Similar to dp83640 delay after soft reset
is needed to set up registers correctly.
Signed-off-by: Max Uvarov <muvarov@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a 'modalias' attribute to devices under the DAX bus so that userspace
is able to dynamically load modules as needed.
Normally, udev can get the modalias from 'uevent', and that is correctly
set up by the DAX bus. However other tooling such as 'libndctl' for
interacting with drivers/nvdimm/, and 'libdaxctl' for drivers/dax/ can
also use the modalias to dynamically load modules via libkmod lookups.
The 'nd' bus set up by the libnvdimm subsystem exports a modalias
attribute. Imitate this to export the same for the 'dax' bus.
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Commit 5ad7346b4a ("cpufreq: kryo: Add module remove and exit") made
it possible to build the kryo cpufreq driver as a module, but it failed
to release all the resources, i.e. OPP tables, when the module is
unloaded.
This patch fixes it by releasing the OPP tables, by calling
dev_pm_opp_put_supported_hw() for them, from the
qcom_cpufreq_kryo_remove() routine. The array of pointers to the OPP
tables is also allocated dynamically now in qcom_cpufreq_kryo_probe(),
as the pointers will be required while releasing the resources.
Compile tested only.
Cc: 4.18+ <stable@vger.kernel.org> # v4.18+
Fixes: 5ad7346b4a ("cpufreq: kryo: Add module remove and exit")
Reviewed-by: Georgi Djakov <georgi.djakov@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
The prepare_fb call always happens on new_plane_state.
The drm_atomic_helper_cleanup_planes checks to see if
plane state pointer has changed when deciding to call cleanup_fb on
either the new_plane_state or the old_plane_state.
For a non-async atomic commit the state pointer is swapped, so this
helper calls prepare_fb on the new_plane_state and cleanup_fb on the
old_plane_state. This makes sense, since we want to prepare the
framebuffer we are going to use and cleanup the the framebuffer we are
no longer using.
For the async atomic update helpers this differs. The async atomic
update helpers perform in-place updates on the existing state. They call
drm_atomic_helper_cleanup_planes but the state pointer is not swapped.
This means that prepare_fb is called on the new_plane_state and
cleanup_fb is called on the new_plane_state (not the old).
In the case where old_plane_state->fb == new_plane_state->fb then
there should be no behavioral difference between an async update
and a non-async commit. But there are issues that arise when
old_plane_state->fb != new_plane_state->fb.
The first is that the new_plane_state->fb is immediately cleaned up
after it has been prepared, so we're using a fb that we shouldn't
be.
The second occurs during a sequence of async atomic updates and
non-async regular atomic commits. Suppose there are two framebuffers
being interleaved in a double-buffering scenario, fb1 and fb2:
- Async update, oldfb = NULL, newfb = fb1, prepare fb1, cleanup fb1
- Async update, oldfb = fb1, newfb = fb2, prepare fb2, cleanup fb2
- Non-async commit, oldfb = fb2, newfb = fb1, prepare fb1, cleanup fb2
We call cleanup_fb on fb2 twice in this example scenario, and any
further use will result in use-after-free.
The simple fix to this problem is to block framebuffer changes
in the drm_atomic_helper_async_check function for now.
v2: Move check by itself, add a FIXME (Daniel)
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Cc: <stable@vger.kernel.org> # v4.14+
Fixes: fef9df8b59 ("drm/atomic: initial support for asynchronous plane update")
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Acked-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Reviewed-by: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Harry Wentland <harry.wentland@amd.com>
Link: https://patchwork.freedesktop.org/patch/275364/
Signed-off-by: Dave Airlie <airlied@redhat.com>
Clang warns when an expression that equals zero is used as a null
pointer constant (in lieu of NULL):
drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm.c:4435:3:
warning: expression which evaluates to zero treated as a null pointer
constant of type 'const enum color_transfer_func *'
[-Wnon-literal-null-conversion]
TRANSFER_FUNC_UNKNOWN,
^~~~~~~~~~~~~~~~~~~~~
1 warning generated.
