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Linus Torvalds1da177e2005-04-16 15:20:36 -07001<?xml version="1.0" encoding="UTF-8"?>
2<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
3 "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" []>
4
5<book id="LinuxKernelAPI">
6 <bookinfo>
7 <title>The Linux Kernel API</title>
8
9 <legalnotice>
10 <para>
11 This documentation is free software; you can redistribute
12 it and/or modify it under the terms of the GNU General Public
13 License as published by the Free Software Foundation; either
14 version 2 of the License, or (at your option) any later
15 version.
16 </para>
17
18 <para>
19 This program is distributed in the hope that it will be
20 useful, but WITHOUT ANY WARRANTY; without even the implied
21 warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
22 See the GNU General Public License for more details.
23 </para>
24
25 <para>
26 You should have received a copy of the GNU General Public
27 License along with this program; if not, write to the Free
28 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
29 MA 02111-1307 USA
30 </para>
31
32 <para>
33 For more details see the file COPYING in the source
34 distribution of Linux.
35 </para>
36 </legalnotice>
37 </bookinfo>
38
39<toc></toc>
40
Linus Torvalds1da177e2005-04-16 15:20:36 -070041 <chapter id="adt">
42 <title>Data Types</title>
43 <sect1><title>Doubly Linked Lists</title>
44!Iinclude/linux/list.h
45 </sect1>
46 </chapter>
47
48 <chapter id="libc">
49 <title>Basic C Library Functions</title>
50
51 <para>
52 When writing drivers, you cannot in general use routines which are
53 from the C Library. Some of the functions have been found generally
54 useful and they are listed below. The behaviour of these functions
55 may vary slightly from those defined by ANSI, and these deviations
56 are noted in the text.
57 </para>
58
59 <sect1><title>String Conversions</title>
Linus Torvalds1da177e2005-04-16 15:20:36 -070060!Elib/vsprintf.c
61 </sect1>
62 <sect1><title>String Manipulation</title>
Pavel Pisa4dc3b162005-05-01 08:59:25 -070063<!-- All functions are exported at now
64X!Ilib/string.c
65 -->
Linus Torvalds1da177e2005-04-16 15:20:36 -070066!Elib/string.c
67 </sect1>
68 <sect1><title>Bit Operations</title>
Randy Dunlapa1a739c2008-10-25 17:24:36 -070069!Iarch/x86/include/asm/bitops.h
Linus Torvalds1da177e2005-04-16 15:20:36 -070070 </sect1>
Randy Dunlap28e83ba2006-06-25 05:48:58 -070071 </chapter>
72
73 <chapter id="kernel-lib">
74 <title>Basic Kernel Library Functions</title>
75
76 <para>
77 The Linux kernel provides more basic utility functions.
78 </para>
79
Randy Dunlap6e1907ff2006-06-25 05:48:57 -070080 <sect1><title>Bitmap Operations</title>
81!Elib/bitmap.c
82!Ilib/bitmap.c
83 </sect1>
Randy Dunlap28e83ba2006-06-25 05:48:58 -070084
85 <sect1><title>Command-line Parsing</title>
86!Elib/cmdline.c
87 </sect1>
Randy Dunlap2f721002006-06-25 05:48:59 -070088
Jan Nikitenkoad241522007-07-17 04:04:03 -070089 <sect1 id="crc"><title>CRC Functions</title>
90!Elib/crc7.c
Randy Dunlap2f721002006-06-25 05:48:59 -070091!Elib/crc16.c
Jan Nikitenkoad241522007-07-17 04:04:03 -070092!Elib/crc-itu-t.c
Randy Dunlap2f721002006-06-25 05:48:59 -070093!Elib/crc32.c
94!Elib/crc-ccitt.c
95 </sect1>
Linus Torvalds1da177e2005-04-16 15:20:36 -070096 </chapter>
97
98 <chapter id="mm">
99 <title>Memory Management in Linux</title>
100 <sect1><title>The Slab Cache</title>
Paul Drynoff800590f2006-06-23 02:03:48 -0700101!Iinclude/linux/slab.h
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102!Emm/slab.c
103 </sect1>
104 <sect1><title>User Space Memory Access</title>
Randy Dunlapa1a739c2008-10-25 17:24:36 -0700105!Iarch/x86/include/asm/uaccess_32.h
Randy Dunlapf3cf31a2007-10-12 21:17:23 -0700106!Earch/x86/lib/usercopy_32.c
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107 </sect1>
Pavel Pisa4dc3b162005-05-01 08:59:25 -0700108 <sect1><title>More Memory Management Functions</title>
Pavel Pisa4dc3b162005-05-01 08:59:25 -0700109!Emm/readahead.c
110!Emm/filemap.c
111!Emm/memory.c
112!Emm/vmalloc.c
Randy Dunlap88ca3b92006-10-04 02:15:25 -0700113!Imm/page_alloc.c
Pavel Pisa4dc3b162005-05-01 08:59:25 -0700114!Emm/mempool.c
Randy Dunlapa80a438b2008-02-06 16:29:55 -0800115!Emm/dmapool.c
Pavel Pisa4dc3b162005-05-01 08:59:25 -0700116!Emm/page-writeback.c
117!Emm/truncate.c
118 </sect1>
119 </chapter>
120
121
122 <chapter id="ipc">
123 <title>Kernel IPC facilities</title>
124
125 <sect1><title>IPC utilities</title>
126!Iipc/util.c
127 </sect1>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 </chapter>
129
130 <chapter id="kfifo">
131 <title>FIFO Buffer</title>
132 <sect1><title>kfifo interface</title>
133!Iinclude/linux/kfifo.h
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134 </sect1>
135 </chapter>
136
Randy Dunlap5b217fa2006-09-29 01:59:10 -0700137 <chapter id="relayfs">
138 <title>relay interface support</title>
139
140 <para>
141 Relay interface support
142 is designed to provide an efficient mechanism for tools and
143 facilities to relay large amounts of data from kernel space to
144 user space.
