linux.git/arch/x86/kernel/cpu/resctrl/pseudo_lock.c, branch v6.5

driver core: class: remove module * from class_create()

2023-03-17T14:16:33+00:00

The module pointer in class_create() never actually did anything, and it
shouldn't have been requred to be set as a parameter even if it did
something.  So just remove it and fix up all callers of the function in
the kernel tree at the same time.

Cc: "Rafael J. Wysocki" 
Acked-by: Benjamin Tissoires 
Link: https://lore.kernel.org/r/20230313181843.1207845-4-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman

Merge tag 'driver-core-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

2022-12-16T11:54:54+00:00

Pull driver core updates from Greg KH:
 "Here is the set of driver core and kernfs changes for 6.2-rc1.

  The "big" change in here is the addition of a new macro,
  container_of_const() that will preserve the "const-ness" of a pointer
  passed into it.

  The "problem" of the current container_of() macro is that if you pass
  in a "const *", out of it can comes a non-const pointer unless you
  specifically ask for it. For many usages, we want to preserve the
  "const" attribute by using the same call. For a specific example, this
  series changes the kobj_to_dev() macro to use it, allowing it to be
  used no matter what the const value is. This prevents every subsystem
  from having to declare 2 different individual macros (i.e.
  kobj_const_to_dev() and kobj_to_dev()) and having the compiler enforce
  the const value at build time, which having 2 macros would not do
  either.

  The driver for all of this have been discussions with the Rust kernel
  developers as to how to properly mark driver core, and kobject,
  objects as being "non-mutable". The changes to the kobject and driver
  core in this pull request are the result of that, as there are lots of
  paths where kobjects and device pointers are not modified at all, so
  marking them as "const" allows the compiler to enforce this.

  So, a nice side affect of the Rust development effort has been already
  to clean up the driver core code to be more obvious about object
  rules.

  All of this has been bike-shedded in quite a lot of detail on lkml
  with different names and implementations resulting in the tiny version
  we have in here, much better than my original proposal. Lots of
  subsystem maintainers have acked the changes as well.

  Other than this change, included in here are smaller stuff like:

   - kernfs fixes and updates to handle lock contention better

   - vmlinux.lds.h fixes and updates

   - sysfs and debugfs documentation updates

   - device property updates

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

* tag 'driver-core-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (58 commits)
  device property: Fix documentation for fwnode_get_next_parent()
  firmware_loader: fix up to_fw_sysfs() to preserve const
  usb.h: take advantage of container_of_const()
  device.h: move kobj_to_dev() to use container_of_const()
  container_of: add container_of_const() that preserves const-ness of the pointer
  driver core: fix up missed drivers/s390/char/hmcdrv_dev.c class.devnode() conversion.
  driver core: fix up missed scsi/cxlflash class.devnode() conversion.
  driver core: fix up some missing class.devnode() conversions.
  driver core: make struct class.devnode() take a const *
  driver core: make struct class.dev_uevent() take a const *
  cacheinfo: Remove of_node_put() for fw_token
  device property: Add a blank line in Kconfig of tests
  device property: Rename goto label to be more precise
  device property: Move PROPERTY_ENTRY_BOOL() a bit down
  device property: Get rid of __PROPERTY_ENTRY_ARRAY_EL*SIZE*()
  kernfs: fix all kernel-doc warnings and multiple typos
  driver core: pass a const * into of_device_uevent()
  kobject: kset_uevent_ops: make name() callback take a const *
  kobject: kset_uevent_ops: make filter() callback take a const *
  kobject: make kobject_namespace take a const *
  ...

x86/resctrl: Move MSR defines into msr-index.h

2022-11-27T22:00:45+00:00

msr-index.h should contain all MSRs for easier grepping for MSR numbers
when dealing with unchecked MSR access warnings, for example.

Move the resctrl ones. Prefix IA32_PQR_ASSOC with "MSR_" while at it.

No functional changes.

