Commit Graph

5348 Commits

Author SHA1 Message Date
David Miller
e9ee9efc0d bpf: Add BPF_F_ANY_ALIGNMENT.
Often we want to write tests cases that check things like bad context
offset accesses.  And one way to do this is to use an odd offset on,
for example, a 32-bit load.

This unfortunately triggers the alignment checks first on platforms
that do not set CONFIG_EFFICIENT_UNALIGNED_ACCESS.  So the test
case see the alignment failure rather than what it was testing for.

It is often not completely possible to respect the original intention
of the test, or even test the same exact thing, while solving the
alignment issue.

Another option could have been to check the alignment after the
context and other validations are performed by the verifier, but
that is a non-trivial change to the verifier.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-11-30 21:38:48 -08:00
Joe Stringer
d74286d2c2 bpf: Improve socket lookup reuseport documentation
Improve the wording around socket lookup for reuseport sockets, and
ensure that both bpf.h headers are in sync.

Signed-off-by: Joe Stringer <joe@wand.net.nz>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-11-30 17:17:38 -08:00
Joe Stringer
f71c6143c2 bpf: Support sk lookup in netns with id 0
David Ahern and Nicolas Dichtel report that the handling of the netns id
0 is incorrect for the BPF socket lookup helpers: rather than finding
the netns with id 0, it is resolving to the current netns. This renders
the netns_id 0 inaccessible.

To fix this, adjust the API for the netns to treat all negative s32
values as a lookup in the current netns (including u64 values which when
truncated to s32 become negative), while any values with a positive
value in the signed 32-bit integer space would result in a lookup for a
socket in the netns corresponding to that id. As before, if the netns
with that ID does not exist, no socket will be found. Any netns outside
of these ranges will fail to find a corresponding socket, as those
values are reserved for future usage.

Signed-off-by: Joe Stringer <joe@wand.net.nz>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Joey Pabalinas <joeypabalinas@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-11-30 17:17:38 -08:00
Nicolas Dichtel
26d31925cd tun: implement carrier change
The userspace may need to control the carrier state.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Didier Pallard <didier.pallard@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-30 17:16:38 -08:00
Daniel Borkmann
b7df9ada9a bpf: fix pointer offsets in context for 32 bit
Currently, pointer offsets in three BPF context structures are
broken in two scenarios: i) 32 bit compiled applications running
on 64 bit kernels, and ii) LLVM compiled BPF programs running
on 32 bit kernels. The latter is due to BPF target machine being
strictly 64 bit. So in each of the cases the offsets will mismatch
in verifier when checking / rewriting context access. Fix this by
providing a helper macro __bpf_md_ptr() that will enforce padding
up to 64 bit and proper alignment, and for context access a macro
bpf_ctx_range_ptr() which will cover full 64 bit member range on
32 bit archs. For flow_keys, we additionally need to force the
size check to sizeof(__u64) as with other pointer types.

Fixes: d58e468b11 ("flow_dissector: implements flow dissector BPF hook")
Fixes: 4f738adba3 ("bpf: create tcp_bpf_ulp allowing BPF to monitor socket TX/RX data")
Fixes: 2dbb9b9e6d ("bpf: Introduce BPF_PROG_TYPE_SK_REUSEPORT")
Reported-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: David S. Miller <davem@davemloft.net>
Tested-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-11-30 17:04:35 -08:00
Eric Dumazet
4f693b55c3 tcp: implement coalescing on backlog queue
In case GRO is not as efficient as it should be or disabled,
we might have a user thread trapped in __release_sock() while
softirq handler flood packets up to the point we have to drop.

This patch balances work done from user thread and softirq,
to give more chances to __release_sock() to complete its work
before new packets are added the the backlog.

This also helps if we receive many ACK packets, since GRO
does not aggregate them.

This patch brings ~60% throughput increase on a receiver
without GRO, but the spectacular gain is really on
1000x release_sock() latency reduction I have measured.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-30 13:26:54 -08:00
David S. Miller
93029d7d40 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
bpf-next 2018-11-30

The following pull-request contains BPF updates for your *net-next* tree.

(Getting out bit earlier this time to pull in a dependency from bpf.)

