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

  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-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
 
 
 
 
 
 
124CRC Functions
125-------------
126
127.. kernel-doc:: lib/crc4.c
128   :export:
129
130.. kernel-doc:: lib/crc7.c
131   :export:
132
133.. kernel-doc:: lib/crc8.c
134   :export:
135
136.. kernel-doc:: lib/crc16.c
137   :export:
138
139.. kernel-doc:: lib/crc32.c
140
141.. kernel-doc:: lib/crc-ccitt.c
142   :export:
143
144.. kernel-doc:: lib/crc-itu-t.c
145   :export:
146
147Base 2 log and power Functions
148------------------------------
149
150.. kernel-doc:: include/linux/log2.h
151   :internal:
152
153Integer power Functions
154-----------------------
155
156.. kernel-doc:: lib/math/int_pow.c
157   :export:
158
159.. kernel-doc:: lib/math/int_sqrt.c
160   :export:
161
162Division Functions
163------------------
164
165.. kernel-doc:: include/asm-generic/div64.h
166   :functions: do_div
167
168.. kernel-doc:: include/linux/math64.h
169   :internal:
170
171.. kernel-doc:: lib/math/div64.c
172   :functions: div_s64_rem div64_u64_rem div64_u64 div64_s64
173
174.. kernel-doc:: lib/math/gcd.c
175   :export:
176
177UUID/GUID
178---------
179
180.. kernel-doc:: lib/uuid.c
181   :export:
182
183Kernel IPC facilities
184=====================
185
186IPC utilities
187-------------
188
189.. kernel-doc:: ipc/util.c
190   :internal:
191
192FIFO Buffer
193===========
194
195kfifo interface
196---------------
197
198.. kernel-doc:: include/linux/kfifo.h
199   :internal:
200
201relay interface support
202=======================
203
204Relay interface support is designed to provide an efficient mechanism
205for tools and facilities to relay large amounts of data from kernel
206space to user space.
207
208relay interface
209---------------
210
211.. kernel-doc:: kernel/relay.c
212   :export:
213
214.. kernel-doc:: kernel/relay.c
215   :internal:
216
217Module Support
218==============
219
220Module Loading
221--------------
222
223.. kernel-doc:: kernel/kmod.c
224   :export:
225
226Inter Module support
227--------------------
228
229Refer to the file kernel/module.c for more information.
230
231Hardware Interfaces
232===================
233
234Interrupt Handling
235------------------
236
237.. kernel-doc:: kernel/irq/manage.c
238   :export:
239
240DMA Channels
241------------
242
243.. kernel-doc:: kernel/dma.c
244   :export:
245
246Resources Management
247--------------------
248
249.. kernel-doc:: kernel/resource.c
250   :internal:
251
252.. kernel-doc:: kernel/resource.c
253   :export:
254
255MTRR Handling
256-------------
257
258.. kernel-doc:: arch/x86/kernel/cpu/mtrr/mtrr.c
259   :export:
260
261Security Framework
262==================
263
264.. kernel-doc:: security/security.c
265   :internal:
266
267.. kernel-doc:: security/inode.c
268   :export:
269
270Audit Interfaces
271================
272
273.. kernel-doc:: kernel/audit.c
274   :export:
275
276.. kernel-doc:: kernel/auditsc.c
277   :internal:
278
279.. kernel-doc:: kernel/auditfilter.c
280   :internal:
281
282Accounting Framework
283====================
284
285.. kernel-doc:: kernel/acct.c
286   :internal:
287
288Block Devices
289=============
290
 
291.. kernel-doc:: block/blk-core.c
292   :export:
293
294.. kernel-doc:: block/blk-core.c
295   :internal:
296
297.. kernel-doc:: block/blk-map.c
298   :export:
299
300.. kernel-doc:: block/blk-sysfs.c
301   :internal:
302
303.. kernel-doc:: block/blk-settings.c
304   :export:
305
306.. kernel-doc:: block/blk-exec.c
307   :export:
308
309.. kernel-doc:: block/blk-flush.c
310   :export:
311
312.. kernel-doc:: block/blk-lib.c
313   :export:
314
315.. kernel-doc:: block/blk-integrity.c
316   :export:
317
318.. kernel-doc:: kernel/trace/blktrace.c
319   :internal:
320
321.. kernel-doc:: block/genhd.c
322   :internal:
323
324.. kernel-doc:: block/genhd.c
 
 
 
325   :export:
326
327Char devices
328============
329
330.. kernel-doc:: fs/char_dev.c
331   :export:
332
333Clock Framework
334===============
335
336The clock framework defines programming interfaces to support software
337management of the system clock tree. This framework is widely used with
338System-On-Chip (SOC) platforms to support power management and various
339devices which may need custom clock rates. Note that these "clocks"
340don't relate to timekeeping or real time clocks (RTCs), each of which
341have separate frameworks. These :c:type:`struct clk <clk>`
342instances may be used to manage for example a 96 MHz signal that is used
343to shift bits into and out of peripherals or busses, or otherwise
344trigger synchronous state machine transitions in system hardware.
345
346Power management is supported by explicit software clock gating: unused
347clocks are disabled, so the system doesn't waste power changing the
348state of transistors that aren't in active use. On some systems this may
349be backed by hardware clock gating, where clocks are gated without being
350disabled in software. Sections of chips that are powered but not clocked
351may be able to retain their last state. This low power state is often
352called a *retention mode*. This mode still incurs leakage currents,
353especially with finer circuit geometries, but for CMOS circuits power is
354mostly used by clocked state changes.
355
356Power-aware drivers only enable their clocks when the device they manage
357is in active use. Also, system sleep states often differ according to
358which clock domains are active: while a "standby" state may allow wakeup
359from several active domains, a "mem" (suspend-to-RAM) state may require
360a more wholesale shutdown of clocks derived from higher speed PLLs and
361oscillators, limiting the number of possible wakeup event sources. A
362driver's suspend method may need to be aware of system-specific clock
363constraints on the target sleep state.
364
365Some platforms support programmable clock generators. These can be used
366by external chips of various kinds, such as other CPUs, multimedia
367codecs, and devices with strict requirements for interface clocking.
368
369.. kernel-doc:: include/linux/clk.h
370   :internal:
371
372Synchronization Primitives
373==========================
374
375Read-Copy Update (RCU)
376----------------------
377
378.. kernel-doc:: include/linux/rcupdate.h
379
380.. kernel-doc:: kernel/rcu/tree.c
381
382.. kernel-doc:: kernel/rcu/tree_exp.h
383
384.. kernel-doc:: kernel/rcu/update.c
385
386.. kernel-doc:: include/linux/srcu.h
387
388.. kernel-doc:: kernel/rcu/srcutree.c
389
390.. kernel-doc:: include/linux/rculist_bl.h
391
392.. kernel-doc:: include/linux/rculist.h
393
394.. kernel-doc:: include/linux/rculist_nulls.h
395
396.. kernel-doc:: include/linux/rcu_sync.h
397
398.. kernel-doc:: kernel/rcu/sync.c