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mistachio wants to merge 72 commits into
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6.6 build check#1
mistachio wants to merge 72 commits into
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6.6-velinux-rdt-snc

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maciejwieczorretman and others added 30 commits September 18, 2024 13:45
commit f05fd4c upstream.

The kernel test robot reported kernel-doc warnings here:

  arch/x86/kernel/cpu/resctrl/rdtgroup.c:915: warning: Function parameter or member 'of' not described in 'rdt_bit_usage_show'
  arch/x86/kernel/cpu/resctrl/rdtgroup.c:915: warning: Function parameter or member 'seq' not described in 'rdt_bit_usage_show'
  arch/x86/kernel/cpu/resctrl/rdtgroup.c:915: warning: Function parameter or member 'v' not described in 'rdt_bit_usage_show'
  arch/x86/kernel/cpu/resctrl/rdtgroup.c:1144: warning: Function parameter or member 'type' not described in '__rdtgroup_cbm_overlaps'
  arch/x86/kernel/cpu/resctrl/rdtgroup.c:1224: warning: Function parameter or member 'rdtgrp' not described in 'rdtgroup_mode_test_exclusive'
  arch/x86/kernel/cpu/resctrl/rdtgroup.c:1261: warning: Function parameter or member 'of' not described in 'rdtgroup_mode_write'
  arch/x86/kernel/cpu/resctrl/rdtgroup.c:1261: warning: Function parameter or member 'buf' not described in 'rdtgroup_mode_write'
  arch/x86/kernel/cpu/resctrl/rdtgroup.c:1261: warning: Function parameter or member 'nbytes' not described in 'rdtgroup_mode_write'
  arch/x86/kernel/cpu/resctrl/rdtgroup.c:1261: warning: Function parameter or member 'off' not described in 'rdtgroup_mode_write'
  arch/x86/kernel/cpu/resctrl/rdtgroup.c:1370: warning: Function parameter or member 'of' not described in 'rdtgroup_size_show'
  arch/x86/kernel/cpu/resctrl/rdtgroup.c:1370: warning: Function parameter or member 's' not described in 'rdtgroup_size_show'
  arch/x86/kernel/cpu/resctrl/rdtgroup.c:1370: warning: Function parameter or member 'v' not described in 'rdtgroup_size_show'

The first two functions are missing an argument description while the
other three are file callbacks and don't require a kernel-doc comment.

Intel-SIG: commit f05fd4c x86/resctrl: Fix remaining kernel-doc warnings.
Incremental backporting patches for Intel RDT on Intel Xeon platform.

Closes: https://lore.kernel.org/oe-kbuild-all/202310070434.mD8eRNAz-lkp@intel.com/
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Newman <peternewman@google.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lore.kernel.org/r/20231011064843.246592-1-maciej.wieczor-retman@intel.com
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit fe2a20e upstream.

The resctrl task assignment for monitor or control group needs to be
done one at a time. For example:

  $mount -t resctrl resctrl /sys/fs/resctrl/
  $mkdir /sys/fs/resctrl/ctrl_grp1
  $echo 123 > /sys/fs/resctrl/ctrl_grp1/tasks
  $echo 456 > /sys/fs/resctrl/ctrl_grp1/tasks
  $echo 789 > /sys/fs/resctrl/ctrl_grp1/tasks

This is not user-friendly when dealing with hundreds of tasks.

Support multiple task assignment in one command with tasks ids separated
by commas. For example:

  $echo 123,456,789 > /sys/fs/resctrl/ctrl_grp1/tasks

Intel-SIG: commit fe2a20e x86/resctrl: Add multiple tasks to the resctrl group at once.
Incremental backporting patches for Intel RDT on Intel Xeon platform.

Signed-off-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Peter Newman <peternewman@google.com>
Reviewed-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com>
Link: https://lore.kernel.org/r/20231017002308.134480-2-babu.moger@amd.com
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit 6846dc1 upstream.

The rftype flags are bitmaps used for adding files under the resctrl
filesystem. Some of these bitmap defines have one extra level of
indirection which is not necessary.

Drop the RF_* defines and simplify the macros.

  [ bp: Massage commit message. ]

Intel-SIG: commit 6846dc1 x86/resctrl: Simplify rftype flag definitions.
Incremental backporting patches for Intel RDT on Intel Xeon platform.

Signed-off-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Peter Newman <peternewman@google.com>
Reviewed-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com>
Link: https://lore.kernel.org/r/20231017002308.134480-3-babu.moger@amd.com
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit d415924 upstream.

resctrl associates rftype flags with its files so that files can be chosen
based on the resource, whether it is info or base, and if it is control
or monitor type file. These flags use the RF_ as well as RFTYPE_ prefixes.

Change the prefix to RFTYPE_ for all these flags to be consistent.

Intel-SIG: commit d415924 x86/resctrl: Rename rftype flags for consistency.
Incremental backporting patches for Intel RDT on Intel Xeon platform.

Signed-off-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Peter Newman <peternewman@google.com>
Reviewed-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com>
Link: https://lore.kernel.org/r/20231017002308.134480-4-babu.moger@amd.com
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit df5f3a1 upstream.

rdt_enable_ctx() enables the features provided during resctrl mount.

Additions to rdt_enable_ctx() are required to also modify error paths
of rdt_enable_ctx() callers to ensure correct unwinding if errors
are encountered after calling rdt_enable_ctx(). This is error prone.

Introduce rdt_disable_ctx() to refactor the error unwinding of
rdt_enable_ctx() to simplify future additions. This also simplifies
cleanup in rdt_kill_sb().

Intel-SIG: commit df5f3a1 x86/resctrl: Unwind properly from rdt_enable_ctx().
Incremental backporting patches for Intel RDT on Intel Xeon platform.

Suggested-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Peter Newman <peternewman@google.com>
Reviewed-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com>
Link: https://lore.kernel.org/r/20231017002308.134480-5-babu.moger@amd.com
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit d27567a upstream.

The default resource group and its files are created during kernel init
time. Upcoming changes will make some resctrl files optional based on
a mount parameter. If optional files are to be added to the default
group based on the mount option, then each new file needs to be created
separately and call kernfs_activate() again.

Create all files of the default resource group during resctrl mount,
destroyed during unmount, to avoid scattering resctrl file addition
across two separate code flows.

Intel-SIG: commit d27567a x86/resctrl: Move default group file creation to mount.
Incremental backporting patches for Intel RDT on Intel Xeon platform.

Signed-off-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Peter Newman <peternewman@google.com>
Reviewed-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com>
Link: https://lore.kernel.org/r/20231017002308.134480-6-babu.moger@amd.com
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit cb07d71 upstream.

Add "-o debug" option to mount resctrl filesystem in debug mode.  When
in debug mode resctrl displays files that have the new RFTYPE_DEBUG flag
to help resctrl debugging.

Intel-SIG: commit cb07d71 x86/resctrl: Introduce "-o debug" mount option.
Incremental backporting patches for Intel RDT on Intel Xeon platform.

