diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/Changes | 4 | ||||
| -rw-r--r-- | Documentation/CodingStyle | 18 | ||||
| -rw-r--r-- | Documentation/DMA-API.txt | 2 | ||||
| -rw-r--r-- | Documentation/DocBook/uio-howto.tmpl | 88 | ||||
| -rw-r--r-- | Documentation/IO-mapping.txt | 4 | ||||
| -rw-r--r-- | Documentation/block/biodoc.txt | 5 | ||||
| -rw-r--r-- | Documentation/cgroups/memcg_test.txt | 24 | ||||
| -rw-r--r-- | Documentation/cputopology.txt | 6 | ||||
| -rw-r--r-- | Documentation/filesystems/nfs-rdma.txt | 4 | ||||
| -rw-r--r-- | Documentation/filesystems/proc.txt | 28 | ||||
| -rw-r--r-- | Documentation/ja_JP/stable_kernel_rules.txt | 15 | ||||
| -rw-r--r-- | Documentation/kbuild/kbuild.txt | 29 | ||||
| -rw-r--r-- | Documentation/kernel-parameters.txt | 7 | ||||
| -rw-r--r-- | Documentation/lguest/Makefile | 2 | ||||
| -rw-r--r-- | Documentation/networking/netconsole.txt | 3 | ||||
| -rw-r--r-- | Documentation/sound/alsa/HD-Audio-Models.txt | 1 | ||||
| -rw-r--r-- | Documentation/usb/dma.txt | 11 |
17 files changed, 200 insertions, 51 deletions
diff --git a/Documentation/Changes b/Documentation/Changes index cb2b141b1c3..b95082be4d5 100644 --- a/Documentation/Changes +++ b/Documentation/Changes @@ -33,10 +33,12 @@ o Gnu make 3.79.1 # make --version o binutils 2.12 # ld -v o util-linux 2.10o # fdformat --version o module-init-tools 0.9.10 # depmod -V -o e2fsprogs 1.29 # tune2fs +o e2fsprogs 1.41.4 # e2fsck -V o jfsutils 1.1.3 # fsck.jfs -V o reiserfsprogs 3.6.3 # reiserfsck -V 2>&1|grep reiserfsprogs o xfsprogs 2.6.0 # xfs_db -V +o squashfs-tools 4.0 # mksquashfs -version +o btrfs-progs 0.18 # btrfsck o pcmciautils 004 # pccardctl -V o quota-tools 3.09 # quota -V o PPP 2.4.0 # pppd --version diff --git a/Documentation/CodingStyle b/Documentation/CodingStyle index 1875e502f87..72968cd5eaf 100644 --- a/Documentation/CodingStyle +++ b/Documentation/CodingStyle @@ -483,17 +483,25 @@ values. To do the latter, you can stick the following in your .emacs file: (* (max steps 1) c-basic-offset))) +(add-hook 'c-mode-common-hook + (lambda () + ;; Add kernel style + (c-add-style + "linux-tabs-only" + '("linux" (c-offsets-alist + (arglist-cont-nonempty + c-lineup-gcc-asm-reg + c-lineup-arglist-tabs-only)))))) + (add-hook 'c-mode-hook (lambda () (let ((filename (buffer-file-name))) ;; Enable kernel mode for the appropriate files (when (and filename - (string-match "~/src/linux-trees" filename)) + (string-match (expand-file-name "~/src/linux-trees") + filename)) (setq indent-tabs-mode t) - (c-set-style "linux") - (c-set-offset 'arglist-cont-nonempty - '(c-lineup-gcc-asm-reg - c-lineup-arglist-tabs-only)))))) + (c-set-style "linux-tabs-only"))))) This will make emacs go better with the kernel coding style for C files below ~/src/linux-trees. diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt index 52441694fe0..2a3fcc55e98 100644 --- a/Documentation/DMA-API.txt +++ b/Documentation/DMA-API.txt @@ -5,7 +5,7 @@ This document describes the DMA API. For a more gentle introduction phrased in terms of the pci_ equivalents (and actual examples) see -DMA-mapping.txt +Documentation/PCI/PCI-DMA-mapping.txt. This API is split into two pieces. Part I describes the API and the corresponding pci_ API. Part II describes the extensions to the API diff --git a/Documentation/DocBook/uio-howto.tmpl b/Documentation/DocBook/uio-howto.tmpl index b787e4721c9..52e1b79ce0e 100644 --- a/Documentation/DocBook/uio-howto.tmpl +++ b/Documentation/DocBook/uio-howto.tmpl @@ -42,6 +42,12 @@ GPL version 2. <revhistory> <revision> + <revnumber>0.7</revnumber> + <date>2008-12-23</date> + <authorinitials>hjk</authorinitials> + <revremark>Added generic platform drivers and offset attribute.