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!Finclude/linux/kernel.h kstrtol
62!Finclude/linux/kernel.h kstrtoul
63!Elib/kstrtox.c
64     </sect1>
65     <sect1><title>String Manipulation</title>
66<!-- All functions are exported at now
67X!Ilib/string.c
68 -->
69!Elib/string.c
70     </sect1>
71     <sect1><title>Bit Operations</title>
72!Iarch/x86/include/asm/bitops.h
73     </sect1>
74  </chapter>
75
76  <chapter id="kernel-lib">
77     <title>Basic Kernel Library Functions</title>
78
79     <para>
80       The Linux kernel provides more basic utility functions.
81     </para>
82
83     <sect1><title>Bitmap Operations</title>
84!Elib/bitmap.c
85!Ilib/bitmap.c
86     </sect1>
87
88     <sect1><title>Command-line Parsing</title>
89!Elib/cmdline.c
90     </sect1>
91
92     <sect1 id="crc"><title>CRC Functions</title>
93!Elib/crc7.c
94!Elib/crc16.c
95!Elib/crc-itu-t.c
96!Elib/crc32.c
97!Elib/crc-ccitt.c
98     </sect1>
99
100     <sect1 id="idr"><title>idr/ida Functions</title>
101!Pinclude/linux/idr.h idr sync
102!Plib/idr.c IDA description
103!Elib/idr.c
104     </sect1>
105  </chapter>
106
107  <chapter id="mm">
108     <title>Memory Management in Linux</title>
109     <sect1><title>The Slab Cache</title>
110!Iinclude/linux/slab.h
111!Emm/slab.c
112!Emm/util.c
113     </sect1>
114     <sect1><title>User Space Memory Access</title>
115!Iarch/x86/include/asm/uaccess_32.h
116!Earch/x86/lib/usercopy_32.c
117     </sect1>
118     <sect1><title>More Memory Management Functions</title>
119!Emm/readahead.c
120!Emm/filemap.c
121!Emm/memory.c
122!Emm/vmalloc.c
123!Imm/page_alloc.c
124!Emm/mempool.c
125!Emm/dmapool.c
126!Emm/page-writeback.c
127!Emm/truncate.c
128     </sect1>
129  </chapter>
130
131
132  <chapter id="ipc">
133     <title>Kernel IPC facilities</title>
134
135     <sect1><title>IPC utilities</title>
136!Iipc/util.c
137     </sect1>
138  </chapter>
139
140  <chapter id="kfifo">
141     <title>FIFO Buffer</title>
142     <sect1><title>kfifo interface</title>
143!Iinclude/linux/kfifo.h
144     </sect1>
145  </chapter>
146
147  <chapter id="relayfs">
148     <title>relay interface support</title>
149
150     <para>
151	Relay interface support
152	is designed to provide an efficient mechanism for tools and
153	facilities to relay large amounts of data from kernel space to
154	user space.
