<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/drivers/base/cacheinfo.c, branch v6.4-rc2</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge tag 'driver-core-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core</title>
<updated>2023-04-27T18:53:57+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-04-27T18:53:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=556eb8b79190151506187bf0b16dda423c34d9a8'/>
<id>556eb8b79190151506187bf0b16dda423c34d9a8</id>
<content type='text'>
Pull driver core updates from Greg KH:
 "Here is the large set of driver core changes for 6.4-rc1.

  Once again, a busy development cycle, with lots of changes happening
  in the driver core in the quest to be able to move "struct bus" and
  "struct class" into read-only memory, a task now complete with these
  changes.

  This will make the future rust interactions with the driver core more
  "provably correct" as well as providing more obvious lifetime rules
  for all busses and classes in the kernel.

  The changes required for this did touch many individual classes and
  busses as many callbacks were changed to take const * parameters
  instead. All of these changes have been submitted to the various
  subsystem maintainers, giving them plenty of time to review, and most
  of them actually did so.

  Other than those changes, included in here are a small set of other
  things:

   - kobject logging improvements

   - cacheinfo improvements and updates

   - obligatory fw_devlink updates and fixes

   - documentation updates

   - device property cleanups and const * changes

   - firwmare loader dependency fixes.

  All of these have been in linux-next for a while with no reported
  problems"

* tag 'driver-core-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (120 commits)
  device property: make device_property functions take const device *
  driver core: update comments in device_rename()
  driver core: Don't require dynamic_debug for initcall_debug probe timing
  firmware_loader: rework crypto dependencies
  firmware_loader: Strip off \n from customized path
  zram: fix up permission for the hot_add sysfs file
  cacheinfo: Add use_arch[|_cache]_info field/function
  arch_topology: Remove early cacheinfo error message if -ENOENT
  cacheinfo: Check cache properties are present in DT
  cacheinfo: Check sib_leaf in cache_leaves_are_shared()
  cacheinfo: Allow early level detection when DT/ACPI info is missing/broken
  cacheinfo: Add arm64 early level initializer implementation
  cacheinfo: Add arch specific early level initializer
  tty: make tty_class a static const structure
  driver core: class: remove struct class_interface * from callbacks
  driver core: class: mark the struct class in struct class_interface constant
  driver core: class: make class_register() take a const *
  driver core: class: mark class_release() as taking a const *
  driver core: remove incorrect comment for device_create*
  MIPS: vpe-cmp: remove module owner pointer from struct class usage.
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull driver core updates from Greg KH:
 "Here is the large set of driver core changes for 6.4-rc1.

  Once again, a busy development cycle, with lots of changes happening
  in the driver core in the quest to be able to move "struct bus" and
  "struct class" into read-only memory, a task now complete with these
  changes.

  This will make the future rust interactions with the driver core more
  "provably correct" as well as providing more obvious lifetime rules
  for all busses and classes in the kernel.

  The changes required for this did touch many individual classes and
  busses as many callbacks were changed to take const * parameters
  instead. All of these changes have been submitted to the various
  subsystem maintainers, giving them plenty of time to review, and most
  of them actually did so.

  Other than those changes, included in here are a small set of other
  things:

   - kobject logging improvements

   - cacheinfo improvements and updates

   - obligatory fw_devlink updates and fixes

   - documentation updates

   - device property cleanups and const * changes

   - firwmare loader dependency fixes.

  All of these have been in linux-next for a while with no reported
  problems"

* tag 'driver-core-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (120 commits)
  device property: make device_property functions take const device *
  driver core: update comments in device_rename()
  driver core: Don't require dynamic_debug for initcall_debug probe timing
  firmware_loader: rework crypto dependencies
  firmware_loader: Strip off \n from customized path
  zram: fix up permission for the hot_add sysfs file
  cacheinfo: Add use_arch[|_cache]_info field/function
  arch_topology: Remove early cacheinfo error message if -ENOENT
  cacheinfo: Check cache properties are present in DT
  cacheinfo: Check sib_leaf in cache_leaves_are_shared()
  cacheinfo: Allow early level detection when DT/ACPI info is missing/broken
  cacheinfo: Add arm64 early level initializer implementation
  cacheinfo: Add arch specific early level initializer
  tty: make tty_class a static const structure
  driver core: class: remove struct class_interface * from callbacks
  driver core: class: mark the struct class in struct class_interface constant
  driver core: class: make class_register() take a const *
  driver core: class: mark class_release() as taking a const *
  driver core: remove incorrect comment for device_create*
  MIPS: vpe-cmp: remove module owner pointer from struct class usage.
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'devicetree-for-6.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux</title>
<updated>2023-04-27T17:09:05+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2023-04-27T17:09:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=cb6fe2ceb667eb78f252d473b03deb23999ab1cf'/>
<id>cb6fe2ceb667eb78f252d473b03deb23999ab1cf</id>
<content type='text'>
Pull more devicetree updates from Rob Herring:

 - First part of DT header detangling dropping cpu.h from of_device.h
   and replacing some includes with forward declarations. A handful of
   drivers needed some adjustment to their includes as a result.

 - Refactor of_device.h to be used by bus drivers rather than various
   device drivers. This moves non-bus related functions out of
   of_device.h. The end goal is for of_platform.h and of_device.h to
   stop including each other.

 - Refactor open coded parsing of "ranges" in some bus drivers to use DT
   address parsing functions

 - Add some new address parsing functions of_property_read_reg(),
   of_range_count(), and of_range_to_resource() in preparation to
   convert more open coded parsing of DT addresses to use them.

 - Treewide clean-ups to use of_property_read_bool() and
   of_property_present() as appropriate. The ones here are the ones that
   didn't get picked up elsewhere.

* tag 'devicetree-for-6.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (34 commits)
  bus: tegra-gmi: Replace of_platform.h with explicit includes
  hte: Use of_property_present() for testing DT property presence
  w1: w1-gpio: Use of_property_read_bool() for boolean properties
  virt: fsl: Use of_property_present() for testing DT property presence
  soc: fsl: Use of_property_present() for testing DT property presence
  sbus: display7seg: Use of_property_read_bool() for boolean properties
  sparc: Use of_property_read_bool() for boolean properties
  sparc: Use of_property_present() for testing DT property presence
  bus: mvebu-mbus: Remove open coded "ranges" parsing
  of/address: Add of_property_read_reg() helper
  of/address: Add of_range_count() helper
  of/address: Add support for 3 address cell bus
  of/address: Add of_range_to_resource() helper
  of: unittest: Add bus address range parsing tests
  of: Drop cpu.h include from of_device.h
  OPP: Adjust includes to remove of_device.h
  irqchip: loongson-eiointc: Add explicit include for cpuhotplug.h
  cpuidle: Adjust includes to remove of_device.h
  cpufreq: sun50i: Add explicit include for cpu.h
  cpufreq: Adjust includes to remove of_device.h
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull more devicetree updates from Rob Herring:

 - First part of DT header detangling dropping cpu.h from of_device.h
   and replacing some includes with forward declarations. A handful of
   drivers needed some adjustment to their includes as a result.

 - Refactor of_device.h to be used by bus drivers rather than various
   device drivers. This moves non-bus related functions out of
   of_device.h. The end goal is for of_platform.h and of_device.h to
   stop including each other.

 - Refactor open coded parsing of "ranges" in some bus drivers to use DT
   address parsing functions

 - Add some new address parsing functions of_property_read_reg(),
   of_range_count(), and of_range_to_resource() in preparation to
   convert more open coded parsing of DT addresses to use them.

 - Treewide clean-ups to use of_property_read_bool() and
   of_property_present() as appropriate. The ones here are the ones that
   didn't get picked up elsewhere.

* tag 'devicetree-for-6.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (34 commits)
  bus: tegra-gmi: Replace of_platform.h with explicit includes
  hte: Use of_property_present() for testing DT property presence
  w1: w1-gpio: Use of_property_read_bool() for boolean properties
  virt: fsl: Use of_property_present() for testing DT property presence
  soc: fsl: Use of_property_present() for testing DT property presence
  sbus: display7seg: Use of_property_read_bool() for boolean properties
  sparc: Use of_property_read_bool() for boolean properties
  sparc: Use of_property_present() for testing DT property presence
  bus: mvebu-mbus: Remove open coded "ranges" parsing
  of/address: Add of_property_read_reg() helper
  of/address: Add of_range_count() helper
  of/address: Add support for 3 address cell bus
  of/address: Add of_range_to_resource() helper
  of: unittest: Add bus address range parsing tests
  of: Drop cpu.h include from of_device.h
  OPP: Adjust includes to remove of_device.h
  irqchip: loongson-eiointc: Add explicit include for cpuhotplug.h
  cpuidle: Adjust includes to remove of_device.h
  cpufreq: sun50i: Add explicit include for cpu.h
  cpufreq: Adjust includes to remove of_device.h
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'cacheinfo-updates-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux into driver-core-next</title>
<updated>2023-04-19T13:09:40+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2023-04-19T13:09:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=a7b3a470fdea9f4a7daa5ae446c4e27c65f00aac'/>
<id>a7b3a470fdea9f4a7daa5ae446c4e27c65f00aac</id>
<content type='text'>
Sudeep writes:

cacheinfo and arch_topology updates for v6.4

The cache information can be extracted from either a Device Tree(DT),
the PPTT ACPI table, or arch registers (clidr_el1 for arm64).

When the DT is used but no cache properties are advertised, the current
code doesn't correctly fallback to using arch information. The changes
fixes the same and also assuse the that L1 data/instruction caches
are private and L2/higher caches are shared when the cache information
is missing in DT/ACPI and is derived form clidr_el1/arch registers.

Currently the cacheinfo is built from the primary CPU prior to secondary
CPUs boot, if the DT/ACPI description contains cache information.
However, if not present, it still reverts to the old behavior, which
allocates the cacheinfo memory on each secondary CPUs which causes
RT kernels to triggers a "BUG: sleeping function called from invalid
context".

The changes here attempts to enable automatic detection for RT kernels
when no DT/ACPI cache information is available, by pre-allocating
cacheinfo memory on the primary CPU.

* tag 'cacheinfo-updates-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux:
  cacheinfo: Add use_arch[|_cache]_info field/function
  arch_topology: Remove early cacheinfo error message if -ENOENT
  cacheinfo: Check cache properties are present in DT
  cacheinfo: Check sib_leaf in cache_leaves_are_shared()
  cacheinfo: Allow early level detection when DT/ACPI info is missing/broken
  cacheinfo: Add arm64 early level initializer implementation
  cacheinfo: Add arch specific early level initializer
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Sudeep writes:

cacheinfo and arch_topology updates for v6.4

The cache information can be extracted from either a Device Tree(DT),
the PPTT ACPI table, or arch registers (clidr_el1 for arm64).

When the DT is used but no cache properties are advertised, the current
code doesn't correctly fallback to using arch information. The changes
fixes the same and also assuse the that L1 data/instruction caches
are private and L2/higher caches are shared when the cache information
is missing in DT/ACPI and is derived form clidr_el1/arch registers.

Currently the cacheinfo is built from the primary CPU prior to secondary
CPUs boot, if the DT/ACPI description contains cache information.
However, if not present, it still reverts to the old behavior, which
allocates the cacheinfo memory on each secondary CPUs which causes
RT kernels to triggers a "BUG: sleeping function called from invalid
context".

The changes here attempts to enable automatic detection for RT kernels
when no DT/ACPI cache information is available, by pre-allocating
cacheinfo memory on the primary CPU.

* tag 'cacheinfo-updates-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux:
  cacheinfo: Add use_arch[|_cache]_info field/function
  arch_topology: Remove early cacheinfo error message if -ENOENT
  cacheinfo: Check cache properties are present in DT
  cacheinfo: Check sib_leaf in cache_leaves_are_shared()
  cacheinfo: Allow early level detection when DT/ACPI info is missing/broken
  cacheinfo: Add arm64 early level initializer implementation
  cacheinfo: Add arch specific early level initializer
</pre>
</div>
</content>
</entry>
<entry>
<title>cacheinfo: Add use_arch[|_cache]_info field/function</title>
<updated>2023-04-14T09:13:39+00:00</updated>
<author>
<name>Pierre Gondois</name>
<email>pierre.gondois@arm.com</email>
</author>
<published>2023-04-14T08:14:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=ef9f643a9f8b62bcbcc51f0e0af8599adc2e17ed'/>
<id>ef9f643a9f8b62bcbcc51f0e0af8599adc2e17ed</id>
<content type='text'>
The cache information can be extracted from either a Device
Tree (DT), the PPTT ACPI table, or arch registers (clidr_el1
for arm64).

The clidr_el1 register is used only if DT/ACPI information is not
available. It does not states how caches are shared among CPUs.