</revremark> + </revision> + <revision> <revnumber>0.6</revnumber> <date>2008-12-05</date> <authorinitials>hjk</authorinitials> @@ -312,6 +318,16 @@ interested in translating it, please email me pointed to by addr. </para> </listitem> +<listitem> + <para> + <filename>offset</filename>: The offset, in bytes, that has to be + added to the pointer returned by <function>mmap()</function> to get + to the actual device memory. This is important if the device's memory + is not page aligned. Remember that pointers returned by + <function>mmap()</function> are always page aligned, so it is good + style to always add this offset. + </para> +</listitem> </itemizedlist> <para> @@ -594,6 +610,78 @@ framework to set up sysfs files for this region. Simply leave it alone. </para> </sect1> +<sect1 id="using_uio_pdrv"> +<title>Using uio_pdrv for platform devices</title> + <para> + In many cases, UIO drivers for platform devices can be handled in a + generic way. In the same place where you define your + <varname>struct platform_device</varname>, you simply also implement + your interrupt handler and fill your + <varname>struct uio_info</varname>. A pointer to this + <varname>struct uio_info</varname> is then used as + <varname>platform_data</varname> for your platform device. + </para> + <para> + You also need to set up an array of <varname>struct resource</varname> + containing addresses and sizes of your memory mappings. This + information is passed to the driver using the + <varname>.resource</varname> and <varname>.num_resources</varname> + elements of <varname>struct platform_device</varname>. + </para> + <para> + You now have to set the <varname>.name</varname> element of + <varname>struct platform_device</varname> to + <varname>"uio_pdrv"</varname> to use the generic UIO platform device + driver. This driver will fill the <varname>mem[]</varname> array + according to the resources given, and register the device. + </para> + <para> + The advantage of this approach is that you only have to edit a file + you need to edit anyway. You do not have to create an extra driver. + </para> +</sect1> + +<sect1 id="using_uio_pdrv_genirq"> +<title>Using uio_pdrv_genirq for platform devices</title> + <para> + Especially in embedded devices, you frequently find chips where the + irq pin is tied to its own dedicated interrupt line. In such cases, + where you can be really sure the interrupt is not shared, we can take + the concept of <varname>uio_pdrv</varname> one step further and use a + generic interrupt handler. That's what + <varname>uio_pdrv_genirq</varname> does. + </para> + <para> + The setup for this driver is the same as described above for + <varname>uio_pdrv</varname>, except that you do not implement an + interrupt handler. The <varname>.handler</varname> element of + <varname>struct uio_info</varname> must remain + <varname>NULL</varname>. The <varname>.irq_flags</varname> element + must not contain <varname>IRQF_SHARED</varname>. + </para> + <para> + You will set the <varname>.name</varname> element of + <varname>struct platform_device</varname> to + <varname>"uio_pdrv_genirq"</varname> to use this driver. + </para> + <para> + The generic interrupt handler of <varname>uio_pdrv_genirq</varname> + will simply disable the interrupt line using + <function>disable_irq_nosync()</function>. After doing its work, + userspace can reenable the interrupt by writing 0x00000001 to the UIO + device file. The driver already implements an + <function>irq_control()</function> to make this possible, you must not + implement your own. + </para> + <para> + Using <varname>uio_pdrv_genirq</varname> not only saves a few lines of + interrupt handler code. You also do not need to know anything about + the chip's internal registers to create the kernel part of the driver. + All you need to know is the irq number of the pin the chip is + connected to. + </para> +</sect1> + </chapter> <chapter id="userspace_driver" xreflabel="Writing a driver in user space"> diff --git a/Documentation/IO-mapping.txt b/Documentation/IO-mapping.txt index 86edb61bdee..78a440695e1 100644 --- a/Documentation/IO-mapping.txt +++ b/Documentation/IO-mapping.txt @@ -1,6 +1,6 @@ [ NOTE: The virt_to_bus() and bus_to_virt() functions