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
 
 
 
 36String Manipulation
 37-------------------
 38
 39.. kernel-doc:: lib/string.c
 40   :export:
 41
 42Bit Operations
 43--------------
 44
 45.. kernel-doc:: arch/x86/include/asm/bitops.h
 46   :internal:
 47
 
 
 
 
 48Basic Kernel Library Functions
 49==============================
 50
 51The Linux kernel provides more basic utility functions.
 52
 
 
 
 
 
 
 
 
 
 
 
 
 53Bitmap Operations
 54-----------------
 55
 56.. kernel-doc:: lib/bitmap.c
 57   :doc: bitmap introduction
 58
 59.. kernel-doc:: include/linux/bitmap.h
 60   :doc: declare bitmap
 61
 62.. kernel-doc:: include/linux/bitmap.h
 63   :doc: bitmap overview
 64
 65.. kernel-doc:: include/linux/bitmap.h
 66   :doc: bitmap bitops
 67
 68.. kernel-doc:: lib/bitmap.c
 69   :export:
 70
 71.. kernel-doc:: lib/bitmap.c
 72   :internal:
 73
 74.. kernel-doc:: include/linux/bitmap.h
 75   :internal:
 76
 77Command-line Parsing
 78--------------------
 79
 80.. kernel-doc:: lib/cmdline.c
 81   :export:
 82
 83CRC Functions
 84-------------
 85
 86.. kernel-doc:: lib/crc4.c
 87   :export:
 88
 89.. kernel-doc:: lib/crc7.c
 90   :export:
 91
 92.. kernel-doc:: lib/crc8.c
 93   :export:
 94
 95.. kernel-doc:: lib/crc16.c
 96   :export:
 97
 98.. kernel-doc:: lib/crc32.c
 99
100.. kernel-doc:: lib/crc-ccitt.c
101   :export:
102
103.. kernel-doc:: lib/crc-itu-t.c
104   :export:
105
106Math Functions in Linux
107=======================
108
109Base 2 log and power Functions
110------------------------------
111
112.. kernel-doc:: include/linux/log2.h
113   :internal:
114
115Division Functions
116------------------
117
118.. kernel-doc:: include/asm-generic/div64.h
119   :functions: do_div
120
121.. kernel-doc:: include/linux/math64.h
122   :internal:
123
124.. kernel-doc:: lib/div64.c
125   :functions: div_s64_rem div64_u64_rem div64_u64 div64_s64
126
127.. kernel-doc:: lib/gcd.c
128   :export:
129
130Sorting
131-------
132
133.. kernel-doc:: lib/sort.c
134   :export:
135
136.. kernel-doc:: lib/list_sort.c
137   :export:
138
139Text Searching
140--------------
141
142.. kernel-doc:: lib/textsearch.c
143   :doc: ts_intro
144
145.. kernel-doc:: lib/textsearch.c
146   :export:
147
148.. kernel-doc:: include/linux/textsearch.h
149   :functions: textsearch_find textsearch_next \
150               textsearch_get_pattern textsearch_get_pattern_len
151
152UUID/GUID
153---------
154
155.. kernel-doc:: lib/uuid.c
 
 
 
156   :export:
157
158Memory Management in Linux
159==========================
160
161The Slab Cache
162--------------
163
164.. kernel-doc:: include/linux/slab.h
165   :internal:
 
