<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/perf, branch v6.1.78</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>perf: hisi: Fix use-after-free when register pmu fails</title>
<updated>2023-11-20T10:52:01+00:00</updated>
<author>
<name>Junhao He</name>
<email>hejunhao3@huawei.com</email>
</author>
<published>2023-10-24T11:36:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b660420f449d094b1fabfa504889810b3a63cdd5'/>
<id>b660420f449d094b1fabfa504889810b3a63cdd5</id>
<content type='text'>
[ Upstream commit b805cafc604bfdb671fae7347a57f51154afa735 ]

When we fail to register the uncore pmu, the pmu context may not been
allocated. The error handing will call cpuhp_state_remove_instance()
to call uncore pmu offline callback, which migrate the pmu context.
Since that's liable to lead to some kind of use-after-free.

Use cpuhp_state_remove_instance_nocalls() instead of
cpuhp_state_remove_instance() so that the notifiers don't execute after
the PMU device has been failed to register.

Fixes: a0ab25cd82ee ("drivers/perf: hisi: Add support for HiSilicon PA PMU driver")
FIxes: 3bf30882c3c7 ("drivers/perf: hisi: Add support for HiSilicon SLLC PMU driver")
Signed-off-by: Junhao He &lt;hejunhao3@huawei.com&gt;
Link: https://lore.kernel.org/r/20231024113630.13472-1-hejunhao3@huawei.com
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit b805cafc604bfdb671fae7347a57f51154afa735 ]

When we fail to register the uncore pmu, the pmu context may not been
allocated. The error handing will call cpuhp_state_remove_instance()
to call uncore pmu offline callback, which migrate the pmu context.
Since that's liable to lead to some kind of use-after-free.

Use cpuhp_state_remove_instance_nocalls() instead of
cpuhp_state_remove_instance() so that the notifiers don't execute after
the PMU device has been failed to register.

Fixes: a0ab25cd82ee ("drivers/perf: hisi: Add support for HiSilicon PA PMU driver")
FIxes: 3bf30882c3c7 ("drivers/perf: hisi: Add support for HiSilicon SLLC PMU driver")
Signed-off-by: Junhao He &lt;hejunhao3@huawei.com&gt;
Link: https://lore.kernel.org/r/20231024113630.13472-1-hejunhao3@huawei.com
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drivers/perf: hisi_pcie: Check the type first in pmu::event_init()</title>
<updated>2023-11-20T10:52:01+00:00</updated>
<author>
<name>Yicong Yang</name>
<email>yangyicong@hisilicon.com</email>
</author>
<published>2023-10-24T09:29:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=104fa6426a8fe9c38113bb58fd1cd526bf4d39d6'/>
<id>104fa6426a8fe9c38113bb58fd1cd526bf4d39d6</id>
<content type='text'>
[ Upstream commit 6d7d51e88e21c0af1ca96a3617afef334bfeffcf ]

Check whether the event type matches the PMU type firstly in
pmu::event_init() before touching the event. Otherwise we'll
change the events of others and lead to incorrect results.
Since in perf_init_event() we may call every pmu's event_init()
in a certain case, we should not modify the event if it's not
ours.

Fixes: 8404b0fbc7fb ("drivers/perf: hisi: Add driver for HiSilicon PCIe PMU")
Signed-off-by: Yicong Yang &lt;yangyicong@hisilicon.com&gt;
Link: https://lore.kernel.org/r/20231024092954.42297-2-yangyicong@huawei.com
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 6d7d51e88e21c0af1ca96a3617afef334bfeffcf ]

Check whether the event type matches the PMU type firstly in
pmu::event_init() before touching the event. Otherwise we'll
change the events of others and lead to incorrect results.
Since in perf_init_event() we may call every pmu's event_init()
in a certain case, we should not modify the event if it's not
ours.

Fixes: 8404b0fbc7fb ("drivers/perf: hisi: Add driver for HiSilicon PCIe PMU")
Signed-off-by: Yicong Yang &lt;yangyicong@hisilicon.com&gt;
Link: https://lore.kernel.org/r/20231024092954.42297-2-yangyicong@huawei.com
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf/arm-cmn: Fix DTC domain detection</title>
<updated>2023-11-20T10:52:01+00:00</updated>
<author>
<name>Robin Murphy</name>
<email>robin.murphy@arm.com</email>
</author>
<published>2023-10-20T17:51:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c6e00bc30ea105e4958709d7510384441556559c'/>
<id>c6e00bc30ea105e4958709d7510384441556559c</id>
<content type='text'>
[ Upstream commit e3e73f511c49c741f6309862c2248958ad77bbaa ]

It transpires that dtm_unit_info is another register which got shuffled
in CMN-700 without me noticing. Fix that in a way which also proactively
fixes the fragile laziness of its consumer, just in case any further
fields ever get added alongside dtc_domain.

