Eric Lee / smarc-fsl-linux-kernel

04 Jan, 2012

1 commit

01 Nov, 2011

2 commits

  • 1986c93f0   miscdevice.h: fix up implicit use of lists and types ... Browse Code »

    By removing the implicit presence of module.h from this file, we
    will see things like:

    In file included from fs/dlm/user.c:9:
    include/linux/miscdevice.h:50: error: field ‘list’ has incomplete type
    include/linux/miscdevice.h:54: error: expected specifier-qualifier-list before ‘mode_t’

    Call out lists.h and types.h for inclusion to fix each of the
    above respectively.

    Signed-off-by: Paul Gortmaker

    Paul Gortmaker
     
  • ddac6021f   miscdevice.h: delete unnecessary inclusion of module.h ... Browse Code »

    This file has a define MODULE_ALIAS_MISCDEV which in turn will
    use the MODULE_ALIAS define, but only if the former is explicitly
    used by modular device driver code (and such code should be
    already including module.h).

    Delete the include, since module.h is such a giant thing that we
    don't want it implicitly sneaking into compiles where it isn't
    specifically required.

    Signed-off-by: Paul Gortmaker

    Paul Gortmaker
     

01 Aug, 2011

1 commit

  • 770fe30a4   loop: add management interface for on-demand device allocation ... Browse Code »

    Loop devices today have a fixed pre-allocated number of usually 8.
    The number can only be changed at module init time. To find a free
    device to use, /dev/loop%i needs to be scanned, and all devices need
    to be opened until a free one is possibly found.

    This adds a new /dev/loop-control device node, that allows to
    dynamically find or allocate a free device, and to add and remove loop
    devices from the running system:
    LOOP_CTL_ADD adds a specific device. Arg is the number
    of the device. It returns the device i or a negative
    error code.

    LOOP_CTL_REMOVE removes a specific device, Arg is the
    number the device. It returns the device i or a negative
    error code.

    LOOP_CTL_GET_FREE finds the next unbound device or allocates
    a new one. No arg is given. It returns the device i or a
    negative error code.

    The loop kernel module gets automatically loaded when
    /dev/loop-control is accessed the first time. The alias
    specified in the module, instructs udev to create this
    'dead' device node, even when the module is not loaded.

    Example:
    cfd = open("/dev/loop-control", O_RDWR);

    # add a new specific loop device
    err = ioctl(cfd, LOOP_CTL_ADD, devnr);

    # remove a specific loop device
    err = ioctl(cfd, LOOP_CTL_REMOVE, devnr);

    # find or allocate a free loop device to use
    devnr = ioctl(cfd, LOOP_CTL_GET_FREE);

    sprintf(loopname, "/dev/loop%i", devnr);
    ffd = open("backing-file", O_RDWR);
    lfd = open(loopname, O_RDWR);
    err = ioctl(lfd, LOOP_SET_FD, ffd);

    Cc: Tejun Heo
    Cc: Karel Zak
    Signed-off-by: Kay Sievers
    Signed-off-by: Jens Axboe

    Kay Sievers
     

21 Aug, 2010

1 commit

  • 8905aaafb   Input: uinput - add devname alias to allow module on-demand load ... Browse Code »

    Recent modprobe and udev versions allow to create device nodes
    for modules which are not loaded. Only the first access will cause
    the in-kernel module loader to pull-in the module. Systems which
    never access the device node will not needlessly load the module,
    and no longer need init scripts or other facilities to unconditionally
    load it.

    Signed-off-by: Kay Sievers
    Signed-off-by: Dmitry Torokhov

    Kay Sievers
     

12 Aug, 2010

1 commit

09 Jun, 2010

1 commit

  • 79907d89c   misc: Fix allocation 'borrowed' by vhost_net ... Browse Code »

    10, 233 is allocated officially to /dev/kmview which is shipping in
    Ubuntu and Debian distributions. vhost_net seem to have borrowed it
    without making a proper request and this causes regressions in the other
    distributions.

    vhost_net can use a dynamic minor so use that instead. Also update the
    file with a comment to try and avoid future misunderstandings.

    cc: stable@kernel.org
    Signed-off-by: Alan Cox
    [ We should have caught this before 2.6.34 got released. - Linus ]
    Signed-off-by: Linus Torvalds

    Alan Cox
     

26 May, 2010

1 commit

  • 578454ff7   driver core: add devname module aliases to allow module on-demand auto-loading ... Browse Code »

    This adds:
    alias: devname:
    to some common kernel modules, which will allow the on-demand loading
    of the kernel module when the device node is accessed.

