soundwire: bus: add enumerated Slave device to device list

Currently Slave devices are only added on startup, either from Device
Tree or ACPI entries. However Slave devices that are physically
present on the bus, but not described in platform firmware, will never
be added to the device list. The user/integrator can only know the
list of devices by looking a dynamic debug logs.

This patch suggests adding a Slave device even if there is no matching
DT or ACPI entry, so that we can see this in sysfs entry.

Initial code from Srinivas. Comments, fixes for ACPI probe and edits
of commit message by Pierre.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Co-developed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200924194430.121058-2-pierre-louis.bossart@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: remove an unnecessary NULL check

The "bus" pointer isn't NULL so the address to a non-zero offset in
middle of "bus" cannot be NULL.  Delete the NULL check.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20200923083235.GB1454948@mwanda
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: cadence: add data port test fail interrupt

The Master ports can report errors in test data modes, enable the
interrupt and just log a message. This capability is useful for Master
sink ports only (Master source ports generate data).

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200920193207.31241-4-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: intel: enable test modes

This patch adds debugfs support to override the Master and Slave data
modes. The settings only take effect prior to a new stream being
prepared/enabled, or on resume.

The test mode can be set to verify data integrity and detect bus
clashes, but can only be used to test capture paths. In this case the
input generated by a Slave source port is replaced by a fixed or
cyclical patterns.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200920193207.31241-3-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: enable Data Port test modes

Test modes are required for all SoundWire IP, and help debug
integration issues. In theory each port can be configured with a
different mode but to simplify this patch only offers separate
configurations for the Master and Slave ports - this covers 99% of the
intended cases during platform integration.

The test mode value is set via platform-specific ways.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200920193207.31241-2-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: intel: use {u32|u16}p_replace_bits

FIELD_PREP() does not replace the bits so it is not apt in case where we
modify a register.

Use u32_replace_bits() or u16_replace_bits() instead.

Fixes: 3b4979cabd4b ("soundwire: intel: use FIELD_{GET|PREP}")
Tested-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Link: https://lore.kernel.org/r/20200917120146.1780323-3-vkoul@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: cadence: use u32p_replace_bits

FIELD_PREP() does not replace the bits so it is not apt in case where we
modify a register.

Use u32p_replace_bits() instead.

Fixes: 3cf25d63b1b9 ("soundwire: cadence: use FIELD_{GET|PREP}")
Tested-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200917120146.1780323-2-vkoul@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: qcom: get max rows and cols info from compatible

currently the max rows and cols values are hardcoded. In reality
these values depend on the IP version. So get these based on
device tree compatible strings.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20200917120138.11313-4-srinivas.kandagatla@linaro.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: qcom: add support to block packing mode

This patch adds support to block pack mode, which is required
on Qcom soundwire controllers v1.5.x on few ports!

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20200917120138.11313-3-srinivas.kandagatla@linaro.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: qcom: clear BIT FIELDs before value set.

According to usage (bitfields.h) of REG_FIELDS,
Modify is:
  reg &= ~REG_FIELD_C;
  reg |= FIELD_PREP(REG_FIELD_C, c);

Patch ("soundwire: qcom : use FIELD_{GET|PREP}") seems to have
accidentally removed clearing bit field while modifying the register.

Fix this by using u32p_replace_bits() to clear and set the values.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20200917120138.11313-2-srinivas.kandagatla@linaro.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: Add generic bandwidth allocation algorithm

This algorithm computes bus parameters like clock frequency, frame
shape and port transport parameters based on active stream(s) running
on the bus.

Developers can also implement their own .compute_params() callback for
specific resource management algorithm, and set if before calling
sdw_add_bus_master()

Credits: this patch is based on an earlier internal contribution by
Vinod Koul, Sanyog Kale, Shreyas Nc and Hardik Shah. All hard-coded
values were removed from the initial contribution to use BIOS
information instead.

Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Acked-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20200908131520.5712-1-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: cadence: add parity error injection through debugfs

The Cadence IP can inject errors, let's make use of this capability to
test Slave parity error checks.

See e.g. example log where both the master and slave detect the parity
error injected on a dummy read command.

cd /sys/kernel/debug/soundwire/master-1/intel-sdw/
echo 1 > cdns-parity-error-injection

[   44.756249] intel-master sdw-master-1: Parity error
[   44.756313] intel-master sdw-master-1: Msg NACK received
[   44.756366] intel-master sdw-master-1: Msg NACKed for Slave 15
[   44.756375] intel-master sdw-master-1: trf on Slave 15 failed:-5
[   44.756382] intel-master sdw-master-1: parity error injection, read: -5
[   44.756649] rt1308 sdw:1:25d:1308:0: Parity error detected

The code makes sure the Master device is resumed, hence the clock
restarted, before sending a parity error.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Link: https://lore.kernel.org/r/20200908134521.6781-8-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: bus: export broadcast read/write capability for tests

Provide prototype and export symbol to enable tests. The bus lock is
handled externally to avoid conflicts e.g. between kernel-generated
traffic and test traffic.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Link: https://lore.kernel.org/r/20200908134521.6781-7-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

ASoC: codecs: realtek-soundwire: ignore initial PARITY errors

The parity calculation is not reset on a Severe Reset, which leads to
misleading/harmless errors reported on startup. The addition of a
quirk helps filter out such errors while leaving the error checks on
in steady-state.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Acked-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20200908134521.6781-6-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: bus: use quirk to filter out invalid parity errors

If a Slave device reports with a quirk that its initial parity check
may be incorrect, filter it but keep the parity checks active in
steady state.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Link: https://lore.kernel.org/r/20200908134521.6781-5-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: slave: add first_interrupt_done status

Some Slaves report incorrect information in their interrupt status
registers after a master/bus reset, track the initial interrupt
handling so that quirks can be introduced to filter out incorrect
information while keeping interrupts enabled in steady state.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Link: https://lore.kernel.org/r/20200908134521.6781-4-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: bus: filter-out unwanted interrupt reports

Unlike the traditional usage, in the SoundWire specification the
interrupt masks only gate the propagation of an interrupt condition to
the PING frame status. They do not gate the changes of the INT_STAT
registers, which will happen regardless of the mask settings. See
Figure 116 of the SoundWire 1.2 specification for an in-depth
description of the interrupt model.

When the bus driver reads the SCP_INT1_STAT register, it will retrieve
all the interrupt status, including for the mask fields that were not
explicitly set. For example, even if the PARITY mask is not set, the
PARITY error status will be reported if an implementation-defined
interrupt for jack detection is enabled and occurs.

Filtering undesired interrupt reports and handling has to be
implemented in software. This patch enables this filtering for the
INT1_IMPL_DEF, PARITY and BUS_CLASH interrupt sources.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Link: https://lore.kernel.org/r/20200908134521.6781-3-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

ASoC/soundwire: bus: use property to set interrupt masks

Add a slave-level property and program the SCP_INT1_MASK as desired by
the codec driver. Since there is no DisCo property this has to be an
implementation-specific firmware property or hard-coded in the driver.

The only functionality change is that implementation-defined
interrupts are no longer set for amplifiers - those interrupts are
typically for jack detection or acoustic event detection/hotwording.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Tested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reviewed-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Acked-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20200908134521.6781-2-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: qcom: fix SLIBMUS/SLIMBUS typo

Fix slimbus case being broken thanks to a typo.

Fixes: 5bd773242f75 ("soundwire: qcom: avoid dependency on CONFIG_SLIMBUS")
Signed-off-by: Jonathan Marek <jonathan@marek.ca>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20200908140818.28373-1-jonathan@marek.ca
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: cadence: fix race condition between suspend and Slave device alerts

In system suspend stress cases, the SOF CI reports timeouts. The root
cause is that an alert is generated while the system suspends. The
interrupt handling generates transactions on the bus that will never
be handled because the interrupts are disabled in parallel.

As a result, the transaction never completes and times out on resume.
This error doesn't seem too problematic since it happens in a work
queue, and the system recovers without issues.

Nevertheless, this race condition should not happen. When doing a
system suspend, or when disabling interrupts, we should make sure the
current transaction can complete, and prevent new work from being
queued.

BugLink: https://github.com/thesofproject/linux/issues/2344
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Acked-by: Jaroslav Kysela <perex@perex.cz>
Link: https://lore.kernel.org/r/20200817222340.18042-1-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: qcom: add v1.5.1 compatible

Add a compatible string for HW version v1.5.1 on sm8250 SoCs.

