1====================
  2The Linux Kernel API
  3====================
  4
  5
  6List Management Functions
  7=========================
  8
  9.. kernel-doc:: include/linux/list.h
 10   :internal:
 11
 12Basic C Library Functions
 13=========================
 14
 15When writing drivers, you cannot in general use routines which are from
 16the C Library. Some of the functions have been found generally useful
 17and they are listed below. The behaviour of these functions may vary
 18slightly from those defined by ANSI, and these deviations are noted in
 19the text.
 20
 21String Conversions
 22------------------
 23
 24.. kernel-doc:: lib/vsprintf.c
 25   :export:
 26
 27.. kernel-doc:: include/linux/kernel.h
 28   :functions: kstrtol
 29
 30.. kernel-doc:: include/linux/kernel.h
 31   :functions: kstrtoul
 32
 33.. kernel-doc:: lib/kstrtox.c
 34   :export:
 35
 36.. kernel-doc:: lib/string_helpers.c
 37   :export:
 38
 39String Manipulation
 40-------------------
 41
 
 
 
 42.. kernel-doc:: lib/string.c
 43   :export:
 44
 45.. kernel-doc:: include/linux/string.h
 46   :internal:
 47
 48.. kernel-doc:: mm/util.c
 49   :functions: kstrdup kstrdup_const kstrndup kmemdup kmemdup_nul memdup_user
 50               vmemdup_user strndup_user memdup_user_nul
 51
 52Basic Kernel Library Functions
 53==============================
 54
 55The Linux kernel provides more basic utility functions.
 56
 57Bit Operations
 58--------------
 59
 60.. kernel-doc:: include/asm-generic/bitops-instrumented.h
 
 
 
 
 
 
 61   :internal:
 62
 63Bitmap Operations
 64-----------------
 65
 66.. kernel-doc:: lib/bitmap.c
 67   :doc: bitmap introduction
 68
 69.. kernel-doc:: include/linux/bitmap.h
 70   :doc: declare bitmap
 71
 72.. kernel-doc:: include/linux/bitmap.h
 73   :doc: bitmap overview
 74
 75.. kernel-doc:: include/linux/bitmap.h
 76   :doc: bitmap bitops
 77
 78.. kernel-doc:: lib/bitmap.c
 79   :export:
 80
 81.. kernel-doc:: lib/bitmap.c
 82   :internal:
 83
 84.. kernel-doc:: include/linux/bitmap.h
 85   :internal:
 86
 87Command-line Parsing
 88--------------------
 89
 90.. kernel-doc:: lib/cmdline.c
 91   :export:
 92
 93Sorting
 94-------
 95
 96.. kernel-doc:: lib/sort.c
 97   :export:
 98
 99.. kernel-doc:: lib/list_sort.c
100   :export:
101
102Text Searching
103--------------
104
105.. kernel-doc:: lib/textsearch.c
106   :doc: ts_intro
107
108.. kernel-doc:: lib/textsearch.c
109   :export:
110
111.. kernel-doc:: include/linux/textsearch.h
112   :functions: textsearch_find textsearch_next \
113               textsearch_get_pattern textsearch_get_pattern_len
114
115CRC and Math Functions in Linux
116===============================
117
 
 
 
 
 
