Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
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 </chapter>
97
98 <chapter id="mm">
99 <title>Memory Management in Linux</title>
100 <sect1><title>The Slab Cache</title>
101!Iinclude/linux/slab.h
102!Emm/slab.c
103 </sect1>
104 <sect1><title>User Space Memory Access</title>
105!Iarch/x86/include/asm/uaccess_32.h
106!Earch/x86/lib/usercopy_32.c
107 </sect1>
108 <sect1><title>More Memory Management Functions</title>
109!Emm/readahead.c
110!Emm/filemap.c
111!Emm/memory.c
112!Emm/vmalloc.c
113!Imm/page_alloc.c
114!Emm/mempool.c
115!Emm/dmapool.c
116!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>
128 </chapter>
129
130 <chapter id="kfifo">
131 <title>FIFO Buffer</title>
132 <sect1><title>kfifo interface</title>
133!Iinclude/linux/kfifo.h
134 </sect1>
135 </chapter>
136
137 <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
153 <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>
171!Ekernel/irq/manage.c
172 </sect1>
173
174 <sect1><title>DMA Channels</title>
175!Ekernel/dma.c
176 </sect1>
177
178 <sect1><title>Resources Management</title>
179!Ikernel/resource.c
180!Ekernel/resource.c
181 </sect1>
182
183 <sect1><title>MTRR Handling</title>
184!Earch/x86/kernel/cpu/mtrr/main.c
185 </sect1>
186
187 <sect1><title>PCI Support Library</title>
188!Edrivers/pci/pci.c
189!Edrivers/pci/pci-driver.c
190!Edrivers/pci/remove.c
191!Edrivers/pci/search.c
192!Edrivers/pci/msi.c
193!Edrivers/pci/bus.c
194!Edrivers/pci/access.c
195!Edrivers/pci/irq.c
196!Edrivers/pci/htirq.c
197<!-- FIXME: Removed for now since no structured comments in source
198X!Edrivers/pci/hotplug.c
199-->
200!Edrivers/pci/probe.c
201!Edrivers/pci/slot.c
202!Edrivers/pci/rom.c
203!Edrivers/pci/iov.c
204!Idrivers/pci/pci-sysfs.c
205 </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>
212 Refer to the file arch/x86/kernel/mca_32.c for more information.
213 </para>
214<!-- FIXME: Removed for now since no structured comments in source
215X!Earch/x86/kernel/mca_32.c
216-->
217 </sect2>
218 <sect2><title>MCA Bus DMA</title>
219!Iarch/x86/include/asm/mca_dma.h
220 </sect2>
221 </sect1>
222 </chapter>
223
224 <chapter id="firmware">
225 <title>Firmware Interfaces</title>
226 <sect1><title>DMI Interfaces</title>
227!Edrivers/firmware/dmi_scan.c
228 </sect1>
229 <sect1><title>EDD Interfaces</title>
230!Idrivers/firmware/edd.c
231 </sect1>
232 </chapter>
233
234 <chapter id="security">
235 <title>Security Framework</title>
236!Isecurity/security.c
237!Esecurity/inode.c
238 </chapter>
239
240 <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
252 <chapter id="blkdev">
253 <title>Block Devices</title>
254!Eblock/blk-core.c
255!Iblock/blk-core.c
256!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
262!Iblock/blk-tag.c
263!Eblock/blk-integrity.c
264!Ikernel/trace/blktrace.c
265!Iblock/genhd.c
266!Eblock/genhd.c
267 </chapter>
268
269 <chapter id="chrdev">
270 <title>Char devices</title>
271!Efs/char_dev.c
272 </chapter>
273
274 <chapter id="miscdev">
275 <title>Miscellaneous Devices</title>
276!Edrivers/char/misc.c
277 </chapter>
278
279 <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
333</book>