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author | Linus Torvalds <torvalds@linux-foundation.org> | 2014-04-19 03:59:52 +0400 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-04-19 03:59:52 +0400 |
commit | 60fbf2bda140f27b0e9ab5b6d17342c9a5f9eacf (patch) | |
tree | 5ab62db9c538de54d8176439b0adebfff2758d31 /Documentation/zh_CN | |
parent | 8cb652bb10e788270b6b8b6df20fba62b479feb2 (diff) | |
parent | 94f8cc0eea03648e5cc5de1a4e7dc464de92cc74 (diff) | |
download | linux-60fbf2bda140f27b0e9ab5b6d17342c9a5f9eacf.tar.xz |
Merge tag 'driver-core-3.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core fixes from Greg KH:
"Here are some driver core fixes for 3.15-rc2. Also in here are some
documentation updates, as well as an API removal that had to wait for
after -rc1 due to the cleanups coming into you from multiple developer
trees (this one and the PPC tree.)
All have been in linux next successfully"
* tag 'driver-core-3.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
drivers/base/dd.c incorrect pr_debug() parameters
Documentation: Update stable address in Chinese and Japanese translations
topology: Fix compilation warning when not in SMP
Chinese: add translation of io_ordering.txt
stable_kernel_rules: spelling/word usage
sysfs, driver-core: remove unused {sysfs|device}_schedule_callback_owner()
kernfs: protect lazy kernfs_iattrs allocation with mutex
fs: Don't return 0 from get_anon_bdev
Diffstat (limited to 'Documentation/zh_CN')
-rw-r--r-- | Documentation/zh_CN/HOWTO | 2 | ||||
-rw-r--r-- | Documentation/zh_CN/io_ordering.txt | 67 | ||||
-rw-r--r-- | Documentation/zh_CN/stable_kernel_rules.txt | 2 |
3 files changed, 69 insertions, 2 deletions
diff --git a/Documentation/zh_CN/HOWTO b/Documentation/zh_CN/HOWTO index 6c914aa87e71..54ea24ff63c7 100644 --- a/Documentation/zh_CN/HOWTO +++ b/Documentation/zh_CN/HOWTO @@ -237,7 +237,7 @@ kernel.org网站的pub/linux/kernel/v2.6/目录下找到它。它的开发遵循 如果没有2.6.x.y版本内核存在,那么最新的2.6.x版本内核就相当于是当前的稳定 版内核。 -2.6.x.y版本由“稳定版”小组(邮件地址<stable@kernel.org>)维护,一般隔周发 +2.6.x.y版本由“稳定版”小组(邮件地址<stable@vger.kernel.org>)维护,一般隔周发 布新版本。 内核源码中的Documentation/stable_kernel_rules.txt文件具体描述了可被稳定 diff --git a/Documentation/zh_CN/io_ordering.txt b/Documentation/zh_CN/io_ordering.txt new file mode 100644 index 000000000000..e592daf4e014 --- /dev/null +++ b/Documentation/zh_CN/io_ordering.txt @@ -0,0 +1,67 @@ +Chinese translated version of Documentation/io_orderings.txt + +If you have any comment or update to the content, please contact the +original document maintainer directly. However, if you have a problem +communicating in English you can also ask the Chinese maintainer for +help. Contact the Chinese maintainer if this translation is outdated +or if there is a problem with the translation. + +Chinese maintainer: Lin Yongting <linyongting@gmail.com> +--------------------------------------------------------------------- +Documentation/io_ordering.txt 的中文翻译 + +如果想评论或更新本文的内容,请直接联系原文档的维护者。如果你使用英文 +交流有困难的话,也可以向中文版维护者求助。如果本翻译更新不及时或者翻 +译存在问题,请联系中文版维护者。 + +中文版维护者: 林永听 Lin Yongting <linyongting@gmail.com> +中文版翻译者: 林永听 Lin Yongting <linyongting@gmail.com> +中文版校译者: 林永听 Lin Yongting <linyongting@gmail.com> + + +以下为正文 +--------------------------------------------------------------------- + +在某些平台上,所谓的内存映射I/O是弱顺序。在这些平台上,驱动开发者有责任 +保证I/O内存映射地址的写操作按程序图意的顺序达到设备。通常读取一个“安全” +设备寄存器或桥寄存器,触发IO芯片清刷未处理的写操作到达设备后才处理读操作, +而达到保证目的。驱动程序通常在spinlock保护的临界区退出之前使用这种技术。 +这也可以保证后面的写操作只在前面的写操作之后到达设备(这非常类似于内存 +屏障操作,mb(),不过仅适用于I/O)。 + +假设一个设备驱动程的具体例子: + + ... +CPU A: spin_lock_irqsave(&dev_lock, flags) +CPU A: val = readl(my_status); +CPU A: ... +CPU A: writel(newval, ring_ptr); +CPU A: spin_unlock_irqrestore(&dev_lock, flags) + ... +CPU B: spin_lock_irqsave(&dev_lock, flags) +CPU B: val = readl(my_status); +CPU B: ... +CPU B: writel(newval2, ring_ptr); +CPU B: spin_unlock_irqrestore(&dev_lock, flags) + ... + +上述例子中,设备可能会先接收到newval2的值,然后接收到newval的值,问题就 +发生了。不过很容易通过下面方法来修复: + + ... +CPU A: spin_lock_irqsave(&dev_lock, flags) +CPU A: val = readl(my_status); +CPU A: ... +CPU A: writel(newval, ring_ptr); +CPU A: (void)readl(safe_register); /* 配置寄存器?*/ +CPU A: spin_unlock_irqrestore(&dev_lock, flags) + ... +CPU B: spin_lock_irqsave(&dev_lock, flags) +CPU B: val = readl(my_status); +CPU B: ... +CPU B: writel(newval2, ring_ptr); +CPU B: (void)readl(safe_register); /* 配置寄存器?*/ +CPU B: spin_unlock_irqrestore(&dev_lock, flags) + +在解决方案中,读取safe_register寄存器,触发IO芯片清刷未处理的写操作, +再处理后面的读操作,防止引发数据不一致问题。 diff --git a/Documentation/zh_CN/stable_kernel_rules.txt b/Documentation/zh_CN/stable_kernel_rules.txt index b5b9b0ab02fd..26ea5ed7cd9c 100644 --- a/Documentation/zh_CN/stable_kernel_rules.txt +++ b/Documentation/zh_CN/stable_kernel_rules.txt @@ -42,7 +42,7 @@ Documentation/stable_kernel_rules.txt 的中文翻译 向稳定版代码树提交补丁的过程: - - 在确认了补丁符合以上的规则后,将补丁发送到stable@kernel.org。 + - 在确认了补丁符合以上的规则后,将补丁发送到stable@vger.kernel.org。 - 如果补丁被接受到队列里,发送者会收到一个ACK回复,如果没有被接受,收 到的是NAK回复。回复需要几天的时间,这取决于开发者的时间安排。 - 被接受的补丁会被加到稳定版本队列里,等待其他开发者的审查。 |