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     <sect1><title>MCA Architecture</title>
216	<sect2><title>MCA Device Functions</title>
217           <para>
218              Refer to the file arch/x86/kernel/mca_32.c for more information.
219           </para>
220<!-- FIXME: Removed for now since no structured comments in source
221X!Earch/x86/kernel/mca_32.c
222-->
223	</sect2>
224	<sect2><title>MCA Bus DMA</title>
225!Iarch/x86/include/asm/mca_dma.h
226	</sect2>
227     </sect1>
228  </chapter>
229
230  <chapter id="firmware">
231     <title>Firmware Interfaces</title>
232     <sect1><title>DMI Interfaces</title>
233!Edrivers/firmware/dmi_scan.c
234     </sect1>
235     <sect1><title>EDD Interfaces</title>
236!Idrivers/firmware/edd.c
237     </sect1>
238  </chapter>
239
240  <chapter id="security">
241     <title>Security Framework</title>
242!Isecurity/security.c
243!Esecurity/inode.c
244  </chapter>
245
246  <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
258  <chapter id="blkdev">
259     <title>Block Devices</title>
260!Eblock/blk-core.c
261!Iblock/blk-core.c
262!Eblock/blk-map.c
263!Iblock/blk-sysfs.c
264!Eblock/blk-settings.c
265!Eblock/blk-exec.c
266!Eblock/blk-flush.c
267!Eblock/blk-lib.c
268!Eblock/blk-tag.c
269!Iblock/blk-tag.c
270!Eblock/blk-integrity.c
271!Ikernel/trace/blktrace.c
272!Iblock/genhd.c
273!Eblock/genhd.c
274  </chapter>
275
276  <chapter id="chrdev">
277	<title>Char devices</title>
278!Efs/char_dev.c
279  </chapter>
280
281  <chapter id="miscdev">
282     <title>Miscellaneous Devices</title>
283!Edrivers/char/misc.c
284  </chapter>
285
286  <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
340</book>
341