 
166
167.. kernel-doc:: mm/slab.c
168   :export:
169
170.. kernel-doc:: mm/util.c
171   :export:
172
173User Space Memory Access
174------------------------
175
176.. kernel-doc:: arch/x86/include/asm/uaccess.h
177   :internal:
178
179.. kernel-doc:: arch/x86/lib/usercopy_32.c
180   :export:
181
182More Memory Management Functions
183--------------------------------
184
185.. kernel-doc:: mm/readahead.c
186   :export:
187
188.. kernel-doc:: mm/filemap.c
189   :export:
190
191.. kernel-doc:: mm/memory.c
192   :export:
193
194.. kernel-doc:: mm/vmalloc.c
195   :export:
196
197.. kernel-doc:: mm/page_alloc.c
198   :internal:
199
200.. kernel-doc:: mm/mempool.c
201   :export:
202
203.. kernel-doc:: mm/dmapool.c
204   :export:
205
206.. kernel-doc:: mm/page-writeback.c
207   :export:
208
209.. kernel-doc:: mm/truncate.c
210   :export:
211
212Kernel IPC facilities
213=====================
214
215IPC utilities
216-------------
217
218.. kernel-doc:: ipc/util.c
219   :internal:
220
221FIFO Buffer
222===========
223
224kfifo interface
225---------------
226
227.. kernel-doc:: include/linux/kfifo.h
228   :internal:
229
230relay interface support
231=======================
232
233Relay interface support is designed to provide an efficient mechanism
234for tools and facilities to relay large amounts of data from kernel
235space to user space.
236
237relay interface
238---------------
239
240.. kernel-doc:: kernel/relay.c
241   :export:
242
243.. kernel-doc:: kernel/relay.c
244   :internal:
245
246Module Support
247==============
248
249Module Loading
250--------------
251
252.. kernel-doc:: kernel/kmod.c
253   :export:
254
255Inter Module support
256--------------------
257
258Refer to the file kernel/module.c for more information.
259
260Hardware Interfaces
261===================
262
263Interrupt Handling
264------------------
265
266.. kernel-doc:: kernel/irq/manage.c
267   :export:
268
269DMA Channels
270------------
271
272.. kernel-doc:: kernel/dma.c
273   :export:
274
275Resources Management
276--------------------
277
278.. kernel-doc:: kernel/resource.c
279   :internal:
280
281.. kernel-doc:: kernel/resource.c
282   :export:
283
284MTRR Handling
285-------------
286
287.. kernel-doc:: arch/x86/kernel/cpu/mtrr/main.c
288   :export:
289
290Security Framework
291==================
292
293.. kernel-doc:: security/security.c
294   :internal:
295
296.. kernel-doc:: security/inode.c
297   :export:
298
299Audit Interfaces
300================
301
302.. kernel-doc:: kernel/audit.c
303   :export:
304
305.. kernel-doc:: kernel/auditsc.c
306   :internal:
307
308.. kernel-doc:: kernel/auditfilter.c
309   :internal:
310
311Accounting Framework
312====================
313
314.. kernel-doc:: kernel/acct.c
315   :internal:
316
317Block Devices
318=============
319
320.. kernel-doc:: block/blk-core.c
321   :export:
322
323.. kernel-doc:: block/blk-core.c
324   :internal:
325
326.. kernel-doc:: block/blk-map.c
327   :export:
328
329.. kernel-doc:: block/blk-sysfs.c
330   :internal:
331
332.. kernel-doc:: block/blk-settings.c
333   :export:
334
335.. kernel-doc:: block/blk-exec.c
336   :export:
337
338.. kernel-doc:: block/blk-flush.c
339   :export:
340
341.. kernel-doc:: block/blk-lib.c
342   :export:
343
344.. kernel-doc:: block/blk-tag.c
345   :export:
346
347.. kernel-doc:: block/blk-tag.c
348   :internal:
349
350.. kernel-doc:: block/blk-integrity.c
351   :export:
352
353.. kernel-doc:: kernel/trace/blktrace.c
354   :internal:
355
356.. kernel-doc:: block/genhd.c
357   :internal:
358
359.. kernel-doc:: block/genhd.c
360   :export:
361
362Char devices
363============
364
365.. kernel-doc:: fs/char_dev.c
366   :export:
367
368Clock Framework
369===============
370
371The clock framework defines programming interfaces to support software
372management of the system clock tree. This framework is widely used with
373System-On-Chip (SOC) platforms to support power management and various
374devices which may need custom clock rates. Note that these "clocks"
375don't relate to timekeeping or real time clocks (RTCs), each of which
376have separate frameworks. These :c:type:`struct clk <clk>`
377instances may be used to manage for example a 96 MHz signal that is used
378to shift bits into and out of peripherals or busses, or otherwise
379trigger synchronous state machine transitions in system hardware.
380
381Power management is supported by explicit software clock gating: unused
382clocks are disabled, so the system doesn't waste power changing the
383state of transistors that aren't in active use. On some systems this may
384be backed by hardware clock gating, where clocks are gated without being
385disabled in software. Sections of chips that are powered but not clocked
386may be able to retain their last state. This low power state is often
387called a *retention mode*. This mode still incurs leakage currents,
388especially with finer circuit geometries, but for CMOS circuits power is
389mostly used by clocked state changes.
390
391Power-aware drivers only enable their clocks when the device they manage
392is in active use. Also, system sleep states often differ according to
393which clock domains are active: while a "standby" state may allow wakeup
394from several active domains, a "mem" (suspend-to-RAM) state may require
395a more wholesale shutdown of clocks derived from higher speed PLLs and
396oscillators, limiting the number of possible wakeup event sources. A
397driver's suspend method may need to be aware of system-specific clock
398constraints on the target sleep state.
399
400Some platforms support programmable clock generators. These can be used
401by external chips of various kinds, such as other CPUs, multimedia
402codecs, and devices with strict requirements for interface clocking.
403
404.. kernel-doc:: include/linux/clk.h
405   :internal:
406
407Synchronization Primitives
408==========================
409
410Read-Copy Update (RCU)
411----------------------
412
413.. kernel-doc:: include/linux/rcupdate.h
414
415.. kernel-doc:: include/linux/rcupdate_wait.h
416
417.. kernel-doc:: include/linux/rcutree.h
418
419.. kernel-doc:: kernel/rcu/tree.c
420
421.. kernel-doc:: kernel/rcu/tree_plugin.h
422
423.. kernel-doc:: kernel/rcu/tree_exp.h
424
425.. kernel-doc:: kernel/rcu/update.c
426
427.. kernel-doc:: include/linux/srcu.h
428
429.. kernel-doc:: kernel/rcu/srcutree.c
430
431.. kernel-doc:: include/linux/rculist_bl.h
432
433.. kernel-doc:: include/linux/rculist.h
434
435.. kernel-doc:: include/linux/rculist_nulls.h
436
437.. kernel-doc:: include/linux/rcu_sync.h
438
439.. kernel-doc:: kernel/rcu/sync.c
440

  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