Alex Elder [Thu, 26 Nov 2020 01:54:55 +0000 (19:54 -0600)]
arm64: dts: qcom: sc7180: limit IPA iommu streams
Recently we learned that Android and Windows firmware don't seem to
like using 3 as an iommu mask value for IPA. A simple fix was to
specify exactly the streams needed explicitly, rather than implying
a range with the mask. Make the same change for the SC7180 platform.
See also:
https://lore.kernel.org/linux-arm-msm/20201123052305.157686-1-bjorn.andersson@linaro.org/
arm64: dts: qcom: sc7180-trogdor: Make pp3300_a the default supply for pp3300_hub
The trogdor design has two options for supplying the 'pp3300_hub' power
rail, it can be supplied by 'pp3300_l7c' or 'pp3300_a'. The 'pp3300_a'
path includes a load switch that can be controlled through GPIO84.
Initially trogdor boards used 'pp3300_l7c' to power the USB hub, newer
revisions (will) use 'pp3300_a' as supply for 'pp3300_hub'.
Add a DT node for the 'pp3300_a' path and a pinctrl entry for the GPIO.
Make this path the default and keep trogdor rev1, lazor rev0 and rev1
on 'pp3300_l7c'. These earlier revisions also allocated the GPIO to the
purpose of controlling the power switch, so there is no need to limit
the pinctrl config to newer revisions. Remove the platform-wide
'always/boot-on' properties from 'pp3300_l7c' and add them to the
boards that use this supply. Also delete the 'always/boot-on'
properties of 'pp3300_hub' for these boards.
Bjorn Andersson [Mon, 23 Nov 2020 05:23:05 +0000 (23:23 -0600)]
arm64: dts: qcom: sdm845: Limit ipa iommu streams
The Android and Windows firmware does not accept the use of 3 as a mask
to cover the IPA streams. But with 0x721 being related to WiFi and 0x723
being unsed the mapping can be reduced to just cover 0x720 and 0x722,
which is accepted.
Stephen Boyd [Sun, 22 Nov 2020 03:41:49 +0000 (19:41 -0800)]
arm64: dts: sdm845: Add iommus property to qup
The SMMU that sits in front of the QUP needs to be programmed properly
so that the i2c geni driver can allocate DMA descriptors. Failure to do
this leads to faults when using devices such as an i2c touchscreen where
the transaction is larger than 32 bytes and we use a DMA buffer.
arm-smmu 15000000.iommu: Unexpected global fault, this could be serious
arm-smmu 15000000.iommu: GFSR 0x00000002, GFSYNR0 0x00000002, GFSYNR1 0x000006c0, GFSYNR2 0x00000000
Add the right SID and mask so this works.
Reviewed-by: Vinod Koul <vkoul@kernel.org> Tested-by: Caleb Connolly <caleb@connolly.tech> Tested-by: Vinod Koul <vkoul@kernel.org> Signed-off-by: Stephen Boyd <swboyd@chromium.org>
[bjorn: Define for second QUP as well, be more specific in sdm845.dtsi] Link: https://lore.kernel.org/r/20201122034149.626045-1-bjorn.andersson@linaro.org Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
arm64: dts: qcom: sc7180: Set 'polling-delay-passive' for thermal zones back to 250 ms
Commit 22337b91022d ("arm64: dts: qcom: sc7180: Changed polling mode
in Thermal-zones node") sets both 'polling-delay' and
'polling-delay-passive' to zero with the rationale that TSENS interrupts
are enabled. A TSENS interrupt fires when the temperature of a thermal
zone reaches a trip point, which makes regular polling below the passive
trip point temperature unnecessary. However the situation is different
when passive cooling is active, regular polling is still needed to
trigger a periodic evaluation of the thermal zone by the thermal governor.
Change 'polling-delay-passive' back to the original value of 250 ms.
Commit 2315ae70af95 ("arm64: dts: qcom: sc7180: Add gpu cooling
support") recently changed the value for the GPU thermal zones from
zero to 100 ms, also set it to 250 ms for uniformity. If some zones
really need different values these can be changed in dedicated patches.
