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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!Ilib/vsprintf.c
61!Elib/vsprintf.c
62 </sect1>
63 <sect1><title>String Manipulation</title>
64<!-- All functions are exported at now
65X!Ilib/string.c
66 -->
67!Elib/string.c
68 </sect1>
69 <sect1><title>Bit Operations</title>
70!Iarch/x86/include/asm/bitops.h
71 </sect1>
72 </chapter>
73
74 <chapter id="kernel-lib">
75 <title>Basic Kernel Library Functions</title>
76
77 <para>
78 The Linux kernel provides more basic utility functions.
79 </para>
80
81 <sect1><title>Bitmap Operations</title>
82!Elib/bitmap.c
83!Ilib/bitmap.c
84 </sect1>
85
86 <sect1><title>Command-line Parsing</title>
87!Elib/cmdline.c
88 </sect1>
89
90 <sect1 id="crc"><title>CRC Functions</title>
91!Elib/crc7.c
92!Elib/crc16.c
93!Elib/crc-itu-t.c
94!Elib/crc32.c
95!Elib/crc-ccitt.c
96 </sect1>
97 </chapter>
98
99 <chapter id="mm">
100 <title>Memory Management in Linux</title>
101 <sect1><title>The Slab Cache</title>
102!Iinclude/linux/slab.h
103!Emm/slab.c
104 </sect1>
105 <sect1><title>User Space Memory Access</title>
106!Iarch/x86/include/asm/uaccess_32.h
107!Earch/x86/lib/usercopy_32.c
108 </sect1>
109 <sect1><title>More Memory Management Functions</title>
110!Emm/readahead.c
111!Emm/filemap.c
112!Emm/memory.c
113!Emm/vmalloc.c
114!Imm/page_alloc.c
115!Emm/mempool.c
116!Emm/dmapool.c
117!Emm/page-writeback.c
118!Emm/truncate.c
119 </sect1>
120 </chapter>
121
122
123 <chapter id="ipc">
124 <title>Kernel IPC facilities</title>
125
126 <sect1><title>IPC utilities</title>
127!Iipc/util.c
128 </sect1>
129 </chapter>
130
131 <chapter id="kfifo">
132 <title>FIFO Buffer</title>
133 <sect1><title>kfifo interface</title>
134!Iinclude/linux/kfifo.h
135!Ekernel/kfifo.c
136 </sect1>
137 </chapter>
138
139 <chapter id="relayfs">
140 <title>relay interface support</title>
141
142 <para>
143 Relay interface support
144 is designed to provide an efficient mechanism for tools and
145 facilities to relay large amounts of data from kernel space to
146 user space.