145 </para>
146
147 <sect1><title>relay interface</title>
148!Ekernel/relay.c
149!Ikernel/relay.c
150 </sect1>
151 </chapter>
152
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153 <chapter id="modload">
154 <title>Module Support</title>
155 <sect1><title>Module Loading</title>
156!Ekernel/kmod.c
157 </sect1>
158 <sect1><title>Inter Module support</title>
159 <para>
160 Refer to the file kernel/module.c for more information.
161 </para>
162<!-- FIXME: Removed for now since no structured comments in source
163X!Ekernel/module.c
164-->
165 </sect1>
166 </chapter>
167
168 <chapter id="hardware">
169 <title>Hardware Interfaces</title>
170 <sect1><title>Interrupt Handling</title>
Randy Dunlap8f2709b2005-11-07 01:01:05 -0800171!Ekernel/irq/manage.c
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172 </sect1>
173
Randy Dunlapeed34d02006-10-03 01:13:50 -0700174 <sect1><title>DMA Channels</title>
175!Ekernel/dma.c
176 </sect1>
177
Pavel Pisa4dc3b162005-05-01 08:59:25 -0700178 <sect1><title>Resources Management</title>
Randy Dunlap2b549602006-07-30 03:03:40 -0700179!Ikernel/resource.c
Randy Dunlape1ca66d2006-10-03 01:13:51 -0700180!Ekernel/resource.c
Pavel Pisa4dc3b162005-05-01 08:59:25 -0700181 </sect1>
182
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 <sect1><title>MTRR Handling</title>
Randy Dunlapf3cf31a2007-10-12 21:17:23 -0700184!Earch/x86/kernel/cpu/mtrr/main.c
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185 </sect1>
Randy Dunlapb0ef3712006-06-25 05:49:18 -0700186
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 <sect1><title>PCI Support Library</title>
188!Edrivers/pci/pci.c
Pavel Pisa4dc3b162005-05-01 08:59:25 -0700189!Edrivers/pci/pci-driver.c
190!Edrivers/pci/remove.c
Randy Dunlapd75763d2006-07-30 03:03:41 -0700191!Edrivers/pci/search.c
Pavel Pisa4dc3b162005-05-01 08:59:25 -0700192!Edrivers/pci/msi.c
193!Edrivers/pci/bus.c
Randy Dunlapcffb2fa2009-04-10 15:17:50 -0700194!Edrivers/pci/access.c
195!Edrivers/pci/irq.c
196!Edrivers/pci/htirq.c
Randy Dunlapf05aab82005-10-23 11:58:19 -0700197<!-- FIXME: Removed for now since no structured comments in source
198X!Edrivers/pci/hotplug.c
199-->
Pavel Pisa4dc3b162005-05-01 08:59:25 -0700200!Edrivers/pci/probe.c
Randy Dunlapcffb2fa2009-04-10 15:17:50 -0700201!Edrivers/pci/slot.c
Pavel Pisa4dc3b162005-05-01 08:59:25 -0700202!Edrivers/pci/rom.c
Yu Zhao15b49be2009-03-20 11:25:18 +0800203!Edrivers/pci/iov.c
Randy Dunlapcffb2fa2009-04-10 15:17:50 -0700204!Idrivers/pci/pci-sysfs.c
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205 </sect1>
206 <sect1><title>PCI Hotplug Support Library</title>
207!Edrivers/pci/hotplug/pci_hotplug_core.c
208 </sect1>
209 <sect1><title>MCA Architecture</title>
210 <sect2><title>MCA Device Functions</title>
211 <para>
Randy Dunlapf3cf31a2007-10-12 21:17:23 -0700212 Refer to the file arch/x86/kernel/mca_32.c for more information.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213 </para>
214<!-- FIXME: Removed for now since no structured comments in source
Randy Dunlapf3cf31a2007-10-12 21:17:23 -0700215X!Earch/x86/kernel/mca_32.c
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216-->
217 </sect2>
218 <sect2><title>MCA Bus DMA</title>
Randy Dunlapa1a739c2008-10-25 17:24:36 -0700219!Iarch/x86/include/asm/mca_dma.h
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 </sect2>
221 </sect1>
222 </chapter>
223
Randy Dunlapb0ef3712006-06-25 05:49:18 -0700224 <chapter id="firmware">
225 <title>Firmware Interfaces</title>
226 <sect1><title>DMI Interfaces</title>
227!Edrivers/firmware/dmi_scan.c
228 </sect1>
Randy Dunlap6e8c8182007-02-10 01:46:03 -0800229 <sect1><title>EDD Interfaces</title>
230!Idrivers/firmware/edd.c
231 </sect1>
Randy Dunlapb0ef3712006-06-25 05:49:18 -0700232 </chapter>
233
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234 <chapter id="security">
235 <title>Security Framework</title>
James Morris20510f22007-10-16 23:31:32 -0700236!Isecurity/security.c