Add a use_arch_cache_info field/function to identify when the
DT/ACPI doesn't provide cache information. Use this information
to assume L1 caches are privates and L2 and higher are shared among
all CPUs.

Signed-off-by: Pierre Gondois &lt;pierre.gondois@arm.com&gt;
Link: https://lore.kernel.org/r/20230414081453.244787-5-pierre.gondois@arm.com
Signed-off-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The cache information can be extracted from either a Device
Tree (DT), the PPTT ACPI table, or arch registers (clidr_el1
for arm64).

The clidr_el1 register is used only if DT/ACPI information is not
available. It does not states how caches are shared among CPUs.

Add a use_arch_cache_info field/function to identify when the
DT/ACPI doesn't provide cache information. Use this information
to assume L1 caches are privates and L2 and higher are shared among
all CPUs.

Signed-off-by: Pierre Gondois &lt;pierre.gondois@arm.com&gt;
Link: https://lore.kernel.org/r/20230414081453.244787-5-pierre.gondois@arm.com
Signed-off-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cacheinfo: Check cache properties are present in DT</title>
<updated>2023-04-14T09:13:38+00:00</updated>
<author>
<name>Pierre Gondois</name>
<email>pierre.gondois@arm.com</email>
</author>
<published>2023-04-14T08:14:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=cde0fbff07eff7e4e0e85fa053fe19a24c86b1e0'/>
<id>cde0fbff07eff7e4e0e85fa053fe19a24c86b1e0</id>
<content type='text'>
If a Device Tree (DT) is used, the presence of cache properties is
assumed. Not finding any is not considered. For arm64 platforms,
cache information can be fetched from the clidr_el1 register.
Checking whether cache information is available in the DT
allows to switch to using clidr_el1.

init_of_cache_level()
\-of_count_cache_leaves()
will assume there a 2 cache leaves (L1 data/instruction caches), which
can be different from clidr_el1 information.

cache_setup_of_node() tries to read cache properties in the DT.
If there are none, this is considered a success. Knowing no
information was available would allow to switch to using clidr_el1.

Fixes: de0df442ee49 ("cacheinfo: Check 'cache-unified' property to count cache leaves")
Reported-by: Alexandre Ghiti &lt;alexghiti@rivosinc.com&gt;
Link: https://lore.kernel.org/all/20230404-hatred-swimmer-6fecdf33b57a@spud/
Signed-off-by: Pierre Gondois &lt;pierre.gondois@arm.com&gt;
Reviewed-by: Conor Dooley &lt;conor.dooley@microchip.com&gt;
Link: https://lore.kernel.org/r/20230414081453.244787-3-pierre.gondois@arm.com
Signed-off-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
If a Device Tree (DT) is used, the presence of cache properties is
assumed. Not finding any is not considered. For arm64 platforms,
cache information can be fetched from the clidr_el1 register.
Checking whether cache information is available in the DT
allows to switch to using clidr_el1.

init_of_cache_level()
\-of_count_cache_leaves()
will assume there a 2 cache leaves (L1 data/instruction caches), which
can be different from clidr_el1 information.

cache_setup_of_node() tries to read cache properties in the DT.
If there are none, this is considered a success. Knowing no
information was available would allow to switch to using clidr_el1.

Fixes: de0df442ee49 ("cacheinfo: Check 'cache-unified' property to count cache leaves")
Reported-by: Alexandre Ghiti &lt;alexghiti@rivosinc.com&gt;
Link: https://lore.kernel.org/all/20230404-hatred-swimmer-6fecdf33b57a@spud/
Signed-off-by: Pierre Gondois &lt;pierre.gondois@arm.com&gt;
Reviewed-by: Conor Dooley &lt;conor.dooley@microchip.com&gt;
Link: https://lore.kernel.org/r/20230414081453.244787-3-pierre.gondois@arm.com
Signed-off-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cacheinfo: Check sib_leaf in cache_leaves_are_shared()</title>
<updated>2023-04-14T09:13:38+00:00</updated>
<author>
<name>Pierre Gondois</name>
<email>pierre.gondois@arm.com</email>
</author>
<published>2023-04-14T08:14:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=7a306e3eabf2b2fd8cffa69b87b32dbf814d79ce'/>
<id>7a306e3eabf2b2fd8cffa69b87b32dbf814d79ce</id>
<content type='text'>
If there is no ACPI/DT information, it is assumed that L1 caches
are private and L2 (and higher) caches are shared. A cache is
'shared' between two CPUs if it is accessible from these two
CPUs.