This warning is caused by commit bb47de7366 ("drm/amdgpu: Set FreeSync
state using drm VRR properties") and it could be solved by using NULL
instead of TRANSFER_FUNC_UNKNOWN or casting TRANSFER_FUNC_UNKNOWN as a
pointer. However, after looking into it, there doesn't appear to be a
good reason to pass app_tf by reference as it is never mutated along the
way. This is the only code path in which app_tf is used:
mod_freesync_build_vrr_infopacket ->
build_vrr_infopacket_v2 ->
build_vrr_infopacket_fs2_data
Neither mod_freesync_build_vrr_infopacket or build_vrr_infopacket_v2
modify app_tf's value and build_vrr_infopacket_fs2_data expects just
the value so we can avoid dereferencing anything by just passing in
app_tf's value to mod_freesync_build_vrr_infopacket and
build_vrr_infopacket_v2.
There is no functional change because build_vrr_infopacket_fs2_data
doesn't do anything if TRANSFER_FUNC_UNKNOWN is passed to it, the same
as not calling build_vrr_infopacket_fs2_data at all like before this
change when NULL was used for app_tf.
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
For UCLK_FMAX OD feature, SMU overwrites the highest UCLK DPM level freq.
Therefore it can only take values that are greater than the second highest
DPM level freq.
Signed-off-by: Evan Quan <evan.quan@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This patch uses REG32_PCIE wrapper instead of writting pci_index2 and reading
pci_data2 for psp. This sequence should be protected by pcie_idx_lock.
Signed-off-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This patch uses REG32_PCIE wrapper instead of writting pci_index2 and reading
pci_data2 for powerplay. This sequence should be protected by pcie_idx_lock.
Signed-off-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
[Why]
For MST, link not disabled until all streams disabled
[How]
Add check for stream_count before setting link_active = false for MST
Signed-off-by: Anthony Koo <Anthony.Koo@amd.com>
Reviewed-by: Wenjing Liu <Wenjing.Liu@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This was noticed by Gustavo and his -Wimplicit-fallthrough
patches. However, in this case, I believe we should have breaks
rather than falling though, that said, in practice we should
never fall through in the first place so there should be no
change in behavior.
Reviewed-by: Evan Quan <evan.quan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
drm/imx: handle pending updates better, add plane zpos property support
- Add a mechanism to only send commit done events once all pending
updates have been applied. This closes a small race window where
already armed events could fire even though the double buffered
hardware update just missed the update window.
- Add plane zpos property support to allow placing the overlay plane
behind the primary plane.
- Allow building imx-drm on all platforms under COMPILE_TEST.
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Philipp Zabel <pza@pengutronix.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20190222112350.m3ucezilqx6cyest@pengutronix.de
security_mmap_addr() does a capability check with current_cred(), but
we can reach this code from contexts like a VFS write handler where
current_cred() must not be used.
This can be abused on systems without SMAP to make NULL pointer
dereferences exploitable again.
Fixes: 8869477a49 ("security: protect from stack expansion into low vm addresses")
Cc: stable@kernel.org
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Yonghong Song says:
====================
The inner_map_meta->spin_lock_off is not set correctly during
map creation for BPF_MAP_TYPE_ARRAY_OF_MAPS and BPF_MAP_TYPE_HASH_OF_MAPS.
This may lead verifier error due to misinformation.
This patch set fixed the issue with Patch #1 for the kernel change
and Patch #2 for enhanced selftest test_maps.
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Commit d83525ca62 ("bpf: introduce bpf_spin_lock")
introduced bpf_spin_lock and the field spin_lock_off
in kernel internal structure bpf_map has the following
meaning:
>=0 valid offset, <0 error
For every map created, the kernel will ensure
spin_lock_off has correct value.
Currently, bpf_map->spin_lock_off is not copied
from the inner map to the map_in_map inner_map_meta
during a map_in_map type map creation, so
inner_map_meta->spin_lock_off = 0.
This will give verifier wrong information that
inner_map has bpf_spin_lock and the bpf_spin_lock
is defined at offset 0. An access to offset 0
of a value pointer will trigger the following error:
bpf_spin_lock cannot be accessed directly by load/store
This patch fixed the issue by copy inner map's spin_lock_off
value to inner_map_meta->spin_lock_off.