 
118CRC Functions
119-------------
120
121.. kernel-doc:: lib/crc4.c
122   :export:
123
124.. kernel-doc:: lib/crc7.c
125   :export:
126
127.. kernel-doc:: lib/crc8.c
128   :export:
129
130.. kernel-doc:: lib/crc16.c
131   :export:
132
133.. kernel-doc:: lib/crc32.c
134
135.. kernel-doc:: lib/crc-ccitt.c
136   :export:
137
138.. kernel-doc:: lib/crc-itu-t.c
139   :export:
140
141Base 2 log and power Functions
142------------------------------
143
144.. kernel-doc:: include/linux/log2.h
145   :internal:
146
147Integer power Functions
148-----------------------
149
150.. kernel-doc:: lib/math/int_pow.c
151   :export:
152
153.. kernel-doc:: lib/math/int_sqrt.c
154   :export:
155
156Division Functions
157------------------
158
159.. kernel-doc:: include/asm-generic/div64.h
160   :functions: do_div
161
162.. kernel-doc:: include/linux/math64.h
163   :internal:
164
165.. kernel-doc:: lib/math/div64.c
166   :functions: div_s64_rem div64_u64_rem div64_u64 div64_s64
167
168.. kernel-doc:: lib/math/gcd.c
169   :export:
170
171UUID/GUID
172---------
173
174.. kernel-doc:: lib/uuid.c
175   :export:
176
177Kernel IPC facilities
178=====================
179
180IPC utilities
181-------------
182
183.. kernel-doc:: ipc/util.c
184   :internal:
185
186FIFO Buffer
187===========
188
189kfifo interface
190---------------
191
192.. kernel-doc:: include/linux/kfifo.h
193   :internal:
194
195relay interface support
196=======================
197
198Relay interface support is designed to provide an efficient mechanism
199for tools and facilities to relay large amounts of data from kernel
200space to user space.
201
202relay interface
203---------------
204
205.. kernel-doc:: kernel/relay.c
206   :export:
207
208.. kernel-doc:: kernel/relay.c
209   :internal:
210
211Module Support
212==============
213
214Module Loading
215--------------
216
217.. kernel-doc:: kernel/kmod.c
218   :export:
219
220Inter Module support
221--------------------
222
223Refer to the file kernel/module.c for more information.
224
225Hardware Interfaces
226===================
227
228Interrupt Handling
229------------------
230
231.. kernel-doc:: kernel/irq/manage.c
232   :export:
233
234DMA Channels
235------------
236
237.. kernel-doc:: kernel/dma.c
238   :export:
239
240Resources Management
241--------------------
242
243.. kernel-doc:: kernel/resource.c
244   :internal:
245
246.. kernel-doc:: kernel/resource.c
247   :export:
248
249MTRR Handling
250-------------
251
252.. kernel-doc:: arch/x86/kernel/cpu/mtrr/mtrr.c
253   :export:
254
255Security Framework
256==================
257
258.. kernel-doc:: security/security.c
259   :internal:
260
261.. kernel-doc:: security/inode.c
262   :export:
263
264Audit Interfaces
265================
266
267.. kernel-doc:: kernel/audit.c
268   :export:
269
270.. kernel-doc:: kernel/auditsc.c
271   :internal:
272
273.. kernel-doc:: kernel/auditfilter.c
274   :internal:
275
276Accounting Framework
277====================
278
279.. kernel-doc:: kernel/acct.c
280   :internal:
281
282Block Devices
283=============
284
 
285.. kernel-doc:: block/blk-core.c
286   :export:
287
288.. kernel-doc:: block/blk-core.c
289   :internal:
290
291.. kernel-doc:: block/blk-map.c
292   :export:
293
294.. kernel-doc:: block/blk-sysfs.c
295   :internal:
296
297.. kernel-doc:: block/blk-settings.c
298   :export:
299
300.. kernel-doc:: block/blk-exec.c
301   :export:
302
303.. kernel-doc:: block/blk-flush.c
304   :export:
305
306.. kernel-doc:: block/blk-lib.c
307   :export:
308
309.. kernel-doc:: block/blk-integrity.c
310   :export:
311
312.. kernel-doc:: kernel/trace/blktrace.c
313   :internal:
314
315.. kernel-doc:: block/genhd.c
316   :internal:
317
318.. kernel-doc:: block/genhd.c
 
 
 