Signed-off-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Peter Newman <peternewman@google.com>
Reviewed-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com>
Link: https://lore.kernel.org/r/20231017002308.134480-7-babu.moger@amd.com
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit ca8dad2 upstream.

In x86, hardware uses CLOSID to identify a control group. When a user
creates a control group this information is not visible to the user. It
can help resctrl debugging.

Add CLOSID(ctrl_hw_id) to the control groups display in the resctrl
interface. Users can see this detail when resctrl is mounted with the
"-o debug" option.

Other architectures do not use "CLOSID". Use the names ctrl_hw_id to refer
to "CLOSID" in an effort to keep the naming generic.

For example:
  $cat /sys/fs/resctrl/ctrl_grp1/ctrl_hw_id
  1

Intel-SIG: commit ca8dad2 x86/resctrl: Display CLOSID for resource group.
Incremental backporting patches for Intel RDT on Intel Xeon platform.

Signed-off-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Peter Newman <peternewman@google.com>
Reviewed-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com>
Link: https://lore.kernel.org/r/20231017002308.134480-8-babu.moger@amd.com
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit 918f211 upstream.

Files unique to monitoring groups have the RFTYPE_MON flag. When a new
monitoring group is created the resctrl files with flags RFTYPE_BASE
(files common to all resource groups) and RFTYPE_MON (files unique to
monitoring groups) are created to support interacting with the new
monitoring group.

A resource group can support both monitoring and control, also termed
a CTRL_MON resource group. CTRL_MON groups should get both monitoring
and control resctrl files but that is not the case. Only the
RFTYPE_BASE and RFTYPE_CTRL files are created for CTRL_MON groups.

Ensure that files with the RFTYPE_MON flag are created for CTRL_MON groups.

Intel-SIG: commit 918f211 x86/resctrl: Add support for the files of MON groups only.
Incremental backporting patches for Intel RDT on Intel Xeon platform.

Signed-off-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Peter Newman <peternewman@google.com>
Reviewed-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com>
Link: https://lore.kernel.org/r/20231017002308.134480-9-babu.moger@amd.com
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit 4cee14b upstream.

In x86, hardware uses RMID to identify a monitoring group. When a user
creates a monitor group these details are not visible. These details
can help resctrl debugging.

Add RMID(mon_hw_id) to the monitor groups display in the resctrl interface.
Users can see these details when resctrl is mounted with "-o debug" option.

Add RFTYPE_MON_BASE that complements existing RFTYPE_CTRL_BASE and
represents files belonging to monitoring groups.

Other architectures do not use "RMID". Use the name mon_hw_id to refer
to "RMID" in an effort to keep the naming generic.

For example:
  $cat /sys/fs/resctrl/mon_groups/mon_grp1/mon_hw_id
  3

Intel-SIG: commit 4cee14b x86/resctrl: Display RMID of resource group.
Incremental backporting patches for Intel RDT on Intel Xeon platform.

Signed-off-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Peter Newman <peternewman@google.com>
Reviewed-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com>
Link: https://lore.kernel.org/r/20231017002308.134480-10-babu.moger@amd.com
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit 1b908de upstream.

In a "W=1" build gcc throws a warning:

  arch/x86/kernel/cpu/resctrl/core.c: In function ‘cache_alloc_hsw_probe’:
  arch/x86/kernel/cpu/resctrl/core.c:139:16: warning: variable ‘h’ set but not used

Switch from wrmsr_safe() to wrmsrl_safe(), and from rdmsr() to rdmsrl()
using a single u64 argument for the MSR value instead of the pair of u32
for the high and low halves.

Intel-SIG: commit 1b908de x86/resctrl: Fix unused variable warning in cache_alloc_hsw_probe().
Incremental backporting patches for Intel RDT on Intel Xeon platform.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Babu Moger <babu.moger@amd.com>
Acked-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lore.kernel.org/r/ZULCd/TGJL9Dmncf@agluck-desk3
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit fc747ee upstream.

The kernel test robot reported the following warning after commit

  54e35eb ("x86/resctrl: Read supported bandwidth sources from CPUID").

even though the issue is present even in the original commit

  92bd5a1 ("x86/resctrl: Add interface to write mbm_total_bytes_config")

which added this function. The reported warning is:

  $ make C=1 CHECK=scripts/coccicheck arch/x86/kernel/cpu/resctrl/rdtgroup.o
  ...
  arch/x86/kernel/cpu/resctrl/rdtgroup.c:1621:5-8: Unneeded variable: "ret". Return "0" on line 1655

Remove the local variable 'ret'.

  [ bp: Massage commit message, make mbm_config_write_domain() void. ]

Intel-SIG: commit fc747ee x86/resctrl: Remove redundant variable in mbm_config_write_domain().
Incremental backporting patches for Intel RDT on Intel Xeon platform.

Fixes: 92bd5a1 ("x86/resctrl: Add interface to write mbm_total_bytes_config")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202401241810.jbd8Ipa1-lkp@intel.com/
Signed-off-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lore.kernel.org/r/202401241810.jbd8Ipa1-lkp@intel.com
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit 31a5c0b upstream.

tick_nohz_full_mask lists the CPUs that are nohz_full. This is only needed when
CONFIG_NO_HZ_FULL is defined. tick_nohz_full_cpu() allows a specific CPU to be
tested against the mask, and evaluates to false when CONFIG_NO_HZ_FULL is not
defined.

The resctrl code needs to pick a CPU to run some work on, a new helper prefers
housekeeping CPUs by examining the tick_nohz_full_mask. Hiding the declaration
behind #ifdef CONFIG_NO_HZ_FULL forces all the users to be behind an #ifdef
too.

Move the tick_nohz_full_mask declaration, this lets callers drop the #ifdef,
and guard access to tick_nohz_full_mask with IS_ENABLED() or something like
tick_nohz_full_cpu().

The definition does not need to be moved as any callers should be removed at
compile time unless CONFIG_NO_HZ_FULL is defined.

Intel-SIG: commit 31a5c0b tick/nohz: Move tick_nohz_full_mask declaration outside the #ifdef.
Incremental backporting patches for Intel RDT on Intel Xeon platform.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Reinette Chatre <reinette.chatre@intel.com> # for resctrl dependency
Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64
Link: https://lore.kernel.org/r/20240213184438.16675-2-james.morse@arm.com
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit 3f7b073 upstream.

rmid_ptrs[] is allocated from dom_data_init() but never free()d.

While the exit text ends up in the linker script's DISCARD section,
the direction of travel is for resctrl to be/have loadable modules.

Add resctrl_put_mon_l3_config() to cleanup any memory allocated
by rdt_get_mon_l3_config().

There is no reason to backport this to a stable kernel.

Intel-SIG: commit 3f7b073 x86/resctrl: Free rmid_ptrs from resctrl_exit().
Incremental backporting patches for Intel RDT on Intel Xeon platform.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Babu Moger <babu.moger@amd.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64
Link: https://lore.kernel.org/r/20240213184438.16675-3-james.morse@arm.com
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit b1de313 upstream.

When monitoring is supported, each monitor and control group is allocated an
RMID. For control groups, rdtgroup_mkdir_ctrl_mon() later goes on to allocate
the CLOSID.