Each CPU owns a representation (i.e. has a dedicated cacheinfo struct)
of the caches it has access to. cache_leaves_are_shared() tries to
identify whether two representations are designating the same actual
cache.

In cache_leaves_are_shared(), if 'this_leaf' is a L2 cache (or higher)
and 'sib_leaf' is a L1 cache, the caches are detected as shared as
only this_leaf's cache level is checked.
This is leads to setting sib_leaf as being shared with another CPU,
which is incorrect as this is a L1 cache.

Check 'sib_leaf-&gt;level'. Also update the comment as the function is
called when populating 'shared_cpu_map'.

Fixes: f16d1becf96f ("cacheinfo: Use cache identifiers to check if the caches are shared if available")
Signed-off-by: Pierre Gondois &lt;pierre.gondois@arm.com&gt;
Reviewed-by: Conor Dooley &lt;conor.dooley@microchip.com&gt;
Link: https://lore.kernel.org/r/20230414081453.244787-2-pierre.gondois@arm.com
Signed-off-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
If there is no ACPI/DT information, it is assumed that L1 caches
are private and L2 (and higher) caches are shared. A cache is
'shared' between two CPUs if it is accessible from these two
CPUs.

Each CPU owns a representation (i.e. has a dedicated cacheinfo struct)
of the caches it has access to. cache_leaves_are_shared() tries to
identify whether two representations are designating the same actual
cache.

In cache_leaves_are_shared(), if 'this_leaf' is a L2 cache (or higher)
and 'sib_leaf' is a L1 cache, the caches are detected as shared as
only this_leaf's cache level is checked.
This is leads to setting sib_leaf as being shared with another CPU,
which is incorrect as this is a L1 cache.

Check 'sib_leaf-&gt;level'. Also update the comment as the function is
called when populating 'shared_cpu_map'.

Fixes: f16d1becf96f ("cacheinfo: Use cache identifiers to check if the caches are shared if available")
Signed-off-by: Pierre Gondois &lt;pierre.gondois@arm.com&gt;
Reviewed-by: Conor Dooley &lt;conor.dooley@microchip.com&gt;
Link: https://lore.kernel.org/r/20230414081453.244787-2-pierre.gondois@arm.com
Signed-off-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cacheinfo: Adjust includes to remove of_device.h</title>
<updated>2023-04-13T22:46:34+00:00</updated>
<author>
<name>Rob Herring</name>
<email>robh@kernel.org</email>
</author>
<published>2023-03-29T15:52:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=b9581552b0b94586fa7296613a5d8a4a63e801be'/>
<id>b9581552b0b94586fa7296613a5d8a4a63e801be</id>
<content type='text'>
Now that of_cpu_device_node_get() is defined in of.h, of_device.h is just
implicitly including other includes, and is no longer needed. Update the
includes to use of.h instead of of_device.h.

Acked-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
Acked-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Link: https://lore.kernel.org/r/20230329-dt-cpu-header-cleanups-v1-10-581e2605fe47@kernel.org
Signed-off-by: Rob Herring &lt;robh@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Now that of_cpu_device_node_get() is defined in of.h, of_device.h is just
implicitly including other includes, and is no longer needed. Update the
includes to use of.h instead of of_device.h.

Acked-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
Acked-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Link: https://lore.kernel.org/r/20230329-dt-cpu-header-cleanups-v1-10-581e2605fe47@kernel.org
Signed-off-by: Rob Herring &lt;robh@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cacheinfo: Add arch specific early level initializer</title>
<updated>2023-04-13T08:32:32+00:00</updated>
<author>
<name>Radu Rendec</name>
<email>rrendec@redhat.com</email>
</author>
<published>2023-04-12T18:57:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=6539cffa94957241c096099a57d05fa4d8c7db8a'/>
<id>6539cffa94957241c096099a57d05fa4d8c7db8a</id>
<content type='text'>
This patch gives architecture specific code the ability to initialize
the cache level and allocate cacheinfo memory early, when cache level
initialization runs on the primary CPU for all possible CPUs.

This is part of a patch series that attempts to further the work in
commit 5944ce092b97 ("arch_topology: Build cacheinfo from primary CPU").
Previously, in the absence of any DT/ACPI cache info, architecture
specific cache detection and info allocation for secondary CPUs would
happen in non-preemptible context during early CPU initialization and
trigger a "BUG: sleeping function called from invalid context" splat on
an RT kernel.