319   :export:
320
321Char devices
322============
323
324.. kernel-doc:: fs/char_dev.c
325   :export:
326
327Clock Framework
328===============
329
330The clock framework defines programming interfaces to support software
331management of the system clock tree. This framework is widely used with
332System-On-Chip (SOC) platforms to support power management and various
333devices which may need custom clock rates. Note that these "clocks"
334don't relate to timekeeping or real time clocks (RTCs), each of which
335have separate frameworks. These :c:type:`struct clk <clk>`
336instances may be used to manage for example a 96 MHz signal that is used
337to shift bits into and out of peripherals or busses, or otherwise
338trigger synchronous state machine transitions in system hardware.
339
340Power management is supported by explicit software clock gating: unused
341clocks are disabled, so the system doesn't waste power changing the
342state of transistors that aren't in active use. On some systems this may
343be backed by hardware clock gating, where clocks are gated without being
344disabled in software. Sections of chips that are powered but not clocked
345may be able to retain their last state. This low power state is often
346called a *retention mode*. This mode still incurs leakage currents,
347especially with finer circuit geometries, but for CMOS circuits power is
348mostly used by clocked state changes.
349
350Power-aware drivers only enable their clocks when the device they manage
351is in active use. Also, system sleep states often differ according to
352which clock domains are active: while a "standby" state may allow wakeup
353from several active domains, a "mem" (suspend-to-RAM) state may require
354a more wholesale shutdown of clocks derived from higher speed PLLs and
355oscillators, limiting the number of possible wakeup event sources. A
356driver's suspend method may need to be aware of system-specific clock
357constraints on the target sleep state.
358
359Some platforms support programmable clock generators. These can be used
360by external chips of various kinds, such as other CPUs, multimedia
361codecs, and devices with strict requirements for interface clocking.
362
363.. kernel-doc:: include/linux/clk.h
364   :internal:
365
366Synchronization Primitives
367==========================
368
369Read-Copy Update (RCU)
370----------------------
371
372.. kernel-doc:: include/linux/rcupdate.h
373
374.. kernel-doc:: kernel/rcu/tree.c
375
376.. kernel-doc:: kernel/rcu/tree_exp.h
377
378.. kernel-doc:: kernel/rcu/update.c
379
380.. kernel-doc:: include/linux/srcu.h
381
382.. kernel-doc:: kernel/rcu/srcutree.c
383
384.. kernel-doc:: include/linux/rculist_bl.h
385
386.. kernel-doc:: include/linux/rculist.h
387
388.. kernel-doc:: include/linux/rculist_nulls.h
389
390.. kernel-doc:: include/linux/rcu_sync.h
391
392.. kernel-doc:: kernel/rcu/sync.c

  1====================
  2The Linux Kernel API
  3====================
  4
  5
  6List Management Functions
  7=========================
  8
  9.. kernel-doc:: include/linux/list.h
 10   :internal:
 11
 12Basic C Library Functions
 13=========================
 14
 15When writing drivers, you cannot in general use routines which are from
 16the C Library. Some of the functions have been found generally useful
 17and they are listed below. The behaviour of these functions may vary
 18slightly from those defined by ANSI, and these deviations are noted in
 19the text.
 20
 21String Conversions
 22------------------
 23
 24.. kernel-doc:: lib/vsprintf.c
 25   :export:
 26
 27.. kernel-doc:: include/linux/kstrtox.h
 28   :functions: kstrtol kstrtoul
 
 
 
