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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>
Randy Dunlap56083ab2010-10-26 14:19:08 -070096
97 <sect1 id="idr"><title>idr/ida Functions</title>
98!Pinclude/linux/idr.h idr sync
99!Plib/idr.c IDA description
100!Elib/idr.c
101 </sect1>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102 </chapter>
103
104 <chapter id="mm">
105 <title>Memory Management in Linux</title>
106 <sect1><title>The Slab Cache</title>
Paul Drynoff800590f2006-06-23 02:03:48 -0700107!Iinclude/linux/slab.h
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108!Emm/slab.c
109 </sect1>
110 <sect1><title>User Space Memory Access</title>
Randy Dunlapa1a739c2008-10-25 17:24:36 -0700111!Iarch/x86/include/asm/uaccess_32.h
Randy Dunlapf3cf31a2007-10-12 21:17:23 -0700112!Earch/x86/lib/usercopy_32.c
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113 </sect1>
Pavel Pisa4dc3b162005-05-01 08:59:25 -0700114 <sect1><title>More Memory Management Functions</title>
Pavel Pisa4dc3b162005-05-01 08:59:25 -0700115!Emm/readahead.c
116!Emm/filemap.c
117!Emm/memory.c
118!Emm/vmalloc.c
Randy Dunlap88ca3b92006-10-04 02:15:25 -0700119!Imm/page_alloc.c
Pavel Pisa4dc3b162005-05-01 08:59:25 -0700120!Emm/mempool.c
Randy Dunlapa80a438b2008-02-06 16:29:55 -0800121!Emm/dmapool.c
Pavel Pisa4dc3b162005-05-01 08:59:25 -0700122!Emm/page-writeback.c
123!Emm/truncate.c
124 </sect1>
125 </chapter>
126
127
128 <chapter id="ipc">
129 <title>Kernel IPC facilities</title>
130
131 <sect1><title>IPC utilities</title>
132!Iipc/util.c
133 </sect1>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134 </chapter>
135
136 <chapter id="kfifo">
137 <title>FIFO Buffer</title>
138 <sect1><title>kfifo interface</title>
139!Iinclude/linux/kfifo.h
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140 </sect1>
141 </chapter>
142
Randy Dunlap5b217fa2006-09-29 01:59:10 -0700143 <chapter id="relayfs">
144 <title>relay interface support</title>
145
146 <para>
147 Relay interface support
148 is designed to provide an efficient mechanism for tools and
149 facilities to relay large amounts of data from kernel space to
150 user space.
