linux-stable.git/arch/x86/kernel/cpu/resctrl/ctrlmondata.c, branch v6.2

x86/resctrl: Remove arch_has_empty_bitmaps

2022-10-24T08:30:29+00:00

The field arch_has_empty_bitmaps is not required anymore. The field
min_cbm_bits is enough to validate the CBM (capacity bit mask) if the
architecture can support the zero CBM or not.

Suggested-by: Reinette Chatre 
Signed-off-by: Babu Moger 
Signed-off-by: Borislav Petkov 
Reviewed-by: Reinette Chatre 
Reviewed-by: Fenghua Yu 
Link: https://lore.kernel.org/r/166430979654.372014.615622285687642644.stgit@bmoger-ubuntu

x86/resctrl: Make resctrl_arch_rmid_read() return values in bytes

2022-09-23T12:25:05+00:00

resctrl_arch_rmid_read() returns a value in chunks, as read from the
hardware. This needs scaling to bytes by mon_scale, as provided by
the architecture code.

Now that resctrl_arch_rmid_read() performs the overflow and corrections
itself, it may as well return a value in bytes directly. This allows
the accesses to the architecture specific 'hw' structure to be removed.

Move the mon_scale conversion into resctrl_arch_rmid_read().
mbm_bw_count() is updated to calculate bandwidth from bytes.

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/20220902154829.30399-22-james.morse@arm.com

x86/resctrl: Abstract __rmid_read()

2022-09-23T12:17:20+00:00

__rmid_read() selects the specified eventid and returns the counter
value from the MSR. The error handling is architecture specific, and
handled by the callers, rdtgroup_mondata_show() and __mon_event_count().

Error handling should be handled by architecture specific code, as
a different architecture may have different requirements. MPAM's
counters can report that they are 'not ready', requiring a second
read after a short delay. This should be hidden from resctrl.

Make __rmid_read() the architecture specific function for reading
a counter. Rename it resctrl_arch_rmid_read() and move the error
handling into it.

A read from a counter that hardware supports but resctrl does not
now returns -EINVAL instead of -EIO from the default case in
__mon_event_count(). It isn't possible for user-space to see this
change as resctrl doesn't expose counters it doesn't support.

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/20220902154829.30399-16-james.morse@arm.com

x86/resctrl: Allow update_mba_bw() to update controls directly

2022-09-22T15:43:44+00:00

update_mba_bw() calculates a new control value for the MBA resource
based on the user provided mbps_val and the current measured
bandwidth. Some control values need remapping by delay_bw_map().

It does this by calling wrmsrl() directly. This needs splitting
up to be done by an architecture specific helper, so that the
remainder can eventually be moved to /fs/.

Add resctrl_arch_update_one() to apply one configuration value
to the provided resource and domain. This avoids the staging
and cross-calling that is only needed with changes made by
user-space. delay_bw_map() moves to be part of the arch code,
to maintain the 'percentage control' view of MBA resources
in resctrl.

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/20220902154829.30399-12-james.morse@arm.com

x86/resctrl: Switch over to the resctrl mbps_val list

2022-09-22T15:34:08+00:00

Updates to resctrl's software controller follow the same path as
other configuration updates, but they don't modify the hardware state.
rdtgroup_schemata_write() uses parse_line() and the resource's
parse_ctrlval() function to stage the configuration.
resctrl_arch_update_domains() then updates the mbps_val[] array
instead, and resctrl_arch_update_domains() skips the rdt_ctrl_update()
call that would update hardware.

This complicates the interface between resctrl's filesystem parts
and architecture specific code. It should be possible for mba_sc
to be completely implemented by the filesystem parts of resctrl. This
would allow it to work on a second architecture with no additional code.
resctrl_arch_update_domains() using the mbps_val[] array prevents this.

Change parse_bw() to write the configuration value directly to the
mbps_val[] array in the domain structure. Change rdtgroup_schemata_write()
to skip the call to resctrl_arch_update_domains(), meaning all the
mba_sc specific code in resctrl_arch_update_domains() can be removed.
On the read-side, show_doms() and update_mba_bw() are changed to read
the mbps_val[] array from the domain structure. With this,
resctrl_arch_get_config() no longer needs to consider mba_sc resources.