155     </para>
156
157     <sect1><title>relay interface</title>
158!Ekernel/relay.c
159!Ikernel/relay.c
160     </sect1>
161  </chapter>
162
163  <chapter id="modload">
164     <title>Module Support</title>
165     <sect1><title>Module Loading</title>
166!Ekernel/kmod.c
167     </sect1>
168     <sect1><title>Inter Module support</title>
169        <para>
170           Refer to the file kernel/module.c for more information.
171        </para>
172<!-- FIXME: Removed for now since no structured comments in source
173X!Ekernel/module.c
174-->
175     </sect1>
176  </chapter>
177
178  <chapter id="hardware">
179     <title>Hardware Interfaces</title>
180     <sect1><title>Interrupt Handling</title>
181!Ekernel/irq/manage.c
182     </sect1>
183
184     <sect1><title>DMA Channels</title>
185!Ekernel/dma.c
186     </sect1>
187
188     <sect1><title>Resources Management</title>
189!Ikernel/resource.c
190!Ekernel/resource.c
191     </sect1>
192
193     <sect1><title>MTRR Handling</title>
194!Earch/x86/kernel/cpu/mtrr/main.c
195     </sect1>
196
197     <sect1><title>PCI Support Library</title>
198!Edrivers/pci/pci.c
199!Edrivers/pci/pci-driver.c
200!Edrivers/pci/remove.c
201!Edrivers/pci/search.c
202!Edrivers/pci/msi.c
203!Edrivers/pci/bus.c
204!Edrivers/pci/access.c
205!Edrivers/pci/irq.c
206!Edrivers/pci/htirq.c
207<!-- FIXME: Removed for now since no structured comments in source
208X!Edrivers/pci/hotplug.c
209-->
210!Edrivers/pci/probe.c
211!Edrivers/pci/slot.c
212!Edrivers/pci/rom.c
213!Edrivers/pci/iov.c
214!Idrivers/pci/pci-sysfs.c
215     </sect1>
216     <sect1><title>PCI Hotplug Support Library</title>
217!Edrivers/pci/hotplug/pci_hotplug_core.c
218     </sect1>
219  </chapter>
220
221  <chapter id="firmware">
222     <title>Firmware Interfaces</title>
223     <sect1><title>DMI Interfaces</title>
224!Edrivers/firmware/dmi_scan.c
225     </sect1>
226     <sect1><title>EDD Interfaces</title>
227!Idrivers/firmware/edd.c
228     </sect1>
229  </chapter>
230
231  <chapter id="security">
232     <title>Security Framework</title>
233!Isecurity/security.c
234!Esecurity/inode.c
235  </chapter>
236
237  <chapter id="audit">
238     <title>Audit Interfaces</title>
239!Ekernel/audit.c
240!Ikernel/auditsc.c
241!Ikernel/auditfilter.c
242  </chapter>
243
244  <chapter id="accounting">
245     <title>Accounting Framework</title>
246!Ikernel/acct.c
247  </chapter>
248
249  <chapter id="blkdev">
250     <title>Block Devices</title>
251!Eblock/blk-core.c
252!Iblock/blk-core.c
253!Eblock/blk-map.c
254!Iblock/blk-sysfs.c
255!Eblock/blk-settings.c
256!Eblock/blk-exec.c
257!Eblock/blk-flush.c
258!Eblock/blk-lib.c
259!Eblock/blk-tag.c
260!Iblock/blk-tag.c
261!Eblock/blk-integrity.c
262!Ikernel/trace/blktrace.c
263!Iblock/genhd.c
264!Eblock/genhd.c
265  </chapter>
266
267  <chapter id="chrdev">
268	<title>Char devices</title>
269!Efs/char_dev.c
270  </chapter>
271
272  <chapter id="miscdev">
273     <title>Miscellaneous Devices</title>
274!Edrivers/char/misc.c
275  </chapter>
276
277  <chapter id="clk">
278     <title>Clock Framework</title>
279
280     <para>
281	The clock framework defines programming interfaces to support
282	software management of the system clock tree.
283	This framework is widely used with System-On-Chip (SOC) platforms
284	to support power management and various devices which may need
285	custom clock rates.
286	Note that these "clocks" don't relate to timekeeping or real
287	time clocks (RTCs), each of which have separate frameworks.
288	These <structname>struct clk</structname> instances may be used
289	to manage for example a 96 MHz signal that is used to shift bits
290	into and out of peripherals or busses, or otherwise trigger
291	synchronous state machine transitions in system hardware.
292     </para>
293
294     <para>
295	Power management is supported by explicit software clock gating:
296	unused clocks are disabled, so the system doesn't waste power
297	changing the state of transistors that aren't in active use.
298	On some systems this may be backed by hardware clock gating,
299	where clocks are gated without being disabled in software.
300	Sections of chips that are powered but not clocked may be able
301	to retain their last state.
302	This low power state is often called a <emphasis>retention
303	mode</emphasis>.
304	This mode still incurs leakage currents, especially with finer
305	circuit geometries, but for CMOS circuits power is mostly used
306	by clocked state changes.
307     </para>
308
309     <para>
310	Power-aware drivers only enable their clocks when the device
311	they manage is in active use.  Also, system sleep states often
312	differ according to which clock domains are active:  while a
313	"standby" state may allow wakeup from several active domains, a
314	"mem" (suspend-to-RAM) state may require a more wholesale shutdown
315	of clocks derived from higher speed PLLs and oscillators, limiting
316	the number of possible wakeup event sources.  A driver's suspend
317	method may need to be aware of system-specific clock constraints
318	on the target sleep state.
319     </para>
320
321     <para>
322        Some platforms support programmable clock generators.  These
323	can be used by external chips of various kinds, such as other
324	CPUs, multimedia codecs, and devices with strict requirements
325	for interface clocking.
326     </para>
327
328!Iinclude/linux/clk.h
329  </chapter>
330
331</book>
332