    Ideally all these modules would be compiled-in, but distros seems too
    much in love with their modularization that we need to cover the common
    cases with this new facility. It will allow us to remove a bunch of pretty
    useless init scripts and modprobes from init scripts.

    The static device node aliases will be carried in the module itself. The
    program depmod will extract this information to a file in the module directory:
    $ cat /lib/modules/2.6.34-00650-g537b60d-dirty/modules.devname
    # Device nodes to trigger on-demand module loading.
    microcode cpu/microcode c10:184
    fuse fuse c10:229
    ppp_generic ppp c108:0
    tun net/tun c10:200
    dm_mod mapper/control c10:235

    Udev will pick up the depmod created file on startup and create all the
    static device nodes which the kernel modules specify, so that these modules
    get automatically loaded when the device node is accessed:
    $ /sbin/udevd --debug
    ...
    static_dev_create_from_modules: mknod '/dev/cpu/microcode' c10:184
    static_dev_create_from_modules: mknod '/dev/fuse' c10:229
    static_dev_create_from_modules: mknod '/dev/ppp' c108:0
    static_dev_create_from_modules: mknod '/dev/net/tun' c10:200
    static_dev_create_from_modules: mknod '/dev/mapper/control' c10:235
    udev_rules_apply_static_dev_perms: chmod '/dev/net/tun' 0666
    udev_rules_apply_static_dev_perms: chmod '/dev/fuse' 0666

    A few device nodes are switched to statically allocated numbers, to allow
    the static nodes to work. This might also useful for systems which still run
    a plain static /dev, which is completely unsafe to use with any dynamic minor
    numbers.

    Note:
    The devname aliases must be limited to the *common* and *single*instance*
    device nodes, like the misc devices, and never be used for conceptually limited
    systems like the loop devices, which should rather get fixed properly and get a
    control node for losetup to talk to, instead of creating a random number of
    device nodes in advance, regardless if they are ever used.

    This facility is to hide the mess distros are creating with too modualized
    kernels, and just to hide that these modules are not compiled-in, and not to
    paper-over broken concepts. Thanks! :)

    Cc: Greg Kroah-Hartman
    Cc: David S. Miller
    Cc: Miklos Szeredi
    Cc: Chris Mason
    Cc: Alasdair G Kergon
    Cc: Tigran Aivazian
    Cc: Ian Kent
    Signed-Off-By: Kay Sievers
    Signed-off-by: Greg Kroah-Hartman

    Kay Sievers
     

15 Jan, 2010

1 commit

  • 3a4d5c94e   vhost_net: a kernel-level virtio server ... Browse Code »

    What it is: vhost net is a character device that can be used to reduce
    the number of system calls involved in virtio networking.
    Existing virtio net code is used in the guest without modification.

    There's similarity with vringfd, with some differences and reduced scope
    - uses eventfd for signalling
    - structures can be moved around in memory at any time (good for
    migration, bug work-arounds in userspace)
    - write logging is supported (good for migration)
    - support memory table and not just an offset (needed for kvm)

    common virtio related code has been put in a separate file vhost.c and
    can be made into a separate module if/when more backends appear. I used
    Rusty's lguest.c as the source for developing this part : this supplied
    me with witty comments I wouldn't be able to write myself.

    What it is not: vhost net is not a bus, and not a generic new system
    call. No assumptions are made on how guest performs hypercalls.
    Userspace hypervisors are supported as well as kvm.

