Documentation/DocBook/kernel-api.tmpl

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   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="Basics">
  42      <title>Driver Basics</title>
  43      <sect1><title>Driver Entry and Exit points</title>
  44 !Iinclude/linux/init.h
  45      </sect1>
  46
  47      <sect1><title>Atomic and pointer manipulation</title>
  48 !Iinclude/asm-i386/atomic.h
  49 !Iinclude/asm-i386/unaligned.h
  50      </sect1>
  51
  52      <sect1><title>Delaying, scheduling, and timer routines</title>
  53 !Iinclude/linux/sched.h
  54 !Ekernel/sched.c
  55 !Ekernel/timer.c
  56      </sect1>
  57      <sect1><title>High-resolution timers</title>
  58 !Iinclude/linux/ktime.h
  59 !Iinclude/linux/hrtimer.h
  60 !Ekernel/hrtimer.c
  61      </sect1>
  62      <sect1><title>Workqueues and Kevents</title>
  63 !Ekernel/workqueue.c
  64      </sect1>
  65      <sect1><title>Internal Functions</title>
  66 !Ikernel/exit.c
  67 !Ikernel/signal.c
  68 !Iinclude/linux/kthread.h
  69 !Ekernel/kthread.c
  70      </sect1>
  71
  72      <sect1><title>Kernel objects manipulation</title>
  73 <!--
  74 X!Iinclude/linux/kobject.h
  75 -->
  76 !Elib/kobject.c
  77      </sect1>
  78
  79      <sect1><title>Kernel utility functions</title>
  80 !Iinclude/linux/kernel.h
  81 !Ekernel/printk.c
  82 !Ekernel/panic.c
  83 !Ekernel/sys.c
  84 !Ekernel/rcupdate.c
  85      </sect1>
  86
  87      <sect1><title>Device Resource Management</title>
  88 !Edrivers/base/devres.c
  89      </sect1>
  90
  91   </chapter>
  92
  93   <chapter id="adt">
  94      <title>Data Types</title>
  95      <sect1><title>Doubly Linked Lists</title>
  96 !Iinclude/linux/list.h
  97      </sect1>
  98   </chapter>
  99
 100   <chapter id="libc">
 101      <title>Basic C Library Functions</title>
 102
 103      <para>
 104        When writing drivers, you cannot in general use routines which are
 105        from the C Library.  Some of the functions have been found generally
 106        useful and they are listed below.  The behaviour of these functions
 107        may vary slightly from those defined by ANSI, and these deviations
 108        are noted in the text.