Signed-off-by: Jonathan Marek <jonathan@marek.ca>
Tested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20200905173905.16541-5-jonathan@marek.ca
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: qcom: add support for mmio soundwire master devices

Adds support for qcom soundwire devices with memory mapped IO registers.

Signed-off-by: Jonathan Marek <jonathan@marek.ca>
Tested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20200905173905.16541-4-jonathan@marek.ca
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: qcom: avoid dependency on CONFIG_SLIMBUS

The driver may be used without slimbus, so don't depend on slimbus.

Signed-off-by: Jonathan Marek <jonathan@marek.ca>
Tested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20200905173905.16541-3-jonathan@marek.ca
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: qcom: fix abh/ahb typo

The function name qcom_swrm_abh_reg_read should say ahb, fix that.

Signed-off-by: Jonathan Marek <jonathan@marek.ca>
Tested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20200905173905.16541-2-jonathan@marek.ca
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: intel: remove stream handling from .prepare and .hw_free

Now that the stream is handled at the dai-link level (in the machine
driver), we can remove the stream handling at the dai level. We still
need these callbacks to perform dai-level resource handling
(i.e. addition/removal of a master).

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200903204739.31206-5-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: intel: remove .trigger operation

Now that the stream trigger is handled at the dai-link level, there is
no need for a dai-level trigger any longer.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200903204739.31206-4-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: intel: fix NULL/ERR_PTR confusion

snd_soc_dai_get_sdw_stream() can only return the pointer to stream or
an ERR_PTR value, NULL is not a possible value.

Fixes: 09553140c8d7b ('soundwire: intel: implement get_sdw_stream() operations')
Reported-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200903204739.31206-3-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: stream: fix NULL/IS_ERR confusion

snd_soc_dai_get_sdw_stream() can only return -ENOTSUPP or the stream,
NULL is not a possible value.

Fixes: 4550569bd779f ('soundwire: stream: add helper to startup/shutdown streams')
Reported-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200903204739.31206-2-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: remove SDW_REG_SHIFT()

soundwire had defined SDW_REG_SHIFT to calculate shift values for
bitmasks, but now that we have better things in bitfield.h, remove this.

Signed-off-by: Vinod Koul <vkoul@kernel.org>
Tested-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200903114504.1202143-10-vkoul@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: intel_init: use FIELD_{GET|PREP}

use FIELD_{GET|PREP} in intel_init driver to get/set field values
instead of open coding masks and shift operations.

Signed-off-by: Vinod Koul <vkoul@kernel.org>
Tested-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200903114504.1202143-9-vkoul@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: intel: use FIELD_{GET|PREP}

use FIELD_{GET|PREP} in intel driver to get/set field values instead of
open coding masks and shift operations.

Signed-off-by: Vinod Koul <vkoul@kernel.org>
Tested-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200903114504.1202143-8-vkoul@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: cadence: use FIELD_{GET|PREP}

use FIELD_{GET|PREP} in cadence driver to get/set field values instead
of open coding masks and shift operations.

Signed-off-by: Vinod Koul <vkoul@kernel.org>
Tested-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200903114504.1202143-7-vkoul@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: qcom : use FIELD_{GET|PREP}

use FIELD_{GET|PREP} in qcom driver to get/set field values instead of
open coding masks and shift operations.
Also, remove now unused register shift defines

Signed-off-by: Vinod Koul <vkoul@kernel.org>
Tested-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200903114504.1202143-6-vkoul@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: stream: use FIELD_{GET|PREP}

use FIELD_{GET|PREP} in stream code to get/set field values instead of
open coding masks and shift operations.

Signed-off-by: Vinod Koul <vkoul@kernel.org>
Tested-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200903114504.1202143-5-vkoul@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: slave: use SDW_DISCO_LINK_ID()

use SDW_DISCO_LINK_ID() in slave code to extract field values instead of
open coding masks and shift operations to extract link_id

Signed-off-by: Vinod Koul <vkoul@kernel.org>
Tested-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200903114504.1202143-4-vkoul@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: bus: use FIELD_GET()

use FIELD_GET() in bus code to extract field values instead of open
coding masks and shift operations.

Signed-off-by: Vinod Koul <vkoul@kernel.org>
Tested-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200903114504.1202143-3-vkoul@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: define and use addr bit masks

Soundwire addr is a 52bit value encoding link, version, unique id,
mfg id, part id and class id. Define bit masks for these and use
FIELD_GET() to extract these fields.

Signed-off-by: Vinod Koul <vkoul@kernel.org>
Tested-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200903114504.1202143-2-vkoul@kernel.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: intel: don't manage link power individually

Each link has separate power controls, but experimental results show
we need to use an all-or-none approach to the link power management.

This change has marginal power impacts, the DSP needs to be powered
anyways before SoundWire links can be powered, and even when powered a
link can be in clock-stopped mode.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200901150556.19432-11-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: intel: pass link_mask information to each master

While the hardware exposes independent bits to power-up each master,
the recommended sequence is to power all links or none. Idle links can
still use the clock stop mode while the master is powered.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200901150556.19432-10-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: intel: add error log for clock-stop invalid configs

Detect cases where the clock is assumed to be stopped but the IP is
not in the relevant state. There is no real way to recover here, but
adding an error log can help detect bad programming sequences or race
conditions.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200901150556.19432-9-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: stream: enable hw_sync as needed by hardware

Use platform-specific information to decide when to use hw_sync, not
only a number of links > 1.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200901150556.19432-8-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: intel: add multi-link hw_synchronization information

set the flags as required by hardware implementation

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200901150556.19432-7-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: bus: update multi-link definition with hw sync details

Hardware-based synchronization is typically required when the
bus->multi_link flag is set.

On Intel platforms, when the Cadence IP is configured in 'Multi Master
Mode', the hardware synchronization is required even when a stream
only uses a single segment. The existing code only deal with hardware
synchronization when a stream uses more than one segment so to remain
backwards compatible we add a configuration threshold. For Intel cases
this threshold will be set to one, other platforms may be able to use
the SSP-based sync in those cases.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200901150556.19432-6-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: intel: add missing support for all clock stop modes

Deal with the BUS_RESET case, which is the default. The only change is
to add support for the exit sequence using the syncArm/syncGo mode for
the exit reset sequence.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200901150556.19432-5-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: intel: add multi-link support

The multi-link support is enabled with a hardware gsync signal
connecting all links. All commands and operations which typically are
handled on an SSP boundary will be deferred further and enabled across
all links with the 'syncGo' sequence.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200901150556.19432-4-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: intel: ignore software command retries

with multiple links synchronized in hardware, retrying commands in
software is not recommended.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200901150556.19432-3-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: intel: disable shim wake on suspend

If we enabled the clock stop mode and suspend, we need to disable the
shim wake. We do so only if the parent is pm_runtime active due to
power rail dependencies.

GitHub issue: https://github.com/thesofproject/linux/issues/1678
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200901150556.19432-2-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: fix port_ready[] dynamic allocation in mipi_disco

The existing code allocates memory for the total number of ports.
This only works if the ports are contiguous, but will break if e.g. a
Devices uses port0, 1, and 14. The port_ready[] array would contain 3
elements, which would lead to an out-of-bounds access. Conversely in
other cases, the wrong port index would be used leading to timeouts on
prepare.

This can be fixed by allocating for the worst-case of 15
ports (DP0..DP14). In addition since the number is now fixed, we can
use an array instead of a dynamic allocation.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@linux.intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Link: https://lore.kernel.org/r/20200831134318.11443-4-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: add definition for maximum number of ports

A Device may have at most 15 physical ports (DP0, DP1..DP14).

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@linux.intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Link: https://lore.kernel.org/r/20200831134318.11443-3-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

ASoC: codecs: soundwire: remove port_ready[] usage from codecs.

port_ready will be changed to a fixed array in sdw.h and all initialization
work will be done at soundwire side in the following patch. So remove them
from codec drivers.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Rander Wang <rander.wang@linux.intel.com>
Reviewed-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Acked-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20200831134318.11443-2-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: intel: fix intel_suspend/resume defined but not used warning

When CONFIG_PM_SLEEP is not defined, GCC throws compilation warnings:

drivers/soundwire/intel.c:1799:12: warning: ‘intel_resume’ defined but not
used [-Wunused-function]
 static int intel_resume(struct device *dev)
            ^~~~~~~~~~~~
drivers/soundwire/intel.c:1683:12: warning: ‘intel_suspend’ defined but not
used [-Wunused-function]
 static int intel_suspend(struct device *dev)
            ^~~~~~~~~~~~~

Fix by using __maybe_unused macro.

