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1<?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
41 <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>
60!Elib/vsprintf.c
61 </sect1>
62 <sect1><title>String Manipulation</title>
63<!-- All functions are exported at now
64X!Ilib/string.c
65 -->
66!Elib/string.c
67 </sect1>
68 <sect1><title>Bit Operations</title>
69!Iarch/x86/include/asm/bitops.h
70 </sect1>
71 </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
80 <sect1><title>Bitmap Operations</title>
81!Elib/bitmap.c
82!Ilib/bitmap.c
83 </sect1>
84
85 <sect1><title>Command-line Parsing</title>
86!Elib/cmdline.c
87 </sect1>
88
89 <sect1 id="crc"><title>CRC Functions</title>
90!Elib/crc7.c
91!Elib/crc16.c
92!Elib/crc-itu-t.c
93!Elib/crc32.c
94!Elib/crc-ccitt.c
95 </sect1>
96
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>
102 </chapter>
103
104 <chapter id="mm">
105 <title>Memory Management in Linux</title>
106 <sect1><title>The Slab Cache</title>
107!Iinclude/linux/slab.h
108!Emm/slab.c
109 </sect1>
110 <sect1><title>User Space Memory Access</title>
111!Iarch/x86/include/asm/uaccess_32.h
112!Earch/x86/lib/usercopy_32.c
113 </sect1>
114 <sect1><title>More Memory Management Functions</title>
115!Emm/readahead.c
116!Emm/filemap.c
117!Emm/memory.c
118!Emm/vmalloc.c
119!Imm/page_alloc.c
120!Emm/mempool.c
121!Emm/dmapool.c
122!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>
134 </chapter>
135
136 <chapter id="kfifo">
137 <title>FIFO Buffer</title>
138 <sect1><title>kfifo interface</title>
139!Iinclude/linux/kfifo.h
140 </sect1>
141 </chapter>
142
143 <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
159 <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>
177!Ekernel/irq/manage.c
178 </sect1>
179
180 <sect1><title>DMA Channels</title>
181!Ekernel/dma.c
182 </sect1>
183
184 <sect1><title>Resources Management</title>
185!Ikernel/resource.c
186!Ekernel/resource.c
187 </sect1>
188
189 <sect1><title>MTRR Handling</title>
190!Earch/x86/kernel/cpu/mtrr/main.c
191 </sect1>
192
193 <sect1><title>PCI Support Library</title>
194!Edrivers/pci/pci.c
195!Edrivers/pci/pci-driver.c
196!Edrivers/pci/remove.c
197!Edrivers/pci/search.c
198!Edrivers/pci/msi.c
199!Edrivers/pci/bus.c
200!Edrivers/pci/access.c
201!Edrivers/pci/irq.c
202!Edrivers/pci/htirq.c
203<!-- FIXME: Removed for now since no structured comments in source
204X!Edrivers/pci/hotplug.c
205-->
206!Edrivers/pci/probe.c
207!Edrivers/pci/slot.c
208!Edrivers/pci/rom.c
209!Edrivers/pci/iov.c
210!Idrivers/pci/pci-sysfs.c
211 </sect1>
212 <sect1><title>PCI Hotplug Support Library</title>
213!Edrivers/pci/hotplug/pci_hotplug_core.c
214 </sect1>
215 </chapter>
216
217 <chapter id="firmware">
218 <title>Firmware Interfaces</title>
219 <sect1><title>DMI Interfaces</title>
220!Edrivers/firmware/dmi_scan.c
221 </sect1>
222 <sect1><title>EDD Interfaces</title>
223!Idrivers/firmware/edd.c
224 </sect1>
225 </chapter>
226
227 <chapter id="security">
228 <title>Security Framework</title>
229!Isecurity/security.c
230!Esecurity/inode.c
231 </chapter>
232
233 <chapter id="audit">
234 <title>Audit Interfaces</title>
235!Ekernel/audit.c
236!Ikernel/auditsc.c
237!Ikernel/auditfilter.c
238 </chapter>
239
240 <chapter id="accounting">
241 <title>Accounting Framework</title>
242!Ikernel/acct.c
243 </chapter>
244
245 <chapter id="blkdev">
246 <title>Block Devices</title>
247!Eblock/blk-core.c
248!Iblock/blk-core.c
249!Eblock/blk-map.c
250!Iblock/blk-sysfs.c
251!Eblock/blk-settings.c
252!Eblock/blk-exec.c
253!Eblock/blk-flush.c
254!Eblock/blk-lib.c
255!Eblock/blk-tag.c
256!Iblock/blk-tag.c
257!Eblock/blk-integrity.c
258!Ikernel/trace/blktrace.c
259!Iblock/genhd.c
260!Eblock/genhd.c
261 </chapter>
262
263 <chapter id="chrdev">
264 <title>Char devices</title>
265!Efs/char_dev.c
266 </chapter>
267
268 <chapter id="miscdev">
269 <title>Miscellaneous Devices</title>
270!Edrivers/char/misc.c
271 </chapter>
272
273 <chapter id="clk">
274 <title>Clock Framework</title>
275
276 <para>
277 The clock framework defines programming interfaces to support
278 software management of the system clock tree.
279 This framework is widely used with System-On-Chip (SOC) platforms
280 to support power management and various devices which may need
281 custom clock rates.
282 Note that these "clocks" don't relate to timekeeping or real
283 time clocks (RTCs), each of which have separate frameworks.
284 These <structname>struct clk</structname> instances may be used
285 to manage for example a 96 MHz signal that is used to shift bits
286 into and out of peripherals or busses, or otherwise trigger
287 synchronous state machine transitions in system hardware.
288 </para>
289
290 <para>
291 Power management is supported by explicit software clock gating:
292 unused clocks are disabled, so the system doesn't waste power
293 changing the state of transistors that aren't in active use.
294 On some systems this may be backed by hardware clock gating,
295 where clocks are gated without being disabled in software.
296 Sections of chips that are powered but not clocked may be able
297 to retain their last state.
298 This low power state is often called a <emphasis>retention
299 mode</emphasis>.
300 This mode still incurs leakage currents, especially with finer
301 circuit geometries, but for CMOS circuits power is mostly used
302 by clocked state changes.
303 </para>
304
305 <para>
306 Power-aware drivers only enable their clocks when the device
307 they manage is in active use. Also, system sleep states often
308 differ according to which clock domains are active: while a
309 "standby" state may allow wakeup from several active domains, a
310 "mem" (suspend-to-RAM) state may require a more wholesale shutdown
311 of clocks derived from higher speed PLLs and oscillators, limiting
312 the number of possible wakeup event sources. A driver's suspend
313 method may need to be aware of system-specific clock constraints
314 on the target sleep state.
315 </para>
316
317 <para>
318 Some platforms support programmable clock generators. These
319 can be used by external chips of various kinds, such as other
320 CPUs, multimedia codecs, and devices with strict requirements
321 for interface clocking.
322 </para>
323
324!Iinclude/linux/clk.h
325 </chapter>
326
327</book>