Nikita Travkin [Fri, 13 Nov 2020 17:59:15 +0000 (22:59 +0500)]
arm64: dts: qcom: msm8916-longcheer-l8150: Add flash LED
L8150 uses SGM3785 Flash LED driver. It is similar to SGM3140 but
can also be controlled with PWM. Since SoC doesn't have PWM, add
led to the device tree using sgm3140 driver.
There's a proximity sensor on Lazor devices, but only for LTE SKUs.
Enable it only on the Lazor LTE SKUs and also configure it properly so
it works.
Cc: Douglas Anderson <dianders@chromium.org> Cc: Matthias Kaehlcke <mka@chromium.org> Reviewed-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Stephen Boyd <swboyd@chromium.org> Link: https://lore.kernel.org/r/20201120183825.547310-1-swboyd@chromium.org Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Stephen Boyd [Fri, 20 Nov 2020 20:09:13 +0000 (12:09 -0800)]
arm64: dts: qcom: sc7180: Remove double pull-up on p-sensor-int-l
This interrupt has an external pull-up so we don't need to pull it up
again. Drop the internal pull here. Note I don't think this really
changes anything, just noticed while looking at this irq pin.
Reviewed-by: Douglas Anderson <dianders@chromium.org> Cc: Douglas Anderson <dianders@chromium.org> Signed-off-by: Stephen Boyd <swboyd@chromium.org> Link: https://lore.kernel.org/r/20201120200913.618274-1-swboyd@chromium.org Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
RB5 makes use of the two USB controllers onboard. USB0 is connected
to the Type C port and USB1 is connected to USB3.1 HUB which exposes
following downstream ports:
* 2 Type A ports
* 2 HS/SS ports on the expansion connector
* USB to LAN device
Hence, enable these two controllers with the required PHYs.
arm64: dts: qcom: sm8250: correct compatible for sm8250-mtp
Qualcomm boards should define two compatible strings: one for board,
anoter one for SoC family. sm8250-mtp.dts lists just the board
compatible, which makes it incompatible with qcom.yaml schema.
Jonathan Marek [Tue, 9 Jun 2020 19:40:22 +0000 (15:40 -0400)]
arm64: dts: qcom: sm8250: add apps_smmu node
Add the apps_smmu node for sm8250.
For UFS, now that the kernel initializes the iommu, the stream mappings
set by the bootloader are cleared. Adding the iommus property is required
so that new mappings are created for UFS.
Jonathan Marek [Tue, 9 Jun 2020 19:40:21 +0000 (15:40 -0400)]
arm64: dts: qcom: sm8150: add apps_smmu node
Add the apps_smmu node for sm8150.
For UFS, now that the kernel initializes the iommu, the stream mappings
set by the bootloader are cleared. Adding the iommus property is required
so that new mappings are created for UFS.
Signed-off-by: Jonathan Marek <jonathan@marek.ca> Reviewed-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org> Tested-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org> Link: https://lore.kernel.org/r/20200609194030.17756-4-jonathan@marek.ca Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Douglas Anderson [Wed, 11 Nov 2020 15:37:01 +0000 (07:37 -0800)]
arm64: dts: qcom: sc7180: Assign numbers to eMMC and SD
After many years of struggle, commit fa2d0aa96941 ("mmc: core: Allow
setting slot index via device tree alias") finally allows the use of
aliases to number SD/MMC slots. Let's do that for sc7180 SoCs so that
if eMMC and SD are both used they have consistent numbers across boots
and kernel changes.
Picking numbers can be tricky. Do we call these "1" and "2" to match
the name in documentation or "0" and "1" with the assertion that we
should always start at 0 and count up?
While the "start counting at 0" makes sense if there are not already
well-defined numbers for all sd/mmc controllers, in the case of sc7180
there _are_ well defined numbers. IMO it is less confusing to use
those and match the docs.
Konrad Dybcio [Mon, 5 Oct 2020 15:03:11 +0000 (17:03 +0200)]
arm64: dts: qcom: Add support for Microsoft Lumia 950 XL (Cityman)
Add device tree support for Microsoft Lumia 950 XL smartphone.