Fixes: 23760a014417 ("perf/arm-cmn: Add CMN-700 support")
Signed-off-by: Robin Murphy &lt;robin.murphy@arm.com&gt;
Reviewed-by: Ilkka Koskinen &lt;ilkka@os.amperecomputing.com&gt;
Link: https://lore.kernel.org/r/3076ee83d0554f6939fbb6ee49ab2bdb28d8c7ee.1697824215.git.robin.murphy@arm.com
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit e3e73f511c49c741f6309862c2248958ad77bbaa ]

It transpires that dtm_unit_info is another register which got shuffled
in CMN-700 without me noticing. Fix that in a way which also proactively
fixes the fragile laziness of its consumer, just in case any further
fields ever get added alongside dtc_domain.

Fixes: 23760a014417 ("perf/arm-cmn: Add CMN-700 support")
Signed-off-by: Robin Murphy &lt;robin.murphy@arm.com&gt;
Reviewed-by: Ilkka Koskinen &lt;ilkka@os.amperecomputing.com&gt;
Link: https://lore.kernel.org/r/3076ee83d0554f6939fbb6ee49ab2bdb28d8c7ee.1697824215.git.robin.murphy@arm.com
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf/arm-cmn: Revamp model detection</title>
<updated>2023-11-20T10:52:01+00:00</updated>
<author>
<name>Robin Murphy</name>
<email>robin.murphy@arm.com</email>
</author>
<published>2023-06-12T17:16:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=28fa550a49e818d6445e787f584759b1bf21d9d4'/>
<id>28fa550a49e818d6445e787f584759b1bf21d9d4</id>
<content type='text'>
[ Upstream commit 7819e05a0dceac20c5ff78ec9b252faf3b76b824 ]

CMN implements a set of CoreSight-format peripheral ID registers which
in principle we should be able to use to identify the hardware. However
so far we have avoided trying to use the part number field since the
TRMs have all described it as "configuration dependent". It turns out,
though, that this is a quirk of the documentation generation process,
and in fact the part number should always be a stable well-defined field
which we can trust.

To that end, revamp our model detection to rely less on ACPI/DT, and
pave the way towards further using the hardware information as an
identifier for userspace jevent metrics. This includes renaming the
revision constants to maximise readability.

Signed-off-by: Robin Murphy &lt;robin.murphy@arm.com&gt;
Reviewed-and-tested-by: Ilkka Koskinen &lt;ilkka@os.amperecomputing.com&gt;
Link: https://lore.kernel.org/r/3c791eaae814b0126f9adbd5419bfb4a600dade7.1686588640.git.robin.murphy@arm.com
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
Stable-dep-of: e3e73f511c49 ("perf/arm-cmn: Fix DTC domain detection")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 7819e05a0dceac20c5ff78ec9b252faf3b76b824 ]

CMN implements a set of CoreSight-format peripheral ID registers which
in principle we should be able to use to identify the hardware. However
so far we have avoided trying to use the part number field since the
TRMs have all described it as "configuration dependent". It turns out,
though, that this is a quirk of the documentation generation process,
and in fact the part number should always be a stable well-defined field
which we can trust.

To that end, revamp our model detection to rely less on ACPI/DT, and
pave the way towards further using the hardware information as an
identifier for userspace jevent metrics. This includes renaming the
revision constants to maximise readability.

