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| <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN" |
| "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" []> |
| |
| <book id="LinuxKernelAPI"> |
| <bookinfo> |
| <title>The Linux Kernel API</title> |
| |
| <legalnotice> |
| <para> |
| This documentation is free software; you can redistribute |
| it and/or modify it under the terms of the GNU General Public |
| License as published by the Free Software Foundation; either |
| version 2 of the License, or (at your option) any later |
| version. |
| </para> |
| |
| <para> |
| This program is distributed in the hope that it will be |
| useful, but WITHOUT ANY WARRANTY; without even the implied |
| warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. |
| See the GNU General Public License for more details. |
| </para> |
| |
| <para> |
| You should have received a copy of the GNU General Public |
| License along with this program; if not, write to the Free |
| Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, |
| MA 02111-1307 USA |
| </para> |
| |
| <para> |
| For more details see the file COPYING in the source |
| distribution of Linux. |
| </para> |
| </legalnotice> |
| </bookinfo> |
| |
| <toc></toc> |
| |
| <chapter id="adt"> |
| <title>Data Types</title> |
| <sect1><title>Doubly Linked Lists</title> |
| !Iinclude/linux/list.h |
| </sect1> |
| </chapter> |
| |
| <chapter id="libc"> |
| <title>Basic C Library Functions</title> |
| |
| <para> |
| When writing drivers, you cannot in general use routines which are |
| from the C Library. Some of the functions have been found generally |
| useful and they are listed below. The behaviour of these functions |
| may vary slightly from those defined by ANSI, and these deviations |
| are noted in the text. |
| </para> |
| |
| <sect1><title>String Conversions</title> |
| !Elib/vsprintf.c |
| !Finclude/linux/kernel.h kstrtol |
| !Finclude/linux/kernel.h kstrtoul |
| !Elib/kstrtox.c |
| </sect1> |
| <sect1><title>String Manipulation</title> |
| <!-- All functions are exported at now |
| X!Ilib/string.c |
| --> |
| !Elib/string.c |
| </sect1> |
| <sect1><title>Bit Operations</title> |
| !Iarch/x86/include/asm/bitops.h |
| </sect1> |
| </chapter> |
| |
| <chapter id="kernel-lib"> |
| <title>Basic Kernel Library Functions</title> |
| |
| <para> |
| The Linux kernel provides more basic utility functions. |
| </para> |
| |
| <sect1><title>Bitmap Operations</title> |
| !Elib/bitmap.c |
| !Ilib/bitmap.c |
| </sect1> |
| |
| <sect1><title>Command-line Parsing</title> |
| !Elib/cmdline.c |
| </sect1> |
| |
| <sect1 id="crc"><title>CRC Functions</title> |
| !Elib/crc7.c |
| !Elib/crc16.c |
| !Elib/crc-itu-t.c |
| !Elib/crc32.c |
| !Elib/crc-ccitt.c |
| </sect1> |
| |
| <sect1 id="idr"><title>idr/ida Functions</title> |
| !Pinclude/linux/idr.h idr sync |
| !Plib/idr.c IDA description |
| !Elib/idr.c |
| </sect1> |
| </chapter> |
| |
| <chapter id="mm"> |
| <title>Memory Management in Linux</title> |
| <sect1><title>The Slab Cache</title> |
| !Iinclude/linux/slab.h |
| !Emm/slab.c |
| !Emm/util.c |
| </sect1> |
| <sect1><title>User Space Memory Access</title> |
| !Iarch/x86/include/asm/uaccess_32.h |
| !Earch/x86/lib/usercopy_32.c |
| </sect1> |
| <sect1><title>More Memory Management Functions</title> |
| !Emm/readahead.c |
| !Emm/filemap.c |
| !Emm/memory.c |
| !Emm/vmalloc.c |
| !Imm/page_alloc.c |
| !Emm/mempool.c |
| !Emm/dmapool.c |
| !Emm/page-writeback.c |
| !Emm/truncate.c |
| </sect1> |
| </chapter> |
| |
| |
| <chapter id="ipc"> |
| <title>Kernel IPC facilities</title> |
| |
| <sect1><title>IPC utilities</title> |
| !Iipc/util.c |
| </sect1> |
| </chapter> |
| |
| <chapter id="kfifo"> |
| <title>FIFO Buffer</title> |
| <sect1><title>kfifo interface</title> |
| !Iinclude/linux/kfifo.h |
| </sect1> |
| </chapter> |
| |
| <chapter id="relayfs"> |
| <title>relay interface support</title> |
| |
| <para> |
| Relay interface support |
| is designed to provide an efficient mechanism for tools and |
| facilities to relay large amounts of data from kernel space to |
| user space. |
| </para> |
| |
| <sect1><title>relay interface</title> |
| !Ekernel/relay.c |
| !Ikernel/relay.c |
| </sect1> |
| </chapter> |
| |
| <chapter id="modload"> |
| <title>Module Support</title> |
| <sect1><title>Module Loading</title> |
| !Ekernel/kmod.c |
| </sect1> |
| <sect1><title>Inter Module support</title> |
| <para> |
| Refer to the file kernel/module.c for more information. |
| </para> |
| <!-- FIXME: Removed for now since no structured comments in source |
| X!Ekernel/module.c |
| --> |
| </sect1> |
| </chapter> |
| |
| <chapter id="hardware"> |
| <title>Hardware Interfaces</title> |