Fixes: d83525ca62 ("bpf: introduce bpf_spin_lock")
Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
We store 2 multilevel tables in iommu_table - one for the hardware and
one with the corresponding userspace addresses. Before allocating
the tables, the iommu_table_group_ops::get_table_size() hook returns
the combined size of the two and VFIO SPAPR TCE IOMMU driver adjusts
the locked_vm counter correctly. When the table is actually allocated,
the amount of allocated memory is stored in iommu_table::it_allocated_size
and used to decrement the locked_vm counter when we release the memory
used by the table; .get_table_size() and .create_table() calculate it
independently but the result is expected to be the same.
However the allocator does not add the userspace table size to
.it_allocated_size so when we destroy the table because of VFIO PCI
unplug (i.e. VFIO container is gone but the userspace keeps running),
we decrement locked_vm by just a half of size of memory we are
releasing.
To make things worse, since we enabled on-demand allocation of
indirect levels, it_allocated_size contains only the amount of memory
actually allocated at the table creation time which can just be a
fraction. It is not a problem with incrementing locked_vm (as
get_table_size() value is used) but it is with decrementing.
As the result, we leak locked_vm and may not be able to allocate more
IOMMU tables after few iterations of hotplug/unplug.
This sets it_allocated_size in the pnv_pci_ioda2_ops::create_table()
hook to what pnv_pci_ioda2_get_table_size() returns so from now on we
have a single place which calculates the maximum memory a table can
occupy. The original meaning of it_allocated_size is somewhat lost now
though.
We do not ditch it_allocated_size whatsoever here and we do not call
get_table_size() from vfio_iommu_spapr_tce.c when decrementing
locked_vm as we may have multiple IOMMU groups per container and even
though they all are supposed to have the same get_table_size()
implementation, there is a small chance for failure or confusion.
Fixes: 090bad39b2 ("powerpc/powernv: Add indirect levels to it_userspace")
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Add support for Generic Mux controls, when Mdio mux node is a consumer
of mux produced by some other device.
Signed-off-by: Pankaj Bansal <pankaj.bansal@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When we use the bindings defined in Documentation/devicetree/bindings/mux
to define mdio mux in producer and consumer terms, it results in two
devices. one is mux producer and other is mux consumer.
Add the bindings needed for Mdio mux consumer devices.
Signed-off-by: Pankaj Bansal <pankaj.bansal@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Current fib_multipath_hash_policy can make hash based on the L3 or
L4. But it only work on the outer IP. So a specific tunnel always
has the same hash value. But a specific tunnel may contain so many
inner connections.
This patch provide a generic multipath_hash in floi_common. It can
make a user-define hash which can mix with L3 or L4 hash.
Signed-off-by: wenxu <wenxu@ucloud.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull additional syscall ABI cleanup for y2038 from Arnd Bergmann:
This is a follow-up to the y2038 syscall patches already merged in the tip
tree. As the final 32-bit RISC-V syscall ABI is still being decided on,
this is the last chance to make a few corrections to leave out interfaces
based on 32-bit time_t along with the old off_t and rlimit types.
The series achieves this in a few steps:
- A couple of bug fixes for minor regressions I introduced
in the original series
- A couple of older patches from Yury Norov that I had never
merged in the past, these fix up the openat/open_by_handle_at and
getrlimit/setrlimit syscalls to disallow the old versions of off_t
and rlimit.
- Hiding the deprecated system calls behind an #ifdef in
include/uapi/asm-generic/unistd.h
- Change arch/riscv to drop all these ABIs.
Originally, the plan was to also leave these out on C-Sky, but that now
has a glibc port that uses the older interfaces, so we need to leave
them in place.
Florian Fainelli says:
====================
net: Remove switchdev_ops
This patch series completes the removal of the switchdev_ops by
converting switchdev_port_attr_set() to use either the blocking
(process) or non-blocking (atomic) notifier since we typically need to
deal with both depending on where in the bridge code we get called from.