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/20220902154829.30399-10-james.morse@arm.com

x86/resctrl: Make resctrl_arch_get_config() return its value

2021-08-11T16:42:53+00:00

resctrl_arch_get_config() has no return, but does pass a single value
back via one of its arguments.

Return the value instead.

Suggested-by: Borislav Petkov 
Signed-off-by: James Morse 
Signed-off-by: Borislav Petkov 
Link: https://lkml.kernel.org/r/20210811163831.14917-1-james.morse@arm.com

x86/resctrl: Expand resctrl_arch_update_domains()'s msr_param range

2021-08-11T16:37:02+00:00

resctrl_arch_update_domains() specifies the one closid that has been
modified and needs copying to the hardware.

resctrl_arch_update_domains() takes a struct rdt_resource and a closid
as arguments, but copies all the staged configurations for that closid
into the ctrl_val[] array.

resctrl_arch_update_domains() is called once per schema, but once the
resources and domains are merged, the second call of a L2CODE/L2DATA
pair will find no staged configurations, as they were previously
applied. The msr_param of the first call only has one index, so would
only have update the hardware for the last staged configuration.

To avoid a second round of IPIs when changing L2CODE and L2DATA in one
go, expand the range of the msr_param if multiple staged configurations
are found.

Signed-off-by: James Morse 
Signed-off-by: Borislav Petkov 
Reviewed-by: Reinette Chatre 
Tested-by: Babu Moger 
Link: https://lkml.kernel.org/r/20210728170637.25610-24-james.morse@arm.com

x86/resctrl: Calculate the index from the configuration type

2021-08-11T16:19:06+00:00

resctrl uses cbm_idx() to map a closid to an index in the configuration
array. This is based on a multiplier and offset that are held in the
resource.

To merge the resources, the resctrl arch code needs to calculate the
index from something else, as there will only be one resource.

Decide based on the staged configuration type. This makes the static
mult and offset parameters redundant.

 [ bp: Remove superfluous brackets in get_config_index() ]

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/20210728170637.25610-21-james.morse@arm.com

x86/resctrl: Apply offset correction when config is staged

2021-08-11T16:03:28+00:00

When resctrl comes to copy the CAT MSR values from the ctrl_val[] array
into hardware, it applies an offset adjustment based on the type of
the resource. CODE and DATA resources have their closid mapped into an
odd/even range. This mapping is based on a property of the resource.

This happens once the new control value has been written to the ctrl_val[]
array. Once the CDP resources are merged, there will only be a single
property that needs to cover both odd/even mappings to the single
ctrl_val[] array. The offset adjustment must be applied before the new
value is written to the array.

Move the logic from cat_wrmsr() to resctrl_arch_update_domains(). The
value provided to apply_config() is now an index in the array, not the
closid. The parameters provided via struct msr_param are now indexes
too. As resctrl's use of closid is a u32, struct msr_param's type is
changed to match.

With this, the CODE and DATA resources only use the odd or even
indexes in the array. This allows the temporary num_closid/2 fixes in
domain_setup_ctrlval() and reset_all_ctrls() to be removed.

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/20210728170637.25610-20-james.morse@arm.com

x86/resctrl: Pass configuration type to resctrl_arch_get_config()

2021-08-11T15:53:53+00:00

The ctrl_val[] array for a struct rdt_hw_resource only holds
configurations of one type. The type is implicit.

Once the CDP resources are merged, the ctrl_val[] array will hold all
the configurations for the hardware resource. When a particular type of
configuration is needed, it must be specified explicitly.

Pass the expected type from the schema into resctrl_arch_get_config().
Nothing uses this yet, but once a single ctrl_val[] array is used for
the three struct rdt_hw_resources that share hardware, the type will be
used to return the correct configuration value from the shared array.

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/20210728170637.25610-18-james.morse@arm.com