 29
 30.. kernel-doc:: lib/kstrtox.c
 31   :export:
 32
 33.. kernel-doc:: lib/string_helpers.c
 34   :export:
 35
 36String Manipulation
 37-------------------
 38
 39.. kernel-doc:: include/linux/fortify-string.h
 40   :internal:
 41
 42.. kernel-doc:: lib/string.c
 43   :export:
 44
 45.. kernel-doc:: include/linux/string.h
 46   :internal:
 47
 48.. kernel-doc:: mm/util.c
 49   :functions: kstrdup kstrdup_const kstrndup kmemdup kmemdup_nul memdup_user
 50               vmemdup_user strndup_user memdup_user_nul
 51
 52Basic Kernel Library Functions
 53==============================
 54
 55The Linux kernel provides more basic utility functions.
 56
 57Bit Operations
 58--------------
 59
 60.. kernel-doc:: include/asm-generic/bitops/instrumented-atomic.h
 61   :internal:
 62
 63.. kernel-doc:: include/asm-generic/bitops/instrumented-non-atomic.h
 64   :internal:
 65
 66.. kernel-doc:: include/asm-generic/bitops/instrumented-lock.h
 67   :internal:
 68
 69Bitmap Operations
 70-----------------
 71
 72.. kernel-doc:: lib/bitmap.c
 73   :doc: bitmap introduction
 74
 75.. kernel-doc:: include/linux/bitmap.h
 76   :doc: declare bitmap
 77
 78.. kernel-doc:: include/linux/bitmap.h
 79   :doc: bitmap overview
 80
 81.. kernel-doc:: include/linux/bitmap.h
 82   :doc: bitmap bitops
 83
 84.. kernel-doc:: lib/bitmap.c
 85   :export:
 86
 87.. kernel-doc:: lib/bitmap.c
 88   :internal:
 89
 90.. kernel-doc:: include/linux/bitmap.h
 91   :internal:
 92
 93Command-line Parsing
 94--------------------
 95
 96.. kernel-doc:: lib/cmdline.c
 97   :export:
 98
 99Sorting
100-------
101
102.. kernel-doc:: lib/sort.c
103   :export:
104
105.. kernel-doc:: lib/list_sort.c
106   :export:
107
108Text Searching
109--------------
110
111.. kernel-doc:: lib/textsearch.c
112   :doc: ts_intro
113
114.. kernel-doc:: lib/textsearch.c
115   :export:
116
117.. kernel-doc:: include/linux/textsearch.h
118   :functions: textsearch_find textsearch_next \
119               textsearch_get_pattern textsearch_get_pattern_len
120
121CRC and Math Functions in Linux
122===============================
123
124Arithmetic Overflow Checking
125----------------------------
126
127.. kernel-doc:: include/linux/overflow.h
128   :internal:
129
130CRC Functions
131-------------
132
133.. kernel-doc:: lib/crc4.c
134   :export:
135
136.. kernel-doc:: lib/crc7.c
137   :export:
138
139.. kernel-doc:: lib/crc8.c
140   :export:
141
142.. kernel-doc:: lib/crc16.c
143   :export:
144
145.. kernel-doc:: lib/crc32.c
146
147.. kernel-doc:: lib/crc-ccitt.c
148   :export:
149
150.. kernel-doc:: lib/crc-itu-t.c
151   :export:
152
153Base 2 log and power Functions
154------------------------------
155
156.. kernel-doc:: include/linux/log2.h
157   :internal:
158
159Integer power Functions
160-----------------------
161
162.. kernel-doc:: lib/math/int_pow.c
163   :export:
164
165.. kernel-doc:: lib/math/int_sqrt.c
166   :export:
167
168Division Functions
169------------------
170
171.. kernel-doc:: include/asm-generic/div64.h
172   :functions: do_div
173
174.. kernel-doc:: include/linux/math64.h
175   :internal:
176
 
 
 
177.. kernel-doc:: lib/math/gcd.c
178   :export:
179
180UUID/GUID
181---------
182
183.. kernel-doc:: lib/uuid.c
184   :export:
185
186Kernel IPC facilities
187=====================
188
189IPC utilities
190-------------
191
192.. kernel-doc:: ipc/util.c
193   :internal:
194
195FIFO Buffer
196===========
197
198kfifo interface
199---------------
200
201.. kernel-doc:: include/linux/kfifo.h
202   :internal:
203
204relay interface support
205=======================
206
207Relay interface support is designed to provide an efficient mechanism
208for tools and facilities to relay large amounts of data from kernel
209space to user space.
210
211relay interface
212---------------
213
214.. kernel-doc:: kernel/relay.c
215   :export:
216
217.. kernel-doc:: kernel/relay.c
218   :internal:
219
220Module Support
221==============
222
223Module Loading
224--------------
225
226.. kernel-doc:: kernel/kmod.c
227   :export:
228
229Inter Module support
230--------------------
231
232Refer to the files in kernel/module/ for more information.
233
234Hardware Interfaces
235===================
236
 
 
 
 
 