The main changes are:

1) Add libbpf ABI versioning and document API naming conventions
   as well as ABI versioning process, from Andrey.

2) Add a new sk_msg_pop_data() helper for sk_msg based BPF
   programs that is used in conjunction with sk_msg_push_data()
   for adding / removing meta data to the msg data, from John.

3) Optimize convert_bpf_ld_abs() for 0 offset and fix various
   lib and testsuite build failures on 32 bit, from David.

4) Make BPF prog dump for !JIT identical to how we dump subprogs
   when JIT is in use, from Yonghong.

5) Rename btf_get_from_id() to make it more conform with libbpf
   API naming conventions, from Martin.

6) Add a missing BPF kselftest config item, from Naresh.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-29 18:15:07 -08:00
David S. Miller
e561bb29b6 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Trivial conflict in net/core/filter.c, a locally computed
'sdif' is now an argument to the function.

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-28 22:10:54 -08:00
Dave Airlie
1ec28f8b8a Merge v4.20-rc4 into drm-next
Requested by Boris Brezillon for some vc4 fixes that are needed for future vc4 work.

Signed-off-by: Dave Airlie <airlied@redhat.com>
2018-11-29 10:34:03 +10:00
Dave Airlie
61647c77cb Merge tag 'drm-misc-next-2018-11-28' of git://anongit.freedesktop.org/drm/drm-misc into drm-next
drm-misc-next for v4.21:

Core Changes:
- Merge drm_info.c into drm_debugfs.c
- Complete the fake drm_crtc_commit's hw_done/flip_done sooner.
- Remove deprecated drm_obj_ref/unref functions. All drivers use get/put now.
- Decrease stack use of drm_gem_prime_mmap.
- Improve documentation for dumb callbacks.

Driver Changes:
- Add edid support to virtio.
- Wait on implicit fence in meson and sun4i.
- Add support for BGRX8888 to sun4i.
- Preparation patches for sun4i driver to start supporting linear and tiled YUV formats.
- Add support for HDMI 1.4 4k modes to meson, and support for VIC alternate timings.
- Drop custom dumb_map in vkms.
- Small fixes and cleanups to v3d.

Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/151a3270-b1be-ed75-bd58-6b29d741f592@linux.intel.com
2018-11-29 10:28:49 +10:00
John Fastabend
7246d8ed4d bpf: helper to pop data from messages
This adds a BPF SK_MSG program helper so that we can pop data from a
msg. We use this to pop metadata from a previous push data call.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-11-28 22:07:57 +01:00
Thomas Gleixner
9137bb27e6 x86/speculation: Add prctl() control for indirect branch speculation
Add the PR_SPEC_INDIRECT_BRANCH option for the PR_GET_SPECULATION_CTRL and
PR_SET_SPECULATION_CTRL prctls to allow fine grained per task control of
indirect branch speculation via STIBP and IBPB.

Invocations:
 Check indirect branch speculation status with
 - prctl(PR_GET_SPECULATION_CTRL, PR_SPEC_INDIRECT_BRANCH, 0, 0, 0);

 Enable indirect branch speculation with
 - prctl(PR_SET_SPECULATION_CTRL, PR_SPEC_INDIRECT_BRANCH, PR_SPEC_ENABLE, 0, 0);

 Disable indirect branch speculation with
 - prctl(PR_SET_SPECULATION_CTRL, PR_SPEC_INDIRECT_BRANCH, PR_SPEC_DISABLE, 0, 0);

 Force disable indirect branch speculation with
 - prctl(PR_SET_SPECULATION_CTRL, PR_SPEC_INDIRECT_BRANCH, PR_SPEC_FORCE_DISABLE, 0, 0);

See Documentation/userspace-api/spec_ctrl.rst.

Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Casey Schaufler <casey.schaufler@intel.com>
Cc: Asit Mallick <asit.k.mallick@intel.com>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Jon Masters <jcm@redhat.com>
Cc: Waiman Long <longman9394@gmail.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: Dave Stewart <david.c.stewart@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20181125185005.866780996@linutronix.de
2018-11-28 11:57:13 +01:00
Nicolas Dichtel
288f06a001 netns: enable to dump full nsid translation table
Like the previous patch, the goal is to ease to convert nsids from one
netns to another netns.
A new attribute (NETNSA_CURRENT_NSID) is added to the kernel answer when
NETNSA_TARGET_NSID is provided, thus the user can easily convert nsids.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-27 16:20:20 -08:00
Nicolas Dichtel
cff478b9d9 netns: add support of NETNSA_TARGET_NSID
Like it was done for link and address, add the ability to perform get/dump
in another netns by specifying a target nsid attribute.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-27 16:20:20 -08:00
Nikolay Aleksandrov
70e4272b4c net: bridge: add no_linklocal_learn bool option
Use the new boolopt API to add an option which disables learning from
link-local packets. The default is kept as before and learning is
enabled. This is a simple map from a boolopt bit to a bridge private
flag that is tested before learning.

v2: pass NULL for extack via sysfs

Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-27 15:04:15 -08:00
Nikolay Aleksandrov
a428afe82f net: bridge: add support for user-controlled bool options
We have been adding many new bridge options, a big number of which are
boolean but still take up netlink attribute ids and waste space in the skb.
Recently we discussed learning from link-local packets[1] and decided
yet another new boolean option will be needed, thus introducing this API
to save some bridge nl space.
The API supports changing the value of multiple boolean options at once
via the br_boolopt_multi struct which has an optmask (which options to
set, bit per opt) and optval (options' new values). Future boolean
options will only be added to the br_boolopt_id enum and then will have
to be handled in br_boolopt_toggle/get. The API will automatically
add the ability to change and export them via netlink, sysfs can use the
single boolopt function versions to do the same. The behaviour with
failing/succeeding is the same as with normal netlink option changing.

If an option requires mapping to internal kernel flag or needs special
configuration to be enabled then it should be handled in
br_boolopt_toggle. It should also be able to retrieve an option's current
state via br_boolopt_get.

v2: WARN_ON() on unsupported option as that shouldn't be possible and
    also will help catch people who add new options without handling
    them for both set and get. Pass down extack so if an option desires
    it could set it on error and be more user-friendly.

[1] https://www.spinics.net/lists/netdev/msg532698.html

Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-27 15:04:15 -08:00
Tiwei Bie
89a9157e12 virtio: add packed ring types and macros
Add types and macros for packed ring.

Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-26 22:17:39 -08:00
David S. Miller
4afe60a97b Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2018-11-26

The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) Extend BTF to support function call types and improve the BPF
   symbol handling with this info for kallsyms and bpftool program
   dump to make debugging easier, from Martin and Yonghong.

2) Optimize LPM lookups by making longest_prefix_match() handle
   multiple bytes at a time, from Eric.

3) Adds support for loading and attaching flow dissector BPF progs
   from bpftool, from Stanislav.

4) Extend the sk_lookup() helper to be supported from XDP, from Nitin.

5) Enable verifier to support narrow context loads with offset > 0
   to adapt to LLVM code generation (currently only offset of 0 was
   supported). Add test cases as well, from Andrey.

6) Simplify passing device functions for offloaded BPF progs by
   adding callbacks to bpf_prog_offload_ops instead of ndo_bpf.
   Also convert nfp and netdevsim to make use of them, from Quentin.

7) Add support for sock_ops based BPF programs to send events to
   the perf ring-buffer through perf_event_output helper, from
   Sowmini and Daniel.

8) Add read / write support for skb->tstamp from tc BPF and cg BPF
   programs to allow for supporting rate-limiting in EDT qdiscs
   like fq from BPF side, from Vlad.

9) Extend libbpf API to support map in map types and add test cases
   for it as well to BPF kselftests, from Nikita.

10) Account the maximum packet offset accessed by a BPF program in
    the verifier and use it for optimizing nfp JIT, from Jiong.

11) Fix error handling regarding kprobe_events in BPF sample loader,
    from Daniel T.