 109      </para>
 110
 111      <sect1><title>String Conversions</title>
 112 !Ilib/vsprintf.c
 113 !Elib/vsprintf.c
 114      </sect1>
 115      <sect1><title>String Manipulation</title>
 116 <!-- All functions are exported at now
 117 X!Ilib/string.c
 118  -->
 119 !Elib/string.c
 120      </sect1>
 121      <sect1><title>Bit Operations</title>
 122 !Iinclude/asm-i386/bitops.h
 123      </sect1>
 124   </chapter>
 125
 126   <chapter id="kernel-lib">
 127      <title>Basic Kernel Library Functions</title>
 128
 129      <para>
 130        The Linux kernel provides more basic utility functions.
 131      </para>
 132
 133      <sect1><title>Bitmap Operations</title>
 134 !Elib/bitmap.c
 135 !Ilib/bitmap.c
 136      </sect1>
 137
 138      <sect1><title>Command-line Parsing</title>
 139 !Elib/cmdline.c
 140      </sect1>
 141
 142      <sect1><title>CRC Functions</title>
 143 !Elib/crc16.c
 144 !Elib/crc32.c
 145 !Elib/crc-ccitt.c
 146      </sect1>
 147   </chapter>
 148
 149   <chapter id="mm">
 150      <title>Memory Management in Linux</title>
 151      <sect1><title>The Slab Cache</title>
 152 !Iinclude/linux/slab.h
 153 !Emm/slab.c
 154      </sect1>
 155      <sect1><title>User Space Memory Access</title>
 156 !Iinclude/asm-i386/uaccess.h
 157 !Earch/i386/lib/usercopy.c
 158      </sect1>
 159      <sect1><title>More Memory Management Functions</title>
 160 !Iinclude/linux/rmap.h
 161 !Emm/readahead.c
 162 !Emm/filemap.c
 163 !Emm/memory.c
 164 !Emm/vmalloc.c
 165 !Imm/page_alloc.c
 166 !Emm/mempool.c
 167 !Emm/page-writeback.c
 168 !Emm/truncate.c
 169      </sect1>
 170   </chapter>
 171
 172
 173   <chapter id="ipc">
 174      <title>Kernel IPC facilities</title>
 175
 176      <sect1><title>IPC utilities</title>
 177 !Iipc/util.c
 178      </sect1>
 179   </chapter>
 180
 181   <chapter id="kfifo">
 182      <title>FIFO Buffer</title>
 183      <sect1><title>kfifo interface</title>
 184 !Iinclude/linux/kfifo.h
 185 !Ekernel/kfifo.c
 186      </sect1>
 187   </chapter>
 188
 189   <chapter id="relayfs">
 190      <title>relay interface support</title>
 191
 192      <para>
 193         Relay interface support
 194         is designed to provide an efficient mechanism for tools and
 195         facilities to relay large amounts of data from kernel space to
 196         user space.
 197      </para>
 198
 199      <sect1><title>relay interface</title>
 200 !Ekernel/relay.c
 201 !Ikernel/relay.c
 202      </sect1>
 203   </chapter>
 204
 205   <chapter id="netcore">
 206      <title>Linux Networking</title>
 207      <sect1><title>Networking Base Types</title>
 208 !Iinclude/linux/net.h
 209      </sect1>
 210      <sect1><title>Socket Buffer Functions</title>
 211 !Iinclude/linux/skbuff.h
 212 !Iinclude/net/sock.h
 213 !Enet/socket.c
 214 !Enet/core/skbuff.c
 215 !Enet/core/sock.c
 216 !Enet/core/datagram.c
 217 !Enet/core/stream.c
 218      </sect1>
 219      <sect1><title>Socket Filter</title>
 220 !Enet/core/filter.c
 221      </sect1>
 222      <sect1><title>Generic Network Statistics</title>
 223 !Iinclude/linux/gen_stats.h
 224 !Enet/core/gen_stats.c
 225 !Enet/core/gen_estimator.c
 226      </sect1>
 227      <sect1><title>SUN RPC subsystem</title>
 228 <!-- The !D functionality is not perfect, garbage has to be protected by comments