have been - superseded by the functionality provided by the PCI DMA - interface (see Documentation/DMA-mapping.txt). They continue + superseded by the functionality provided by the PCI DMA interface + (see Documentation/PCI/PCI-DMA-mapping.txt). They continue to be documented below for historical purposes, but new code must not use them. --davidm 00/12/12 ] diff --git a/Documentation/block/biodoc.txt b/Documentation/block/biodoc.txt index 3c5434c83da..5d2480d33b4 100644 --- a/Documentation/block/biodoc.txt +++ b/Documentation/block/biodoc.txt @@ -186,8 +186,9 @@ a virtual address mapping (unlike the earlier scheme of virtual address do not have a corresponding kernel virtual address space mapping) and low-memory pages. -Note: Please refer to DMA-mapping.txt for a discussion on PCI high mem DMA -aspects and mapping of scatter gather lists, and support for 64 bit PCI. +Note: Please refer to Documentation/PCI/PCI-DMA-mapping.txt for a discussion +on PCI high mem DMA aspects and mapping of scatter gather lists, and support +for 64 bit PCI. Special handling is required only for cases where i/o needs to happen on pages at physical memory addresses beyond what the device can support. In these diff --git a/Documentation/cgroups/memcg_test.txt b/Documentation/cgroups/memcg_test.txt index 19533f93b7a..523a9c16c40 100644 --- a/Documentation/cgroups/memcg_test.txt +++ b/Documentation/cgroups/memcg_test.txt @@ -1,6 +1,6 @@ Memory Resource Controller(Memcg) Implementation Memo. -Last Updated: 2008/12/15 -Base Kernel Version: based on 2.6.28-rc8-mm. +Last Updated: 2009/1/19 +Base Kernel Version: based on 2.6.29-rc2. Because VM is getting complex (one of reasons is memcg...), memcg's behavior is complex. This is a document for memcg's internal behavior. @@ -340,3 +340,23 @@ Under below explanation, we assume CONFIG_MEM_RES_CTRL_SWAP=y. # mount -t cgroup none /cgroup -t cpuset,memory,cpu,devices and do task move, mkdir, rmdir etc...under this. + + 9.7 swapoff. + Besides management of swap is one of complicated parts of memcg, + call path of swap-in at swapoff is not same as usual swap-in path.. + It's worth to be tested explicitly. + + For example, test like following is good. + (Shell-A) + # mount -t cgroup none /cgroup -t memory + # mkdir /cgroup/test + # echo 40M > /cgroup/test/memory.limit_in_bytes + # echo 0 > /cgroup/test/tasks + Run malloc(100M) program under this. You'll see 60M of swaps. + (Shell-B) + # move all tasks in /cgroup/test to /cgroup + # /sbin/swapoff -a + # rmdir /test/cgroup + # kill malloc task. + + Of course, tmpfs v.s. swapoff test should be tested, too. diff --git a/Documentation/cputopology.txt b/Documentation/cputopology.txt index 45932ec21ce..b41f3e58aef 100644 --- a/Documentation/cputopology.txt +++ b/Documentation/cputopology.txt @@ -18,11 +18,11 @@ For an architecture to support this feature, it must define some of these macros in include/asm-XXX/topology.h: #define topology_physical_package_id(cpu) #define topology_core_id(cpu) -#define topology_thread_siblings(cpu) -#define topology_core_siblings(cpu) +#define topology_thread_cpumask(cpu) +#define topology_core_cpumask(cpu) The type of **_id is int. -The type of siblings is cpumask_t. +The type of siblings is (const) struct cpumask *. To be consistent on all architectures, include/linux/topology.h provides default definitions for any of the above macros that are diff --git a/Documentation/filesystems/nfs-rdma.txt b/Documentation/filesystems/nfs-rdma.txt index 44bd766f2e5..85eaeaddd27 100644 --- a/Documentation/filesystems/nfs-rdma.txt +++ b/Documentation/filesystems/nfs-rdma.txt @@ -251,7 +251,7 @@ NFS/RDMA Setup Instruct the server to listen on the RDMA transport: - $ echo rdma 2050 > /proc/fs/nfsd/portlist + $ echo rdma 20049 > /proc/fs/nfsd/portlist - On the client system @@ -263,7 +263,7 @@ NFS/RDMA Setup Regardless of how the client was built (module or built-in), use this command to mount the NFS/RDMA server: - $ mount -o