This was tested with the forwarding selftests and DSA hardware.
Ido, hopefully this captures your comments done on v1, if not, can you
illustrate with some pseudo-code what you had in mind if that's okay?
Changes in v3:
- added Reviewed-by tags from Ido where relevant
- added missing notifier_to_errno() in net/bridge/br_switchdev.c when
calling the atomic notifier for PRE_BRIDGE_FLAGS
- kept mlxsw_sp_switchdev_init() in mlxsw/
Changes in v2:
- do not check for SWITCHDEV_F_DEFER when calling the blocking notifier
and instead directly call the atomic notifier from the single location
where this is required
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Now that we have converted all possible callers to using a switchdev
notifier for attributes we do not have a need for implementing
switchdev_ops anymore, and this can be removed from all drivers the
net_device structure.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Drop switchdev_ops.switchdev_port_attr_set. Drop the uses of this field
from all clients, which were migrated to use switchdev notification in
the previous patches.
Add a new function switchdev_port_attr_notify() that sends the switchdev
notifications SWITCHDEV_PORT_ATTR_SET and calls the blocking (process)
notifier chain.
We have one odd case within net/bridge/br_switchdev.c with the
SWITCHDEV_ATTR_ID_PORT_PRE_BRIDGE_FLAGS attribute identifier that
requires executing from atomic context, we deal with that one
specifically.
Drop __switchdev_port_attr_set() and update switchdev_port_attr_set()
likewise.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Following patches will change the way we communicate setting a port's
attribute and use a blocking notifier to perform those tasks.
Prepare ethsw to support receiving notifier events targeting
SWITCHDEV_PORT_ATTR_SET and simply translate that into the existing
swdev_port_attr_set() call.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Following patches will change the way we communicate setting a port's
attribute and use notifiers to perform those tasks.
Ocelot does not currently have an atomic notifier registered for
switchdev events, so we need to register one in order to deal with
atomic context SWITCHDEV_PORT_ATTR_SET events.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Following patches will change the way we communicate setting a port's
attribute and use a notifier to perform those tasks.
Prepare mlxsw to support receiving notifier events targeting
SWITCHDEV_PORT_ATTR_SET and utilize the switchdev_handle_port_attr_set()
to handle stacking of devices.
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Following patches will change the way we communicate setting a port's
attribute and use notifiers towards that goal.
Prepare DSA to support receiving notifier events targeting
SWITCHDEV_PORT_ATTR_SET from both atomic and process context and use a
small helper to translate the event notifier into something that
dsa_slave_port_attr_set() can process.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Following patches will change the way we communicate setting a port's
attribute and use notifiers towards that goal.
Prepare rocker to support receiving notifier events targeting
SWITCHDEV_PORT_ATTR_SET from both atomic and process context and use a
small helper to translate the event notifier into something that
rocker_port_attr_set() can process.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In preparation for allowing switchdev enabled drivers to veto specific
attribute settings from within the context of the caller, introduce a
new switchdev notifier type for port attributes.
Suggested-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In VRR mode, keep track of the vblank count of the last
completed pageflip in amdgpu_crtc->last_flip_vblank, as
recorded in the pageflip completion handler after each
completed flip.
Use that count to prevent mmio programming a new pageflip
within the same vblank in which the last pageflip completed,
iow. to throttle pageflips to at most one flip per video
frame, while at the same time allowing to request a flip
not only before start of vblank, but also anywhere within
vblank.
The old logic did the same, and made sense for regular fixed
refresh rate flipping, but in vrr mode it prevents requesting
a flip anywhere inside the possibly huge vblank, thereby
reducing framerate in vrr mode instead of improving it, by
delaying a slightly delayed flip requests up to a maximum
vblank duration + 1 scanout duration. This would limit VRR
usefulness to only help applications with a very high GPU
demand, which can submit the flip request before start of
vblank, but then have to wait long for fences to complete.
With this method a flip can be both requested and - after
fences have completed - executed, ie. it doesn't matter if
the request (amdgpu_dm_do_flip()) gets delayed until deep
into the extended vblank due to cpu execution delays. This
also allows clients which want to regulate framerate within
the vrr range a much more fine-grained control of flip timing,
a feature that might be useful for video playback, and is
very useful for neuroscience/vision research applications.