 229 !Dnet/sunrpc/sunrpc_syms.c
 230 -->
 231 !Enet/sunrpc/xdr.c
 232 !Enet/sunrpc/svcsock.c
 233 !Enet/sunrpc/sched.c
 234      </sect1>
 235   </chapter>
 236
 237   <chapter id="netdev">
 238      <title>Network device support</title>
 239      <sect1><title>Driver Support</title>
 240 !Enet/core/dev.c
 241 !Enet/ethernet/eth.c
 242 !Iinclude/linux/etherdevice.h
 243 !Edrivers/net/phy/phy.c
 244 !Idrivers/net/phy/phy.c
 245 !Edrivers/net/phy/phy_device.c
 246 !Idrivers/net/phy/phy_device.c
 247 !Edrivers/net/phy/mdio_bus.c
 248 !Idrivers/net/phy/mdio_bus.c
 249 <!-- FIXME: Removed for now since no structured comments in source
 250 X!Enet/core/wireless.c
 251 -->
 252      </sect1>
 253      <sect1><title>Synchronous PPP</title>
 254 !Edrivers/net/wan/syncppp.c
 255      </sect1>
 256   </chapter>
 257
 258   <chapter id="modload">
 259      <title>Module Support</title>
 260      <sect1><title>Module Loading</title>
 261 !Ekernel/kmod.c
 262      </sect1>
 263      <sect1><title>Inter Module support</title>
 264         <para>
 265            Refer to the file kernel/module.c for more information.
 266         </para>
 267 <!-- FIXME: Removed for now since no structured comments in source
 268 X!Ekernel/module.c
 269 -->
 270      </sect1>
 271   </chapter>
 272
 273   <chapter id="hardware">
 274      <title>Hardware Interfaces</title>
 275      <sect1><title>Interrupt Handling</title>
 276 !Ekernel/irq/manage.c
 277      </sect1>
 278
 279      <sect1><title>DMA Channels</title>
 280 !Ekernel/dma.c
 281      </sect1>
 282
 283      <sect1><title>Resources Management</title>
 284 !Ikernel/resource.c
 285 !Ekernel/resource.c
 286      </sect1>
 287
 288      <sect1><title>MTRR Handling</title>
 289 !Earch/i386/kernel/cpu/mtrr/main.c
 290      </sect1>
 291
 292      <sect1><title>PCI Support Library</title>
 293 !Edrivers/pci/pci.c
 294 !Edrivers/pci/pci-driver.c
 295 !Edrivers/pci/remove.c
 296 !Edrivers/pci/pci-acpi.c
 297 !Edrivers/pci/search.c
 298 !Edrivers/pci/msi.c
 299 !Edrivers/pci/bus.c
 300 <!-- FIXME: Removed for now since no structured comments in source
 301 X!Edrivers/pci/hotplug.c
 302 -->
 303 !Edrivers/pci/probe.c
 304 !Edrivers/pci/rom.c
 305      </sect1>
 306      <sect1><title>PCI Hotplug Support Library</title>
 307 !Edrivers/pci/hotplug/pci_hotplug_core.c
 308      </sect1>
 309      <sect1><title>MCA Architecture</title>
 310         <sect2><title>MCA Device Functions</title>
 311            <para>
 312               Refer to the file arch/i386/kernel/mca.c for more information.
 313            </para>
 314 <!-- FIXME: Removed for now since no structured comments in source
 315 X!Earch/i386/kernel/mca.c
 316 -->
 317         </sect2>
 318         <sect2><title>MCA Bus DMA</title>
 319 !Iinclude/asm-i386/mca_dma.h
 320         </sect2>
 321      </sect1>
 322   </chapter>
 323
 324   <chapter id="firmware">
 325      <title>Firmware Interfaces</title>
 326      <sect1><title>DMI Interfaces</title>
 327 !Edrivers/firmware/dmi_scan.c
 328      </sect1>
 329      <sect1><title>EDD Interfaces</title>
 330 !Idrivers/firmware/edd.c
 331      </sect1>
 332   </chapter>
 333
 334   <chapter id="security">
 335      <title>Security Framework</title>
 336 !Esecurity/security.c
 337   </chapter>
 338
 339   <chapter id="audit">
 340      <title>Audit Interfaces</title>
 341 !Ekernel/audit.c
 342 !Ikernel/auditsc.c
 343 !Ikernel/auditfilter.c