Signed-off-by: Robin Murphy &lt;robin.murphy@arm.com&gt;
Reviewed-and-tested-by: Ilkka Koskinen &lt;ilkka@os.amperecomputing.com&gt;
Link: https://lore.kernel.org/r/3c791eaae814b0126f9adbd5419bfb4a600dade7.1686588640.git.robin.murphy@arm.com
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
Stable-dep-of: e3e73f511c49 ("perf/arm-cmn: Fix DTC domain detection")
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>drivers/perf: hisi: use cpuhp_state_remove_instance_nocalls() for hisi_hns3_pmu uninit process</title>
<updated>2023-11-20T10:52:01+00:00</updated>
<author>
<name>Hao Chen</name>
<email>chenhao418@huawei.com</email>
</author>
<published>2023-10-19T09:13:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4589403a343bb0c72a6faf5898386ff964d4e01a'/>
<id>4589403a343bb0c72a6faf5898386ff964d4e01a</id>
<content type='text'>
[ Upstream commit 50b560783f7f71790bcf70e9e9855155fb0af8c1 ]

When tearing down a 'hisi_hns3' PMU, we mistakenly run the CPU hotplug
callbacks after the device has been unregistered, leading to fireworks
when we try to execute empty function callbacks within the driver:

  | Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
  | CPU: 0 PID: 15 Comm: cpuhp/0 Tainted: G        W  O      5.12.0-rc4+ #1
  | Hardware name:  , BIOS KpxxxFPGA 1P B600 V143 04/22/2021
  | pstate: 80400009 (Nzcv daif +PAN -UAO -TCO BTYPE=--)
  | pc : perf_pmu_migrate_context+0x98/0x38c
  | lr : perf_pmu_migrate_context+0x94/0x38c
  |
  | Call trace:
  |  perf_pmu_migrate_context+0x98/0x38c
  |  hisi_hns3_pmu_offline_cpu+0x104/0x12c [hisi_hns3_pmu]

Use cpuhp_state_remove_instance_nocalls() instead of
cpuhp_state_remove_instance() so that the notifiers don't execute after
the PMU device has been unregistered.

Fixes: 66637ab137b4 ("drivers/perf: hisi: add driver for HNS3 PMU")
Signed-off-by: Hao Chen &lt;chenhao418@huawei.com&gt;
Signed-off-by: Jijie Shao &lt;shaojijie@huawei.com&gt;
Reviewed-by: Yicong Yang &lt;yangyicong@hisilicon.com&gt;
Link: https://lore.kernel.org/r/20231019091352.998964-1-shaojijie@huawei.com
[will: Rewrote commit message]
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 50b560783f7f71790bcf70e9e9855155fb0af8c1 ]

When tearing down a 'hisi_hns3' PMU, we mistakenly run the CPU hotplug
callbacks after the device has been unregistered, leading to fireworks
when we try to execute empty function callbacks within the driver:

  | Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
  | CPU: 0 PID: 15 Comm: cpuhp/0 Tainted: G        W  O      5.12.0-rc4+ #1
  | Hardware name:  , BIOS KpxxxFPGA 1P B600 V143 04/22/2021
  | pstate: 80400009 (Nzcv daif +PAN -UAO -TCO BTYPE=--)
  | pc : perf_pmu_migrate_context+0x98/0x38c
  | lr : perf_pmu_migrate_context+0x94/0x38c
  |
  | Call trace:
  |  perf_pmu_migrate_context+0x98/0x38c
  |  hisi_hns3_pmu_offline_cpu+0x104/0x12c [hisi_hns3_pmu]

Use cpuhp_state_remove_instance_nocalls() instead of
cpuhp_state_remove_instance() so that the notifiers don't execute after
the PMU device has been unregistered.

Fixes: 66637ab137b4 ("drivers/perf: hisi: add driver for HNS3 PMU")
Signed-off-by: Hao Chen &lt;chenhao418@huawei.com&gt;
Signed-off-by: Jijie Shao &lt;shaojijie@huawei.com&gt;
Reviewed-by: Yicong Yang &lt;yangyicong@hisilicon.com&gt;
Link: https://lore.kernel.org/r/20231019091352.998964-1-shaojijie@huawei.com
[will: Rewrote commit message]
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf/arm-cmn: Fix the unhandled overflow status of counter 4 to 7</title>
<updated>2023-10-19T21:08:50+00:00</updated>
<author>
<name>Jing Zhang</name>
<email>renyu.zj@linux.alibaba.com</email>
</author>
<published>2023-09-25T03:22:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1c8f6c7b837568e755cebe325d56c90759035b24'/>
<id>1c8f6c7b837568e755cebe325d56c90759035b24</id>
<content type='text'>
[ Upstream commit 7f949f6f54ff593123ab95b6247bfa4542a65580 ]

The register por_dt_pmovsr Bits[7:0] indicates overflow from counters 7
to 0. But in arm_cmn_handle_irq(), only handled the overflow status of
Bits[3:0] which results in unhandled overflow status of counters 4 to 7.

