area_resize(void *address, size_t size, unsigned int flags)
74{
75 return __SYSCALL3(SYS_AS_AREA_RESIZE, (sysarg_t) address,
76 (sysarg_t) size, (sysarg_t) flags);
77}
78
79/** Destroy address space area.
80 *
81 * @param address Virtual address pointing into the address space area being
82 * destroyed.
83 *
84 * @return zero on success or a code from @ref errno.h on failure.
85 *
86 */
87int as_area_destroy(void *address)
88{
89 return __SYSCALL1(SYS_AS_AREA_DESTROY, (sysarg_t) address);
90}
91
92/** Change address-space area flags.
93 *
94 * @param address Virtual address pointing into the address space area being
95 * modified.
96 * @param flags New flags describing type of the area.
97 *
98 * @return zero on success or a code from @ref errno.h on failure.
99 *
100 */
101int as_area_change_flags(void *address, unsigned int flags)
102{
103 return __SYSCALL2(SYS_AS_AREA_CHANGE_FLAGS, (sysarg_t) address,
104 (sysarg_t) flags);
105}
106
107/** Find mapping to physical address.
108 *
109 * @param virt Virtual address to find mapping for.
110 * @param[out] phys Physical adress.
111 *
112 * @return EOK on no error.
113 * @retval ENOENT if no mapping was found.
114 *
115 */
116int as_get_physical_mapping(const void *virt, uintptr_t *phys)
117{
118 return (int) __SYSCALL2(SYS_PAGE_FIND_MAPPING, (sysarg_t) virt,
119 (sysarg_t) phys);
120}
121
122/** @}
123 */
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