MPAM's equivalent of RMID are not an independent number, so can't be allocated
until the CLOSID is known. An RMID allocation for one CLOSID may fail, whereas
another may succeed depending on how many monitor groups a control group has.

The RMID allocation needs to move to be after the CLOSID has been allocated.

Move the RMID allocation and mondata dir creation to a helper.

Intel-SIG: commit b1de313 x86/resctrl: Create helper for RMID allocation and mondata dir creation.
Incremental backporting patches for Intel RDT on Intel Xeon platform.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Babu Moger <babu.moger@amd.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64
Link: https://lore.kernel.org/r/20240213184438.16675-4-james.morse@arm.com
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit 311639e upstream.

RMIDs are allocated for each monitor or control group directory, because
each of these needs its own RMID. For control groups,
rdtgroup_mkdir_ctrl_mon() later goes on to allocate the CLOSID.

MPAM's equivalent of RMID is not an independent number, so can't be
allocated until the CLOSID is known. An RMID allocation for one CLOSID
may fail, whereas another may succeed depending on how many monitor
groups a control group has.

The RMID allocation needs to move to be after the CLOSID has been
allocated.

Move the RMID allocation out of mkdir_rdt_prepare() to occur in its caller,
after the mkdir_rdt_prepare() call. This allows the RMID allocator to
know the CLOSID.

Intel-SIG: commit 311639e x86/resctrl: Move RMID allocation out of mkdir_rdt_prepare().
Incremental backporting patches for Intel RDT on Intel Xeon platform.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Babu Moger <babu.moger@amd.com>
Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64
Link: https://lore.kernel.org/r/20240213184438.16675-5-james.morse@arm.com
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit 40fc735 upstream.

x86's RMID are independent of the CLOSID. An RMID can be allocated,
used and freed without considering the CLOSID.

MPAM's equivalent feature is PMG, which is not an independent number,
it extends the CLOSID/PARTID space. For MPAM, only PMG-bits worth of
'RMID' can be allocated for a single CLOSID.
i.e. if there is 1 bit of PMG space, then each CLOSID can have two
monitor groups.

To allow resctrl to disambiguate RMID values for different CLOSID,
everything in resctrl that keeps an RMID value needs to know the CLOSID
too. This will always be ignored on x86.

Intel-SIG: commit 40fc735 x86/resctrl: Track the closid with the rmid.
Incremental backporting patches for Intel RDT on Intel Xeon platform.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Reviewed-by: Xin Hao <xhao@linux.alibaba.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64
Link: https://lore.kernel.org/r/20240213184438.16675-6-james.morse@arm.com
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit 6791e0e upstream.

x86 systems identify traffic using the CLOSID and RMID. The CLOSID is
used to lookup the control policy, the RMID is used for monitoring. For
x86 these are independent numbers.
Arm's MPAM has equivalent features PARTID and PMG, where the PARTID is
used to lookup the control policy. The PMG in contrast is a small number
of bits that are used to subdivide PARTID when monitoring. The
cache-occupancy monitors require the PARTID to be specified when
monitoring.

This means MPAM's PMG field is not unique. There are multiple PMG-0, one
per allocated CLOSID/PARTID. If PMG is treated as equivalent to RMID, it
cannot be allocated as an independent number. Bitmaps like rmid_busy_llc
need to be sized by the number of unique entries for this resource.

Treat the combined CLOSID and RMID as an index, and provide architecture
helpers to pack and unpack an index. This makes the MPAM values unique.
The domain's rmid_busy_llc and rmid_ptrs[] are then sized by index, as
are domain mbm_local[] and mbm_total[].

x86 can ignore the CLOSID field when packing and unpacking an index, and
report as many indexes as RMID.

Intel-SIG: commit 6791e0e x86/resctrl: Access per-rmid structures by index.
Incremental backporting patches for Intel RDT on Intel Xeon platform.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Reviewed-by: Babu Moger <babu.moger@amd.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64
Link: https://lore.kernel.org/r/20240213184438.16675-7-james.morse@arm.com
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit c4c0376 upstream.

MPAMs RMID values are not unique unless the CLOSID is considered as well.

alloc_rmid() expects the RMID to be an independent number.

Pass the CLOSID in to alloc_rmid(). Use this to compare indexes when
allocating. If the CLOSID is not relevant to the index, this ends up comparing
the free RMID with itself, and the first free entry will be used. With MPAM the
CLOSID is included in the index, so this becomes a walk of the free RMID
entries, until one that matches the supplied CLOSID is found.

Intel-SIG: commit c4c0376 x86/resctrl: Allow RMID allocation to be scoped by CLOSID.
Incremental backporting patches for Intel RDT on Intel Xeon platform.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Babu Moger <babu.moger@amd.com>
Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64
Link: https://lore.kernel.org/r/20240213184438.16675-8-james.morse@arm.com
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit b30a55d upstream.

MPAM's PMG bits extend its PARTID space, meaning the same PMG value can be
used for different control groups.

This means once a CLOSID is allocated, all its monitoring ids may still be
dirty, and held in limbo.

Keep track of the number of RMID held in limbo each CLOSID has. This will
allow a future helper to find the 'cleanest' CLOSID when allocating.

The array is only needed when CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID is
defined. This will never be the case on x86.

Intel-SIG: commit b30a55d x86/resctrl: Track the number of dirty RMID a CLOSID has.
Incremental backporting patches for Intel RDT on Intel Xeon platform.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Babu Moger <babu.moger@amd.com>
Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64
Link: https://lore.kernel.org/r/20240213184438.16675-9-james.morse@arm.com
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit 5d920b6 upstream.

The resctrl CLOSID allocator uses a single 32bit word to track which
CLOSID are free. The setting and clearing of bits is open coded.

Convert the existing open coded bit manipulations of closid_free_map
to use __set_bit() and friends. These don't need to be atomic as this
list is protected by the mutex.

Intel-SIG: commit 5d920b6 x86/resctrl: Use __set_bit()/__clear_bit() instead of open coding.
Incremental backporting patches for Intel RDT on Intel Xeon platform.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Babu Moger <babu.moger@amd.com>
Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64
Link: https://lore.kernel.org/r/20240213184438.16675-10-james.morse@arm.com
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
…ty_rmid

commit 6eac36b upstream.

MPAM's PMG bits extend its PARTID space, meaning the same PMG value can be used
for different control groups.

This means once a CLOSID is allocated, all its monitoring ids may still be
dirty, and held in limbo.

Instead of allocating the first free CLOSID, on architectures where
CONFIG_RESCTRL_RMID_DEPENDS_ON_CLOSID is enabled, search
closid_num_dirty_rmid[] to find the cleanest CLOSID.

The CLOSID found is returned to closid_alloc() for the free list
to be updated.

Intel-SIG: commit 6eac36b x86/resctrl: Allocate the cleanest CLOSID by searching closid_num_dirty_rmid.
Incremental backporting patches for Intel RDT on Intel Xeon platform.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Babu Moger <babu.moger@amd.com>
Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64
Link: https://lore.kernel.org/r/20240213184438.16675-11-james.morse@arm.com
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit 6eca639 upstream.