So let the overflow status of DTC counters 4 to 7 to be handled.

Fixes: 0ba64770a2f2 ("perf: Add Arm CMN-600 PMU driver")
Signed-off-by: Jing Zhang &lt;renyu.zj@linux.alibaba.com&gt;
Reviewed-by: Robin Murphy &lt;robin.murphy@arm.com&gt;
Link: https://lore.kernel.org/r/1695612152-123633-1-git-send-email-renyu.zj@linux.alibaba.com
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 7f949f6f54ff593123ab95b6247bfa4542a65580 ]

The register por_dt_pmovsr Bits[7:0] indicates overflow from counters 7
to 0. But in arm_cmn_handle_irq(), only handled the overflow status of
Bits[3:0] which results in unhandled overflow status of counters 4 to 7.

So let the overflow status of DTC counters 4 to 7 to be handled.

Fixes: 0ba64770a2f2 ("perf: Add Arm CMN-600 PMU driver")
Signed-off-by: Jing Zhang &lt;renyu.zj@linux.alibaba.com&gt;
Reviewed-by: Robin Murphy &lt;robin.murphy@arm.com&gt;
Link: https://lore.kernel.org/r/1695612152-123633-1-git-send-email-renyu.zj@linux.alibaba.com
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf/imx_ddr: speed up overflow frequency of cycle</title>
<updated>2023-09-23T09:11:00+00:00</updated>
<author>
<name>Xu Yang</name>
<email>xu.yang_2@nxp.com</email>
</author>
<published>2023-08-11T01:54:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d42d342d313206ef0d08d72311b5d86c72a1756e'/>
<id>d42d342d313206ef0d08d72311b5d86c72a1756e</id>
<content type='text'>
[ Upstream commit e89ecd8368860bf05437eabd07d292c316221cfc ]

For i.MX8MP, we cannot ensure that cycle counter overflow occurs at least
4 times as often as other events. Due to byte counters will count for any
event configured, it will overflow more often. And if byte counters
overflow that related counters would stop since they share the
COUNTER_CNTL. We can speed up cycle counter overflow frequency by setting
counter parameter (CP) field of cycle counter. In this way, we can avoid
stop counting byte counters when interrupt didn't come and the byte
counters can be fetched or updated from each cycle counter overflow
interrupt.

Because we initialize CP filed to shorten counter0 overflow time, the cycle
counter will start couting from a fixed/base value each time. We need to
remove the base from the result too. Therefore, we could get precise result
from cycle counter.

Signed-off-by: Xu Yang &lt;xu.yang_2@nxp.com&gt;
Reviewed-by: Frank Li &lt;Frank.Li@nxp.com&gt;
Link: https://lore.kernel.org/r/20230811015438.1999307-1-xu.yang_2@nxp.com
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit e89ecd8368860bf05437eabd07d292c316221cfc ]

For i.MX8MP, we cannot ensure that cycle counter overflow occurs at least
4 times as often as other events. Due to byte counters will count for any
event configured, it will overflow more often. And if byte counters
overflow that related counters would stop since they share the
COUNTER_CNTL. We can speed up cycle counter overflow frequency by setting
counter parameter (CP) field of cycle counter. In this way, we can avoid
stop counting byte counters when interrupt didn't come and the byte
counters can be fetched or updated from each cycle counter overflow
interrupt.

Because we initialize CP filed to shorten counter0 overflow time, the cycle
counter will start couting from a fixed/base value each time. We need to
remove the base from the result too. Therefore, we could get precise result
from cycle counter.

Signed-off-by: Xu Yang &lt;xu.yang_2@nxp.com&gt;
Reviewed-by: Frank Li &lt;Frank.Li@nxp.com&gt;
Link: https://lore.kernel.org/r/20230811015438.1999307-1-xu.yang_2@nxp.com
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf/smmuv3: Enable HiSilicon Erratum 162001900 quirk for HIP08/09</title>
<updated>2023-09-23T09:11:00+00:00</updated>
<author>
<name>Yicong Yang</name>
<email>yangyicong@hisilicon.com</email>
</author>
<published>2023-08-14T12:40:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9d9b5cbc12f49fbdbbc454383981039005af8211'/>
<id>9d9b5cbc12f49fbdbbc454383981039005af8211</id>
<content type='text'>
[ Upstream commit 0242737dc4eb9f6e9a5ea594b3f93efa0b12f28d ]

Some HiSilicon SMMU PMCG suffers the erratum 162001900 that the PMU
disable control sometimes fail to disable the counters. This will lead
to error or inaccurate data since before we enable the counters the
counter's still counting for the event used in last perf session.

