| paul@93 | 1 | /* |
| paul@93 | 2 | * Generic pager functionality. |
| paul@93 | 3 | * |
| paul@554 | 4 | * Copyright (C) 2021, 2022, 2023 Paul Boddie <paul@boddie.org.uk> |
| paul@93 | 5 | * |
| paul@93 | 6 | * This program is free software; you can redistribute it and/or |
| paul@93 | 7 | * modify it under the terms of the GNU General Public License as |
| paul@93 | 8 | * published by the Free Software Foundation; either version 2 of |
| paul@93 | 9 | * the License, or (at your option) any later version. |
| paul@93 | 10 | * |
| paul@93 | 11 | * This program is distributed in the hope that it will be useful, |
| paul@93 | 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| paul@93 | 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| paul@93 | 14 | * GNU General Public License for more details. |
| paul@93 | 15 | * |
| paul@93 | 16 | * You should have received a copy of the GNU General Public License |
| paul@93 | 17 | * along with this program; if not, write to the Free Software |
| paul@93 | 18 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, |
| paul@93 | 19 | * Boston, MA 02110-1301, USA |
| paul@93 | 20 | */ |
| paul@93 | 21 | |
| paul@554 | 22 | #include <mem/ipc.h> |
| paul@554 | 23 | |
| paul@6 | 24 | #include "dataspace_server.h" |
| paul@6 | 25 | #include "pager.h" |
| paul@6 | 26 | |
| paul@342 | 27 | #include "copied_page_mapper.h" |
| paul@342 | 28 | #include "masked_page_mapper.h" |
| paul@332 | 29 | |
| paul@6 | 30 | |
| paul@6 | 31 | |
| paul@86 | 32 | /* Initialise the pager with a page mapper and the given flags controlling |
| paul@86 | 33 | access to a file. */ |
| paul@86 | 34 | |
| paul@346 | 35 | Pager::Pager(GenericPageMapper *mapper, map_flags_t map_flags) |
| paul@342 | 36 | : _start(0), _size(0), |
| paul@342 | 37 | _mapper(mapper), _mapper_base(mapper), _mapper_masked(NULL), |
| paul@342 | 38 | _mapper_copied(NULL), |
| paul@346 | 39 | _map_flags(map_flags) |
| paul@6 | 40 | { |
| paul@6 | 41 | } |
| paul@6 | 42 | |
| paul@79 | 43 | /* Close the pager. */ |
| paul@79 | 44 | |
| paul@6 | 45 | void Pager::close() |
| paul@6 | 46 | { |
| paul@342 | 47 | if (_mapper_masked != NULL) |
| paul@342 | 48 | { |
| paul@342 | 49 | delete _mapper_masked; |
| paul@342 | 50 | _mapper_masked = NULL; |
| paul@342 | 51 | } |
| paul@342 | 52 | |
| paul@342 | 53 | if (_mapper_copied != NULL) |
| paul@342 | 54 | { |
| paul@342 | 55 | delete _mapper_copied; |
| paul@342 | 56 | _mapper_copied = NULL; |
| paul@342 | 57 | } |
| paul@6 | 58 | } |
| paul@6 | 59 | |
| paul@53 | 60 | /* Flush data to the file. */ |
| paul@53 | 61 | |
| paul@53 | 62 | long Pager::flush(offset_t populated_size, offset_t *size) |
| paul@53 | 63 | { |
| paul@55 | 64 | _mapper->flush_all(_start, populated_size); |
| paul@53 | 65 | |
| paul@55 | 66 | *size = _mapper->get_data_size(); |
| paul@55 | 67 | return L4_EOK; |
| paul@55 | 68 | } |
| paul@53 | 69 | |
| paul@402 | 70 | /* Resize the file. This will only resize the underlying file where masking and |
| paul@402 | 71 | copy-on-write mapping is not being performed. */ |
| paul@53 | 72 | |
| paul@55 | 73 | long Pager::resize(offset_t *size) |
| paul@55 | 74 | { |
| paul@55 | 75 | _mapper->set_data_size(*size); |
| paul@55 | 76 | |
| paul@55 | 77 | *size = _mapper->get_data_size(); |
| paul@53 | 78 | return L4_EOK; |
| paul@53 | 79 | } |
| paul@53 | 80 | |
| paul@7 | 81 | /* Expose a region of the file. */ |
| paul@7 | 82 | |
| paul@339 | 83 | long Pager::mmap(offset_t position, offset_t length, |