It is based on the msm8994 chipset and is able to boot Linux
using a custom EDK2 implementation. EL2 core startup is possible
with spin-table, but for now, we'll stick with PSCI.
The board currently supports:
* Screen console via EFIFB
* SDHCI
* I2C
* UART
* PSCI core bringup
Add configs for lazor rev2 and rev3. There are no relevant deltas
between rev1 and rev2, so just add the rev2 compatible string to the
rev1 config.
One important delta in rev3 is a switch of the power supply for the
onboard USB hub from 'pp3300_l7c' to 'pp3300_a' + a load switch. The
actual regulator switch is done by the patch 'arm64: dts: qcom:
sc7180-trogdor: Make pp3300_a the default supply for pp3300_hub',
since it affects the entire trogdor platform. Here we only add the
.dts files for lazor rev3 and replace the generic compatible entries
in the rev1 .dts files.
Zhen Lei [Fri, 16 Oct 2020 09:08:33 +0000 (17:08 +0800)]
arm64: dts: qcom: clear the warnings caused by empty dma-ranges
The scripts/dtc/checks.c requires that the node have empty "dma-ranges"
property must have the same "#address-cells" and "#size-cells" values as
the parent node. Otherwise, the following warnings is reported:
arch/arm64/boot/dts/qcom/ipq6018.dtsi:185.3-14: Warning \
(dma_ranges_format): /soc:dma-ranges: empty "dma-ranges" property but \
its #address-cells (1) differs from / (2)
arch/arm64/boot/dts/qcom/ipq6018.dtsi:185.3-14: Warning \
(dma_ranges_format): /soc:dma-ranges: empty "dma-ranges" property but \
its #size-cells (1) differs from / (2)
Arnd Bergmann figured out why it's necessary:
Also note that the #address-cells=<1> means that any device under
this bus is assumed to only support 32-bit addressing, and DMA will
have to go through a slow swiotlb in the absence of an IOMMU.
Sibi Sankar [Thu, 15 Oct 2020 18:27:56 +0000 (23:57 +0530)]
arm64: dts: qcom: sc7180-trogdor: Fixup modem memory region
The modem firmware memory requirements vary between 32M/140M on
no-lte/lte skus respectively, so fixup the modem memory region
to reflect the requirements.
Alexandru Stan [Thu, 22 Oct 2020 05:04:44 +0000 (22:04 -0700)]
arm64: dts: qcom: trogdor: Add brightness-levels
We want userspace to represent the human perceived brightness.
Since the led drivers and the leds themselves don't have a
linear response to the value we give them in terms of perceived
brightness, we'll bake the curve into the dts.
The panel also doesn't have a good response under 5%, so we'll avoid
sending it anything lower than that.
Note: Ideally this patch should be coupled with the driver change from
"backlight: pwm_bl: Fix interpolation", but it can work without it,
without looking too ugly.
Douglas Anderson [Mon, 21 Sep 2020 21:27:17 +0000 (14:27 -0700)]
arm64: dts: qcom: Switch sc7180-trogdor to control SPI CS via GPIO
As talked about in the patch ("arm64: dts: qcom: sc7180: Provide
pinconf for SPI to use GPIO for CS"), on some boards it makes much
more sense (and is much more efficient) to think of the SPI Chip
Select as a GPIO. Trogdor is one such board where the SPI parts don't
run in GSI mode and we do a lot of SPI traffic.
Douglas Anderson [Mon, 21 Sep 2020 21:27:16 +0000 (14:27 -0700)]
arm64: dts: qcom: sc7180: Provide pinconf for SPI to use GPIO for CS
When the chip select line is controlled by the QUP, changing CS is a
time consuming operation. We have to send a command over to the geni
and wait for it to Ack us every time we want to change (both making it
high and low). To send this command we have to make a choice in
software when we want to control the chip select, we have to either:
A) Wait for the Ack via interrupt which slows down all SPI transfers
(and incurrs extra processing associated with interrupts).
B) Sit in a loop and poll, waiting for the Ack.
Neither A) nor B) is a great option.
We can avoid all of this by realizing that, at least on some boards,
there is no advantage of considering this line to be a geni line.