Suggested-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200824133234.28115-1-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: intel: refine runtime pm for SDW_INTEL_CLK_STOP_BUS_RESET

When all the links are suspended, the HDaudio controller may suspend
and the power rails to the SoundWire IP may be disabled, requiring a
complete re-initialization/enumeration on resume. However, if one or
more Masters remained active, the HDaudio controller will remain active
and the power rails will remain enabled. As a result, during the link
resume step we can check if the context was preserved by verifying if
the clock was stopped, and avoid doing a complete bus reset and
re-enumeration.

Signed-off-by: Rander Wang <rander.wang@intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200817152923.3259-13-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: intel: support clock_stop mode without quirks

In this mode, on restart the bus restarts immediately, the Slaves
remain synchronized and all context is kept intact.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Rander Wang <rander.wang@intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200817152923.3259-12-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: intel_init: handle power rail dependencies for clock stop mode

When none of the clock stop quirks is specified, the Master IP will
assume the context is preserved and will not reset the Bus and restart
enumeration. Due to power rail dependencies, the HDaudio controller
needs to remain powered and prevented from executing its pm_runtime
suspend routine.

This choice of course has a power impact, and this mode should only be
selected when latency requirements are critical or the parent device
can enter D0ix modes.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200817152923.3259-11-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: intel: add CLK_STOP_NOT_ALLOWED support

In case the clock needs to keep running, we need to prevent the Master
from entering pm_runtime suspend.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200817152923.3259-10-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: intel: add CLK_STOP_BUS_RESET support

Move existing pm_runtime suspend under the CLK_STOP_TEARDOWN case.

In this mode the Master IP will lose all context but in-band wakes are
supported.

On pm_runtime resume a complete re-enumeration will be performed after
a bus reset.

Signed-off-by: Rander Wang <rander.wang@intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200817152923.3259-9-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: intel: add CLK_STOP_TEARDOWN for pm_runtime suspend

Now that we have options, add support for TEARDOWN mode (same
functionality as existing code)

All other modes will be added in follow-up patches.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200817152923.3259-8-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: intel: pm_runtime idle scheduling

Add quirk and pm_runtime idle scheduling to let the Master suspend if
no Slaves become attached. This can happen when a link is not marked
as disabled and has devices exposed in the DSDT, if the power is
controlled by sideband means or the link includes a pluggable
connector.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Rander Wang <rander.wang@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200817152923.3259-7-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: intel: reinitialize IP+DSP in .prepare(), but only when resuming

The .prepare() callback is invoked for normal streaming, underflows or
during the system resume transition. In the latter case, the context
for the ALH PDIs is lost, and the DSP is not initialized properly
either, but the bus parameters don't need to be recomputed.

Conversely, when doing a regular .prepare() during an underflow, the
ALH/SHIM registers shall not be changed as the hardware cannot be
reprogrammed after the DMA started (hardware spec requirement).

This patch adds storage of PDI and hw_params in the DAI dma context,
and the difference between the types of .prepare() usages is handled
via a simple boolean, updated when suspending, and tested for in the
.prepare() case.

Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20200817152923.3259-6-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: intel: call helper to reset Slave states on resume

This helps make sure they are all UNATTACHED and reset the state
machines.

At the moment we perform a bus reset both for system resume and
pm_runtime resume, this will be modified when clock-stop mode is
supported

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200817152923.3259-5-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: intel: fix race condition on system resume

Previous patches took care of the case where the master device is
pm_runtime 'suspended' when a system suspend occurs.

In the case where the master device was not suspended, e.g. if suspend
occurred while streaming audio, Intel validation noticed a race
condition: the pm_runtime suspend may conflict with the enumeration
started by the system resume.

This can be simply fixed by updating the status before exiting system
resume.

GitHub issue: https://github.com/thesofproject/linux/issues/1482
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200817152923.3259-4-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: intel: reset pm_runtime status during system resume

The system resume does the entire bus re-initialization and brings it
to full-power. If the device was pm_runtime suspended, there is no
need to run the pm_runtime resume sequence after the system runtime.

Follow the documentation from runtime_pm.rst, and conditionally
disable, set_active and re-enable the device on system resume.

Note that pm_runtime_suspended() is used instead of
pm_runtime_status_suspended() so that we can deal with the case where
pm_runtime is disabled.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200817152923.3259-3-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: intel: add pm_runtime support

Add basic hooks in DAI .startup and .shutdown callbacks.

The SoundWire IP should be powered between those two calls. The power
dependencies between SoundWire and DSP are handled with the
parent/child relationship, before the SoundWire master device becomes
active the parent device will become active and power-up the shared
rails.

For now the strategy is to rely on complete enumeration when the
device becomes active, so the code is a copy/paste of the sequence for
system suspend/resume. In future patches, the strategy will optionally
be to rely on clock stop if the enumeration time is prohibitive or
when the devices connected to a link can signal a wake.

A module parameter is added to make integration of new Slave devices
easier, to e.g. keep the device active or prevent clock-stop.

Note that we need to we have to disable runtime pm before device
unregister, otherwise we will see "Failed to power up link: -11" error
on module remove test.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200817152923.3259-2-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: intel: Add basic power management support

Implement suspend/resume capabilities (not runtime_pm for now)
The resume part is essentially a full-blown re-enumeration.

When S0ix is supported, we will select clock stop mode when the ACPI
target state is S0, and tear down the link for S3.

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200721203723.18305-2-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

soundwire: master: enable pm runtime

The hierarchy of soundwire devices is platform device -> M device -> S
device. A S device is physically attached on the platform device. So the
platform device should be resumed when a S device is resumed. As the
bridge of platform device and S device, we have to implement runtime pm
on M driver. We have set runtime pm ops in M driver already, but still
need to enable runtime pm.

Signed-off-by: Bard Liao <yung-chuan.liao@linux.intel.com>
Link: https://lore.kernel.org/r/20200726215945.3119-1-yung-chuan.liao@linux.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Linux 5.9-rc1

Merge tag 'io_uring-5.9-2020-08-15' of git://git.kernel.dk/linux-block

Pull io_uring fixes from Jens Axboe:
 "A few differerent things in here.

  Seems like syzbot got some more io_uring bits wired up, and we got a
  handful of reports and the associated fixes are in here.

  General fixes too, and a lot of them marked for stable.

  Lastly, a bit of fallout from the async buffered reads, where we now
  more easily trigger short reads. Some applications don't really like
  that, so the io_read() code now handles short reads internally, and
  got a cleanup along the way so that it's now easier to read (and
  documented). We're now passing tests that failed before"

* tag 'io_uring-5.9-2020-08-15' of git://git.kernel.dk/linux-block:
  io_uring: short circuit -EAGAIN for blocking read attempt
  io_uring: sanitize double poll handling
  io_uring: internally retry short reads
  io_uring: retain iov_iter state over io_read/io_write calls
  task_work: only grab task signal lock when needed
  io_uring: enable lookup of links holding inflight files
  io_uring: fail poll arm on queue proc failure
  io_uring: hold 'ctx' reference around task_work queue + execute
  fs: RWF_NOWAIT should imply IOCB_NOIO
  io_uring: defer file table grabbing request cleanup for locked requests
  io_uring: add missing REQ_F_COMP_LOCKED for nested requests
  io_uring: fix recursive completion locking on oveflow flush
  io_uring: use TWA_SIGNAL for task_work uncondtionally
  io_uring: account locked memory before potential error case
  io_uring: set ctx sq/cq entry count earlier
  io_uring: Fix NULL pointer dereference in loop_rw_iter()
  io_uring: add comments on how the async buffered read retry works
  io_uring: io_async_buf_func() need not test page bit

parisc: fix PMD pages allocation by restoring pmd_alloc_one()

Commit 1355c31eeb7e ("asm-generic: pgalloc: provide generic pmd_alloc_one()
and pmd_free_one()") converted parisc to use generic version of
pmd_alloc_one() but it missed the fact that parisc uses order-1 pages for
PMD.

Restore the original version of pmd_alloc_one() for parisc, just use
GFP_PGTABLE_KERNEL that implies __GFP_ZERO instead of GFP_KERNEL and
memset.