More specifically, this patch adds the early_cache_level() function,
which is called by fetch_cache_info() as a fallback when the number of
cache leaves cannot be extracted from DT/ACPI. In the default generic
(weak) implementation, this new function returns -ENOENT, which
preserves the original behavior for architectures that do not implement
the function.

Since early detection can get the number of cache leaves wrong in some
cases*, additional logic is added to still call init_cache_level() later
on the secondary CPU, therefore giving the architecture specific code an
opportunity to go back and fix the initial guess. Again, the original
behavior is preserved for architectures that do not implement the new
function.

* For example, on arm64, CLIDR_EL1 detection works only when it runs on
  the current CPU. In other words, a CPU cannot detect the cache depth
  for any other CPU than itself.

Signed-off-by: Radu Rendec &lt;rrendec@redhat.com&gt;
Reviewed-by: Pierre Gondois &lt;pierre.gondois@arm.com&gt;
Link: https://lore.kernel.org/r/20230412185759.755408-2-rrendec@redhat.com
Signed-off-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This patch gives architecture specific code the ability to initialize
the cache level and allocate cacheinfo memory early, when cache level
initialization runs on the primary CPU for all possible CPUs.

This is part of a patch series that attempts to further the work in
commit 5944ce092b97 ("arch_topology: Build cacheinfo from primary CPU").
Previously, in the absence of any DT/ACPI cache info, architecture
specific cache detection and info allocation for secondary CPUs would
happen in non-preemptible context during early CPU initialization and
trigger a "BUG: sleeping function called from invalid context" splat on
an RT kernel.

More specifically, this patch adds the early_cache_level() function,
which is called by fetch_cache_info() as a fallback when the number of
cache leaves cannot be extracted from DT/ACPI. In the default generic
(weak) implementation, this new function returns -ENOENT, which
preserves the original behavior for architectures that do not implement
the function.

Since early detection can get the number of cache leaves wrong in some
cases*, additional logic is added to still call init_cache_level() later
on the secondary CPU, therefore giving the architecture specific code an
opportunity to go back and fix the initial guess. Again, the original
behavior is preserved for architectures that do not implement the new
function.

* For example, on arm64, CLIDR_EL1 detection works only when it runs on
  the current CPU. In other words, a CPU cannot detect the cache depth
  for any other CPU than itself.

Signed-off-by: Radu Rendec &lt;rrendec@redhat.com&gt;
Reviewed-by: Pierre Gondois &lt;pierre.gondois@arm.com&gt;
Link: https://lore.kernel.org/r/20230412185759.755408-2-rrendec@redhat.com
Signed-off-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cacheinfo: Fix LLC is not exported through sysfs</title>
<updated>2023-03-29T10:04:10+00:00</updated>
<author>
<name>Yicong Yang</name>
<email>yangyicong@hisilicon.com</email>
</author>
<published>2023-03-28T11:49:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=5c2712387d4850e0b64121d5fd3e6c4e84ea3266'/>
<id>5c2712387d4850e0b64121d5fd3e6c4e84ea3266</id>
<content type='text'>
After entering 6.3-rc1 the LLC cacheinfo is not exported on our ACPI
based arm64 server. This is because the LLC cacheinfo is partly reset
when secondary CPUs boot up. On arm64 the primary cpu will allocate
and setup cacheinfo:
init_cpu_topology()
  for_each_possible_cpu()
    fetch_cache_info() // Allocate cacheinfo and init levels
detect_cache_attributes()
  cache_shared_cpu_map_setup()
    if (!last_level_cache_is_valid()) // not valid, setup LLC
      cache_setup_properties() // setup LLC

On secondary CPU boot up:
detect_cache_attributes()
  populate_cache_leaves()
    get_cache_type() // Get cache type from clidr_el1,
                     // for LLC type=CACHE_TYPE_NOCACHE
  cache_shared_cpu_map_setup()
    if (!last_level_cache_is_valid()) // Valid and won't go to this branch,
                                      // leave LLC's type=CACHE_TYPE_NOCACHE

The last_level_cache_is_valid() use cacheinfo-&gt;{attributes, fw_token} to
test it's valid or not, but populate_cache_leaves() will only reset
LLC's type, so we won't try to re-setup LLC's type and leave it
CACHE_TYPE_NOCACHE and won't export it through sysfs.