While it's true that geni _can_ control the line, it's also true that
the line can be a GPIO and there is no downside of viewing it that
way. Setting a GPIO is a simple MMIO operation.
This patch provides definitions so a board can easily select the GPIO
mode.
NOTE: apparently, it's possible to run the geni in "GSI" mode. In GSI
the SPI port is allowed to be controlled by more than one user (like
firmware and Linux) and also the port can operate sequences of
operations in one go. In GSI mode it _would_ be invalid to look at
the chip select as a GPIO because that would prevent other users from
using it. In theory GSI mode would also avoid some overhead by
allowing us to sequence the chip select better. However, I'll argue
GSI is not relevant for all boards (and certainly not any boards
supported by mainline today). Why?
- Apparently to run a SPI chip in GSI mode you need to initialize it
(in the bootloader) with a different firmware and then it will
always run in GSI mode. Since there is no support for GSI mode in
the current Linux driver, it must be that existing boards don't have
firmware that's doing that. Note that the kernel device tree
describes hardware but also firmware, so it is legitimate to make
the assumption that we don't have GSI firmware in a given dts file.
- Some boards with sc7180 have SPI connected to the Chrome OS EC or
security chip (Cr50). The protocols for talking to cros_ec and cr50
are extremely complex. Both drivers in Linux fully lock the bus
across several distinct SPI transfers. While I am not an expert on
GSI mode it feels highly unlikely to me that we'd ever be able to
enable GSI mode for these devices.
From a testing perspective, running "flashrom -p ec -r /tmp/foo.bin"
in a loop after this patch shows almost no reduction in time, but the
number of interrupts per command goes from 32357 down to 30611 (about
a 5% reduction).
Stephan Gerhold [Wed, 16 Sep 2020 10:41:35 +0000 (12:41 +0200)]
arm64: dts: qcom: msm8916-pm8916: Stop using s1/l3 as regulators
s1 (VDDCX) and l3 (VDDMX) are now managed by rpmpd as power domains.
This allows us to vote for voltage corners instead of voting for raw
voltages. But we cannot manage these as regulator and power domain at
the same time: The votes by rpmpd would conflict with the ones from
the regulator driver.
All users of these regulators have been converted to power domains.
Make sure that no new users are added by removing s1 and l3 from
the regulator definitions.
This also allows us to remove the arbitrary voltage constraints
we have been using for these regulators. Not all of the voltages
listed there would actually have been safe for the boards.
Stephan Gerhold [Wed, 16 Sep 2020 10:41:34 +0000 (12:41 +0200)]
arm64: dts: qcom: msm8916: Use power domains for MSS/WCNSS remoteprocs
So far we have been making proxy votes for the remote processors
through the regulator interface. Now that we have rpmpd it's better
to vote for performance states through the power domain interface.
This also allows us to move these supplies back to msm8916.dtsi
because the device tree binding for RPMPD is independent of the
underlying regulator/PMIC.
Stephan Gerhold [Wed, 16 Sep 2020 10:41:29 +0000 (12:41 +0200)]
arm64: dts: qcom: msm8916: Add RPM power domains
MSM8916 has two RPM power domains: VDDCX and VDDMX.
So far we have been managing them by voting for raw voltages through
the regulator subsystem, but it's better to manage them with corners
as actual power domains.
Add the device tree node for rpmpd so we can manage them as real
power domains instead of using the regulators.
arm64: dts: qcom: sc7180: Fix one forgotten interconnect reference
In commit e23b1220a246 ("arm64: dts: qcom: sc7180: Increase the number
of interconnect cells") we missed increasing the cells on one
interconnect. That's no bueno. Fix it.
NOTE: it appears that things aren't totally broken without this fix,
but clearly something isn't going to be working right. If nothing
else, without this fix I see this in the logs:
OF: /soc@0/mdss@ae00000: could not get #interconnect-cells for /soc@0/interrupt-controller@17a00000
Fixes: e23b1220a246 ("arm64: dts: qcom: sc7180: Increase the number of interconnect cells") Reviewed-by: Georgi Djakov <georgi.djakov@linaro.org> Reviewed-by: Rob Clark <robdclark@chromium.org> Signed-off-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20201001141838.1.I08054d1d976eed64ffa1b0e21d568e0dc6040b54@changeid Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Kathiravan T [Wed, 14 Oct 2020 15:46:17 +0000 (21:16 +0530)]
arm64: dts: ipq6018: update the reserved-memory node
Memory region reserved for the TZ is changed long back. Let's
update the same to align with the corret region. Its size also
increased to 4MB from 2MB.