151 </para>
152
153 <sect1><title>relay interface</title>
154!Ekernel/relay.c
155!Ikernel/relay.c
156 </sect1>
157 </chapter>
158
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159 <chapter id="modload">
160 <title>Module Support</title>
161 <sect1><title>Module Loading</title>
162!Ekernel/kmod.c
163 </sect1>
164 <sect1><title>Inter Module support</title>
165 <para>
166 Refer to the file kernel/module.c for more information.
167 </para>
168<!-- FIXME: Removed for now since no structured comments in source
169X!Ekernel/module.c
170-->
171 </sect1>
172 </chapter>
173
174 <chapter id="hardware">
175 <title>Hardware Interfaces</title>
176 <sect1><title>Interrupt Handling</title>
Randy Dunlap8f2709b2005-11-07 01:01:05 -0800177!Ekernel/irq/manage.c
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178 </sect1>
179
Randy Dunlapeed34d02006-10-03 01:13:50 -0700180 <sect1><title>DMA Channels</title>
181!Ekernel/dma.c
182 </sect1>
183
Pavel Pisa4dc3b162005-05-01 08:59:25 -0700184 <sect1><title>Resources Management</title>
Randy Dunlap2b549602006-07-30 03:03:40 -0700185!Ikernel/resource.c
Randy Dunlape1ca66d2006-10-03 01:13:51 -0700186!Ekernel/resource.c
Pavel Pisa4dc3b162005-05-01 08:59:25 -0700187 </sect1>
188
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189 <sect1><title>MTRR Handling</title>
Randy Dunlapf3cf31a2007-10-12 21:17:23 -0700190!Earch/x86/kernel/cpu/mtrr/main.c
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191 </sect1>
Randy Dunlapb0ef3712006-06-25 05:49:18 -0700192
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 <sect1><title>PCI Support Library</title>
194!Edrivers/pci/pci.c
Pavel Pisa4dc3b162005-05-01 08:59:25 -0700195!Edrivers/pci/pci-driver.c
196!Edrivers/pci/remove.c
Randy Dunlapd75763d2006-07-30 03:03:41 -0700197!Edrivers/pci/search.c
Pavel Pisa4dc3b162005-05-01 08:59:25 -0700198!Edrivers/pci/msi.c
199!Edrivers/pci/bus.c
Randy Dunlapcffb2fa2009-04-10 15:17:50 -0700200!Edrivers/pci/access.c
201!Edrivers/pci/irq.c
202!Edrivers/pci/htirq.c
Randy Dunlapf05aab82005-10-23 11:58:19 -0700203<!-- FIXME: Removed for now since no structured comments in source
204X!Edrivers/pci/hotplug.c
205-->
Pavel Pisa4dc3b162005-05-01 08:59:25 -0700206!Edrivers/pci/probe.c
Randy Dunlapcffb2fa2009-04-10 15:17:50 -0700207!Edrivers/pci/slot.c
Pavel Pisa4dc3b162005-05-01 08:59:25 -0700208!Edrivers/pci/rom.c
Yu Zhao15b49be2009-03-20 11:25:18 +0800209!Edrivers/pci/iov.c
Randy Dunlapcffb2fa2009-04-10 15:17:50 -0700210!Idrivers/pci/pci-sysfs.c
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211 </sect1>
212 <sect1><title>PCI Hotplug Support Library</title>
213!Edrivers/pci/hotplug/pci_hotplug_core.c
214 </sect1>
215 <sect1><title>MCA Architecture</title>
216 <sect2><title>MCA Device Functions</title>
217 <para>
Randy Dunlapf3cf31a2007-10-12 21:17:23 -0700218 Refer to the file arch/x86/kernel/mca_32.c for more information.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219 </para>
220<!-- FIXME: Removed for now since no structured comments in source
Randy Dunlapf3cf31a2007-10-12 21:17:23 -0700221X!Earch/x86/kernel/mca_32.c
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222-->
223 </sect2>
224 <sect2><title>MCA Bus DMA</title>
Randy Dunlapa1a739c2008-10-25 17:24:36 -0700225!Iarch/x86/include/asm/mca_dma.h
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226 </sect2>
227 </sect1>
228 </chapter>
229
Randy Dunlapb0ef3712006-06-25 05:49:18 -0700230 <chapter id="firmware">
231 <title>Firmware Interfaces</title>
232 <sect1><title>DMI Interfaces</title>
233!Edrivers/firmware/dmi_scan.c
234 </sect1>
Randy Dunlap6e8c8182007-02-10 01:46:03 -0800235 <sect1><title>EDD Interfaces</title>
236!Idrivers/firmware/edd.c
237 </sect1>
Randy Dunlapb0ef3712006-06-25 05:49:18 -0700238 </chapter>
239
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240 <chapter id="security">
241 <title>Security Framework</title>
James Morris20510f22007-10-16 23:31:32 -0700242!Isecurity/security.c
Randy Dunlap3f23d812008-08-17 21:44:22 -0700243!Esecurity/inode.c