When switching tasks, the CLOSID and RMID that the new task should use
are stored in struct task_struct. For x86 the CLOSID known by resctrl,
the value in task_struct, and the value written to the CPU register are
all the same thing.

MPAM's CPU interface has two different PARTIDs - one for data accesses
the other for instruction fetch. Storing resctrl's CLOSID value in
struct task_struct implies the arch code knows whether resctrl is using
CDP.

Move the matching and setting of the struct task_struct properties to
use helpers. This allows arm64 to store the hardware format of the
register, instead of having to convert it each time.

__rdtgroup_move_task()s use of READ_ONCE()/WRITE_ONCE() ensures torn
values aren't seen as another CPU may schedule the task being moved
while the value is being changed. MPAM has an additional corner-case
here as the PMG bits extend the PARTID space.

If the scheduler sees a new-CLOSID but old-RMID, the task will dirty an
RMID that the limbo code is not watching causing an inaccurate count.

x86's RMID are independent values, so the limbo code will still be
watching the old-RMID in this circumstance.

To avoid this, arm64 needs both the CLOSID/RMID WRITE_ONCE()d together.
Both values must be provided together.

Because MPAM's RMID values are not unique, the CLOSID must be provided
when matching the RMID.

Intel-SIG: commit 6eca639 x86/resctrl: Move CLOSID/RMID matching and setting to use helpers.
Incremental backporting patches for Intel RDT on Intel Xeon platform.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Babu Moger <babu.moger@amd.com>
Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64
Link: https://lore.kernel.org/r/20240213184438.16675-12-james.morse@arm.com
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit a4846aa upstream.

The limbo and overflow code picks a CPU to use from the domain's list of online
CPUs. Work is then scheduled on these CPUs to maintain the limbo list and any
counters that may overflow.

cpumask_any() may pick a CPU that is marked nohz_full, which will either
penalise the work that CPU was dedicated to, or delay the processing of limbo
list or counters that may overflow. Perhaps indefinitely. Delaying the overflow
handling will skew the bandwidth values calculated by mba_sc, which expects to
be called once a second.

Add cpumask_any_housekeeping() as a replacement for cpumask_any() that prefers
housekeeping CPUs. This helper will still return a nohz_full CPU if that is the
only option. The CPU to use is re-evaluated each time the limbo/overflow work
runs. This ensures the work will move off a nohz_full CPU once a housekeeping
CPU is available.

Intel-SIG: commit a4846aa x86/resctrl: Add cpumask_any_housekeeping() for limbo/overflow.
Incremental backporting patches for Intel RDT on Intel Xeon platform.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Babu Moger <babu.moger@amd.com>
Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64
Link: https://lore.kernel.org/r/20240213184438.16675-13-james.morse@arm.com
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit 09909e0 upstream.

Intel is blessed with an abundance of monitors, one per RMID, that can be
read from any CPU in the domain. MPAMs monitors reside in the MMIO MSC,
the number implemented is up to the manufacturer. This means when there are
fewer monitors than needed, they need to be allocated and freed.

MPAM's CSU monitors are used to back the 'llc_occupancy' monitor file. The
CSU counter is allowed to return 'not ready' for a small number of
micro-seconds after programming. To allow one CSU hardware monitor to be
used for multiple control or monitor groups, the CPU accessing the
monitor needs to be able to block when configuring and reading the
counter.

Worse, the domain may be broken up into slices, and the MMIO accesses
for each slice may need performing from different CPUs.

These two details mean MPAMs monitor code needs to be able to sleep, and
IPI another CPU in the domain to read from a resource that has been sliced.

mon_event_read() already invokes mon_event_count() via IPI, which means
this isn't possible. On systems using nohz-full, some CPUs need to be
interrupted to run kernel work as they otherwise stay in user-space
running realtime workloads. Interrupting these CPUs should be avoided,
and scheduling work on them may never complete.

Change mon_event_read() to pick a housekeeping CPU, (one that is not using
nohz_full) and schedule mon_event_count() and wait. If all the CPUs
in a domain are using nohz-full, then an IPI is used as the fallback.

This function is only used in response to a user-space filesystem request
(not the timing sensitive overflow code).

This allows MPAM to hide the slice behaviour from resctrl, and to keep
the monitor-allocation in monitor.c. When the IPI fallback is used on
machines where MPAM needs to make an access on multiple CPUs, the counter
read will always fail.

Intel-SIG: commit 09909e0 x86/resctrl: Queue mon_event_read() instead of sending an IPI.
Incremental backporting patches for Intel RDT on Intel Xeon platform.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Reviewed-by: Peter Newman <peternewman@google.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Babu Moger <babu.moger@amd.com>
Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64
Link: https://lore.kernel.org/r/20240213184438.16675-14-james.morse@arm.com
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit 6fde142 upstream.

MPAM's cache occupancy counters can take a little while to settle once the
monitor has been configured. The maximum settling time is described to the
driver via a firmware table. The value could be large enough that it makes
sense to sleep. To avoid exposing this to resctrl, it should be hidden behind
MPAM's resctrl_arch_rmid_read().

resctrl_arch_rmid_read() may be called via IPI meaning it is unable to sleep.
In this case, it should return an error if it needs to sleep. This will only
affect MPAM platforms where the cache occupancy counter isn't available
immediately, nohz_full is in use, and there are no housekeeping CPUs in the
necessary domain.

There are three callers of resctrl_arch_rmid_read(): __mon_event_count() and
__check_limbo() are both called from a non-migrateable context.
mon_event_read() invokes __mon_event_count() using smp_call_on_cpu(), which
adds work to the target CPUs workqueue.  rdtgroup_mutex() is held, meaning this
cannot race with the resctrl cpuhp callback. __check_limbo() is invoked via
schedule_delayed_work_on() also adds work to a per-cpu workqueue.

The remaining call is add_rmid_to_limbo() which is called in response to
a user-space syscall that frees an RMID. This opportunistically reads the LLC
occupancy counter on the current domain to see if the RMID is over the dirty
threshold. This has to disable preemption to avoid reading the wrong domain's
value. Disabling preemption here prevents resctrl_arch_rmid_read() from
sleeping.

add_rmid_to_limbo() walks each domain, but only reads the counter on one
domain. If the system has more than one domain, the RMID will always be added
to the limbo list. If the RMIDs usage was not over the threshold, it will be
removed from the list when __check_limbo() runs.  Make this the default
behaviour. Free RMIDs are always added to the limbo list for each domain.

The user visible effect of this is that a clean RMID is not available for
re-allocation immediately after 'rmdir()' completes. This behaviour was never
portable as it never happened on a machine with multiple domains.

Removing this path allows resctrl_arch_rmid_read() to sleep if its called with
interrupts unmasked. Document this is the expected behaviour, and add
a might_sleep() annotation to catch changes that won't work on arm64.