12) Add support for queue and stack map type in bpftool, from David.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-26 13:08:17 -08:00
David S. Miller
b1bf78bfb2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-11-24 17:01:43 -08:00
Linus Torvalds
e195ca6cb6 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid
Pull HID fixes from Jiri Kosina:

 - revert of the high-resolution scrolling feature, as it breaks certain
   hardware due to incompatibilities between Logitech and Microsoft
   worlds. Peter Hutterer is working on a fixed implementation. Until
   that is finished, revert by Benjamin Tissoires.

 - revert of incorrect strncpy->strlcpy conversion in uhid, from David
   Herrmann

 - fix for buggy sendfile() implementation on uhid device node, from
   Eric Biggers

 - a few assorted device-ID specific quirks

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/hid/hid:
  Revert "Input: Add the `REL_WHEEL_HI_RES` event code"
  Revert "HID: input: Create a utility class for counting scroll events"
  Revert "HID: logitech: Add function to enable HID++ 1.0 "scrolling acceleration""
  Revert "HID: logitech: Enable high-resolution scrolling on Logitech mice"
  Revert "HID: logitech: Use LDJ_DEVICE macro for existing Logitech mice"
  Revert "HID: logitech: fix a used uninitialized GCC warning"
  Revert "HID: input: simplify/fix high-res scroll event handling"
  HID: Add quirk for Primax PIXART OEM mice
  HID: i2c-hid: Disable runtime PM for LG touchscreen
  HID: multitouch: Add pointstick support for Cirque Touchpad
  HID: steam: remove input device when a hid client is running.
  Revert "HID: uhid: use strlcpy() instead of strncpy()"
  HID: uhid: forbid UHID_CREATE under KERNEL_DS or elevated privileges
  HID: input: Ignore battery reported by Symbol DS4308
  HID: Add quirk for Microsoft PIXART OEM mouse
2018-11-24 12:58:47 -08:00
John Sheu
d644cca50f media: vb2: Allow reqbufs(0) with "in use" MMAP buffers
Videobuf2 presently does not allow VIDIOC_REQBUFS to destroy outstanding
buffers if the queue is of type V4L2_MEMORY_MMAP, and if the buffers are
considered "in use".  This is different behavior than for other memory
types and prevents us from deallocating buffers in following two cases:

1) There are outstanding mmap()ed views on the buffer. However even if
   we put the buffer in reqbufs(0), there will be remaining references,
   due to vma .open/close() adjusting vb2 buffer refcount appropriately.
   This means that the buffer will be in fact freed only when the last
   mmap()ed view is unmapped.

2) Buffer has been exported as a DMABUF. Refcount of the vb2 buffer
   is managed properly by VB2 DMABUF ops, i.e. incremented on DMABUF
   get and decremented on DMABUF release. This means that the buffer
   will be alive until all importers release it.

Considering both cases above, there does not seem to be any need to
prevent reqbufs(0) operation, because buffer lifetime is already
properly managed by both mmap() and DMABUF code paths. Let's remove it
and allow userspace freeing the queue (and potentially allocating a new
one) even though old buffers might be still in processing.

To let userspace know that the kernel now supports orphaning buffers
that are still in use, add a new V4L2_BUF_CAP_SUPPORTS_ORPHANED_BUFS
to be set by reqbufs and create_bufs.

[p.zabel@pengutronix.de: added V4L2_BUF_CAP_SUPPORTS_ORPHANED_BUFS,
 updated documentation, and added back debug message]

Signed-off-by: John Sheu <sheu@chromium.org>
Reviewed-by: Pawel Osciak <posciak@chromium.org>
Signed-off-by: Tomasz Figa <tfiga@chromium.org>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
[hverkuil-cisco@xs4all.nl: added V4L2-BUF-CAP-SUPPORTS-ORPHANED-BUFS ref]
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2018-11-23 06:41:39 -05:00
Vlad Dumitrescu
f11216b242 bpf: add skb->tstamp r/w access from tc clsact and cg skb progs
This could be used to rate limit egress traffic in concert with a qdisc
which supports Earliest Departure Time, such as FQ.

Write access from cg skb progs only with CAP_SYS_ADMIN, since the value
will be used by downstream qdiscs. It might make sense to relax this.