rdma,port=2050 <IPoIB-server-name-or-address>:/<export> /mnt + $ mount -o rdma,port=20049 <IPoIB-server-name-or-address>:/<export> /mnt To verify that the mount is using RDMA, run "cat /proc/mounts" and check the "proto" field for the given mount. diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index bbebc3a43ac..a87be42f821 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -2027,6 +2027,34 @@ increase the likelihood of this process being killed by the oom-killer. Valid values are in the range -16 to +15, plus the special value -17, which disables oom-killing altogether for this process. +The process to be killed in an out-of-memory situation is selected among all others +based on its badness score. This value equals the original memory size of the process +and is then updated according to its CPU time (utime + stime) and the +run time (uptime - start time). The longer it runs the smaller is the score. +Badness score is divided by the square root of the CPU time and then by +the double square root of the run time. + +Swapped out tasks are killed first. Half of each child's memory size is added to +the parent's score if they do not share the same memory. Thus forking servers +are the prime candidates to be killed. Having only one 'hungry' child will make +parent less preferable than the child. + +/proc/<pid>/oom_score shows process' current badness score. + +The following heuristics are then applied: + * if the task was reniced, its score doubles + * superuser or direct hardware access tasks (CAP_SYS_ADMIN, CAP_SYS_RESOURCE + or CAP_SYS_RAWIO) have their score divided by 4 + * if oom condition happened in one cpuset and checked task does not belong + to it, its score is divided by 8 + * the resulting score is multiplied by two to the power of oom_adj, i.e. + points <<= oom_adj when it is positive and + points >>= -(oom_adj) otherwise + +The task with the highest badness score is then selected and its children +are killed, process itself will be killed in an OOM situation when it does +not have children or some of them disabled oom like described above. + 2.13 /proc/<pid>/oom_score - Display current oom-killer score ------------------------------------------------------------- diff --git a/Documentation/ja_JP/stable_kernel_rules.txt b/Documentation/ja_JP/stable_kernel_rules.txt index b3ffe870de3..14265837c4c 100644 --- a/Documentation/ja_JP/stable_kernel_rules.txt +++ b/Documentation/ja_JP/stable_kernel_rules.txt @@ -12,11 +12,11 @@ file at first. ================================== これは、 -linux-2.6.24/Documentation/stable_kernel_rules.txt +linux-2.6.29/Documentation/stable_kernel_rules.txt の和訳です。 翻訳団体： JF プロジェクト < http://www.linux.or.jp/JF/ > -翻訳日： 2007/12/30 +翻訳日： 2009/1/14 翻訳者： Tsugikazu Shibata <tshibata at ab dot jp dot nec dot com> 校正者： 武井伸光さん、<takei at webmasters dot gr dot jp> かねこさん (Seiji Kaneko) <skaneko at a2 dot mbn dot or dot jp> @@ -38,12 +38,15 @@ linux-2.6.24/Documentation/stable_kernel_rules.txt - ビルドエラー(CONFIG_BROKENになっているものを除く), oops, ハング、デー タ破壊、現実のセキュリティ問題、その他 "ああ、これはダメだね"という ようなものを修正しなければならない。短く言えば、重大な問題。 + - 新しい device ID とクオークも受け入れられる。 - どのように競合状態が発生するかの説明も一緒に書かれていない限り、 "理論的には競合状態になる"ようなものは不可。 - いかなる些細な修正も含めることはできない。(スペルの修正、空白のクリー ンアップなど) - - 対応するサブシステムメンテナが受け入れたものでなければならない。 - Documentation/SubmittingPatches の規則に従ったものでなければならない。 + - パッチ自体か同等の修正が Linus のツリーに既に存在しなければならない。 + Linus のツリーでのコミットID を -stable へのパッチ投稿の際に引用す + ること。 -stable ツリーにパッチを送付する手続き- @@ -52,8 +55,10 @@ linux-2.6.24/Documentation/stable_kernel_rules.txt - 送信者はパッチがキューに受け付けられた際には ACK を、却下された場合 には NAK を受け取る。この反応は開発者たちのスケジュールによって、数 日かかる場合がある。 - - もし受け取られたら、パッチは他の開発者たちのレビューのために - -stable キューに追加される。 + - もし受け取られたら、パッチは他の開発者たちと関連するサブシステムの + メンテナーによるレビューのために -stable キューに追加される。 + - パッチに stable@kernel.org のアドレスが付加されているときには、それ + が Linus のツリーに入る時に自動的に stable チームに email される。 - セキュリティパッチはこのエイリアス (stable@kernel.org) に送られるべ きではなく、代わりに security@kernel.org のアドレスに送られる。 