Intel-SIG: commit 6fde142 x86/resctrl: Allow resctrl_arch_rmid_read() to sleep.
Incremental backporting patches for Intel RDT on Intel Xeon platform.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Babu Moger <babu.moger@amd.com>
Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64
Link: https://lore.kernel.org/r/20240213184438.16675-15-james.morse@arm.com
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
…d_read()

commit e557999 upstream.

Depending on the number of monitors available, Arm's MPAM may need to
allocate a monitor prior to reading the counter value. Allocating a
contended resource may involve sleeping.

__check_limbo() and mon_event_count() each make multiple calls to
resctrl_arch_rmid_read(), to avoid extra work on contended systems,
the allocation should be valid for multiple invocations of
resctrl_arch_rmid_read().

The memory or hardware allocated is not specific to a domain.

Add arch hooks for this allocation, which need calling before
resctrl_arch_rmid_read(). The allocated monitor is passed to
resctrl_arch_rmid_read(), then freed again afterwards. The helper
can be called on any CPU, and can sleep.

Intel-SIG: commit e557999 x86/resctrl: Allow arch to allocate memory needed in resctrl_arch_rmid_read().
Incremental backporting patches for Intel RDT on Intel Xeon platform.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Babu Moger <babu.moger@amd.com>
Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64
Link: https://lore.kernel.org/r/20240213184438.16675-16-james.morse@arm.com
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit 13e5769 upstream.

The rdt_enable_key is switched when resctrl is mounted, and used to prevent
a second mount of the filesystem. It also enables the architecture's context
switch code.

This requires another architecture to have the same set of static keys, as
resctrl depends on them too. The existing users of these static keys are
implicitly also checking if the filesystem is mounted.

Make the resctrl_mounted checks explicit: resctrl can keep track of whether it
has been mounted once. This doesn't need to be combined with whether the arch
code is context switching the CLOSID.

rdt_mon_enable_key is never used just to test that resctrl is mounted, but does
also have this implication. Add a resctrl_mounted to all uses of
rdt_mon_enable_key.

This will allow the static key changing to be moved behind resctrl_arch_ calls.

Intel-SIG: commit 13e5769 x86/resctrl: Make resctrl_mounted checks explicit.
Incremental backporting patches for Intel RDT on Intel Xeon platform.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Babu Moger <babu.moger@amd.com>
Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64
Link: https://lore.kernel.org/r/20240213184438.16675-17-james.morse@arm.com
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit 5db6a4a upstream.

resctrl enables three static keys depending on the features it has enabled.
Another architecture's context switch code may look different, any static keys
that control it should be buried behind helpers.

Move the alloc/mon logic into arch-specific helpers as a preparatory step for
making the rdt_enable_key's status something the arch code decides.

This means other architectures don't have to mirror the static keys.

Intel-SIG: commit 5db6a4a x86/resctrl: Move alloc/mon static keys into helpers.
Incremental backporting patches for Intel RDT on Intel Xeon platform.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Babu Moger <babu.moger@amd.com>
Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64
Link: https://lore.kernel.org/r/20240213184438.16675-18-james.morse@arm.com
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit 0a2f4d9 upstream.

rdt_enable_key is switched when resctrl is mounted. It was also previously used
to prevent a second mount of the filesystem.

Any other architecture that wants to support resctrl has to provide identical
static keys.

Now that there are helpers for enabling and disabling the alloc/mon keys,
resctrl doesn't need to switch this extra key, it can be done by the arch code.
Use the static-key increment and decrement helpers, and change resctrl to
ensure the calls are balanced.

Intel-SIG: commit 0a2f4d9 x86/resctrl: Make rdt_enable_key the arch's decision to switch.
Incremental backporting patches for Intel RDT on Intel Xeon platform.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Babu Moger <babu.moger@amd.com>
Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64
Link: https://lore.kernel.org/r/20240213184438.16675-19-james.morse@arm.com
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
hfxsp and others added 30 commits September 18, 2024 13:46
commit 931be44 upstream.

In our production environment, after removing monitor groups, those
unused RMIDs get stuck in the limbo list forever because their
llc_occupancy is always larger than the threshold. But the unused RMIDs
can be successfully freed by turning up the threshold.

In order to know how much the threshold should be, perf can be used to
acquire the llc_occupancy of RMIDs in each rdt domain.

Instead of using perf tool to track llc_occupancy and filter the log
manually, it is more convenient for users to use tracepoint to do this
work. So add a new tracepoint that shows the llc_occupancy of busy RMIDs
when scanning the limbo list.

Intel-SIG: commit 931be44 x86/resctrl: Add tracepoint for llc_occupancy tracking.
Incremental backporting patches for Intel RDT on Intel Xeon platform.

Suggested-by: Reinette Chatre <reinette.chatre@intel.com>
Suggested-by: James Morse <james.morse@arm.com>
Signed-off-by: Haifeng Xu <haifeng.xu@shopee.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: James Morse <james.morse@arm.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lore.kernel.org/r/20240408092303.26413-3-haifeng.xu@shopee.com
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit 739c976 upstream.

Commit

  6791e0e ("x86/resctrl: Access per-rmid structures by index")

adds logic to map individual monitoring groups into a global index space used
for tracking allocated RMIDs.

Attempts to free the default RMID are ignored in free_rmid(), and this works
fine on x86.

With arm64 MPAM, there is a latent bug here however: on platforms with no
monitors exposed through resctrl, each control group still gets a different
monitoring group ID as seen by the hardware, since the CLOSID always forms part
of the monitoring group ID.

This means that when removing a control group, the code may try to free this
group's default monitoring group RMID for real.  If there are no monitors
however, the RMID tracking table rmid_ptrs[] would be a waste of memory and is
never allocated, leading to a splat when free_rmid() tries to dereference the
table.

One option would be to treat RMID 0 as special for every CLOSID, but this would
be ugly since bookkeeping still needs to be done for these monitoring group IDs
when there are monitors present in the hardware.

Instead, add a gating check of resctrl_arch_mon_capable() in free_rmid(), and
just do nothing if the hardware doesn't have monitors.

This fix mirrors the gating checks already present in
mkdir_rdt_prepare_rmid_alloc() and elsewhere.

No functional change on x86.

  [ bp: Massage commit message. ]

Intel-SIG: commit 739c976 x86/resctrl: Don't try to free nonexistent RMIDs.
Incremental backporting patches for Intel RDT on Intel Xeon platform.

Fixes: 6791e0e ("x86/resctrl: Access per-rmid structures by index")
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lore.kernel.org/r/20240618140152.83154-1-Dave.Martin@arm.com
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit 195fb51 upstream.

Avoid upcoming #include hell when <linux/cachinfo.h> wants to use
lockdep_assert_cpus_held() and creates a #include loop that would
break the build for arch/riscv.

  [ bp: s/cpu/CPU/g ]

Intel-SIG: commit 195fb51 cpu: Move CPU hotplug function declarations into their own header.
Backporting patches for Intel RDT monitoring with SNC on Intel Xeon platform.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20240610003927.341707-2-tony.luck@intel.com
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit ddefcfd upstream.

This file was created with a direct cut and paste from cpu.h so
kept the legacy declaration style.