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244 </chapter>
245
Randy Dunlap862f5f02006-06-23 02:05:52 -0700246 <chapter id="audit">
247 <title>Audit Interfaces</title>
248!Ekernel/audit.c
249!Ikernel/auditsc.c
250!Ikernel/auditfilter.c
251 </chapter>
252
253 <chapter id="accounting">
254 <title>Accounting Framework</title>
255!Ikernel/acct.c
256 </chapter>
257
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258 <chapter id="blkdev">
259 <title>Block Devices</title>
Randy Dunlapcaf03fe2008-01-30 11:51:00 -0800260!Eblock/blk-core.c
Randy Dunlap5d87a052008-02-20 09:01:22 +0100261!Iblock/blk-core.c
Randy Dunlapcaf03fe2008-01-30 11:51:00 -0800262!Eblock/blk-map.c
263!Iblock/blk-sysfs.c
264!Eblock/blk-settings.c
265!Eblock/blk-exec.c
Mike Snitzer4d152902010-10-21 14:54:19 +0200266!Eblock/blk-flush.c
267!Eblock/blk-lib.c
Randy Dunlapcaf03fe2008-01-30 11:51:00 -0800268!Eblock/blk-tag.c
Randy Dunlap5d87a052008-02-20 09:01:22 +0100269!Iblock/blk-tag.c
Randy Dunlap710027a2008-08-19 20:13:11 +0200270!Eblock/blk-integrity.c
Randy Dunlap88cacbb2009-04-05 15:45:34 -0700271!Ikernel/trace/blktrace.c
Randy Dunlap710027a2008-08-19 20:13:11 +0200272!Iblock/genhd.c
273!Eblock/genhd.c
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274 </chapter>
275
Jonathan Corbetcf3e43d2006-09-29 02:00:44 -0700276 <chapter id="chrdev">
277 <title>Char devices</title>
278!Efs/char_dev.c
279 </chapter>
280
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281 <chapter id="miscdev">
282 <title>Miscellaneous Devices</title>
283!Edrivers/char/misc.c
284 </chapter>
285
David Brownelle275ac42008-04-28 02:11:56 -0700286 <chapter id="clk">
287 <title>Clock Framework</title>
288
289 <para>
290 The clock framework defines programming interfaces to support
291 software management of the system clock tree.
292 This framework is widely used with System-On-Chip (SOC) platforms
293 to support power management and various devices which may need
294 custom clock rates.
295 Note that these "clocks" don't relate to timekeeping or real
296 time clocks (RTCs), each of which have separate frameworks.
297 These <structname>struct clk</structname> instances may be used
298 to manage for example a 96 MHz signal that is used to shift bits
299 into and out of peripherals or busses, or otherwise trigger
300 synchronous state machine transitions in system hardware.
301 </para>
302
303 <para>
304 Power management is supported by explicit software clock gating:
305 unused clocks are disabled, so the system doesn't waste power
306 changing the state of transistors that aren't in active use.
307 On some systems this may be backed by hardware clock gating,
308 where clocks are gated without being disabled in software.
309 Sections of chips that are powered but not clocked may be able
310 to retain their last state.
311 This low power state is often called a <emphasis>retention
312 mode</emphasis>.
313 This mode still incurs leakage currents, especially with finer
314 circuit geometries, but for CMOS circuits power is mostly used
315 by clocked state changes.
316 </para>
317
318 <para>
319 Power-aware drivers only enable their clocks when the device
320 they manage is in active use. Also, system sleep states often
321 differ according to which clock domains are active: while a
322 "standby" state may allow wakeup from several active domains, a
323 "mem" (suspend-to-RAM) state may require a more wholesale shutdown
324 of clocks derived from higher speed PLLs and oscillators, limiting
325 the number of possible wakeup event sources. A driver's suspend
326 method may need to be aware of system-specific clock constraints
327 on the target sleep state.
328 </para>
329
330 <para>
331 Some platforms support programmable clock generators. These
332 can be used by external chips of various kinds, such as other
333 CPUs, multimedia codecs, and devices with strict requirements
334 for interface clocking.
335 </para>
336
337!Iinclude/linux/clk.h
338 </chapter>
339
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340</book>