Fixes: 1355c31eeb7e ("asm-generic: pgalloc: provide generic pmd_alloc_one() and pmd_free_one()")
Reported-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Tested-by: Meelis Roos <mroos@linux.ee>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lkml.kernel.org/r/9f2b5ebd-e4a4-0fa1-6cd3-4b9f6892d1ad@linux.ee
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'block-5.9-2020-08-14' of git://git.kernel.dk/linux-block

Pull block fixes from Jens Axboe:
 "A few fixes on the block side of things:

   - Discard granularity fix (Coly)

   - rnbd cleanups (Guoqing)

   - md error handling fix (Dan)

   - md sysfs fix (Junxiao)

   - Fix flush request accounting, which caused an IO slowdown for some
     configurations (Ming)

   - Properly propagate loop flag for partition scanning (Lennart)"

* tag 'block-5.9-2020-08-14' of git://git.kernel.dk/linux-block:
  block: fix double account of flush request's driver tag
  loop: unset GENHD_FL_NO_PART_SCAN on LOOP_CONFIGURE
  rnbd: no need to set bi_end_io in rnbd_bio_map_kern
  rnbd: remove rnbd_dev_submit_io
  md-cluster: Fix potential error pointer dereference in resize_bitmaps()
  block: check queue's limits.discard_granularity in __blkdev_issue_discard()
  md: get sysfs entry after redundancy attr group create

Merge tag 'riscv-for-linus-5.9-mw1' of git://git./linux/kernel/git/riscv/linux

Pull RISC-V fix from Palmer Dabbelt:
 "I collected a single fix during the merge window: we managed to break
  the early trap setup on !MMU, this fixes it"

* tag 'riscv-for-linus-5.9-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: Setup exception vector for nommu platform

Merge tag 'sh-for-5.9' of git://git.libc.org/linux-sh

Pull arch/sh updates from Rich Felker:
 "Cleanup, SECCOMP_FILTER support, message printing fixes, and other
  changes to arch/sh"

* tag 'sh-for-5.9' of git://git.libc.org/linux-sh: (34 commits)
  sh: landisk: Add missing initialization of sh_io_port_base
  sh: bring syscall_set_return_value in line with other architectures
  sh: Add SECCOMP_FILTER
  sh: Rearrange blocks in entry-common.S
  sh: switch to copy_thread_tls()
  sh: use the generic dma coherent remap allocator
  sh: don't allow non-coherent DMA for NOMMU
  dma-mapping: consolidate the NO_DMA definition in kernel/dma/Kconfig
  sh: unexport register_trapped_io and match_trapped_io_handler
  sh: don't include <asm/io_trapped.h> in <asm/io.h>
  sh: move the ioremap implementation out of line
  sh: move ioremap_fixed details out of <asm/io.h>
  sh: remove __KERNEL__ ifdefs from non-UAPI headers
  sh: sort the selects for SUPERH alphabetically
  sh: remove -Werror from Makefiles
  sh: Replace HTTP links with HTTPS ones
  arch/sh/configs: remove obsolete CONFIG_SOC_CAMERA*
  sh: stacktrace: Remove stacktrace_ops.stack()
  sh: machvec: Modernize printing of kernel messages
  sh: pci: Modernize printing of kernel messages
  ...

io_uring: short circuit -EAGAIN for blocking read attempt

One case was missed in the short IO retry handling, and that's hitting
-EAGAIN on a blocking attempt read (eg from io-wq context). This is a
problem on sockets that are marked as non-blocking when created, they
don't carry any REQ_F_NOWAIT information to help us terminate them
instead of perpetually retrying.

Fixes: 227c0c9673d8 ("io_uring: internally retry short reads")
Signed-off-by: Jens Axboe <axboe@kernel.dk>

io_uring: sanitize double poll handling

There's a bit of confusion on the matching pairs of poll vs double poll,
depending on if the request is a pure poll (IORING_OP_POLL_ADD) or
poll driven retry.

Add io_poll_get_double() that returns the double poll waitqueue, if any,
and io_poll_get_single() that returns the original poll waitqueue. With
that, remove the argument to io_poll_remove_double().

Finally ensure that wait->private is cleared once the double poll handler
has run, so that remove knows it's already been seen.

Cc: stable@vger.kernel.org # v5.8
Reported-by: syzbot+7f617d4a9369028b8a2c@syzkaller.appspotmail.com
Fixes: 18bceab101ad ("io_uring: allow POLL_ADD with double poll_wait() users")
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Merge tag 'perf-tools-2020-08-14' of git://git./linux/kernel/git/acme/linux

Pull more perf tools updates from Arnaldo Carvalho de Melo:
 "Fixes:
   - Fixes for 'perf bench numa'.

   - Always memset source before memcpy in 'perf bench mem'.

   - Quote CC and CXX for their arguments to fix build in environments
     using those variables to pass more than just the compiler names.

   - Fix module symbol processing, addressing regression detected via
     "perf test".

   - Allow multiple probes in record+script_probe_vfs_getname.sh 'perf
     test' entry.

  Improvements:
   - Add script to autogenerate socket family name id->string table from
     copy of kernel header, used so far in 'perf trace'.

   - 'perf ftrace' improvements to provide similar options for this
     utility so that one can go from 'perf record', 'perf trace', etc to
     'perf ftrace' just by changing the name of the subcommand.

   - Prefer new "sched:sched_waking" trace event when it exists in 'perf
     sched' post processing.

   - Update POWER9 metrics to utilize other metrics.

   - Fall back to querying debuginfod if debuginfo not found locally.

  Miscellaneous:
   - Sync various kvm headers with kernel sources"

* tag 'perf-tools-2020-08-14' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux: (40 commits)
  perf ftrace: Make option description initials all capital letters
  perf build-ids: Fall back to debuginfod query if debuginfo not found
  perf bench numa: Remove dead code in parse_nodes_opt()
  perf stat: Update POWER9 metrics to utilize other metrics
  perf ftrace: Add change log
  perf: ftrace: Add set_tracing_options() to set all trace options
  perf ftrace: Add option --tid to filter by thread id
  perf ftrace: Add option -D/--delay to delay tracing
  perf: ftrace: Allow set graph depth by '--graph-opts'
  perf ftrace: Add support for trace option tracing_thresh
  perf ftrace: Add option 'verbose' to show more info for graph tracer
  perf ftrace: Add support for tracing option 'irq-info'
  perf ftrace: Add support for trace option funcgraph-irqs
  perf ftrace: Add support for trace option sleep-time
  perf ftrace: Add support for tracing option 'func_stack_trace'
  perf tools: Add general function to parse sublevel options
  perf ftrace: Add option '--inherit' to trace children processes
  perf ftrace: Show trace column header
  perf ftrace: Add option '-m/--buffer-size' to set per-cpu buffer size
  perf ftrace: Factor out function write_tracing_file_int()
  ...

Merge tag 'x86-urgent-2020-08-15' of git://git./linux/kernel/git/tip/tip

Pull x86 fixes from Ingo Molnar:
 "Misc fixes and small updates all around the place:

   - Fix mitigation state sysfs output

   - Fix an FPU xstate/sxave code assumption bug triggered by
     Architectural LBR support

   - Fix Lightning Mountain SoC TSC frequency enumeration bug

   - Fix kexec debug output

   - Fix kexec memory range assumption bug

   - Fix a boundary condition in the crash kernel code

   - Optimize porgatory.ro generation a bit

   - Enable ACRN guests to use X2APIC mode

   - Reduce a __text_poke() IRQs-off critical section for the benefit of
     PREEMPT_RT"

* tag 'x86-urgent-2020-08-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/alternatives: Acquire pte lock with interrupts enabled
  x86/bugs/multihit: Fix mitigation reporting when VMX is not in use
  x86/fpu/xstate: Fix an xstate size check warning with architectural LBRs
  x86/purgatory: Don't generate debug info for purgatory.ro
  x86/tsr: Fix tsc frequency enumeration bug on Lightning Mountain SoC
  kexec_file: Correctly output debugging information for the PT_LOAD ELF header
  kexec: Improve & fix crash_exclude_mem_range() to handle overlapping ranges
  x86/crash: Correct the address boundary of function parameters
  x86/acrn: Remove redundant chars from ACRN signature
  x86/acrn: Allow ACRN guest to use X2APIC mode

Merge tag 'sched-urgent-2020-08-15' of git://git./linux/kernel/git/tip/tip

Pull scheduler fixes from Ingo Molnar:
 "Two fixes: fix a new tracepoint's output value, and fix the formatting
  of show-state syslog printouts"

* tag 'sched-urgent-2020-08-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/debug: Fix the alignment of the show-state debug output
  sched: Fix use of count for nr_running tracepoint

Merge tag 'perf-urgent-2020-08-15' of git://git./linux/kernel/git/tip/tip

Pull perf fixes from Ingo Molnar:
 "Misc fixes, an expansion of perf syscall access to CAP_PERFMON
  privileged tools, plus a RAPL HW-enablement for Intel SPR platforms"