But the Linux coding standard for function declarations in header
files is to avoid use of "extern".

Drop "extern" from all function declarations.

Intel-SIG: commit ddefcfd cpu: Drop "extern" from function declarations in cpuhplock.h.
Backporting patches for Intel RDT monitoring with SNC on Intel Xeon platform.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20240610003927.341707-3-tony.luck@intel.com
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit 685cb16 upstream.

Resctrl open codes a search for information about a given cache level in
a couple of places (and more are on the way).

Provide a new inline function get_cpu_cacheinfo_level() in
<linux/cacheinfo.h> to do the search and return a pointer to the
cacheinfo structure.

Add lockdep_assert_cpus_held() to enforce the comment that cpuhp lock
must be held.

Simplify the existing get_cpu_cacheinfo_id() by using this new function
to do the search.

Intel-SIG: commit 685cb16 cacheinfo: Add function to get cacheinfo for a given CPU and cache level.
Backporting patches for Intel RDT monitoring with SNC on Intel Xeon platform.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lore.kernel.org/r/20240610003927.341707-4-tony.luck@intel.com
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit f385f02 upstream.

pseudo_lock_region_init() and rdtgroup_cbm_to_size() open code a search for
details of a particular cache level.

Replace with get_cpu_cacheinfo_level().

Intel-SIG: commit f385f02 x86/resctrl: Replace open coded cacheinfo searches.
Backporting patches for Intel RDT monitoring with SNC on Intel Xeon platform.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lore.kernel.org/r/20240610003927.341707-5-tony.luck@intel.com
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit f436cb6 upstream.

Resctrl resources operate on subsets of CPUs in the system with the
defining attribute of each subset being an instance of a particular
level of cache. E.g. all CPUs sharing an L3 cache would be part of the
same domain.

In preparation for features that are scoped at the NUMA node level,
change the code from explicit references to "cache_level" to a more
generic scope. At this point the only options for this scope are groups
of CPUs that share an L2 cache or L3 cache.

Clean up the error handling when looking up domains. Report invalid ids
before calling rdt_find_domain() in preparation for better messages when
scope can be other than cache scope. This means that rdt_find_domain()
will never return an error. So remove checks for error from the call sites.

Intel-SIG: commit f436cb6 x86/resctrl: Prepare for new domain scope.
Backporting patches for Intel RDT monitoring with SNC on Intel Xeon platform.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://lore.kernel.org/r/20240628215619.76401-2-tony.luck@intel.com
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit c103d4d upstream.

The rdt_domain structure is used for both control and monitor features.
It is about to be split into separate structures for these two usages
because the scope for control and monitoring features for a resource
will be different for future resources.

To allow for common code that scans a list of domains looking for a
specific domain id, move all the common fields ("list", "id", "cpu_mask")
into their own structure within the rdt_domain structure.

Intel-SIG: commit c103d4d x86/resctrl: Prepare to split rdt_domain structure.
Backporting patches for Intel RDT monitoring with SNC on Intel Xeon platform.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://lore.kernel.org/r/20240628215619.76401-3-tony.luck@intel.com
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit cd84f72 upstream.

Resctrl assumes that control and monitor operations on a resource are
performed at the same scope.

Prepare for systems that use different scope (specifically Intel needs
to split the RDT_RESOURCE_L3 resource to use L3 scope for cache control
and NODE scope for cache occupancy and memory bandwidth monitoring).

Create separate domain lists for control and monitor operations.

Note that errors during initialization of either control or monitor
functions on a domain would previously result in that domain being
excluded from both control and monitor operations. Now the domains are
allocated independently it is no longer required to disable both control
and monitor operations if either fail.

Intel-SIG: commit cd84f72 x86/resctrl: Prepare for different scope for control/monitor operations.
Backporting patches for Intel RDT monitoring with SNC on Intel Xeon platform.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://lore.kernel.org/r/20240628215619.76401-4-tony.luck@intel.com
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit cae2bcb upstream.

The same rdt_domain structure is used for both control and monitor
functions. But this results in wasted memory as some of the fields are
only used by control functions, while most are only used for monitor
functions.

Split into separate rdt_ctrl_domain and rdt_mon_domain structures with
just the fields required for control and monitoring respectively.

Similar split of the rdt_hw_domain structure into rdt_hw_ctrl_domain
and rdt_hw_mon_domain.

Intel-SIG: commit cae2bcb x86/resctrl: Split the rdt_domain and rdt_hw_domain structures.
Backporting patches for Intel RDT monitoring with SNC on Intel Xeon platform.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://lore.kernel.org/r/20240628215619.76401-5-tony.luck@intel.com
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit 1a17160 upstream.

Currently supported resctrl features are all domain scoped the same as the
scope of the L2 or L3 caches.

Add RESCTRL_L3_NODE as a new option for features that are scoped at the
same granularity as NUMA nodes. This is needed for Intel's Sub-NUMA
Cluster (SNC) feature where monitoring features are divided between
nodes that share an L3 cache.

Intel-SIG: commit 1a17160 x86/resctrl: Add node-scope to the options for feature scope.
Backporting patches for Intel RDT monitoring with SNC on Intel Xeon platform.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://lore.kernel.org/r/20240628215619.76401-6-tony.luck@intel.com
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit e13db55 upstream.

Intel Sub-NUMA Cluster (SNC) is a feature that subdivides the CPU cores
and memory controllers on a socket into two or more groups. These are
presented to the operating system as NUMA nodes.

This may enable some workloads to have slightly lower latency to memory
as the memory controller(s) in an SNC node are electrically closer to the
CPU cores on that SNC node. This cost may be offset by lower bandwidth
since the memory accesses for each core can only be interleaved between
the memory controllers on the same SNC node.

Resctrl monitoring on an Intel system depends upon attaching RMIDs to tasks
to track L3 cache occupancy and memory bandwidth. There is an MSR that
controls how the RMIDs are shared between SNC nodes.

The default mode divides them numerically. E.g. when there are two SNC
nodes on a socket the lower number half of the RMIDs are given to the
first node, the remainder to the second node. This would be difficult
to use with the Linux resctrl interface as specific RMID values assigned
to resctrl groups are not visible to users.

RMID sharing mode divides the physical RMIDs evenly between SNC nodes
but uses a logical RMID in the IA32_PQR_ASSOC MSR. For example a system
with 200 physical RMIDs (as enumerated by CPUID leaf 0xF) that has two
SNC nodes per L3 cache instance would have 100 logical RMIDs available
for Linux to use. A task running on SNC node 0 with RMID 5 would
accumulate LLC occupancy and MBM bandwidth data in physical RMID 5.
Another task using RMID 5, but running on SNC node 1 would accumulate
data in physical RMID 105.

Even with this renumbering SNC mode requires several changes in resctrl
behavior for correct operation.

Add a static global to arch/x86/kernel/cpu/resctrl/monitor.c to indicate
how many SNC domains share an L3 cache instance.  Initialize this to
"1". Runtime detection of SNC mode will adjust this value.