This patch tries to fix this by hardening the global disable process.
Before disable the PMU, writing an invalid event type (0xffff) to
focibly stop the counters. Correspondingly restore each events on
pmu::pmu_enable().

Signed-off-by: Yicong Yang &lt;yangyicong@hisilicon.com&gt;
Link: https://lore.kernel.org/r/20230814124012.58013-1-yangyicong@huawei.com
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 0242737dc4eb9f6e9a5ea594b3f93efa0b12f28d ]

Some HiSilicon SMMU PMCG suffers the erratum 162001900 that the PMU
disable control sometimes fail to disable the counters. This will lead
to error or inaccurate data since before we enable the counters the
counter's still counting for the event used in last perf session.

This patch tries to fix this by hardening the global disable process.
Before disable the PMU, writing an invalid event type (0xffff) to
focibly stop the counters. Correspondingly restore each events on
pmu::pmu_enable().

Signed-off-by: Yicong Yang &lt;yangyicong@hisilicon.com&gt;
Link: https://lore.kernel.org/r/20230814124012.58013-1-yangyicong@huawei.com
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf/imx_ddr: don't enable counter0 if none of 4 counters are used</title>
<updated>2023-09-13T07:42:29+00:00</updated>
<author>
<name>Xu Yang</name>
<email>xu.yang_2@nxp.com</email>
</author>
<published>2023-08-11T01:54:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=048d1a8b9da8d4d36ae4b092342740f08bb7346a'/>
<id>048d1a8b9da8d4d36ae4b092342740f08bb7346a</id>
<content type='text'>
[ Upstream commit f4e2bd91ddf5e8543cbe7ad80b3fba3d2dc63fa3 ]

In current driver, counter0 will be enabled after ddr_perf_pmu_enable()
is called even though none of the 4 counters are used. This will cause
counter0 continue to count until ddr_perf_pmu_disabled() is called. If
pmu is not disabled all the time, the pmu interrupt will be asserted
from time to time due to counter0 will overflow and irq handler will
clear it. It's not an expected behavior. This patch will not enable
counter0 if none of 4 counters are used.

Fixes: 9a66d36cc7ac ("drivers/perf: imx_ddr: Add DDR performance counter support to perf")
Signed-off-by: Xu Yang &lt;xu.yang_2@nxp.com&gt;
Reviewed-by: Frank Li &lt;Frank.Li@nxp.com&gt;
Link: https://lore.kernel.org/r/20230811015438.1999307-2-xu.yang_2@nxp.com
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit f4e2bd91ddf5e8543cbe7ad80b3fba3d2dc63fa3 ]

In current driver, counter0 will be enabled after ddr_perf_pmu_enable()
is called even though none of the 4 counters are used. This will cause
counter0 continue to count until ddr_perf_pmu_disabled() is called. If
pmu is not disabled all the time, the pmu interrupt will be asserted
from time to time due to counter0 will overflow and irq handler will
clear it. It's not an expected behavior. This patch will not enable
counter0 if none of 4 counters are used.

Fixes: 9a66d36cc7ac ("drivers/perf: imx_ddr: Add DDR performance counter support to perf")
Signed-off-by: Xu Yang &lt;xu.yang_2@nxp.com&gt;
Reviewed-by: Frank Li &lt;Frank.Li@nxp.com&gt;
Link: https://lore.kernel.org/r/20230811015438.1999307-2-xu.yang_2@nxp.com
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf: RISC-V: Remove PERF_HES_STOPPED flag checking in riscv_pmu_start()</title>
<updated>2023-07-23T11:49:44+00:00</updated>
<author>
<name>Eric Lin</name>
<email>eric.lin@sifive.com</email>
</author>
<published>2023-07-10T15:43:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=aeb62beaf9cbd0a72e7f97c9af6d3e7f76ce2946'/>
<id>aeb62beaf9cbd0a72e7f97c9af6d3e7f76ce2946</id>
<content type='text'>
commit 66843b14fb71825fdd73ab12f6594f2243b402be upstream.