Signed-off-by: Borislav Petkov 
Link: https://lore.kernel.org/r/20221106212923.20699-1-bp@alien8.de

driver core: make struct class.devnode() take a const *

2022-11-24T16:12:27+00:00

The devnode() in struct class should not be modifying the device that is
passed into it, so mark it as a const * and propagate the function
signature changes out into all relevant subsystems that use this
callback.

Cc: Fenghua Yu 
Cc: Reinette Chatre 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: x86@kernel.org
Cc: "H. Peter Anvin" 
Cc: FUJITA Tomonori 
Cc: Jens Axboe 
Cc: Justin Sanders 
Cc: Arnd Bergmann 
Cc: Sumit Semwal 
Cc: Benjamin Gaignard 
Cc: Liam Mark 
Cc: Laura Abbott 
Cc: Brian Starkey 
Cc: John Stultz 
Cc: "Christian König" 
Cc: Maarten Lankhorst 
Cc: Maxime Ripard 
Cc: Thomas Zimmermann 
Cc: David Airlie 
Cc: Daniel Vetter 
Cc: Jason Gunthorpe 
Cc: Leon Romanovsky 
Cc: Dennis Dalessandro 
Cc: Dmitry Torokhov 
Cc: Mauro Carvalho Chehab 
Cc: Sean Young 
Cc: Frank Haverkamp 
Cc: Jiri Slaby 
Cc: "Michael S. Tsirkin" 
Cc: Jason Wang 
Cc: Alex Williamson 
Cc: Cornelia Huck 
Cc: Kees Cook 
Cc: Anton Vorontsov 
Cc: Colin Cross 
Cc: Tony Luck 
Cc: Jaroslav Kysela 
Cc: Takashi Iwai 
Cc: Hans Verkuil 
Cc: Christophe JAILLET 
Cc: Xie Yongji 
Cc: Gautam Dawar 
Cc: Dan Carpenter 
Cc: Eli Cohen 
Cc: Parav Pandit 
Cc: Maxime Coquelin 
Cc: alsa-devel@alsa-project.org
Cc: dri-devel@lists.freedesktop.org
Cc: kvm@vger.kernel.org
Cc: linaro-mm-sig@lists.linaro.org
Cc: linux-block@vger.kernel.org
Cc: linux-input@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-media@vger.kernel.org
Cc: linux-rdma@vger.kernel.org
Cc: linux-scsi@vger.kernel.org
Cc: linux-usb@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org
Link: https://lore.kernel.org/r/20221123122523.1332370-2-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman

x86/resctrl: Kill off alloc_enabled

2022-09-22T12:34:33+00:00

rdt_resources_all[] used to have extra entries for L2CODE/L2DATA.
These were hidden from resctrl by the alloc_enabled value.

Now that the L2/L2CODE/L2DATA resources have been merged together,
alloc_enabled doesn't mean anything, it always has the same value as
alloc_capable which indicates allocation is supported by this resource.

Remove alloc_enabled and its helpers.

Signed-off-by: James Morse 
Signed-off-by: Borislav Petkov 
Reviewed-by: Jamie Iles 
Reviewed-by: Shaopeng Tan 
Reviewed-by: Reinette Chatre 
Tested-by: Xin Hao 
Tested-by: Shaopeng Tan 
Tested-by: Cristian Marussi 
Link: https://lore.kernel.org/r/20220902154829.30399-2-james.morse@arm.com

x86/resctrl: Fix to restore to original value when re-enabling hardware prefetch register

2022-08-31T18:42:17+00:00

The current pseudo_lock.c code overwrites the value of the
MSR_MISC_FEATURE_CONTROL to 0 even if the original value is not 0.
Therefore, modify it to save and restore the original values.

Fixes: 018961ae5579 ("x86/intel_rdt: Pseudo-lock region creation/removal core")
Fixes: 443810fe6160 ("x86/intel_rdt: Create debugfs files for pseudo-locking testing")
Fixes: 8a2fc0e1bc0c ("x86/intel_rdt: More precise L2 hit/miss measurements")
Signed-off-by: Kohei Tarumizu 
Signed-off-by: Dave Hansen 
Acked-by: Reinette Chatre 
Link: https://lkml.kernel.org/r/eb660f3c2010b79a792c573c02d01e8e841206ad.1661358182.git.reinette.chatre@intel.com

x86/resctrl: Add a helper to read/set the CDP configuration

2021-08-11T13:54:26+00:00

Whether CDP is enabled for a hardware resource like the L3 cache can be
found by inspecting the alloc_enabled flags of the L3CODE/L3DATA struct
rdt_hw_resources, even if they aren't in use.