Changes v1 -> v2:
  - allow access from cg skb, write only with CAP_SYS_ADMIN

Signed-off-by: Vlad Dumitrescu <vladum@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-11-22 15:47:28 -08:00
Benjamin Tissoires
ffe0e7cf29 Revert "Input: Add the REL_WHEEL_HI_RES event code"
This reverts commit aaf9978c3c.

Quoting Peter:

There is a HID feature report called "Resolution Multiplier"
Described in the "Enhanced Wheel Support in Windows" doc and
the "USB HID Usage Tables" page 30.

http://download.microsoft.com/download/b/d/1/bd1f7ef4-7d72-419e-bc5c-9f79ad7bb66e/wheel.docx
https://www.usb.org/sites/default/files/documents/hut1_12v2.pdf

This was new for Windows Vista, so we're only a decade behind here. I only
accidentally found this a few days ago while debugging a stuck button on a
Microsoft mouse.

The docs above describe it like this: a wheel control by default sends
value 1 per notch. If the resolution multiplier is active, the wheel is
expected to send a value of $multiplier per notch (e.g. MS Sculpt mouse) or
just send events more often, i.e. for less physical motion (e.g. MS Comfort
mouse).

For the latter, you need the right HW of course. The Sculpt mouse has
tactile wheel clicks, so nothing really changes. The Comfort mouse has
continuous motion with no tactile clicks. Similar to the free-wheeling
Logitech mice but without any inertia.

Note that the doc also says that Vista and onwards *always* enable this
feature where available.

An example HID definition looks like this:

       Usage Page Generic Desktop (0x01)
       Usage Resolution Multiplier (0x48)
       Logical Minimum 0
       Logical Maximum 1
       Physical Minimum 1
       Physical Maximum 16
       Report Size 2 # in bits
       Report Count 1
       Feature (Data, Var, Abs)

So the actual bits have values 0 or 1 and that reflects real values 1 or 16.
We've only seen single-bits so far, so there's low-res and hi-res, but
nothing in between.

The multiplier is available for HID usages "Wheel" and "AC Pan" (horiz wheel).
Microsoft suggests that

> Vendors should ship their devices with smooth scrolling disabled and allow
> Windows to enable it. This ensures that the device works like a regular HID
> device on legacy operating systems that do not support smooth scrolling.
(see the wheel doc linked above)

The mice that we tested so far do reset on unplug.

Device Support looks to be all (?) Microsoft mice but nothing else

Not supported:
- Logitech G500s, G303
- Roccat Kone XTD
- all the cheap Lenovo, HP, Dell, Logitech USB mice that come with a
  workstation that I could find don't have it.
- Etekcity something something
- Razer Imperator

Supported:
- Microsoft Comfort Optical Mouse 3000 - yes, physical: 1:4
- Microsoft Sculpt Ergonomic Mouse - yes, physical: 1:12
- Microsoft Surface mouse - yes, physical: 1:4

So again, I think this is really just available on Microsoft mice, but
probably all decent MS mice released over the last decade.

Looking at the hardware itself:

- no noticeable notches in the weel
- low-res: 18 events per 360deg rotation (click angle 20 deg)
- high-res: 72 events per 360deg → matches multiplier of 4

- I can feel the notches during wheel turns
- low-res: 24 events per 360 deg rotation (click angle 15 deg)
  - horiz wheel is tilt-based, continuous output value 1
- high-res: 24 events per 360deg with value 12 → matches multiplier of 12
  - horiz wheel output rate doubles/triples?, values is 3

- It's a touch strip, not a wheel so no notches
- high-res: events have value 4 instead of 1
  a bit strange given that it doesn't actually have notches.

Ok, why is this an issue for the current API? First, because the logitech
multiplier used in Harry's patches looks suspiciously like the Resolution
Multiplier so I think we should assume it's the same thing. Nestor, can you
shed some light on that?