Joe Perches [Thu, 22 Oct 2020 02:36:07 +0000 (19:36 -0700)]
treewide: Convert macro and uses of __section(foo) to __section("foo")
Use a more generic form for __section that requires quotes to avoid
complications with clang and gcc differences.
Remove the quote operator # from compiler_attributes.h __section macro.
Convert all unquoted __section(foo) uses to quoted __section("foo").
Also convert __attribute__((section("foo"))) uses to __section("foo")
even if the __attribute__ has multiple list entry forms.
Rasmus Villemoes [Sat, 24 Oct 2020 01:04:26 +0000 (03:04 +0200)]
kernel/sys.c: fix prototype of prctl_get_tid_address()
tid_addr is not a "pointer to (pointer to int in userspace)"; it is in
fact a "pointer to (pointer to int in userspace) in userspace". So
sparse rightfully complains about passing a kernel pointer to
put_user().
Eric Biggers [Fri, 23 Oct 2020 23:27:16 +0000 (16:27 -0700)]
mm: remove kzfree() compatibility definition
Commit 453431a54934 ("mm, treewide: rename kzfree() to
kfree_sensitive()") renamed kzfree() to kfree_sensitive(),
but it left a compatibility definition of kzfree() to avoid
being too disruptive.
Since then a few more instances of kzfree() have slipped in.
Just get rid of them and remove the compatibility definition
once and for all.
Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linus Torvalds [Sun, 25 Oct 2020 18:28:49 +0000 (11:28 -0700)]
Merge tag 'timers-urgent-2020-10-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Thomas Gleixner:
"A time namespace fix and a matching selftest. The futex absolute
timeouts which are based on CLOCK_MONOTONIC require time namespace
corrected. This was missed in the original time namesapce support"
* tag 'timers-urgent-2020-10-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
selftests/timens: Add a test for futex()
futex: Adjust absolute futex timeouts with per time namespace offset
Linus Torvalds [Sun, 25 Oct 2020 18:25:16 +0000 (11:25 -0700)]
Merge tag 'sched-urgent-2020-10-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Thomas Gleixner:
"Two scheduler fixes:
- A trivial build fix for sched_feat() to compile correctly with
CONFIG_JUMP_LABEL=n
- Replace a zero lenght array with a flexible array"
* tag 'sched-urgent-2020-10-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/features: Fix !CONFIG_JUMP_LABEL case
sched: Replace zero-length array with flexible-array
Linus Torvalds [Sun, 25 Oct 2020 18:12:31 +0000 (11:12 -0700)]
Merge tag 'ntb-5.10' of git://github.com/jonmason/ntb
Pull NTB fixes from Jon Mason.
* tag 'ntb-5.10' of git://github.com/jonmason/ntb:
NTB: Use struct_size() helper in devm_kzalloc()
ntb: intel: Fix memleak in intel_ntb_pci_probe
NTB: hw: amd: fix an issue about leak system resources
Linus Torvalds [Sun, 25 Oct 2020 18:10:23 +0000 (11:10 -0700)]
Merge branch 'i2c/for-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c fix from Wolfram Sang:
"Regression fix for rc1 and stable kernels as well"
* 'i2c/for-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
i2c: core: Restore acpi_walk_dep_device_list() getting called after registering the ACPI i2c devs
Linus Torvalds [Sun, 25 Oct 2020 18:05:04 +0000 (11:05 -0700)]
Merge tag '5.10-rc-smb3-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6
Pull more cifs updates from Steve French:
"Add support for stat of various special file types (WSL reparse points
for char, block, fifo)"
* tag '5.10-rc-smb3-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6:
cifs: update internal module version number
smb3: add some missing definitions from MS-FSCC
smb3: remove two unused variables
smb3: add support for stat of WSL reparse points for special file types
Linus Torvalds [Sun, 25 Oct 2020 17:59:34 +0000 (10:59 -0700)]
Merge branch 'parisc-5.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux
Pull more parisc updates from Helge Deller:
- During this merge window O_NONBLOCK was changed to become 000200000,
but we missed that the syscalls timerfd_create(), signalfd4(),
eventfd2(), pipe2(), inotify_init1() and userfaultfd() do a strict
bit-wise check of the flags parameter.