diff --git a/Documentation/kbuild/kbuild.txt b/Documentation/kbuild/kbuild.txt index 923f9ddee8f..f3355b6812d 100644 --- a/Documentation/kbuild/kbuild.txt +++ b/Documentation/kbuild/kbuild.txt @@ -3,7 +3,7 @@ Environment variables KCPPFLAGS -------------------------------------------------- Additional options to pass when preprocessing. The preprocessing options -will be used in all cases where kbuild do preprocessing including +will be used in all cases where kbuild does preprocessing including building C files and assembler files. KAFLAGS @@ -16,7 +16,7 @@ Additional options to the C compiler. KBUILD_VERBOSE -------------------------------------------------- -Set the kbuild verbosity. Can be assinged same values as "V=...". +Set the kbuild verbosity. Can be assigned same values as "V=...". See make help for the full list. Setting "V=..." takes precedence over KBUILD_VERBOSE. @@ -35,14 +35,14 @@ KBUILD_OUTPUT -------------------------------------------------- Specify the output directory when building the kernel. The output directory can also be specificed using "O=...". -Setting "O=..." takes precedence over KBUILD_OUTPUT +Setting "O=..." takes precedence over KBUILD_OUTPUT. ARCH -------------------------------------------------- Set ARCH to the architecture to be built. In most cases the name of the architecture is the same as the directory name found in the arch/ directory. -But some architectures suach as x86 and sparc has aliases. +But some architectures such as x86 and sparc have aliases. x86: i386 for 32 bit, x86_64 for 64 bit sparc: sparc for 32 bit, sparc64 for 64 bit @@ -63,7 +63,7 @@ CF is often used on the command-line like this: INSTALL_PATH -------------------------------------------------- INSTALL_PATH specifies where to place the updated kernel and system map -images. Default is /boot, but you can set it to other values +images. Default is /boot, but you can set it to other values. MODLIB @@ -90,7 +90,7 @@ INSTALL_MOD_STRIP will used as the options to the strip command. INSTALL_FW_PATH -------------------------------------------------- -INSTALL_FW_PATH specify where to install the firmware blobs. +INSTALL_FW_PATH specifies where to install the firmware blobs. The default value is: $(INSTALL_MOD_PATH)/lib/firmware @@ -99,7 +99,7 @@ The value can be overridden in which case the default value is ignored. INSTALL_HDR_PATH -------------------------------------------------- -INSTALL_HDR_PATH specify where to install user space headers when +INSTALL_HDR_PATH specifies where to install user space headers when executing "make headers_*". The default value is: @@ -112,22 +112,23 @@ The value can be overridden in which case the default value is ignored. KBUILD_MODPOST_WARN -------------------------------------------------- -KBUILD_MODPOST_WARN can be set to avoid error out in case of undefined -symbols in the final module linking stage. +KBUILD_MODPOST_WARN can be set to avoid errors in case of undefined +symbols in the final module linking stage. It changes such errors +into warnings. -KBUILD_MODPOST_FINAL +KBUILD_MODPOST_NOFINAL -------------------------------------------------- KBUILD_MODPOST_NOFINAL can be set to skip the final link of modules. -This is solely usefull to speed up test compiles. +This is solely useful to speed up test compiles. KBUILD_EXTRA_SYMBOLS -------------------------------------------------- -For modules use symbols from another modules. +For modules that use symbols from other modules. See more details in modules.txt. ALLSOURCE_ARCHS -------------------------------------------------- -For tags/TAGS/cscope targets, you can specify more than one archs -to be included in the databases, separated by blankspace. e.g. +For tags/TAGS/cscope targets, you can specify more than one arch +to be included in the databases, separated by blank space. E.g.: $ make ALLSOURCE_ARCHS="x86 mips arm" tags diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 8511d3532c2..d8362cf9909 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -577,9 +577,6 @@ and is between 