- `REL_WHEEL` is defined as the number of notches, emulated where needed.
- `REL_WHEEL_HI_RES` is the movement of the user's finger in microns.
- `WM_MOUSEWHEEL` (Windows) is is a multiple of 120, defined as "the threshold
  for action to be taken and one such action"
  https://docs.microsoft.com/en-us/windows/desktop/inputdev/wm-mousewheel

If the multiplier is set to M, this means we need an accumulated value of M
until we can claim there was a wheel click. So after enabling the multiplier
and setting it to the maximum (like Windows):
- M units are 15deg rotation → 1 unit is 2620/M micron (see below). This is
  the `REL_WHEEL_HI_RES` value.
  - wheel diameter 20mm: 15 deg rotation is 2.62mm, 2620 micron (pi * 20mm /
    (360deg/15deg))
- For every M units accumulated, send one `REL_WHEEL` event

The problem here is that we've now hardcoded 20mm/15 deg into the kernel and
we have no way of getting the size of the wheel or the click angle into the
kernel.

In userspace we now have to undo the kernel's calculation. If our click angle
is e.g. 20 degree we have to undo the (lossy) calculation from the kernel and
calculate the correct angle instead. This also means the 15 is a hardcoded
option forever and cannot be changed.

In hid-logitech-hidpp.c, the microns per unit is hardcoded per device.
Harry, did you measure those by hand? We'd need to update the kernel for
every device and there are 10 years worth of devices from MS alone.

The multiplier default is 8 which is in the right ballpark, so I'm pretty
sure this is the same as the Resolution Multiplier, just in HID++ lingo. And
given that the 120 magic factor is what Windows uses in the end, I can't
imagine Logitech rolling their own thing here. Nestor?

And we're already fairly inaccurate with the microns anyway. The MX Anywhere
2S has a click angle of 20 degrees (18 stops) and a 17mm wheel, so a wheel
notch is approximately 2.67mm, one event at multiplier 8 (1/8 of a notch)
would be 334 micron. That's only 80% of the fallback value of 406 in the
kernel. Multiplier 6 gives us 445micron (10% off). I'm assuming multiplier 7
doesn't exist because it's not a factor of 120.

Summary:

Best option may be to simply do what Windows is doing, all the HW manufacturers
have to use that approach after all. Switch `REL_WHEEL_HI_RES` to report in
fractions of 120, with 120 being one notch and divide that by the multiplier
for the actual events. So e.g. the Logitech multiplier 8 would send value 15
for each event in hi-res mode. This can be converted in userspace to
whatever userspace needs (combined with a hwdb there that tells you wheel
size/click angle/...).

Conflicts:
	include/uapi/linux/input-event-codes.h -> I kept the new
         reserved event in the code, so I had to adapt the revert
         slightly

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: Harry Cutts <hcutts@chromium.org>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
2018-11-22 08:57:44 +01:00
Gerd Hoffmann
610c0c2b28 virtio-gpu: add VIRTIO_GPU_F_EDID feature
The feature allows the guest request an EDID blob (describing monitor
capabilities) for a given scanout (aka virtual monitor connector).

It brings a new command message, which has just a scanout field (beside
the standard virtio-gpu header) and a response message which carries the
EDID data.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Dave Airlie <airlied@redhat.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20181030063206.19528-2-kraxel@redhat.com
2018-11-21 12:06:59 +01:00
Paul Burton
3cd6408328 MIPS: ptrace: introduce NT_MIPS_MSA regset
The current methods for obtaining FP context via ptrace only provide
either 32 or 64 bits per data register. With MSA, where vector registers
are aliased with scalar FP data registers, those registers are 128 bits
wide. Thus a new mechanism is required for userland to access those
registers via ptrace. This patch introduces an NT_MIPS_MSA regset which
provides, in this order:

  - The full 128 bits value of each vector register, in native
    endianness saved as though elements are doubles. That is, the format
    of each vector register is as would be obtained by saving it to
    memory using an st.d instruction.

  - The 32 bit scalar FP implementation register (FIR).

  - The 32 bit scalar FP control & status register (FCSR).

  - The 32 bit MSA implementation register (MSAIR).

  - The 32 bit MSA control & status register (MSACSR).

The provision of the FIR & FCSR registers in addition to the MSA
equivalents allows scalar FP context to be retrieved as a subset of
the context available via this regset. Along with the MSA equivalents
they also nicely form the final 128 bit "register" of the regset.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/21180/
Cc: linux-mips@linux-mips.org
2018-11-20 21:05:39 -08:00