To provide backward compatibility with existing userspace we
introduce parisc specific wrappers for those syscalls which filter
out the old O_NONBLOCK value and replaces it with the new one.
- Prevent HIL bus driver to get stuck when keyboard or mouse isn't
attached
- Improve error return codes when setting rtc time
- Minor documentation fix in pata_ns87415.c
* 'parisc-5.10-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
ata: pata_ns87415.c: Document support on parisc with superio chip
parisc: Add wrapper syscalls to fix O_NONBLOCK flag usage
hil/parisc: Disable HIL driver when it gets stuck
parisc: Improve error return codes when setting rtc time
Linus Torvalds [Sun, 25 Oct 2020 17:55:35 +0000 (10:55 -0700)]
Merge tag 'for-linus-5.10b-rc1c-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull more xen updates from Juergen Gross:
- a series for the Xen pv block drivers adding module parameters for
better control of resource usge
- a cleanup series for the Xen event driver
* tag 'for-linus-5.10b-rc1c-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
Documentation: add xen.fifo_events kernel parameter description
xen/events: unmask a fifo event channel only if it was masked
xen/events: only register debug interrupt for 2-level events
xen/events: make struct irq_info private to events_base.c
xen: remove no longer used functions
xen-blkfront: Apply changed parameter name to the document
xen-blkfront: add a parameter for disabling of persistent grants
xen-blkback: add a parameter for disabling of persistent grants
Linus Torvalds [Sun, 25 Oct 2020 17:45:26 +0000 (10:45 -0700)]
Merge tag 'safesetid-5.10' of git://github.com/micah-morton/linux
Pull SafeSetID updates from Micah Morton:
"The changes are mostly contained to within the SafeSetID LSM, with the
exception of a few 1-line changes to change some ns_capable() calls to
ns_capable_setid() -- causing a flag (CAP_OPT_INSETID) to be set that
is examined by SafeSetID code and nothing else in the kernel.
The changes to SafeSetID internally allow for setting up GID
transition security policies, as already existed for UIDs"
* tag 'safesetid-5.10' of git://github.com/micah-morton/linux:
LSM: SafeSetID: Fix warnings reported by test bot
LSM: SafeSetID: Add GID security policy handling
LSM: Signal to SafeSetID when setting group IDs
Linus Torvalds [Sun, 25 Oct 2020 17:40:08 +0000 (10:40 -0700)]
Merge tag '20201024-v4-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/wtarreau/prandom
Pull random32 updates from Willy Tarreau:
"Make prandom_u32() less predictable.
This is the cleanup of the latest series of prandom_u32
experimentations consisting in using SipHash instead of Tausworthe to
produce the randoms used by the network stack.
The changes to the files were kept minimal, and the controversial
commit that used to take noise from the fast_pool (f227e3ec3b5c) was
reverted. Instead, a dedicated "net_rand_noise" per_cpu variable is
fed from various sources of activities (networking, scheduling) to
perturb the SipHash state using fast, non-trivially predictable data,
instead of keeping it fully deterministic. The goal is essentially to
make any occasional memory leakage or brute-force attempt useless.
The resulting code was verified to be very slightly faster on x86_64
than what is was with the controversial commit above, though this
remains barely above measurement noise. It was also tested on i386 and
arm, and build- tested only on arm64"
Link: https://lore.kernel.org/netdev/20200808152628.GA27941@SDF.ORG/
* tag '20201024-v4-5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/wtarreau/prandom:
random32: add a selftest for the prandom32 code
random32: add noise from network and scheduling activity
random32: make prandom_u32() output unpredictable
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