    How it works: Basically, we connect virtio frontend (configured by
    userspace) to a backend. The backend could be a network device, or a tap
    device. Backend is also configured by userspace, including vlan/mac
    etc.

    Status: This works for me, and I haven't see any crashes.
    Compared to userspace, people reported improved latency (as I save up to
    4 system calls per packet), as well as better bandwidth and CPU
    utilization.

    Features that I plan to look at in the future:
    - mergeable buffers
    - zero copy
    - scalability tuning: figure out the best threading model to use

    Note on RCU usage (this is also documented in vhost.h, near
    private_pointer which is the value protected by this variant of RCU):
    what is happening is that the rcu_dereference() is being used in a
    workqueue item. The role of rcu_read_lock() is taken on by the start of
    execution of the workqueue item, of rcu_read_unlock() by the end of
    execution of the workqueue item, and of synchronize_rcu() by
    flush_workqueue()/flush_work(). In the future we might need to apply
    some gcc attribute or sparse annotation to the function passed to
    INIT_WORK(). Paul's ack below is for this RCU usage.

    (Includes fixes by Alan Cox ,
    David L Stevens ,
    Chris Wright )

    Acked-by: Rusty Russell
    Acked-by: Arnd Bergmann
    Acked-by: "Paul E. McKenney"
    Signed-off-by: Michael S. Tsirkin
    Signed-off-by: David S. Miller

    Michael S. Tsirkin
     

20 Sep, 2009

1 commit

  • e454cea20   Driver-Core: extend devnode callbacks to provide permissions ... Browse Code »

    This allows subsytems to provide devtmpfs with non-default permissions
    for the device node. Instead of the default mode of 0600, null, zero,
    random, urandom, full, tty, ptmx now have a mode of 0666, which allows
    non-privileged processes to access standard device nodes in case no
    other userspace process applies the expected permissions.

    This also fixes a wrong assignment in pktcdvd and a checkpatch.pl complain.

    Signed-off-by: Kay Sievers
    Signed-off-by: Greg Kroah-Hartman

    Kay Sievers
     

16 Jun, 2009

1 commit

14 Mar, 2009

1 commit

26 Nov, 2008

1 commit

20 Apr, 2008

1 commit

  • b844eba29   PM: Remove destroy_suspended_device() ... Browse Code »

    After 2.6.24 there was a plan to make the PM core acquire all device
    semaphores during a suspend/hibernation to protect itself from
    concurrent operations involving device objects. That proved to be
    too heavy-handed and we found a better way to achieve the goal, but
    before it happened, we had introduced the functions
    device_pm_schedule_removal() and destroy_suspended_device() to allow
    drivers to "safely" destroy a suspended device and we had adapted some
    drivers to use them. Now that these functions are no longer necessary,
    it seems reasonable to remove them and modify their users to use the
    normal device unregistration instead.

    Signed-off-by: Rafael J. Wysocki
    Acked-by: Pavel Machek
    Signed-off-by: Greg Kroah-Hartman

    Rafael J. Wysocki
     

06 Feb, 2008

1 commit

03 May, 2007

1 commit

02 Dec, 2006

1 commit

27 Jun, 2006

1 commit

29 Mar, 2006

1 commit

  • 99ac48f54   [PATCH] mark f_ops const in the inode ... Browse Code »

    Mark the f_ops members of inodes as const, as well as fix the
    ripple-through this causes by places that copy this f_ops and then "do
    stuff" with it.

    Signed-off-by: Arjan van de Ven
    Signed-off-by: Alexey Dobriyan
    Signed-off-by: Andrew Morton
    Signed-off-by: Linus Torvalds

    Arjan van de Ven
     

17 Apr, 2005

1 commit

  • 1da177e4c   Linux-2.6.12-rc2 ... Browse Code »

    Initial git repository build. I'm not bothering with the full history,
    even though we have it. We can create a separate "historical" git
    archive of that later if we want to, and in the meantime it's about
    3.2GB when imported into git - space that would just make the early
    git days unnecessarily complicated, when we don't have a lot of good
    infrastructure for it.

    Let it rip!

    Linus Torvalds