 344   </chapter>
 345
 346   <chapter id="accounting">
 347      <title>Accounting Framework</title>
 348 !Ikernel/acct.c
 349   </chapter>
 350
 351   <chapter id="pmfuncs">
 352      <title>Power Management</title>
 353 !Ekernel/power/pm.c
 354   </chapter>
 355
 356   <chapter id="devdrivers">
 357      <title>Device drivers infrastructure</title>
 358      <sect1><title>Device Drivers Base</title>
 359 <!--
 360 X!Iinclude/linux/device.h
 361 -->
 362 !Edrivers/base/driver.c
 363 !Edrivers/base/core.c
 364 !Edrivers/base/class.c
 365 !Edrivers/base/firmware_class.c
 366 !Edrivers/base/transport_class.c
 367 !Edrivers/base/dmapool.c
 368 <!-- Cannot be included, because
 369      attribute_container_add_class_device_adapter
 370  and attribute_container_classdev_to_container
 371      exceed allowed 44 characters maximum
 372 X!Edrivers/base/attribute_container.c
 373 -->
 374 !Edrivers/base/sys.c
 375 <!--
 376 X!Edrivers/base/interface.c
 377 -->
 378 !Edrivers/base/platform.c
 379 !Edrivers/base/bus.c
 380      </sect1>
 381      <sect1><title>Device Drivers Power Management</title>
 382 !Edrivers/base/power/main.c
 383 !Edrivers/base/power/resume.c
 384 !Edrivers/base/power/suspend.c
 385      </sect1>
 386      <sect1><title>Device Drivers ACPI Support</title>
 387 <!-- Internal functions only
 388 X!Edrivers/acpi/sleep/main.c
 389 X!Edrivers/acpi/sleep/wakeup.c
 390 X!Edrivers/acpi/motherboard.c
 391 X!Edrivers/acpi/bus.c
 392 -->
 393 !Edrivers/acpi/scan.c
 394 !Idrivers/acpi/scan.c
 395 <!-- No correct structured comments
 396 X!Edrivers/acpi/pci_bind.c
 397 -->
 398      </sect1>
 399      <sect1><title>Device drivers PnP support</title>
 400 !Edrivers/pnp/core.c
 401 <!-- No correct structured comments
 402 X!Edrivers/pnp/system.c
 403  -->
 404 !Edrivers/pnp/card.c
 405 !Edrivers/pnp/driver.c
 406 !Edrivers/pnp/manager.c
 407 !Edrivers/pnp/support.c
 408      </sect1>
 409   </chapter>
 410
 411   <chapter id="blkdev">
 412      <title>Block Devices</title>
 413 !Eblock/ll_rw_blk.c
 414   </chapter>
 415
 416   <chapter id="chrdev">
 417         <title>Char devices</title>
 418 !Efs/char_dev.c
 419   </chapter>
 420
 421   <chapter id="miscdev">
 422      <title>Miscellaneous Devices</title>
 423 !Edrivers/char/misc.c
 424   </chapter>
 425
 426   <chapter id="parportdev">
 427      <title>Parallel Port Devices</title>
 428 !Iinclude/linux/parport.h
 429 !Edrivers/parport/ieee1284.c
 430 !Edrivers/parport/share.c
 431 !Idrivers/parport/daisy.c
 432   </chapter>
 433
 434   <chapter id="message_devices">
 435         <title>Message-based devices</title>
 436      <sect1><title>Fusion message devices</title>
 437 !Edrivers/message/fusion/mptbase.c
 438 !Idrivers/message/fusion/mptbase.c
 439 !Edrivers/message/fusion/mptscsih.c
 440 !Idrivers/message/fusion/mptscsih.c
 441 !Idrivers/message/fusion/mptctl.c
 442 !Idrivers/message/fusion/mptspi.c
 443 !Idrivers/message/fusion/mptfc.c
 444 !Idrivers/message/fusion/mptlan.c
 445      </sect1>
 446      <sect1><title>I2O message devices</title>
 447 !Iinclude/linux/i2o.h
 448 !Idrivers/message/i2o/core.h
 449 !Edrivers/message/i2o/iop.c
 450 !Idrivers/message/i2o/iop.c
 451 !Idrivers/message/i2o/config-osm.c
 452 !Edrivers/message/i2o/exec-osm.c
 453 !Idrivers/message/i2o/exec-osm.c
 454 !Idrivers/message/i2o/bus-osm.c
 455 !Edrivers/message/i2o/device.c
 456 !Idrivers/message/i2o/device.c