Since commit 096b52fd2bb4 ("perf: RISC-V: throttle perf events") the
perf_sample_event_took() function was added to report time spent in
overflow interrupts. If the interrupt takes too long, the perf framework
will lower the sysctl_perf_event_sample_rate and max_samples_per_tick.
When hwc-&gt;interrupts is larger than max_samples_per_tick, the
hwc-&gt;interrupts will be set to MAX_INTERRUPTS, and events will be
throttled within the __perf_event_account_interrupt() function.

However, the RISC-V PMU driver doesn't call riscv_pmu_stop() to update the
PERF_HES_STOPPED flag after perf_event_overflow() in pmu_sbi_ovf_handler()
function to avoid throttling. When the perf framework unthrottled the event
in the timer interrupt handler, it triggers riscv_pmu_start() function
and causes a WARN_ON_ONCE() warning, as shown below:

 ------------[ cut here ]------------
 WARNING: CPU: 0 PID: 240 at drivers/perf/riscv_pmu.c:184 riscv_pmu_start+0x7c/0x8e
 Modules linked in:
 CPU: 0 PID: 240 Comm: ls Not tainted 6.4-rc4-g19d0788e9ef2 #1
 Hardware name: SiFive (DT)
 epc : riscv_pmu_start+0x7c/0x8e
  ra : riscv_pmu_start+0x28/0x8e
 epc : ffffffff80aef864 ra : ffffffff80aef810 sp : ffff8f80004db6f0
  gp : ffffffff81c83750 tp : ffffaf80069f9bc0 t0 : ffff8f80004db6c0
  t1 : 0000000000000000 t2 : 000000000000001f s0 : ffff8f80004db720
  s1 : ffffaf8008ca1068 a0 : 0000ffffffffffff a1 : 0000000000000000
  a2 : 0000000000000001 a3 : 0000000000000870 a4 : 0000000000000000
  a5 : 0000000000000000 a6 : 0000000000000840 a7 : 0000000000000030
  s2 : 0000000000000000 s3 : ffffaf8005165800 s4 : ffffaf800424da00
  s5 : ffffffffffffffff s6 : ffffffff81cc7590 s7 : 0000000000000000
  s8 : 0000000000000006 s9 : 0000000000000001 s10: ffffaf807efbc340
  s11: ffffaf807efbbf00 t3 : ffffaf8006a16028 t4 : 00000000dbfbb796
  t5 : 0000000700000000 t6 : ffffaf8005269870
 status: 0000000200000100 badaddr: 0000000000000000 cause: 0000000000000003
 [&lt;ffffffff80aef864&gt;] riscv_pmu_start+0x7c/0x8e
 [&lt;ffffffff80185b56&gt;] perf_adjust_freq_unthr_context+0x15e/0x174
 [&lt;ffffffff80188642&gt;] perf_event_task_tick+0x88/0x9c
 [&lt;ffffffff800626a8&gt;] scheduler_tick+0xfe/0x27c
 [&lt;ffffffff800b5640&gt;] update_process_times+0x9a/0xba
 [&lt;ffffffff800c5bd4&gt;] tick_sched_handle+0x32/0x66
 [&lt;ffffffff800c5e0c&gt;] tick_sched_timer+0x64/0xb0
 [&lt;ffffffff800b5e50&gt;] __hrtimer_run_queues+0x156/0x2f4
 [&lt;ffffffff800b6bdc&gt;] hrtimer_interrupt+0xe2/0x1fe
 [&lt;ffffffff80acc9e8&gt;] riscv_timer_interrupt+0x38/0x42
 [&lt;ffffffff80090a16&gt;] handle_percpu_devid_irq+0x90/0x1d2
 [&lt;ffffffff8008a9f4&gt;] generic_handle_domain_irq+0x28/0x36

After referring other PMU drivers like Arm, Loongarch, Csky, and Mips,
they don't call *_pmu_stop() to update with PERF_HES_STOPPED flag
after perf_event_overflow() function nor do they add PERF_HES_STOPPED
flag checking in *_pmu_start() which don't cause this warning.

Thus, it's recommended to remove this unnecessary check in
riscv_pmu_start() function to prevent this warning.

Signed-off-by: Eric Lin &lt;eric.lin@sifive.com&gt;
Link: https://lore.kernel.org/r/20230710154328.19574-1-eric.lin@sifive.com
Fixes: 096b52fd2bb4 ("perf: RISC-V: throttle perf events")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 66843b14fb71825fdd73ab12f6594f2243b402be upstream.