| paul@339 | 84 | offset_t start_visible, offset_t end_visible, |
| paul@332 | 85 | offset_t *start_pos, offset_t *end_pos, offset_t *size) |
| paul@6 | 86 | { |
| paul@90 | 87 | /* Define region characteristics. */ |
| paul@90 | 88 | |
| paul@7 | 89 | _start = trunc(position, PAGE_SIZE); |
| paul@7 | 90 | _size = round(position + length, PAGE_SIZE) - _start; |
| paul@6 | 91 | |
| paul@402 | 92 | /* Return the start and end positions plus file size. */ |
| paul@90 | 93 | |
| paul@7 | 94 | *start_pos = _start; |
| paul@7 | 95 | *end_pos = _start + _size; |
| paul@342 | 96 | *size = _mapper_base->get_data_size(); |
| paul@7 | 97 | |
| paul@332 | 98 | /* Permit masking of mapped regions. */ |
| paul@332 | 99 | |
| paul@342 | 100 | if ((start_visible || end_visible) && |
| paul@342 | 101 | ((*start_pos != start_visible) || (*end_pos != end_visible))) |
| paul@332 | 102 | { |
| paul@342 | 103 | /* Introduce the masked page and copied page mappers. */ |
| paul@342 | 104 | |
| paul@342 | 105 | _mapper_masked = new MaskedPageMapper(_mapper_base, start_visible, end_visible); |
| paul@342 | 106 | _mapper_copied = new CopiedPageMapper(_mapper_masked); |
| paul@342 | 107 | _mapper = _mapper_copied; |
| paul@332 | 108 | } |
| paul@332 | 109 | else |
| paul@342 | 110 | _mapper = _mapper_base; |
| paul@332 | 111 | |
| paul@7 | 112 | return L4_EOK; |
| paul@6 | 113 | } |
| paul@6 | 114 | |
| paul@6 | 115 | /* Map a flexpage corresponding to the dataspace 'offset' involving a 'hot_spot' |
| paul@6 | 116 | (flexpage offset). */ |
| paul@6 | 117 | |
| paul@410 | 118 | long Pager::map(offset_t offset, map_address_t hot_spot, map_flags_t map_flags, |
| paul@90 | 119 | l4_snd_fpage_t *region) |
| paul@6 | 120 | { |
| paul@6 | 121 | offset_t file_offset = _start + offset; |
| paul@6 | 122 | offset_t max_offset = _start + _size; |
| paul@87 | 123 | |
| paul@332 | 124 | /* Prevent access beyond that defined by the pager. |
| paul@332 | 125 | NOTE: Permitting executable requests here. This needs to be configured |
| paul@332 | 126 | when opening the pager or by another means. */ |
| paul@87 | 127 | |
| paul@346 | 128 | if (map_flags & (~(_map_flags | L4RE_DS_F_X))) |
| paul@87 | 129 | return -L4_EACCESS; |
| paul@87 | 130 | |
| paul@342 | 131 | /* Obtain a flexpage from the page mapper. */ |
| paul@6 | 132 | |
| paul@346 | 133 | Flexpage *flexpage = _mapper->get(file_offset, map_flags); |
| paul@332 | 134 | |
| paul@6 | 135 | /* Issue the flexpage via the IPC system. */ |
| paul@6 | 136 | |
| paul@342 | 137 | long err = ipc_prepare_flexpage(flexpage, file_offset, max_offset, |
| paul@346 | 138 | hot_spot, map_flags, region); |
| paul@6 | 139 | |
| paul@37 | 140 | if (!err) |
| paul@87 | 141 | err = complete_Dataspace_map(*region); |
| paul@6 | 142 | |
| paul@342 | 143 | /* After the obtained flexpage is issued, it is queued for future reuse, if |
| paul@342 | 144 | appropriate for the mapper concerned. */ |
| paul@6 | 145 | |
| paul@342 | 146 | _mapper->queue(flexpage); |
| paul@6 | 147 | |
| paul@37 | 148 | if (err) |
| paul@87 | 149 | return err; |
| paul@37 | 150 | |
| paul@6 | 151 | return IPC_MESSAGE_SENT; |
| paul@6 | 152 | } |
| paul@6 | 153 | |
| paul@6 | 154 | /* Return the total size of the data. */ |
| paul@6 | 155 | |
| paul@6 | 156 | offset_t Pager::get_data_size() |
| paul@6 | 157 | { |
| paul@6 | 158 | return _mapper->get_data_size(); |
| paul@6 | 159 | } |
| paul@6 | 160 | |
| paul@6 | 161 | // vim: tabstop=4 expandtab shiftwidth=4 |