Update all places to take appropriate action when SNC mode is enabled:
1) The number of logical RMIDs per L3 cache available for use is the
   number of physical RMIDs divided by the number of SNC nodes.
2) Likewise the "mon_scale" value must be divided by the number of SNC
   nodes.
3) Add a function to convert from logical RMID values (assigned to
   tasks and loaded into the IA32_PQR_ASSOC MSR on context switch)
   to physical RMID values to load into IA32_QM_EVTSEL MSR when
   reading counters on each SNC node.

Intel-SIG: commit e13db55 x86/resctrl: Introduce snc_nodes_per_l3_cache.
Backporting patches for Intel RDT monitoring with SNC on Intel Xeon platform.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://lore.kernel.org/r/20240628215619.76401-7-tony.luck@intel.com
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
…SNC) systems

commit ac20aa4 upstream.

When SNC is enabled there is a mismatch between the MBA control function
which operates at L3 cache scope and the MBM monitor functions which
measure memory bandwidth on each SNC node.

Block use of the mba_MBps when scopes for MBA/MBM do not match.

Improve user diagnostics by adding invalfc() message when mba_MBps
is not supported.

Intel-SIG: commit ac20aa4 x86/resctrl: Block use of mba_MBps mount option on Sub-NUMA Cluster (SNC) systems.
Backporting patches for Intel RDT monitoring with SNC on Intel Xeon platform.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://lore.kernel.org/r/20240628215619.76401-8-tony.luck@intel.com
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit 328ea68 upstream.

When SNC is enabled, monitoring data is collected at the SNC node granularity,
but must be reported at L3-cache granularity for backwards compatibility in
addition to reporting at the node level.

Add a "ci" field to the rdt_mon_domain structure to save the cache information
about the enclosing L3 cache for the domain.  This provides:

1) The cache id which is needed to compose the name of the legacy monitoring
   directory, and to determine which domains should be summed to provide
   L3-scoped data.

2) The shared_cpu_map which is needed to determine which CPUs can be used to
   read the RMID counters with the MSR interface.

This is the first step to an eventual goal of monitor reporting files like this
(for a system with two SNC nodes per L3):

  $ cd /sys/fs/resctrl/mon_data
  $ tree mon_L3_00
  mon_L3_00			<- 00 here is L3 cache id
  ├── llc_occupancy		\  These files provide legacy support
  ├── mbm_local_bytes		 > for non-SNC aware monitor apps
  ├── mbm_total_bytes		/  that expect data at L3 cache level
  ├── mon_sub_L3_00		<- 00 here is SNC node id
  │   ├── llc_occupancy		\  These files are finer grained
  │   ├── mbm_local_bytes		 > data from each SNC node
  │   └── mbm_total_bytes		/
  └── mon_sub_L3_01
      ├── llc_occupancy		\
      ├── mbm_local_bytes		 > As above, but for node 1.
      └── mbm_total_bytes		/

  [ bp: Massage commit message. ]

Intel-SIG: commit 328ea68 x86/resctrl: Prepare for new Sub-NUMA Cluster (SNC) monitor files.
Backporting patches for Intel RDT monitoring with SNC on Intel Xeon platform.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://lore.kernel.org/r/20240628215619.76401-9-tony.luck@intel.com
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
…ains

commit fb1f51f upstream.

When a user reads a monitor file rdtgroup_mondata_show() calls mon_event_read()
to package up all the required details into an rmid_read structure which is
passed across the smp_call*() infrastructure to code that will read data from
hardware and return the value (or error status) in the rmid_read structure.

Sub-NUMA Cluster (SNC) mode adds files with new semantics. These require the
smp_call-ed code to sum event data from all domains that share an L3 cache.

Add a pointer to the L3 "cacheinfo" structure to struct rmid_read for the data
collection routines to use to pick the domains to be summed.

  [ Reinette: the rmid_read structure has become complex enough so document each
    of its fields and provide the kerneldoc documentation for struct rmid_read. ]

Intel-SIG: commit fb1f51f x86/resctrl: Add a new field to struct rmid_read for summation of domains.
Backporting patches for Intel RDT monitoring with SNC on Intel Xeon platform.

Co-developed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://lore.kernel.org/r/20240628215619.76401-10-tony.luck@intel.com
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit 587edd7 upstream.

New semantics rely on some struct rmid_read members having NULL values to
distinguish between the SNC and non-SNC scenarios.  resctrl can thus no longer
rely on this struct not being initialized properly.

Initialize all on-stack declarations of struct rmid_read:

  rdtgroup_mondata_show()
  mbm_update()
  mkdir_mondata_subdir()

to ensure that garbage values from the stack are not passed down to other
functions.

  [ bp: Massage commit message. ]

Intel-SIG: commit 587edd7 x86/resctrl: Initialize on-stack struct rmid_read instances.
Backporting patches for Intel RDT monitoring with SNC on Intel Xeon platform.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://lore.kernel.org/r/20240628215619.76401-11-tony.luck@intel.com
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit 603cf1e upstream.

In Sub-NUMA Cluster (SNC) mode Linux must create the monitor
files in the original "mon_L3_XX" directories and also in each
of the "mon_sub_L3_YY" directories.

Refactor mkdir_mondata_subdir() to move the creation of monitoring files
into a helper function to avoid the need to duplicate code later.

No functional change.

Intel-SIG: commit 603cf1e x86/resctrl: Refactor mkdir_mondata_subdir() with a helper function.
Backporting patches for Intel RDT monitoring with SNC on Intel Xeon platform.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://lore.kernel.org/r/20240628215619.76401-12-tony.luck@intel.com
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit 92b5d0b upstream.

When Sub-NUMA Cluster (SNC) mode is enabled, the legacy monitor reporting files
must report the sum of the data from all of the SNC nodes that share the L3
cache that is referenced by the monitor file.

Resctrl squeezes all the attributes of these files into 32 bits so they can be
stored in the "priv" field of struct kernfs_node.

Currently, only three monitor events are defined by enum resctrl_event_id so
reducing it from 8 bits to 7 bits still provides more than enough space to
represent all the known event types.

But note that this choice was arbitrary.  The "rid" field is also far wider
than needed for the current number of resource id types.  This structure is
purely internal to resctrl, no ABI issues with modifying it. Subsequent changes
may rearrange the allocation of bits between each of the fields as needed.

Give the bit to a new "sum" field that indicates that reading this file must
sum across SNC nodes. This bit also indicates that the domid field is the id of
an L3 cache (instead of a domain id) to find which domains must be summed.

Fix up other issues in the kerneldoc description for mon_data_bits.

Intel-SIG: commit 92b5d0b x86/resctrl: Allocate a new field in union mon_data_bits.
Backporting patches for Intel RDT monitoring with SNC on Intel Xeon platform.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://lore.kernel.org/r/20240628215619.76401-13-tony.luck@intel.com
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit 0158ed6 upstream.

When SNC mode is enabled, create subdirectories and files to monitor at the SNC
node granularity. Legacy behavior is preserved by tagging the monitor files at
the L3 granularity with the "sum" attribute.  When the user reads these files
the kernel will read monitor data from all SNC nodes that share the same L3
cache instance and return the aggregated value to the user.