Randy Dunlap3f23d812008-08-17 21:44:22 -0700237!Esecurity/inode.c
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238 </chapter>
239
Randy Dunlap862f5f02006-06-23 02:05:52 -0700240 <chapter id="audit">
241 <title>Audit Interfaces</title>
242!Ekernel/audit.c
243!Ikernel/auditsc.c
244!Ikernel/auditfilter.c
245 </chapter>
246
247 <chapter id="accounting">
248 <title>Accounting Framework</title>
249!Ikernel/acct.c
250 </chapter>
251
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 <chapter id="blkdev">
253 <title>Block Devices</title>
Randy Dunlapcaf03fe2008-01-30 11:51:00 -0800254!Eblock/blk-core.c
Randy Dunlap5d87a052008-02-20 09:01:22 +0100255!Iblock/blk-core.c
Randy Dunlapcaf03fe2008-01-30 11:51:00 -0800256!Eblock/blk-map.c
257!Iblock/blk-sysfs.c
258!Eblock/blk-settings.c
259!Eblock/blk-exec.c
260!Eblock/blk-barrier.c
261!Eblock/blk-tag.c
Randy Dunlap5d87a052008-02-20 09:01:22 +0100262!Iblock/blk-tag.c
Randy Dunlap710027a2008-08-19 20:13:11 +0200263!Eblock/blk-integrity.c
Randy Dunlap88cacbb2009-04-05 15:45:34 -0700264!Ikernel/trace/blktrace.c
Randy Dunlap710027a2008-08-19 20:13:11 +0200265!Iblock/genhd.c
266!Eblock/genhd.c
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267 </chapter>
268
Jonathan Corbetcf3e43d2006-09-29 02:00:44 -0700269 <chapter id="chrdev">
270 <title>Char devices</title>
271!Efs/char_dev.c
272 </chapter>
273
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274 <chapter id="miscdev">
275 <title>Miscellaneous Devices</title>
276!Edrivers/char/misc.c
277 </chapter>
278
David Brownelle275ac42008-04-28 02:11:56 -0700279 <chapter id="clk">
280 <title>Clock Framework</title>
281
282 <para>
283 The clock framework defines programming interfaces to support
284 software management of the system clock tree.
285 This framework is widely used with System-On-Chip (SOC) platforms
286 to support power management and various devices which may need
287 custom clock rates.
288 Note that these "clocks" don't relate to timekeeping or real
289 time clocks (RTCs), each of which have separate frameworks.
290 These <structname>struct clk</structname> instances may be used
291 to manage for example a 96 MHz signal that is used to shift bits
292 into and out of peripherals or busses, or otherwise trigger
293 synchronous state machine transitions in system hardware.
294 </para>
295
296 <para>
297 Power management is supported by explicit software clock gating:
298 unused clocks are disabled, so the system doesn't waste power
299 changing the state of transistors that aren't in active use.
300 On some systems this may be backed by hardware clock gating,
301 where clocks are gated without being disabled in software.
302 Sections of chips that are powered but not clocked may be able
303 to retain their last state.
304 This low power state is often called a <emphasis>retention
305 mode</emphasis>.
306 This mode still incurs leakage currents, especially with finer
307 circuit geometries, but for CMOS circuits power is mostly used
308 by clocked state changes.
309 </para>
310
311 <para>
312 Power-aware drivers only enable their clocks when the device
313 they manage is in active use. Also, system sleep states often
314 differ according to which clock domains are active: while a
315 "standby" state may allow wakeup from several active domains, a
316 "mem" (suspend-to-RAM) state may require a more wholesale shutdown
317 of clocks derived from higher speed PLLs and oscillators, limiting
318 the number of possible wakeup event sources. A driver's suspend
319 method may need to be aware of system-specific clock constraints
320 on the target sleep state.
321 </para>
322
323 <para>
324 Some platforms support programmable clock generators. These
325 can be used by external chips of various kinds, such as other
326 CPUs, multimedia codecs, and devices with strict requirements
327 for interface clocking.
328 </para>
329
330!Iinclude/linux/clk.h
331 </chapter>
332
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333</book>