| <sect1><title>Interrupt Handling</title> |
| !Ekernel/irq/manage.c |
| </sect1> |
| |
| <sect1><title>DMA Channels</title> |
| !Ekernel/dma.c |
| </sect1> |
| |
| <sect1><title>Resources Management</title> |
| !Ikernel/resource.c |
| !Ekernel/resource.c |
| </sect1> |
| |
| <sect1><title>MTRR Handling</title> |
| !Earch/x86/kernel/cpu/mtrr/main.c |
| </sect1> |
| |
| <sect1><title>PCI Support Library</title> |
| !Edrivers/pci/pci.c |
| !Edrivers/pci/pci-driver.c |
| !Edrivers/pci/remove.c |
| !Edrivers/pci/search.c |
| !Edrivers/pci/msi.c |
| !Edrivers/pci/bus.c |
| !Edrivers/pci/access.c |
| !Edrivers/pci/irq.c |
| !Edrivers/pci/htirq.c |
| <!-- FIXME: Removed for now since no structured comments in source |
| X!Edrivers/pci/hotplug.c |
| --> |
| !Edrivers/pci/probe.c |
| !Edrivers/pci/slot.c |
| !Edrivers/pci/rom.c |
| !Edrivers/pci/iov.c |
| !Idrivers/pci/pci-sysfs.c |
| </sect1> |
| <sect1><title>PCI Hotplug Support Library</title> |
| !Edrivers/pci/hotplug/pci_hotplug_core.c |
| </sect1> |
| </chapter> |
| |
| <chapter id="firmware"> |
| <title>Firmware Interfaces</title> |
| <sect1><title>DMI Interfaces</title> |
| !Edrivers/firmware/dmi_scan.c |
| </sect1> |
| <sect1><title>EDD Interfaces</title> |
| !Idrivers/firmware/edd.c |
| </sect1> |
| </chapter> |
| |
| <chapter id="security"> |
| <title>Security Framework</title> |
| !Isecurity/security.c |
| !Esecurity/inode.c |
| </chapter> |
| |
| <chapter id="audit"> |
| <title>Audit Interfaces</title> |
| !Ekernel/audit.c |
| !Ikernel/auditsc.c |
| !Ikernel/auditfilter.c |
| </chapter> |
| |
| <chapter id="accounting"> |
| <title>Accounting Framework</title> |
| !Ikernel/acct.c |
| </chapter> |
| |
| <chapter id="blkdev"> |
| <title>Block Devices</title> |
| !Eblock/blk-core.c |
| !Iblock/blk-core.c |
| !Eblock/blk-map.c |
| !Iblock/blk-sysfs.c |
| !Eblock/blk-settings.c |
| !Eblock/blk-exec.c |
| !Eblock/blk-flush.c |
| !Eblock/blk-lib.c |
| !Eblock/blk-tag.c |
| !Iblock/blk-tag.c |
| !Eblock/blk-integrity.c |
| !Ikernel/trace/blktrace.c |
| !Iblock/genhd.c |
| !Eblock/genhd.c |
| </chapter> |
| |
| <chapter id="chrdev"> |
| <title>Char devices</title> |
| !Efs/char_dev.c |
| </chapter> |
| |
| <chapter id="miscdev"> |
| <title>Miscellaneous Devices</title> |
| !Edrivers/char/misc.c |
| </chapter> |
| |
| <chapter id="clk"> |
| <title>Clock Framework</title> |
| |
| <para> |
| The clock framework defines programming interfaces to support |
| software management of the system clock tree. |
| This framework is widely used with System-On-Chip (SOC) platforms |
| to support power management and various devices which may need |
| custom clock rates. |
| Note that these "clocks" don't relate to timekeeping or real |
| time clocks (RTCs), each of which have separate frameworks. |
| These <structname>struct clk</structname> instances may be used |
| to manage for example a 96 MHz signal that is used to shift bits |
| into and out of peripherals or busses, or otherwise trigger |
| synchronous state machine transitions in system hardware. |
| </para> |
| |
| <para> |
| Power management is supported by explicit software clock gating: |
| unused clocks are disabled, so the system doesn't waste power |
| changing the state of transistors that aren't in active use. |
| On some systems this may be backed by hardware clock gating, |
| where clocks are gated without being disabled in software. |
| Sections of chips that are powered but not clocked may be able |
| to retain their last state. |
| This low power state is often called a <emphasis>retention |
| mode</emphasis>. |
| This mode still incurs leakage currents, especially with finer |
| circuit geometries, but for CMOS circuits power is mostly used |
| by clocked state changes. |
| </para> |
| |
| <para> |
| Power-aware drivers only enable their clocks when the device |
| they manage is in active use. Also, system sleep states often |
| differ according to which clock domains are active: while a |
| "standby" state may allow wakeup from several active domains, a |
| "mem" (suspend-to-RAM) state may require a more wholesale shutdown |
| of clocks derived from higher speed PLLs and oscillators, limiting |
| the number of possible wakeup event sources. A driver's suspend |
| method may need to be aware of system-specific clock constraints |
| on the target sleep state. |
| </para> |
| |
| <para> |
| Some platforms support programmable clock generators. These |
| can be used by external chips of various kinds, such as other |
| CPUs, multimedia codecs, and devices with strict requirements |
| for interface clocking. |
| </para> |
| |
| !Iinclude/linux/clk.h |
| </chapter> |
| |
| </book> |