147 </para>
148
149 <sect1><title>relay interface</title>
150!Ekernel/relay.c
151!Ikernel/relay.c
152 </sect1>
153 </chapter>
154
155 <chapter id="modload">
156 <title>Module Support</title>
157 <sect1><title>Module Loading</title>
158!Ekernel/kmod.c
159 </sect1>
160 <sect1><title>Inter Module support</title>
161 <para>
162 Refer to the file kernel/module.c for more information.
163 </para>
164<!-- FIXME: Removed for now since no structured comments in source
165X!Ekernel/module.c
166-->
167 </sect1>
168 </chapter>
169
170 <chapter id="hardware">
171 <title>Hardware Interfaces</title>
172 <sect1><title>Interrupt Handling</title>
173!Ekernel/irq/manage.c
174 </sect1>
175
176 <sect1><title>DMA Channels</title>
177!Ekernel/dma.c
178 </sect1>
179
180 <sect1><title>Resources Management</title>
181!Ikernel/resource.c
182!Ekernel/resource.c
183 </sect1>
184
185 <sect1><title>MTRR Handling</title>
186!Earch/x86/kernel/cpu/mtrr/main.c
187 </sect1>
188
189 <sect1><title>PCI Support Library</title>
190!Edrivers/pci/pci.c
191!Edrivers/pci/pci-driver.c
192!Edrivers/pci/remove.c
193!Edrivers/pci/search.c
194!Edrivers/pci/msi.c
195!Edrivers/pci/bus.c
196!Edrivers/pci/access.c
197!Edrivers/pci/irq.c
198!Edrivers/pci/htirq.c
199<!-- FIXME: Removed for now since no structured comments in source
200X!Edrivers/pci/hotplug.c
201-->
202!Edrivers/pci/probe.c
203!Edrivers/pci/slot.c
204!Edrivers/pci/rom.c
205!Edrivers/pci/iov.c
206!Idrivers/pci/pci-sysfs.c
207 </sect1>
208 <sect1><title>PCI Hotplug Support Library</title>
209!Edrivers/pci/hotplug/pci_hotplug_core.c
210 </sect1>
211 <sect1><title>MCA Architecture</title>
212 <sect2><title>MCA Device Functions</title>
213 <para>
214 Refer to the file arch/x86/kernel/mca_32.c for more information.
215 </para>
216<!-- FIXME: Removed for now since no structured comments in source
217X!Earch/x86/kernel/mca_32.c
218-->
219 </sect2>
220 <sect2><title>MCA Bus DMA</title>
221!Iarch/x86/include/asm/mca_dma.h
222 </sect2>
223 </sect1>
224 </chapter>
225
226 <chapter id="firmware">
227 <title>Firmware Interfaces</title>
228 <sect1><title>DMI Interfaces</title>
229!Edrivers/firmware/dmi_scan.c
230 </sect1>
231 <sect1><title>EDD Interfaces</title>
232!Idrivers/firmware/edd.c
233 </sect1>
234 </chapter>
235
236 <chapter id="security">
237 <title>Security Framework</title>
238!Isecurity/security.c
239!Esecurity/inode.c
240 </chapter>
241
242 <chapter id="audit">
243 <title>Audit Interfaces</title>
244!Ekernel/audit.c
245!Ikernel/auditsc.c
246!Ikernel/auditfilter.c
247 </chapter>
248
249 <chapter id="accounting">
250 <title>Accounting Framework</title>
251!Ikernel/acct.c
252 </chapter>
253
254 <chapter id="blkdev">
255 <title>Block Devices</title>
256!Eblock/blk-core.c
257!Iblock/blk-core.c
258!Eblock/blk-map.c
259!Iblock/blk-sysfs.c
260!Eblock/blk-settings.c
261!Eblock/blk-exec.c
262!Eblock/blk-barrier.c
263!Eblock/blk-tag.c
264!Iblock/blk-tag.c
265!Eblock/blk-integrity.c
266!Ikernel/trace/blktrace.c
267!Iblock/genhd.c
268!Eblock/genhd.c
269 </chapter>
270
271 <chapter id="chrdev">
272 <title>Char devices</title>
273!Efs/char_dev.c
274 </chapter>
275
276 <chapter id="miscdev">
277 <title>Miscellaneous Devices</title>
278!Edrivers/char/misc.c
279 </chapter>
280
281 <chapter id="clk">
282 <title>Clock Framework</title>
283
284 <para>
285 The clock framework defines programming interfaces to support
286 software management of the system clock tree.
287 This framework is widely used with System-On-Chip (SOC) platforms
288 to support power management and various devices which may need
289 custom clock rates.
290 Note that these "clocks" don't relate to timekeeping or real
291 time clocks (RTCs), each of which have separate frameworks.
292 These <structname>struct clk</structname> instances may be used
293 to manage for example a 96 MHz signal that is used to shift bits
294 into and out of peripherals or busses, or otherwise trigger
295 synchronous state machine transitions in system hardware.
296 </para>
297
298 <para>
299 Power management is supported by explicit software clock gating:
300 unused clocks are disabled, so the system doesn't waste power
301 changing the state of transistors that aren't in active use.
302 On some systems this may be backed by hardware clock gating,
303 where clocks are gated without being disabled in software.
304 Sections of chips that are powered but not clocked may be able
305 to retain their last state.
306 This low power state is often called a <emphasis>retention
307 mode</emphasis>.
308 This mode still incurs leakage currents, especially with finer
309 circuit geometries, but for CMOS circuits power is mostly used
310 by clocked state changes.
311 </para>
312
313 <para>
314 Power-aware drivers only enable their clocks when the device
315 they manage is in active use. Also, system sleep states often
316 differ according to which clock domains are active: while a
317 "standby" state may allow wakeup from several active domains, a
318 "mem" (suspend-to-RAM) state may require a more wholesale shutdown
319 of clocks derived from higher speed PLLs and oscillators, limiting
320 the number of possible wakeup event sources. A driver's suspend
321 method may need to be aware of system-specific clock constraints
322 on the target sleep state.
323 </para>
324
325 <para>
326 Some platforms support programmable clock generators. These
327 can be used by external chips of various kinds, such as other
328 CPUs, multimedia codecs, and devices with strict requirements
329 for interface clocking.
330 </para>
331
332!Iinclude/linux/clk.h
333 </chapter>
334
335</book>