Since commit 096b52fd2bb4 ("perf: RISC-V: throttle perf events") the
perf_sample_event_took() function was added to report time spent in
overflow interrupts. If the interrupt takes too long, the perf framework
will lower the sysctl_perf_event_sample_rate and max_samples_per_tick.
When hwc-&gt;interrupts is larger than max_samples_per_tick, the
hwc-&gt;interrupts will be set to MAX_INTERRUPTS, and events will be
throttled within the __perf_event_account_interrupt() function.

However, the RISC-V PMU driver doesn't call riscv_pmu_stop() to update the
PERF_HES_STOPPED flag after perf_event_overflow() in pmu_sbi_ovf_handler()
function to avoid throttling. When the perf framework unthrottled the event
in the timer interrupt handler, it triggers riscv_pmu_start() function
and causes a WARN_ON_ONCE() warning, as shown below:

 ------------[ cut here ]------------
 WARNING: CPU: 0 PID: 240 at drivers/perf/riscv_pmu.c:184 riscv_pmu_start+0x7c/0x8e
 Modules linked in:
 CPU: 0 PID: 240 Comm: ls Not tainted 6.4-rc4-g19d0788e9ef2 #1
 Hardware name: SiFive (DT)
 epc : riscv_pmu_start+0x7c/0x8e
  ra : riscv_pmu_start+0x28/0x8e
 epc : ffffffff80aef864 ra : ffffffff80aef810 sp : ffff8f80004db6f0
  gp : ffffffff81c83750 tp : ffffaf80069f9bc0 t0 : ffff8f80004db6c0
  t1 : 0000000000000000 t2 : 000000000000001f s0 : ffff8f80004db720
  s1 : ffffaf8008ca1068 a0 : 0000ffffffffffff a1 : 0000000000000000
  a2 : 0000000000000001 a3 : 0000000000000870 a4 : 0000000000000000
  a5 : 0000000000000000 a6 : 0000000000000840 a7 : 0000000000000030
  s2 : 0000000000000000 s3 : ffffaf8005165800 s4 : ffffaf800424da00
  s5 : ffffffffffffffff s6 : ffffffff81cc7590 s7 : 0000000000000000
  s8 : 0000000000000006 s9 : 0000000000000001 s10: ffffaf807efbc340
  s11: ffffaf807efbbf00 t3 : ffffaf8006a16028 t4 : 00000000dbfbb796
  t5 : 0000000700000000 t6 : ffffaf8005269870
 status: 0000000200000100 badaddr: 0000000000000000 cause: 0000000000000003
 [&lt;ffffffff80aef864&gt;] riscv_pmu_start+0x7c/0x8e
 [&lt;ffffffff80185b56&gt;] perf_adjust_freq_unthr_context+0x15e/0x174
 [&lt;ffffffff80188642&gt;] perf_event_task_tick+0x88/0x9c
 [&lt;ffffffff800626a8&gt;] scheduler_tick+0xfe/0x27c
 [&lt;ffffffff800b5640&gt;] update_process_times+0x9a/0xba
 [&lt;ffffffff800c5bd4&gt;] tick_sched_handle+0x32/0x66
 [&lt;ffffffff800c5e0c&gt;] tick_sched_timer+0x64/0xb0
 [&lt;ffffffff800b5e50&gt;] __hrtimer_run_queues+0x156/0x2f4
 [&lt;ffffffff800b6bdc&gt;] hrtimer_interrupt+0xe2/0x1fe
 [&lt;ffffffff80acc9e8&gt;] riscv_timer_interrupt+0x38/0x42
 [&lt;ffffffff80090a16&gt;] handle_percpu_devid_irq+0x90/0x1d2
 [&lt;ffffffff8008a9f4&gt;] generic_handle_domain_irq+0x28/0x36

After referring other PMU drivers like Arm, Loongarch, Csky, and Mips,
they don't call *_pmu_stop() to update with PERF_HES_STOPPED flag
after perf_event_overflow() function nor do they add PERF_HES_STOPPED
flag checking in *_pmu_start() which don't cause this warning.

Thus, it's recommended to remove this unnecessary check in
riscv_pmu_start() function to prevent this warning.

Signed-off-by: Eric Lin &lt;eric.lin@sifive.com&gt;
Link: https://lore.kernel.org/r/20230710154328.19574-1-eric.lin@sifive.com
Fixes: 096b52fd2bb4 ("perf: RISC-V: throttle perf events")
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt &lt;palmer@rivosinc.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