Note that the "domid" field for files that must sum across SNC domains has the
L3 cache instance id, while non-summing files use the domain id.

The "sum" files do not need to make a call to mon_event_read() to initialize
the MBM counters. This will be handled by initializing the individual SNC nodes
that share the L3.

Intel-SIG: commit 0158ed6 x86/resctrl: Create Sub-NUMA Cluster (SNC) monitor files.
Backporting patches for Intel RDT monitoring with SNC on Intel Xeon platform.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://lore.kernel.org/r/20240628215619.76401-14-tony.luck@intel.com
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit 6b48b80 upstream.

In SNC mode, there are multiple subdirectories in each L3 level monitor
directory (one for each SNC node). If all the CPUs in an SNC node are taken
offline, just remove the SNC directory for that node. In non-SNC mode, or when
the last SNC node directory is removed, remove the L3 monitor directory.

Add a helper function to avoid duplicated code.

Intel-SIG: commit 6b48b80 x86/resctrl: Handle removing directories in Sub-NUMA Cluster (SNC) mode.
Backporting patches for Intel RDT monitoring with SNC on Intel Xeon platform.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lore.kernel.org/r/20240702173820.90368-2-tony.luck@intel.com
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
…ounter

commit c8c7d3d upstream.

mon_event_read() fills out most fields of the struct rmid_read that is passed
via an smp_call*() function to a CPU that is part of the correct domain to
read the monitor counters.

With Sub-NUMA Cluster (SNC) mode there are now two cases to handle:

1) Reading a file that returns a value for a single domain.
   + Choose the CPU to execute from the domain cpu_mask

2) Reading a file that must sum across domains sharing an L3 cache
   instance.
   + Indicate to called code that a sum is needed by passing a NULL
     rdt_mon_domain pointer.
   + Choose the CPU from the L3 shared_cpu_map.

Intel-SIG: commit c8c7d3d x86/resctrl: Fill out rmid_read structure for smp_call*() to read a counter.
Backporting patches for Intel RDT monitoring with SNC on Intel Xeon platform.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://lore.kernel.org/r/20240628215619.76401-16-tony.luck@intel.com
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit 9fbb303 upstream.

Legacy resctrl monitor files must provide the sum of event values across
all Sub-NUMA Cluster (SNC) domains that share an L3 cache instance.

There are now two cases:
1) A specific domain is provided in struct rmid_read
   This is either a non-SNC system, or the request is to read data
   from just one SNC node.
2) Domain pointer is NULL. In this case the cacheinfo field in struct
   rmid_read indicates that all SNC nodes that share that L3 cache
   instance should have the event read and return the sum of all
   values.

Update the CPU sanity check. The existing check that an event is read
from a CPU in the requested domain still applies when reading a single
domain. But when summing across domains a more relaxed check that the
current CPU is in the scope of the L3 cache instance is appropriate
since the MSRs to read events are scoped at L3 cache level.

Intel-SIG: commit 9fbb303 x86/resctrl: Make __mon_event_count() handle sum domains.
Backporting patches for Intel RDT monitoring with SNC on Intel Xeon platform.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://lore.kernel.org/r/20240628215619.76401-17-tony.luck@intel.com
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit 21b362c upstream.

Hardware has two RMID configuration options for SNC systems. The default
mode divides RMID counters between SNC nodes. E.g. with 200 RMIDs and
two SNC nodes per L3 cache RMIDs 0..99 are used on node 0, and 100..199
on node 1. This isn't compatible with Linux resctrl usage. On this
example system a process using RMID 5 would only update monitor counters
while running on SNC node 0.

The other mode is "RMID Sharing Mode". This is enabled by clearing bit
0 of the RMID_SNC_CONFIG (0xCA0) model specific register. In this mode
the number of logical RMIDs is the number of physical RMIDs (from CPUID
leaf 0xF) divided by the number of SNC nodes per L3 cache instance. A
process can use the same RMID across different SNC nodes.

See the "Intel Resource Director Technology Architecture Specification"
for additional details.

When SNC is enabled, update the MSR when a monitor domain is marked
online. Technically this is overkill. It only needs to be done once
per L3 cache instance rather than per SNC domain. But there is no harm
in doing it more than once, and this is not in a critical path.

Intel-SIG: commit 21b362c x86/resctrl: Enable shared RMID mode on Sub-NUMA Cluster (SNC) systems.
Backporting patches for Intel RDT monitoring with SNC on Intel Xeon platform.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lore.kernel.org/r/20240702173820.90368-3-tony.luck@intel.com
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit 1348815 upstream.

There isn't a simple hardware bit that indicates whether a CPU is running in
Sub-NUMA Cluster (SNC) mode. Infer the state by comparing the number of CPUs
sharing the L3 cache with CPU0 to the number of CPUs in the same NUMA node as
CPU0.

Add the missing definition of pr_fmt() to monitor.c. This wasn't noticed
before as there are only "can't happen" console messages from this file.

  [ bp: Massage commit message. ]

Intel-SIG: commit 1348815 x86/resctrl: Detect Sub-NUMA Cluster (SNC) mode.
Backporting patches for Intel RDT monitoring with SNC on Intel Xeon platform.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://lore.kernel.org/r/20240628215619.76401-19-tony.luck@intel.com
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit ea34999 upstream.

With Sub-NUMA Cluster (SNC) mode enabled, the scope of monitoring resources
is per-NODE instead of per-L3 cache. Backwards compatibility is maintained
by providing files in the mon_L3_XX directories that sum event counts
for all SNC nodes sharing an L3 cache.

New files provide per-SNC node event counts.

Users should be aware that SNC mode also affects the amount of L3 cache
available for allocation within each SNC node.

Intel-SIG: commit ea34999 x86/resctrl: Update documentation with Sub-NUMA cluster changes.
Backporting patches for Intel RDT monitoring with SNC on Intel Xeon platform.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://lore.kernel.org/r/20240628215619.76401-20-tony.luck@intel.com
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
commit a547a58 upstream.

When using resctrl on systems with Sub-NUMA Clustering enabled, monitoring
groups may be allocated RMID values which would overrun the
arch_mbm_{local,total} arrays.

This is due to inconsistencies in whether the SNC-adjusted num_rmid value or
the unadjusted value in resctrl_arch_system_num_rmid_idx() is used. The
num_rmid value for the L3 resource is currently:

  resctrl_arch_system_num_rmid_idx() / snc_nodes_per_l3_cache

As a simple fix, make resctrl_arch_system_num_rmid_idx() return the
SNC-adjusted, L3 num_rmid value on x86.

Intel-SIG: commit a547a58 x86/resctrl: Fix arch_mbm_* array overrun on SNC.
Backporting patches for Intel RDT monitoring with SNC on Intel Xeon platform.

Fixes: e13db55 ("x86/resctrl: Introduce snc_nodes_per_l3_cache")
Signed-off-by: Peter Newman <peternewman@google.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lore.kernel.org/r/20240822190212.1848788-1-peternewman@google.com
[ Xiaochen Shen: amend commit log ]
Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
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