* tag 'perf-urgent-2020-08-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/rapl: Add support for Intel SPR platform
  perf/x86/rapl: Support multiple RAPL unit quirks
  perf/x86/rapl: Fix missing psys sysfs attributes
  hw_breakpoint: Remove unused __register_perf_hw_breakpoint() declaration
  kprobes: Remove show_registers() function prototype
  perf/core: Take over CAP_SYS_PTRACE creds to CAP_PERFMON capability

Merge tag 'locking-urgent-2020-08-15' of git://git./linux/kernel/git/tip/tip

Pull locking fixlets from Ingo Molnar:
 "A documentation fix and a 'fallthrough' macro update"

* tag 'locking-urgent-2020-08-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  futex: Convert to use the preferred 'fallthrough' macro
  Documentation/locking/locktypes: Fix a typo

Merge tag '9p-for-5.9-rc1' of git://github.com/martinetd/linux

Pull 9p updates from Dominique Martinet:

 - some code cleanup

 - a couple of static analysis fixes

 - setattr: try to pick a fid associated with the file rather than the
   dentry, which might sometimes matter

* tag '9p-for-5.9-rc1' of git://github.com/martinetd/linux:
  9p: Remove unneeded cast from memory allocation
  9p: remove unused code in 9p
  net/9p: Fix sparse endian warning in trans_fd.c
  9p: Fix memory leak in v9fs_mount
  9p: retrieve fid from file when file instance exist.

Merge tag '5.9-rc-smb3-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs fixes from Steve French:
 "Three small cifs/smb3 fixes, one for stable fixing mkdir path with
  the 'idsfromsid' mount option"

* tag '5.9-rc-smb3-fixes-part2' of git://git.samba.org/sfrench/cifs-2.6:
  SMB3: Fix mkdir when idsfromsid configured on mount
  cifs: Convert to use the fallthrough macro
  cifs: Fix an error pointer dereference in cifs_mount()

Merge tag 'nfs-for-5.9-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client updates from Trond Myklebust:
 "Stable fixes:
   - pNFS: Don't return layout segments that are being used for I/O
   - pNFS: Don't move layout segments off the active list when being used for I/O

  Features:
   - NFS: Add support for user xattrs through the NFSv4.2 protocol
   - NFS: Allow applications to speed up readdir+statx() using AT_STATX_DONT_SYNC
   - NFSv4.0 allow nconnect for v4.0

  Bugfixes and cleanups:
   - nfs: ensure correct writeback errors are returned on close()
   - nfs: nfs_file_write() should check for writeback errors
   - nfs: Fix getxattr kernel panic and memory overflow
   - NFS: Fix the pNFS/flexfiles mirrored read failover code
   - SUNRPC: dont update timeout value on connection reset
   - freezer: Add unsafe versions of freezable_schedule_timeout_interruptible for NFS
   - sunrpc: destroy rpc_inode_cachep after unregister_filesystem"

* tag 'nfs-for-5.9-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (32 commits)
  NFS: Fix flexfiles read failover
  fs: nfs: delete repeated words in comments
  rpc_pipefs: convert comma to semicolon
  nfs: Fix getxattr kernel panic and memory overflow
  NFS: Don't return layout segments that are in use
  NFS: Don't move layouts to plh_return_segs list while in use
  NFS: Add layout segment info to pnfs read/write/commit tracepoints
  NFS: Add tracepoints for layouterror and layoutstats.
  NFS: Report the stateid + status in trace_nfs4_layoutreturn_on_close()
  SUNRPC dont update timeout value on connection reset
  nfs: nfs_file_write() should check for writeback errors
  nfs: ensure correct writeback errors are returned on close()
  NFSv4.2: xattr cache: get rid of cache discard work queue
  NFS: remove redundant initialization of variable result
  NFSv4.0 allow nconnect for v4.0
  freezer: Add unsafe versions of freezable_schedule_timeout_interruptible for NFS
  sunrpc: destroy rpc_inode_cachep after unregister_filesystem
  NFSv4.2: add client side xattr caching.
  NFSv4.2: hook in the user extended attribute handlers
  NFSv4.2: add the extended attribute proc functions.
  ...

Merge tag 'edac_updates_for_5.9_pt2' of git://git./linux/kernel/git/ras/ras

Pull edac fix from Tony Luck:
 "Fix for the ie31200 driver that missed the first pull"

* tag 'edac_updates_for_5.9_pt2' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras:
  EDAC/ie31200: Fallback if host bridge device is already initialized

Merge tag 'devicetree-fixes-for-5.9' of git://git./linux/kernel/git/robh/linux

Pull devicetree fixes from Rob Herring:
 "Another round of 'allOf' removals and whitespace clean-ups of schemas"

* tag 'devicetree-fixes-for-5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
  dt-bindings: Remove more cases of 'allOf' containing a '$ref'
  dt-bindings: Whitespace clean-ups in schema files

Merge tag 'acpi-5.9-rc1-2' of git://git./linux/kernel/git/rafael/linux-pm

Pull more ACPI updates from Rafael Wysocki:
 "Add new hardware support to the ACPI driver for AMD SoCs, the x86 clk
  driver and the Designware i2c driver (changes from Akshu Agrawal and
  Pu Wen)"

* tag 'acpi-5.9-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  clk: x86: Support RV architecture
  ACPI: APD: Add a fmw property is_raven
  clk: x86: Change name from ST to FCH
  ACPI: APD: Change name from ST to FCH
  i2c: designware: Add device HID for Hygon I2C controller

Merge tag 'pm-5.9-rc1-3' of git://git./linux/kernel/git/rafael/linux-pm

Pull one more power management update from Rafael Wysocki:
 "Modify the intel_pstate driver to allow it to work in the passive mode
  with hardware-managed P-states (HWP) enabled"

* tag 'pm-5.9-rc1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq: intel_pstate: Implement passive mode with HWP enabled

Merge tag 'mfd-next-5.9-1' of git://git./linux/kernel/git/lee/mfd

Pull MFD updates from Lee Jones:
 "Core Frameworks
   - Make better attempt at matching device with the correct OF node
   - Allow batch removal of hierarchical sub-devices

  New Drivers
   - Add STM32 Clocksource driver
   - Add support for Khadas System Control Microcontroller

  Driver Removal
   - Remove unused driver for TI's SMSC ECE1099

  New Device Support
   - Add support for Intel Emmitsburg PCH to Intel LPSS PCI
   - Add support for Intel Tiger Lake PCH-H to Intel LPSS PCI
   - Add support for Dialog DA revision to Dialog DA9063

  New Functionality
   - Add support for AXP803 to be probed by I2C

  Fix-ups
   - Numerous W=1 warning fixes
   - Device Tree changes (stm32-lptimer, gateworks-gsc, khadas,mcu, stmfx, cros-ec, j721e-system-controller)
   - Enabled Regmap 'fast I/O' in stm32-lptimer
   - Change BUG_ON to WARN_ON in arizona-core
   - Remove superfluous code/initialisation (madera, max14577)
   - Trivial formatting/spelling issues (madera-core, madera-i2c, da9055, max77693-private)
   - Switch to of_platform_populate() in sprd-sc27xx-spi
   - Expand out set/get brightness/pwm macros in lm3533-ctrlbank
   - Disable IRQs on suspend in motorola-cpcap
   - Clean-up error handling in intel_soc_pmic_mrfld
   - Ensure correct removal order of sub-devices in madera
   - Many s/HTTP/HTTPS/ link changes
   - Ensure name used with Regmap is unique in syscon

  Bug Fixes
   - Properly 'put' clock on unbind and error in arizona-core
   - Fix revision handling in da9063
   - Fix 'assignment of read-only location' error in kempld-core
   - Avoid using the Regmap API when atomic in rn5t618
   - Redefine volatile register description in rn5t618
   - Use locking to protect event handler in dln2"

* tag 'mfd-next-5.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd: (76 commits)
  mfd: syscon: Use a unique name with regmap_config
  mfd: Replace HTTP links with HTTPS ones
  mfd: dln2: Run event handler loop under spinlock
  mfd: madera: Improve handling of regulator unbinding
  mfd: mfd-core: Add mechanism for removal of a subset of children
  mfd: intel_soc_pmic_mrfld: Simplify the return expression of intel_scu_ipc_dev_iowrite8()
  mfd: max14577: Remove redundant initialization of variable current_bits
  mfd: rn5t618: Fix caching of battery related registers
  mfd: max77693-private: Drop a duplicated word
  mfd: da9055: pdata.h: Drop a duplicated word
  mfd: rn5t618: Make restart handler atomic safe
  mfd: kempld-core: Fix 'assignment of read-only location' error
  mfd: axp20x: Allow the AXP803 to be probed by I2C
  mfd: da9063: Add support for latest DA silicon revision
  mfd: da9063: Fix revision handling to correctly select reg tables
  dt-bindings: mfd: st,stmfx: Remove I2C unit name
  dt-bindings: mfd: ti,j721e-system-controller.yaml: Add J721e system controller
  mfd: motorola-cpcap: Disable interrupt for suspend
  mfd: smsc-ece1099: Remove driver
  mfd: core: Add OF_MFD_CELL_REG() helper
  ...