 
237DMA Channels
238------------
239
240.. kernel-doc:: kernel/dma.c
241   :export:
242
243Resources Management
244--------------------
245
246.. kernel-doc:: kernel/resource.c
247   :internal:
248
249.. kernel-doc:: kernel/resource.c
250   :export:
251
252MTRR Handling
253-------------
254
255.. kernel-doc:: arch/x86/kernel/cpu/mtrr/mtrr.c
256   :export:
257
258Security Framework
259==================
260
261.. kernel-doc:: security/security.c
262   :internal:
263
264.. kernel-doc:: security/inode.c
265   :export:
266
267Audit Interfaces
268================
269
270.. kernel-doc:: kernel/audit.c
271   :export:
272
273.. kernel-doc:: kernel/auditsc.c
274   :internal:
275
276.. kernel-doc:: kernel/auditfilter.c
277   :internal:
278
279Accounting Framework
280====================
281
282.. kernel-doc:: kernel/acct.c
283   :internal:
284
285Block Devices
286=============
287
288.. kernel-doc:: include/linux/bio.h
289.. kernel-doc:: block/blk-core.c
290   :export:
291
292.. kernel-doc:: block/blk-core.c
293   :internal:
294
295.. kernel-doc:: block/blk-map.c
296   :export:
297
298.. kernel-doc:: block/blk-sysfs.c
299   :internal:
300
301.. kernel-doc:: block/blk-settings.c
302   :export:
303
 
 
 
304.. kernel-doc:: block/blk-flush.c
305   :export:
306
307.. kernel-doc:: block/blk-lib.c
308   :export:
309
310.. kernel-doc:: block/blk-integrity.c
311   :export:
312
313.. kernel-doc:: kernel/trace/blktrace.c
314   :internal:
315
316.. kernel-doc:: block/genhd.c
317   :internal:
318
319.. kernel-doc:: block/genhd.c
320   :export:
321
322.. kernel-doc:: block/bdev.c
323   :export:
324
325Char devices
326============
327
328.. kernel-doc:: fs/char_dev.c
329   :export:
330
331Clock Framework
332===============
333
334The clock framework defines programming interfaces to support software
335management of the system clock tree. This framework is widely used with
336System-On-Chip (SOC) platforms to support power management and various
337devices which may need custom clock rates. Note that these "clocks"
338don't relate to timekeeping or real time clocks (RTCs), each of which
339have separate frameworks. These :c:type:`struct clk <clk>`
340instances may be used to manage for example a 96 MHz signal that is used
341to shift bits into and out of peripherals or busses, or otherwise
342trigger synchronous state machine transitions in system hardware.
343
344Power management is supported by explicit software clock gating: unused
345clocks are disabled, so the system doesn't waste power changing the
346state of transistors that aren't in active use. On some systems this may
347be backed by hardware clock gating, where clocks are gated without being
348disabled in software. Sections of chips that are powered but not clocked
349may be able to retain their last state. This low power state is often
350called a *retention mode*. This mode still incurs leakage currents,
351especially with finer circuit geometries, but for CMOS circuits power is
352mostly used by clocked state changes.
353
354Power-aware drivers only enable their clocks when the device they manage
355is in active use. Also, system sleep states often differ according to
356which clock domains are active: while a "standby" state may allow wakeup
357from several active domains, a "mem" (suspend-to-RAM) state may require
358a more wholesale shutdown of clocks derived from higher speed PLLs and
359oscillators, limiting the number of possible wakeup event sources. A
360driver's suspend method may need to be aware of system-specific clock
361constraints on the target sleep state.
362
363Some platforms support programmable clock generators. These can be used
364by external chips of various kinds, such as other CPUs, multimedia
365codecs, and devices with strict requirements for interface clocking.
366
367.. kernel-doc:: include/linux/clk.h
368   :internal:
369
370Synchronization Primitives
371==========================
372
373Read-Copy Update (RCU)
374----------------------
375
376.. kernel-doc:: include/linux/rcupdate.h
377
378.. kernel-doc:: kernel/rcu/tree.c
379
380.. kernel-doc:: kernel/rcu/tree_exp.h
381
382.. kernel-doc:: kernel/rcu/update.c
383
384.. kernel-doc:: include/linux/srcu.h
385
386.. kernel-doc:: kernel/rcu/srcutree.c
387
388.. kernel-doc:: include/linux/rculist_bl.h
389
390.. kernel-doc:: include/linux/rculist.h
391
392.. kernel-doc:: include/linux/rculist_nulls.h
393
394.. kernel-doc:: include/linux/rcu_sync.h
395
396.. kernel-doc:: kernel/rcu/sync.c