This patch tries to fix this by not re-populating the cache leaves if
the LLC is valid.

Fixes: 5944ce092b97 ("arch_topology: Build cacheinfo from primary CPU")
Signed-off-by: Yicong Yang &lt;yangyicong@hisilicon.com&gt;
Reviewed-by: Pierre Gondois &lt;pierre.gondois@arm.com&gt;
Reviewed-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
Link: https://lore.kernel.org/r/20230328114915.33340-1-yangyicong@huawei.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
After entering 6.3-rc1 the LLC cacheinfo is not exported on our ACPI
based arm64 server. This is because the LLC cacheinfo is partly reset
when secondary CPUs boot up. On arm64 the primary cpu will allocate
and setup cacheinfo:
init_cpu_topology()
  for_each_possible_cpu()
    fetch_cache_info() // Allocate cacheinfo and init levels
detect_cache_attributes()
  cache_shared_cpu_map_setup()
    if (!last_level_cache_is_valid()) // not valid, setup LLC
      cache_setup_properties() // setup LLC

On secondary CPU boot up:
detect_cache_attributes()
  populate_cache_leaves()
    get_cache_type() // Get cache type from clidr_el1,
                     // for LLC type=CACHE_TYPE_NOCACHE
  cache_shared_cpu_map_setup()
    if (!last_level_cache_is_valid()) // Valid and won't go to this branch,
                                      // leave LLC's type=CACHE_TYPE_NOCACHE

The last_level_cache_is_valid() use cacheinfo-&gt;{attributes, fw_token} to
test it's valid or not, but populate_cache_leaves() will only reset
LLC's type, so we won't try to re-setup LLC's type and leave it
CACHE_TYPE_NOCACHE and won't export it through sysfs.

This patch tries to fix this by not re-populating the cache leaves if
the LLC is valid.

Fixes: 5944ce092b97 ("arch_topology: Build cacheinfo from primary CPU")
Signed-off-by: Yicong Yang &lt;yangyicong@hisilicon.com&gt;
Reviewed-by: Pierre Gondois &lt;pierre.gondois@arm.com&gt;
Reviewed-by: Sudeep Holla &lt;sudeep.holla@arm.com&gt;
Link: https://lore.kernel.org/r/20230328114915.33340-1-yangyicong@huawei.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cacheinfo: Initialize variables in fetch_cache_info()</title>
<updated>2023-01-31T15:02:02+00:00</updated>
<author>
<name>Pierre Gondois</name>
<email>pierre.gondois@arm.com</email>
</author>
<published>2023-01-24T15:40:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=ecaef469920fd6d2c7687f19081946f47684a423'/>
<id>ecaef469920fd6d2c7687f19081946f47684a423</id>
<content type='text'>
Set potentially uninitialized variables to 0. This is particularly
relevant when CONFIG_ACPI_PPTT is not set.

Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Link: https://lore.kernel.org/all/202301052307.JYt1GWaJ-lkp@intel.com/
Reported-by: Dan Carpenter &lt;error27@gmail.com&gt;
Link: https://lore.kernel.org/all/Y86iruJPuwNN7rZw@kili/
Fixes: 5944ce092b97 ("arch_topology: Build cacheinfo from primary CPU")
Signed-off-by: Pierre Gondois &lt;pierre.gondois@arm.com&gt;
Reviewed-by: Conor Dooley &lt;conor.dooley@microchip.com&gt;
Link: https://lore.kernel.org/r/20230124154053.355376-2-pierre.gondois@arm.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Set potentially uninitialized variables to 0. This is particularly
relevant when CONFIG_ACPI_PPTT is not set.

Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Link: https://lore.kernel.org/all/202301052307.JYt1GWaJ-lkp@intel.com/
Reported-by: Dan Carpenter &lt;error27@gmail.com&gt;
Link: https://lore.kernel.org/all/Y86iruJPuwNN7rZw@kili/
Fixes: 5944ce092b97 ("arch_topology: Build cacheinfo from primary CPU")
Signed-off-by: Pierre Gondois &lt;pierre.gondois@arm.com&gt;
Reviewed-by: Conor Dooley &lt;conor.dooley@microchip.com&gt;
Link: https://lore.kernel.org/r/20230124154053.355376-2-pierre.gondois@arm.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