In regular non-VRR mode, retain the old flip submission
behavior. This to keep flip scheduling for fullscreen X11/GLX
OpenGL clients intact, if they use the GLX_OML_sync_control
extensions glXSwapBufferMscOML(, ..., target_msc,...) function
with a specific target_msc target vblank count.
glXSwapBuffersMscOML() or DRI3/Present PresentPixmap() will
not flip at the proper target_msc for a non-zero target_msc
if VRR mode is active with this patch. They'd often flip one
frame too early. However, this limitation should not matter
much in VRR mode, as scheduling based on vblank counts is
pretty futile/unusable under variable refresh duration
anyway, so no real extra harm is done.
Signed-off-by: Mario Kleiner <mario.kleiner.de@gmail.com>
Cc: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Michel Dänzer <michel@daenzer.net>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This reverts commit 31a9984876 ("net: sched: fw: don't set arg->stop in
fw_walk() when empty")
Cls API function tcf_proto_is_empty() was changed in commit
6676d5e416 ("net: sched: set dedicated tcf_walker flag when tp is empty")
to no longer depend on arg->stop to determine that classifier instance is
empty. Instead, it adds dedicated arg->nonempty field, which makes the fix
in fw classifier no longer necessary.
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Initialize the .cmd member by using a designated struct
initializer. This fixes warning of missing field initializers,
and makes code a little easier to read.
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Reviewed-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
With Micrel KSZ8061 PHY, the link may occasionally not come up after
Ethernet cable connect. The vendor's (Microchip, former Micrel) errata
sheet 80000688A.pdf descripes the problem and possible workarounds in
detail, see below.
The batch implements workaround 1, which permanently fixes the issue.
DESCRIPTION
Link-up may not occur properly when the Ethernet cable is initially
connected. This issue occurs more commonly when the cable is connected
slowly, but it may occur any time a cable is connected. This issue occurs
in the auto-negotiation circuit, and will not occur if auto-negotiation
is disabled (which requires that the two link partners be set to the
same speed and duplex).
END USER IMPLICATIONS
When this issue occurs, link is not established. Subsequent cable
plug/unplaug cycle will not correct the issue.
WORk AROUND
There are four approaches to work around this issue:
1. This issue can be prevented by setting bit 15 in MMD device address 1,
register 2, prior to connecting the cable or prior to setting the
Restart Auto-negotiation bit in register 0h. The MMD registers are
accessed via the indirect access registers Dh and Eh, or via the Micrel
EthUtil utility as shown here:
. if using the EthUtil utility (usually with a Micrel KSZ8061
Evaluation Board), type the following commands:
> address 1
> mmd 1
> iw 2 b61a
. Alternatively, write the following registers to write to the
indirect MMD register:
Write register Dh, data 0001h
Write register Eh, data 0002h
Write register Dh, data 4001h
Write register Eh, data B61Ah
2. The issue can be avoided by disabling auto-negotiation in the KSZ8061,
either by the strapping option, or by clearing bit 12 in register 0h.
Care must be taken to ensure that the KSZ8061 and the link partner
will link with the same speed and duplex. Note that the KSZ8061
defaults to full-duplex when auto-negotiation is off, but other
devices may default to half-duplex in the event of failed
auto-negotiation.
3. The issue can be avoided by connecting the cable prior to powering-up
or resetting the KSZ8061, and leaving it plugged in thereafter.
4. If the above measures are not taken and the problem occurs, link can
be recovered by setting the Restart Auto-Negotiation bit in
register 0h, or by resetting or power cycling the device. Reset may
be either hardware reset or software reset (register 0h, bit 15).
PLAN
This errata will not be corrected in the future revision.
Fixes: 7ab59dc15e ("drivers/net/phy/micrel_phy: Add support for new PHYs")
Signed-off-by: Alexander Onnasch <alexander.onnasch@landisgyr.com>
Signed-off-by: Rajasingh Thavamani <T.Rajasingh@landisgyr.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>