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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 </sect1>
136 </chapter>
137
138 <chapter id="relayfs">
139 <title>relay interface support</title>
140
141 <para>
142 Relay interface support
143 is designed to provide an efficient mechanism for tools and
144 facilities to relay large amounts of data from kernel space to
145 user space.
146 </para>
147
148 <sect1><title>relay interface</title>
149!Ekernel/relay.c
150!Ikernel/relay.c
151 </sect1>
152 </chapter>
153
154 <chapter id="modload">
155 <title>Module Support</title>
156 <sect1><title>Module Loading</title>
157!Ekernel/kmod.c
158 </sect1>
159 <sect1><title>Inter Module support</title>
160 <para>
161 Refer to the file kernel/module.c for more information.
162 </para>
163<!-- FIXME: Removed for now since no structured comments in source
164X!Ekernel/module.c
165-->
166 </sect1>
167 </chapter>
168
169 <chapter id="hardware">
170 <title>Hardware Interfaces</title>
171 <sect1><title>Interrupt Handling</title>
172!Ekernel/irq/manage.c
173 </sect1>
174
175 <sect1><title>DMA Channels</title>
176!Ekernel/dma.c
177 </sect1>
178
179 <sect1><title>Resources Management</title>
180!Ikernel/resource.c
181!Ekernel/resource.c
182 </sect1>
183
184 <sect1><title>MTRR Handling</title>
185!Earch/x86/kernel/cpu/mtrr/main.c
186 </sect1>
187
188 <sect1><title>PCI Support Library</title>
189!Edrivers/pci/pci.c
190!Edrivers/pci/pci-driver.c
191!Edrivers/pci/remove.c
192!Edrivers/pci/search.c
193!Edrivers/pci/msi.c
194!Edrivers/pci/bus.c
195!Edrivers/pci/access.c
196!Edrivers/pci/irq.c
197!Edrivers/pci/htirq.c
198<!-- FIXME: Removed for now since no structured comments in source
199X!Edrivers/pci/hotplug.c
200-->
201!Edrivers/pci/probe.c
202!Edrivers/pci/slot.c
203!Edrivers/pci/rom.c
204!Edrivers/pci/iov.c
205!Idrivers/pci/pci-sysfs.c
206 </sect1>
207 <sect1><title>PCI Hotplug Support Library</title>
208!Edrivers/pci/hotplug/pci_hotplug_core.c
209 </sect1>
210 <sect1><title>MCA Architecture</title>
211 <sect2><title>MCA Device Functions</title>
212 <para>
213 Refer to the file arch/x86/kernel/mca_32.c for more information.
214 </para>
215<!-- FIXME: Removed for now since no structured comments in source
216X!Earch/x86/kernel/mca_32.c
217-->
218 </sect2>
219 <sect2><title>MCA Bus DMA</title>
220!Iarch/x86/include/asm/mca_dma.h
221 </sect2>
222 </sect1>
223 </chapter>
224
225 <chapter id="firmware">
226 <title>Firmware Interfaces</title>
227 <sect1><title>DMI Interfaces</title>
228!Edrivers/firmware/dmi_scan.c
229 </sect1>
230 <sect1><title>EDD Interfaces</title>
231!Idrivers/firmware/edd.c
232 </sect1>
233 </chapter>
234
235 <chapter id="security">
236 <title>Security Framework</title>
237!Isecurity/security.c
238!Esecurity/inode.c
239 </chapter>
240
241 <chapter id="audit">
242 <title>Audit Interfaces</title>
243!Ekernel/audit.c
244!Ikernel/auditsc.c
245!Ikernel/auditfilter.c
246 </chapter>
247
248 <chapter id="accounting">
249 <title>Accounting Framework</title>
250!Ikernel/acct.c
251 </chapter>
252
253 <chapter id="blkdev">
254 <title>Block Devices</title>
255!Eblock/blk-core.c
256!Iblock/blk-core.c
257!Eblock/blk-map.c
258!Iblock/blk-sysfs.c
259!Eblock/blk-settings.c
260!Eblock/blk-exec.c
261!Eblock/blk-barrier.c
262!Eblock/blk-tag.c
263!Iblock/blk-tag.c
264!Eblock/blk-integrity.c
265!Ikernel/trace/blktrace.c
266!Iblock/genhd.c
267!Eblock/genhd.c
268 </chapter>
269
270 <chapter id="chrdev">
271 <title>Char devices</title>
272!Efs/char_dev.c
273 </chapter>
274
275 <chapter id="miscdev">
276 <title>Miscellaneous Devices</title>
277!Edrivers/char/misc.c
278 </chapter>
279
280 <chapter id="clk">
281 <title>Clock Framework</title>
282
283 <para>
284 The clock framework defines programming interfaces to support
285 software management of the system clock tree.
286 This framework is widely used with System-On-Chip (SOC) platforms
287 to support power management and various devices which may need
288 custom clock rates.
289 Note that these "clocks" don't relate to timekeeping or real
290 time clocks (RTCs), each of which have separate frameworks.
291 These <structname>struct clk</structname> instances may be used
292 to manage for example a 96 MHz signal that is used to shift bits
293 into and out of peripherals or busses, or otherwise trigger
294 synchronous state machine transitions in system hardware.
295 </para>
296
297 <para>
298 Power management is supported by explicit software clock gating:
299 unused clocks are disabled, so the system doesn't waste power
300 changing the state of transistors that aren't in active use.
301 On some systems this may be backed by hardware clock gating,
302 where clocks are gated without being disabled in software.
303 Sections of chips that are powered but not clocked may be able
304 to retain their last state.
305 This low power state is often called a <emphasis>retention
306 mode</emphasis>.
307 This mode still incurs leakage currents, especially with finer
308 circuit geometries, but for CMOS circuits power is mostly used
309 by clocked state changes.
310 </para>
311
312 <para>
313 Power-aware drivers only enable their clocks when the device
314 they manage is in active use. Also, system sleep states often
315 differ according to which clock domains are active: while a
316 "standby" state may allow wakeup from several active domains, a
317 "mem" (suspend-to-RAM) state may require a more wholesale shutdown
318 of clocks derived from higher speed PLLs and oscillators, limiting
319 the number of possible wakeup event sources. A driver's suspend
320 method may need to be aware of system-specific clock constraints
321 on the target sleep state.
322 </para>
323
324 <para>
325 Some platforms support programmable clock generators. These
326 can be used by external chips of various kinds, such as other
327 CPUs, multimedia codecs, and devices with strict requirements
328 for interface clocking.
329 </para>
330
331!Iinclude/linux/clk.h
332 </chapter>
333
334</book>