256 and 4096 characters. It is defined in the file a memory unit (amount[KMG]). See also Documentation/kdump/kdump.txt for a example. - cs4232= [HW,OSS] - Format: <io>,<irq>,<dma>,<dma2>,<mpuio>,<mpuirq> - cs89x0_dma= [HW,NET] Format: <dma> @@ -732,10 +729,6 @@ and is between 256 and 4096 characters. It is defined in the file Default value is 0. Value can be changed at runtime via /selinux/enforce. - es1371= [HW,OSS] - Format: <spdif>,[<nomix>,[<amplifier>]] - See also header of sound/oss/es1371.c. - ether= [HW,NET] Ethernet cards parameters This option is obsoleted by the "netdev=" option, which has equivalent usage. See its documentation for details. diff --git a/Documentation/lguest/Makefile b/Documentation/lguest/Makefile index 725eef81cd4..1f4f9e888bd 100644 --- a/Documentation/lguest/Makefile +++ b/Documentation/lguest/Makefile @@ -1,5 +1,5 @@ # This creates the demonstration utility "lguest" which runs a Linux guest. -CFLAGS:=-Wall -Wmissing-declarations -Wmissing-prototypes -O3 -I../../include -I../../arch/x86/include +CFLAGS:=-Wall -Wmissing-declarations -Wmissing-prototypes -O3 -I../../include -I../../arch/x86/include -U_FORTIFY_SOURCE LDLIBS:=-lz all: lguest diff --git a/Documentation/networking/netconsole.txt b/Documentation/networking/netconsole.txt index 3c2f2b32863..8d022073e3e 100644 --- a/Documentation/networking/netconsole.txt +++ b/Documentation/networking/netconsole.txt @@ -51,7 +51,8 @@ Built-in netconsole starts immediately after the TCP stack is initialized and attempts to bring up the supplied dev at the supplied address. -The remote host can run either 'netcat -u -l -p <port>' or syslogd. +The remote host can run either 'netcat -u -l -p <port>', +'nc -l -u <port>' or syslogd. Dynamic reconfiguration: ======================== diff --git a/Documentation/sound/alsa/HD-Audio-Models.txt b/Documentation/sound/alsa/HD-Audio-Models.txt index 64eb1100eec..0f5d26bea80 100644 --- a/Documentation/sound/alsa/HD-Audio-Models.txt +++ b/Documentation/sound/alsa/HD-Audio-Models.txt @@ -349,6 +349,7 @@ STAC92HD73* STAC92HD83* =========== ref Reference board + mic-ref Reference board with power managment for ports STAC9872 ======== diff --git a/Documentation/usb/dma.txt b/Documentation/usb/dma.txt index e8b50b7de9d..cfdcd16e3ab 100644 --- a/Documentation/usb/dma.txt +++ b/Documentation/usb/dma.txt @@ -6,8 +6,9 @@ in the kernel usb programming guide (kerneldoc, from the source code). API OVERVIEW The big picture is that USB drivers can continue to ignore most DMA issues, -though they still must provide DMA-ready buffers (see DMA-mapping.txt). -That's how they've worked through the 2.4 (and earlier) kernels. +though they still must provide DMA-ready buffers (see +Documentation/PCI/PCI-DMA-mapping.txt). That's how they've worked through +the 2.4 (and earlier) kernels. OR: they can now be DMA-aware. @@ -62,8 +63,8 @@ and effects like cache-trashing can impose subtle penalties. force a consistent memory access ordering by using memory barriers. It's not using a streaming DMA mapping, so it's good for small transfers on systems where the I/O would otherwise thrash an IOMMU mapping. (See - Documentation/DMA-mapping.txt for definitions of "coherent" and "streaming" - DMA mappings.) + Documentation/PCI/PCI-DMA-mapping.txt for definitions of "coherent" and + "streaming" DMA mappings.) Asking for 1/Nth of a page (as well as asking for N pages) is reasonably space-efficient. @@ -93,7 +94,7 @@ WORKING WITH EXISTING BUFFERS Existing buffers aren't usable for DMA without first being mapped into the DMA address space of the device. However, most buffers passed to your driver can safely be used with such DMA mapping. (See the first section -of DMA-mapping.txt, titled "What memory is DMA-able?") +of Documentation/PCI/PCI-DMA-mapping.txt, titled "What memory is DMA-able?") - When you're using scatterlists, you can map everything at once. On some systems, this kicks in an IOMMU and turns the scatterlists into single |