Merge branch 'akpm' (patches from Andrew)

Merge more updates from Andrew Morton:
 "Subsystems affected by this patch series: mm/hotfixes, lz4, exec,
  mailmap, mm/thp, autofs, sysctl, mm/kmemleak, mm/misc and lib"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (35 commits)
  virtio: pci: constify ioreadX() iomem argument (as in generic implementation)
  ntb: intel: constify ioreadX() iomem argument (as in generic implementation)
  rtl818x: constify ioreadX() iomem argument (as in generic implementation)
  iomap: constify ioreadX() iomem argument (as in generic implementation)
  sh: use generic strncpy()
  sh: clkfwk: remove r8/r16/r32
  include/asm-generic/vmlinux.lds.h: align ro_after_init
  mm: annotate a data race in page_zonenum()
  mm/swap.c: annotate data races for lru_rotate_pvecs
  mm/rmap: annotate a data race at tlb_flush_batched
  mm/mempool: fix a data race in mempool_free()
  mm/list_lru: fix a data race in list_lru_count_one
  mm/memcontrol: fix a data race in scan count
  mm/page_counter: fix various data races at memsw
  mm/swapfile: fix and annotate various data races
  mm/filemap.c: fix a data race in filemap_fault()
  mm/swap_state: mark various intentional data races
  mm/page_io: mark various intentional data races
  mm/frontswap: mark various intentional data races
  mm/kmemleak: silence KCSAN splats in checksum
  ...

virtio: pci: constify ioreadX() iomem argument (as in generic implementation)

The ioreadX() helpers have inconsistent interface.  On some architectures
void *__iomem address argument is a pointer to const, on some not.

Implementations of ioreadX() do not modify the memory under the address so
they can be converted to a "const" version for const-safety and
consistency among architectures.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Allen Hubbe <allenbh@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Jon Mason <jdmason@kudzu.us>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Rich Felker <dalias@libc.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200709072837.5869-5-krzk@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ntb: intel: constify ioreadX() iomem argument (as in generic implementation)

The ioreadX() helpers have inconsistent interface.  On some architectures
void *__iomem address argument is a pointer to const, on some not.

Implementations of ioreadX() do not modify the memory under the address so
they can be converted to a "const" version for const-safety and
consistency among architectures.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Dave Jiang <dave.jiang@intel.com>
Cc: Allen Hubbe <allenbh@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Jon Mason <jdmason@kudzu.us>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Rich Felker <dalias@libc.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200709072837.5869-4-krzk@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rtl818x: constify ioreadX() iomem argument (as in generic implementation)

The ioreadX() helpers have inconsistent interface.  On some architectures
void *__iomem address argument is a pointer to const, on some not.

Implementations of ioreadX() do not modify the memory under the address so
they can be converted to a "const" version for const-safety and
consistency among architectures.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Kalle Valo <kvalo@codeaurora.org>
Cc: Allen Hubbe <allenbh@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Jon Mason <jdmason@kudzu.us>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Rich Felker <dalias@libc.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200709072837.5869-3-krzk@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

iomap: constify ioreadX() iomem argument (as in generic implementation)

Patch series "iomap: Constify ioreadX() iomem argument", v3.

The ioread8/16/32() and others have inconsistent interface among the
architectures: some taking address as const, some not.

It seems there is nothing really stopping all of them to take pointer to
const.

This patch (of 4):

The ioreadX() and ioreadX_rep() helpers have inconsistent interface.  On
some architectures void *__iomem address argument is a pointer to const,
on some not.

Implementations of ioreadX() do not modify the memory under the address so
they can be converted to a "const" version for const-safety and
consistency among architectures.

[krzk@kernel.org: sh: clk: fix assignment from incompatible pointer type for ioreadX()]
Link: http://lkml.kernel.org/r/20200723082017.24053-1-krzk@kernel.org
[akpm@linux-foundation.org: fix drivers/mailbox/bcm-pdc-mailbox.c]
Link: http://lkml.kernel.org/r/202007132209.Rxmv4QyS%25lkp@intel.com
Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Jon Mason <jdmason@kudzu.us>
Cc: Allen Hubbe <allenbh@gmail.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Link: http://lkml.kernel.org/r/20200709072837.5869-1-krzk@kernel.org
Link: http://lkml.kernel.org/r/20200709072837.5869-2-krzk@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sh: use generic strncpy()

Current SH will get below warning at strncpy()

In file included from ${LINUX}/arch/sh/include/asm/string.h:3,
                 from ${LINUX}/include/linux/string.h:20,
                 from ${LINUX}/include/linux/bitmap.h:9,
                 from ${LINUX}/include/linux/nodemask.h:95,
                 from ${LINUX}/include/linux/mmzone.h:17,
                 from ${LINUX}/include/linux/gfp.h:6,
                 from ${LINUX}/innclude/linux/slab.h:15,
                 from ${LINUX}/linux/drivers/mmc/host/vub300.c:38:
${LINUX}/drivers/mmc/host/vub300.c: In function 'new_system_port_status':
${LINUX}/arch/sh/include/asm/string_32.h:51:42: warning: array subscript\
  80 is above array bounds of 'char[26]' [-Warray-bounds]
   : "0" (__dest), "1" (__src), "r" (__src+__n)
                                     ~~~~~^~~~

In general, strncpy() should behave like below.

char dest[10];
char *src = "12345";

strncpy(dest, src, 10);
// dest = {'1', '2', '3', '4', '5',
           '\0','\0','\0','\0','\0'}

But, current SH strnpy() has 2 issues.
1st is it will access to out-of-memory (= src + 10).
2nd is it needs big fixup for it, and maintenance __asm__
code is difficult.

To solve these issues, this patch simply uses generic strncpy()
instead of architecture specific one.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alan Modra <amodra@gmail.com>
Cc: Bin Meng <bin.meng@windriver.com>
Cc: Chen Zhou <chenzhou10@huawei.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Romain Naour <romain.naour@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: https://marc.info/?l=linux-renesas-soc&m=157664657013309
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

sh: clkfwk: remove r8/r16/r32

SH will get below warning

${LINUX}/drivers/sh/clk/cpg.c: In function 'r8':
${LINUX}/drivers/sh/clk/cpg.c:41:17: warning: passing argument 1 of 'ioread8'
 discards 'const' qualifier from pointer target type [-Wdiscarded-qualifiers]
  return ioread8(addr);
                 ^~~~
In file included from ${LINUX}/arch/sh/include/asm/io.h:21,
                 from ${LINUX}/include/linux/io.h:13,
                 from ${LINUX}/drivers/sh/clk/cpg.c:14:
${LINUX}/include/asm-generic/iomap.h:29:29: note: expected 'void *' but
argument is of type 'const void *'
 extern unsigned int ioread8(void __iomem *);
                             ^~~~~~~~~~~~~~

We don't need "const" for r8/r16/r32.  And we don't need r8/r16/r32
themselvs.  This patch cleanup these.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alan Modra <amodra@gmail.com>
Cc: Bin Meng <bin.meng@windriver.com>
Cc: Chen Zhou <chenzhou10@huawei.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Romain Naour <romain.naour@gmail.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
X-MARC-Message: https://marc.info/?l=linux-renesas-soc&m=157852973916903
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

include/asm-generic/vmlinux.lds.h: align ro_after_init

Since the patch [1], building the kernel using a toolchain built with
binutils 2.33.1 prevents booting a sh4 system under Qemu.  Apply the patch
provided by Alan Modra [2] that fix alignment of rodata.

