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 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 393