 457 !Idrivers/message/i2o/driver.c
 458 !Idrivers/message/i2o/pci.c
 459 !Idrivers/message/i2o/i2o_block.c
 460 !Idrivers/message/i2o/i2o_scsi.c
 461 !Idrivers/message/i2o/i2o_proc.c
 462      </sect1>
 463   </chapter>
 464
 465   <chapter id="snddev">
 466      <title>Sound Devices</title>
 467 !Iinclude/sound/core.h
 468 !Esound/sound_core.c
 469 !Iinclude/sound/pcm.h
 470 !Esound/core/pcm.c
 471 !Esound/core/device.c
 472 !Esound/core/info.c
 473 !Esound/core/rawmidi.c
 474 !Esound/core/sound.c
 475 !Esound/core/memory.c
 476 !Esound/core/pcm_memory.c
 477 !Esound/core/init.c
 478 !Esound/core/isadma.c
 479 !Esound/core/control.c
 480 !Esound/core/pcm_lib.c
 481 !Esound/core/hwdep.c
 482 !Esound/core/pcm_native.c
 483 !Esound/core/memalloc.c
 484 <!-- FIXME: Removed for now since no structured comments in source
 485 X!Isound/sound_firmware.c
 486 -->
 487   </chapter>
 488
 489   <chapter id="uart16x50">
 490      <title>16x50 UART Driver</title>
 491 !Iinclude/linux/serial_core.h
 492 !Edrivers/serial/serial_core.c
 493 !Edrivers/serial/8250.c
 494   </chapter>
 495
 496   <chapter id="z85230">
 497      <title>Z85230 Support Library</title>
 498 !Edrivers/net/wan/z85230.c
 499   </chapter>
 500
 501   <chapter id="fbdev">
 502      <title>Frame Buffer Library</title>
 503
 504      <para>
 505        The frame buffer drivers depend heavily on four data structures.
 506        These structures are declared in include/linux/fb.h.  They are
 507        fb_info, fb_var_screeninfo, fb_fix_screeninfo and fb_monospecs.
 508        The last three can be made available to and from userland.
 509      </para>
 510
 511      <para>
 512        fb_info defines the current state of a particular video card.
 513        Inside fb_info, there exists a fb_ops structure which is a
 514        collection of needed functions to make fbdev and fbcon work.
 515        fb_info is only visible to the kernel.
 516      </para>
 517
 518      <para>
 519        fb_var_screeninfo is used to describe the features of a video card
 520        that are user defined.  With fb_var_screeninfo, things such as
 521        depth and the resolution may be defined.
 522      </para>
 523
 524      <para>
 525        The next structure is fb_fix_screeninfo. This defines the
 526        properties of a card that are created when a mode is set and can't
 527        be changed otherwise.  A good example of this is the start of the
 528        frame buffer memory.  This "locks" the address of the frame buffer
 529        memory, so that it cannot be changed or moved.
 530      </para>
 531
 532      <para>
 533        The last structure is fb_monospecs. In the old API, there was
 534        little importance for fb_monospecs. This allowed for forbidden things
 535        such as setting a mode of 800x600 on a fix frequency monitor. With
 536        the new API, fb_monospecs prevents such things, and if used
 537        correctly, can prevent a monitor from being cooked.  fb_monospecs
 538        will not be useful until kernels 2.5.x.
 539      </para>
 540
 541      <sect1><title>Frame Buffer Memory</title>
 542 !Edrivers/video/fbmem.c
 543      </sect1>
 544 <!--
 545      <sect1><title>Frame Buffer Console</title>
 546 X!Edrivers/video/console/fbcon.c
 547      </sect1>
 548 -->
 549      <sect1><title>Frame Buffer Colormap</title>
 550 !Edrivers/video/fbcmap.c
 551      </sect1>
 552 <!-- FIXME:
 553   drivers/video/fbgen.c has no docs, which stuffs up the sgml.  Comment
 554   out until somebody adds docs.  KAO
 555      <sect1><title>Frame Buffer Generic Functions</title>
 556 X!Idrivers/video/fbgen.c
 557      </sect1>
 558 KAO -->
 559      <sect1><title>Frame Buffer Video Mode Database</title>
 560 !Idrivers/video/modedb.c
 561 !Edrivers/video/modedb.c
 562      </sect1>
 563      <sect1><title>Frame Buffer Macintosh Video Mode Database</title>
 564 !Edrivers/video/macmodes.c
 565      </sect1>
 566      <sect1><title>Frame Buffer Fonts</title>
 567         <para>
 568            Refer to the file drivers/video/console/fonts.c for more information.
 569         </para>
 570 <!-- FIXME: Removed for now since no structured comments in source
 571 X!Idrivers/video/console/fonts.c
 572 -->
 573      </sect1>
 574   </chapter>
 575
 576   <chapter id="input_subsystem">
 577      <title>Input Subsystem</title>
 578 !Iinclude/linux/input.h
 579 !Edrivers/input/input.c
 580 !Edrivers/input/ff-core.c
 581 !Edrivers/input/ff-memless.c
 582   </chapter>
 583
 584   <chapter id="spi">
 585       <title>Serial Peripheral Interface (SPI)</title>
 586   <para>
 587         SPI is the "Serial Peripheral Interface", widely used with
 588         embedded systems because it is a simple and efficient
 589         interface:  basically a multiplexed shift register.
 590         Its three signal wires hold a clock (SCK, often in the range
 591         of 1-20 MHz), a "Master Out, Slave In" (MOSI) data line, and
 592         a "Master In, Slave Out" (MISO) data line.
 593         SPI is a full duplex protocol; for each bit shifted out the
 594         MOSI line (one per clock) another is shifted in on the MISO line.
 595         Those bits are assembled into words of various sizes on the
 596         way to and from system memory.
 597         An additional chipselect line is usually active-low (nCS);
 598         four signals are normally used for each peripheral, plus
 599         sometimes an interrupt.
 600   </para>
 601   <para>
 602         The SPI bus facilities listed here provide a generalized
 603         interface to declare SPI busses and devices, manage them
 604         according to the standard Linux driver model, and perform
 605         input/output operations.
 606         At this time, only "master" side interfaces are supported,
 607         where Linux talks to SPI peripherals and does not implement
 608         such a peripheral itself.
 609         (Interfaces to support implementing SPI slaves would
 610         necessarily look different.)
 611   </para>
 612   <para>
 613         The programming interface is structured around two kinds of driver,
 614         and two kinds of device.
 615         A "Controller Driver" abstracts the controller hardware, which may
 616         be as simple as a set of GPIO pins or as complex as a pair of FIFOs
 617         connected to dual DMA engines on the other side of the SPI shift
 618         register (maximizing throughput).  Such drivers bridge between
 619         whatever bus they sit on (often the platform bus) and SPI, and
 620         expose the SPI side of their device as a
 621         <structname>struct spi_master</structname>.
 622         SPI devices are children of that master, represented as a
 623         <structname>struct spi_device</structname> and manufactured from
 624         <structname>struct spi_board_info</structname> descriptors which
 625         are usually provided by board-specific initialization code.
 626         A <structname>struct spi_driver</structname> is called a
 627         "Protocol Driver", and is bound to a spi_device using normal
 628         driver model calls.
 629   </para>
 630   <para>
 631         The I/O model is a set of queued messages.  Protocol drivers
 632         submit one or more <structname>struct spi_message</structname>
 633         objects, which are processed and completed asynchronously.
 634         (There are synchronous wrappers, however.)  Messages are
 635         built from one or more <structname>struct spi_transfer</structname>
 636         objects, each of which wraps a full duplex SPI transfer.
 637         A variety of protocol tweaking options are needed, because
 638         different chips adopt very different policies for how they
 639         use the bits transferred with SPI.
 640   </para>
 641 !Iinclude/linux/spi/spi.h
 642 !Fdrivers/spi/spi.c spi_register_board_info
 643 !Edrivers/spi/spi.c
 644   </chapter>
 645
 646 </book>