[1] https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=ebd2263ba9a9124d93bbc0ece63d7e0fae89b40e
[2] https://www.sourceware.org/ml/binutils/2019-12/msg00112.html

Signed-off-by: Romain Naour <romain.naour@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alan Modra <amodra@gmail.com>
Cc: Bin Meng <bin.meng@windriver.com>
Cc: Chen Zhou <chenzhou10@huawei.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: <stable@vger.kernel.org>
Link: https://marc.info/?l=linux-sh&m=158429470221261
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: annotate a data race in page_zonenum()

 BUG: KCSAN: data-race in page_cpupid_xchg_last / put_page

 write (marked) to 0xfffffc0d48ec1a00 of 8 bytes by task 91442 on cpu 3:
  page_cpupid_xchg_last+0x51/0x80
  page_cpupid_xchg_last at mm/mmzone.c:109 (discriminator 11)
  wp_page_reuse+0x3e/0xc0
  wp_page_reuse at mm/memory.c:2453
  do_wp_page+0x472/0x7b0
  do_wp_page at mm/memory.c:2798
  __handle_mm_fault+0xcb0/0xd00
  handle_pte_fault at mm/memory.c:4049
  (inlined by) __handle_mm_fault at mm/memory.c:4163
  handle_mm_fault+0xfc/0x2f0
  handle_mm_fault at mm/memory.c:4200
  do_page_fault+0x263/0x6f9
  do_user_addr_fault at arch/x86/mm/fault.c:1465
  (inlined by) do_page_fault at arch/x86/mm/fault.c:1539
  page_fault+0x34/0x40

 read to 0xfffffc0d48ec1a00 of 8 bytes by task 94817 on cpu 69:
  put_page+0x15a/0x1f0
  page_zonenum at include/linux/mm.h:923
  (inlined by) is_zone_device_page at include/linux/mm.h:929
  (inlined by) page_is_devmap_managed at include/linux/mm.h:948
  (inlined by) put_page at include/linux/mm.h:1023
  wp_page_copy+0x571/0x930
  wp_page_copy at mm/memory.c:2615
  do_wp_page+0x107/0x7b0
  __handle_mm_fault+0xcb0/0xd00
  handle_mm_fault+0xfc/0x2f0
  do_page_fault+0x263/0x6f9
  page_fault+0x34/0x40

 Reported by Kernel Concurrency Sanitizer on:
 CPU: 69 PID: 94817 Comm: systemd-udevd Tainted: G        W  O L 5.5.0-next-20200204+ #6
 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019

A page never changes its zone number. The zone number happens to be
stored in the same word as other bits which are modified, but the zone
number bits will never be modified by any other write, so it can accept
a reload of the zone bits after an intervening write and it don't need
to use READ_ONCE(). Thus, annotate this data race using
ASSERT_EXCLUSIVE_BITS() to also assert that there are no concurrent
writes to it.

Suggested-by: Marco Elver <elver@google.com>
Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Link: http://lkml.kernel.org/r/1581619089-14472-1-git-send-email-cai@lca.pw
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/swap.c: annotate data races for lru_rotate_pvecs

Read to lru_add_pvec->nr could be interrupted and then write to the same
variable.  The write has local interrupt disabled, but the plain reads
result in data races.  However, it is unlikely the compilers could do much
damage here given that lru_add_pvec->nr is a "unsigned char" and there is
an existing compiler barrier.  Thus, annotate the reads using the
data_race() macro.  The data races were reported by KCSAN,

 BUG: KCSAN: data-race in lru_add_drain_cpu / rotate_reclaimable_page

 write to 0xffff9291ebcb8a40 of 1 bytes by interrupt on cpu 23:
  rotate_reclaimable_page+0x2df/0x490
  pagevec_add at include/linux/pagevec.h:81
  (inlined by) rotate_reclaimable_page at mm/swap.c:259
  end_page_writeback+0x1b5/0x2b0
  end_swap_bio_write+0x1d0/0x280
  bio_endio+0x297/0x560
  dec_pending+0x218/0x430 [dm_mod]
  clone_endio+0xe4/0x2c0 [dm_mod]
  bio_endio+0x297/0x560
  blk_update_request+0x201/0x920
  scsi_end_request+0x6b/0x4a0
  scsi_io_completion+0xb7/0x7e0
  scsi_finish_command+0x1ed/0x2a0
  scsi_softirq_done+0x1c9/0x1d0
  blk_done_softirq+0x181/0x1d0
  __do_softirq+0xd9/0x57c
  irq_exit+0xa2/0xc0
  do_IRQ+0x8b/0x190
  ret_from_intr+0x0/0x42
  delay_tsc+0x46/0x80
  __const_udelay+0x3c/0x40
  __udelay+0x10/0x20
  kcsan_setup_watchpoint+0x202/0x3a0
  __tsan_read1+0xc2/0x100
  lru_add_drain_cpu+0xb8/0x3f0
  lru_add_drain+0x25/0x40
  shrink_active_list+0xe1/0xc80
  shrink_lruvec+0x766/0xb70
  shrink_node+0x2d6/0xca0
  do_try_to_free_pages+0x1f7/0x9a0
  try_to_free_pages+0x252/0x5b0
  __alloc_pages_slowpath+0x458/0x1290
  __alloc_pages_nodemask+0x3bb/0x450
  alloc_pages_vma+0x8a/0x2c0
  do_anonymous_page+0x16e/0x6f0
  __handle_mm_fault+0xcd5/0xd40
  handle_mm_fault+0xfc/0x2f0
  do_page_fault+0x263/0x6f9
  page_fault+0x34/0x40

 read to 0xffff9291ebcb8a40 of 1 bytes by task 37761 on cpu 23:
  lru_add_drain_cpu+0xb8/0x3f0
  lru_add_drain_cpu at mm/swap.c:602
  lru_add_drain+0x25/0x40
  shrink_active_list+0xe1/0xc80
  shrink_lruvec+0x766/0xb70
  shrink_node+0x2d6/0xca0
  do_try_to_free_pages+0x1f7/0x9a0
  try_to_free_pages+0x252/0x5b0
  __alloc_pages_slowpath+0x458/0x1290
  __alloc_pages_nodemask+0x3bb/0x450
  alloc_pages_vma+0x8a/0x2c0
  do_anonymous_page+0x16e/0x6f0
  __handle_mm_fault+0xcd5/0xd40
  handle_mm_fault+0xfc/0x2f0
  do_page_fault+0x263/0x6f9
  page_fault+0x34/0x40

 2 locks held by oom02/37761:
  #0: ffff9281e5928808 (&mm->mmap_sem#2){++++}, at: do_page_fault
  #1: ffffffffb3ade380 (fs_reclaim){+.+.}, at: fs_reclaim_acquire.part
 irq event stamp: 1949217
 trace_hardirqs_on_thunk+0x1a/0x1c
 __do_softirq+0x2e7/0x57c
 __do_softirq+0x34c/0x57c
 irq_exit+0xa2/0xc0

 Reported by Kernel Concurrency Sanitizer on:
 CPU: 23 PID: 37761 Comm: oom02 Not tainted 5.6.0-rc3-next-20200226+ #6
 Hardware name: HP ProLiant BL660c Gen9, BIOS I38 10/17/2018

Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Marco Elver <elver@google.com>
Link: http://lkml.kernel.org/r/20200228044018.1263-1-cai@lca.pw
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/rmap: annotate a data race at tlb_flush_batched

mm->tlb_flush_batched could be accessed concurrently as noticed by
KCSAN,

 BUG: KCSAN: data-race in flush_tlb_batched_pending / try_to_unmap_one

 write to 0xffff93f754880bd0 of 1 bytes by task 822 on cpu 6:
  try_to_unmap_one+0x59a/0x1ab0
  set_tlb_ubc_flush_pending at mm/rmap.c:635
  (inlined by) try_to_unmap_one at mm/rmap.c:1538
  rmap_walk_anon+0x296/0x650
  rmap_walk+0xdf/0x100
  try_to_unmap+0x18a/0x2f0
  shrink_page_list+0xef6/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  balance_pgdat+0x652/0xd90
  kswapd+0x396/0x8d0
  kthread+0x1e0/0x200
  ret_from_fork+0x27/0x50

 read to 0xffff93f754880bd0 of 1 bytes by task 6364 on cpu 4:
  flush_tlb_batched_pending+0x29/0x90
  flush_tlb_batched_pending at mm/rmap.c:682
  change_p4d_range+0x5dd/0x1030
  change_pte_range at mm/mprotect.c:44
  (inlined by) change_pmd_range at mm/mprotect.c:212
  (inlined by) change_pud_range at mm/mprotect.c:240
  (inlined by) change_p4d_range at mm/mprotect.c:260
  change_protection+0x222/0x310
  change_prot_numa+0x3e/0x60
  task_numa_work+0x219/0x350
  task_work_run+0xed/0x140
  prepare_exit_to_usermode+0x2cc/0x2e0
  ret_from_intr+0x32/0x42

 Reported by Kernel Concurrency Sanitizer on:
 CPU: 4 PID: 6364 Comm: mtest01 Tainted: G        W    L 5.5.0-next-20200210+ #5
 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019

flush_tlb_batched_pending() is under PTL but the write is not, but
mm->tlb_flush_batched is only a bool type, so the value is unlikely to be
shattered.  Thus, mark it as an intentional data race by using the data
race macro.

Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Marco Elver <elver@google.com>
Link: http://lkml.kernel.org/r/1581450783-8262-1-git-send-email-cai@lca.pw
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/mempool: fix a data race in mempool_free()

mempool_t pool.curr_nr could be accessed concurrently as noticed by
KCSAN,

 BUG: KCSAN: data-race in mempool_free / remove_element

 write to 0xffffffffa937638c of 4 bytes by task 6359 on cpu 113:
  remove_element+0x4a/0x1c0
  remove_element at mm/mempool.c:132
  mempool_alloc+0x102/0x210
  (inlined by) mempool_alloc at mm/mempool.c:399
  bio_alloc_bioset+0x106/0x2c0
  get_swap_bio+0x49/0x230
  __swap_writepage+0x680/0xc30
  swap_writepage+0x9c/0xf0
  pageout+0x33e/0xae0
  shrink_page_list+0x1f57/0x2870
  shrink_inactive_list+0x316/0x880
  shrink_lruvec+0x8dc/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290
  <snip>

 read to 0xffffffffa937638c of 4 bytes by interrupt on cpu 64:
  mempool_free+0x3e/0x150
  mempool_free at mm/mempool.c:492
  bio_free+0x192/0x280
  bio_put+0x91/0xd0
  end_swap_bio_write+0x1d8/0x280
  bio_endio+0x2c2/0x5b0
  dec_pending+0x22b/0x440 [dm_mod]
  clone_endio+0xe4/0x2c0 [dm_mod]
  bio_endio+0x2c2/0x5b0
  blk_update_request+0x217/0x940
  scsi_end_request+0x6b/0x4d0
  scsi_io_completion+0xb7/0x7e0
  scsi_finish_command+0x223/0x310
  scsi_softirq_done+0x1d5/0x210
  blk_mq_complete_request+0x224/0x250
  scsi_mq_done+0xc2/0x250
  pqi_raid_io_complete+0x5a/0x70 [smartpqi]
  pqi_irq_handler+0x150/0x1410 [smartpqi]
  __handle_irq_event_percpu+0x90/0x540
  handle_irq_event_percpu+0x49/0xd0
  handle_irq_event+0x85/0xca
  handle_edge_irq+0x13f/0x3e0
  do_IRQ+0x86/0x190
  <snip>

Since the write is under pool->lock but the read is done as lockless.
Even though the commit 5b990546e334 ("mempool: fix and document
synchronization and memory barrier usage") introduced the smp_wmb() and
smp_rmb() pair to improve the situation, it is adequate to protect it
from data races which could lead to a logic bug, so fix it by adding
READ_ONCE() for the read.

Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Marco Elver <elver@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Link: http://lkml.kernel.org/r/1581446384-2131-1-git-send-email-cai@lca.pw
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/list_lru: fix a data race in list_lru_count_one

struct list_lru_one l.nr_items could be accessed concurrently as noticed
by KCSAN,

 BUG: KCSAN: data-race in list_lru_count_one / list_lru_isolate_move

 write to 0xffffa102789c4510 of 8 bytes by task 823 on cpu 39:
  list_lru_isolate_move+0xf9/0x130
  list_lru_isolate_move at mm/list_lru.c:180
  inode_lru_isolate+0x12b/0x2a0
  __list_lru_walk_one+0x122/0x3d0
  list_lru_walk_one+0x75/0xa0
  prune_icache_sb+0x8b/0xc0
  super_cache_scan+0x1b8/0x250
  do_shrink_slab+0x256/0x6d0
  shrink_slab+0x41b/0x4a0
  shrink_node+0x35c/0xd80
  balance_pgdat+0x652/0xd90
  kswapd+0x396/0x8d0
  kthread+0x1e0/0x200
  ret_from_fork+0x27/0x50

 read to 0xffffa102789c4510 of 8 bytes by task 6345 on cpu 56:
  list_lru_count_one+0x116/0x2f0
  list_lru_count_one at mm/list_lru.c:193
  super_cache_count+0xe8/0x170
  do_shrink_slab+0x95/0x6d0
  shrink_slab+0x41b/0x4a0
  shrink_node+0x35c/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290
  __alloc_pages_nodemask+0x3bb/0x450
  alloc_pages_vma+0x8a/0x2c0
  do_anonymous_page+0x170/0x700
  __handle_mm_fault+0xc9f/0xd00
  handle_mm_fault+0xfc/0x2f0
  do_page_fault+0x263/0x6f9
  page_fault+0x34/0x40

 Reported by Kernel Concurrency Sanitizer on:
 CPU: 56 PID: 6345 Comm: oom01 Tainted: G        W    L 5.5.0-next-20200205+ #4
 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019

A shattered l.nr_items could affect the shrinker behaviour due to a data
race. Fix it by adding READ_ONCE() for the read. Since the writes are
aligned and up to word-size, assume those are safe from data races to
avoid readability issues of writing WRITE_ONCE(var, var + val).

Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Marco Elver <elver@google.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Link: http://lkml.kernel.org/r/1581114679-5488-1-git-send-email-cai@lca.pw
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/memcontrol: fix a data race in scan count

struct mem_cgroup_per_node mz.lru_zone_size[zone_idx][lru] could be
accessed concurrently as noticed by KCSAN,

 BUG: KCSAN: data-race in lruvec_lru_size / mem_cgroup_update_lru_size

 write to 0xffff9c804ca285f8 of 8 bytes by task 50951 on cpu 12:
  mem_cgroup_update_lru_size+0x11c/0x1d0
  mem_cgroup_update_lru_size at mm/memcontrol.c:1266
  isolate_lru_pages+0x6a9/0xf30
  shrink_active_list+0x123/0xcc0
  shrink_lruvec+0x8fd/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290
  __alloc_pages_nodemask+0x3bb/0x450
  alloc_pages_vma+0x8a/0x2c0
  do_anonymous_page+0x170/0x700
  __handle_mm_fault+0xc9f/0xd00
  handle_mm_fault+0xfc/0x2f0
  do_page_fault+0x263/0x6f9
  page_fault+0x34/0x40

 read to 0xffff9c804ca285f8 of 8 bytes by task 50964 on cpu 95:
  lruvec_lru_size+0xbb/0x270
  mem_cgroup_get_zone_lru_size at include/linux/memcontrol.h:536
  (inlined by) lruvec_lru_size at mm/vmscan.c:326
  shrink_lruvec+0x1d0/0x1380
  shrink_node+0x317/0xd80
  do_try_to_free_pages+0x1f7/0xa10
  try_to_free_pages+0x26c/0x5e0
  __alloc_pages_slowpath+0x458/0x1290
  __alloc_pages_nodemask+0x3bb/0x450
  alloc_pages_current+0xa6/0x120
  alloc_slab_page+0x3b1/0x540
  allocate_slab+0x70/0x660
  new_slab+0x46/0x70
  ___slab_alloc+0x4ad/0x7d0
  __slab_alloc+0x43/0x70
  kmem_cache_alloc+0x2c3/0x420
  getname_flags+0x4c/0x230
  getname+0x22/0x30
  do_sys_openat2+0x205/0x3b0
  do_sys_open+0x9a/0xf0
  __x64_sys_openat+0x62/0x80
  do_syscall_64+0x91/0xb47
  entry_SYSCALL_64_after_hwframe+0x49/0xbe

 Reported by Kernel Concurrency Sanitizer on:
 CPU: 95 PID: 50964 Comm: cc1 Tainted: G        W  O L    5.5.0-next-20200204+ #6
 Hardware name: HPE ProLiant DL385 Gen10/ProLiant DL385 Gen10, BIOS A40 07/10/2019

The write is under lru_lock, but the read is done as lockless.  The scan
count is used to determine how aggressively the anon and file LRU lists
should be scanned.  Load tearing could generate an inefficient heuristic,
so fix it by adding READ_ONCE() for the read.

Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Link: http://lkml.kernel.org/r/20200206034945.2481-1-cai@lca.pw
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>