Once these resources are merged, the flags can't be compared. Whether
CDP is enabled needs tracking explicitly. If another architecture is
emulating CDP the behaviour may not be per-resource. 'cdp_capable' needs
to be visible to resctrl, even if its not in use, as this affects the
padding of the schemata table visible to user-space.

Add cdp_enabled to struct rdt_hw_resource and cdp_capable to struct
rdt_resource. Add resctrl_arch_set_cdp_enabled() to let resctrl enable
or disable CDP on a resource. resctrl_arch_get_cdp_enabled() lets it
read the current state.

Signed-off-by: James Morse 
Signed-off-by: Borislav Petkov 
Reviewed-by: Jamie Iles 
Reviewed-by: Reinette Chatre 
Tested-by: Babu Moger 
Link: https://lkml.kernel.org/r/20210728170637.25610-12-james.morse@arm.com

x86/resctrl: Swizzle rdt_resource and resctrl_schema in pseudo_lock_region

2021-08-11T13:51:45+00:00

struct pseudo_lock_region points to the rdt_resource.

Once the resources are merged, this won't be unique. The resource name
is moving into the schema, so that the filesystem portions of resctrl can
generate it.

Swap pseudo_lock_region's rdt_resource pointer for a schema pointer.

Signed-off-by: James Morse 
Signed-off-by: Borislav Petkov 
Reviewed-by: Jamie Iles 
Reviewed-by: Reinette Chatre 
Tested-by: Babu Moger 
Link: https://lkml.kernel.org/r/20210728170637.25610-11-james.morse@arm.com

x86/resctrl: Split struct rdt_resource

2021-08-11T09:51:34+00:00

resctrl is the defacto Linux ABI for SoC resource partitioning features.

To support it on another architecture, it needs to be abstracted from
the features provided by Intel RDT and AMD PQoS, and moved to /fs/.
struct rdt_resource contains a mix of architecture private details
and properties of the filesystem interface user-space uses.

Start by splitting struct rdt_resource, into an architecture private
'hw' struct, which contains the common resctrl structure that would be
used by any architecture. The foreach helpers are most commonly used by
the filesystem code, and should return the common resctrl structure.
for_each_rdt_resource() is changed to walk the common structure in its
parent arch private structure.

Move as much of the structure as possible into the common structure
in the core code's header file. The x86 hardware accessors remain
part of the architecture private code, as do num_closid, mon_scale
and mbm_width.

mon_scale and mbm_width are used to detect overflow of the hardware
counters, and convert them from their native size to bytes. Any
cross-architecture abstraction should be in terms of bytes, making
these properties private.

The hardware's num_closid is kept in the private structure to force the
filesystem code to use a helper to access it. MPAM would return a single
value for the system, regardless of the resource. Using the helper
prevents this field from being confused with the version of num_closid
that is being exposed to user-space (added in a later patch).

After this split, filesystem code touching a 'hw' struct indicates
where an abstraction is needed.

Splitting this structure only moves types around, and should not lead
to any change in behaviour.

Signed-off-by: James Morse 
Signed-off-by: Borislav Petkov 
Reviewed-by: Jamie Iles 
Reviewed-by: Reinette Chatre 
Tested-by: Babu Moger 
Link: https://lkml.kernel.org/r/20210728170637.25610-2-james.morse@arm.com

x86/resctrl: Fix kernel-doc in pseudo_lock.c

2021-06-24T08:21:05+00:00

Add undocumented parameters detected by scripts/kernel-doc.

Signed-off-by: Fabio M. De Francesco 
Signed-off-by: Borislav Petkov 
Reviewed-by: Reinette Chatre 
Link: https://lkml.kernel.org/r/20210616181530.4094-1-fmdefrancesco@gmail.com