linux.git/arch/x86/kernel/cpu/resctrl/ctrlmondata.c, branch v6.0

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

x86/resctrl: Add a helper to read a closid's configuration

2021-08-11T15:46:34+00:00

Functions like show_doms() reach into the architecture's private
structure to retrieve the configuration from the struct rdt_hw_resource.

The hardware configuration may look completely different to the
values resctrl gets from user-space. The staged configuration and
resctrl_arch_update_domains() allow the architecture to convert or
translate these values.

Resctrl shouldn't read or write the ctrl_val[] values directly. Add
a helper to read the current configuration. This will allow another
architecture to scale the bitmaps if necessary, and possibly use
controls that don't take the user-space control format at all.

Of the remaining functions that access ctrl_val[] directly,
apply_config() is part of the architecture-specific code, and is
called via resctrl_arch_update_domains(). reset_all_ctrls() will be an
architecture specific helper.

update_mba_bw() manipulates both ctrl_val[], mbps_val[] and the
hardware. The mbps_val[] that matches the mba_sc state of the resource
is changed, but the other is left unchanged. Abstracting this is the
subject of later patches that affect set_mba_sc() too.

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/20210728170637.25610-17-james.morse@arm.com

x86/resctrl: Rename update_domains() to resctrl_arch_update_domains()

2021-08-11T14:36:58+00:00

update_domains() merges the staged configuration changes into the arch
codes configuration array. Rename to make it clear it is part of the
arch code interface to resctrl.

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/20210728170637.25610-16-james.morse@arm.com

x86/resctrl: Allow different CODE/DATA configurations to be staged

2021-08-11T14:33:42+00:00

Before the CDP resources can be merged, struct rdt_domain will need an
array of struct resctrl_staged_config, one per type of configuration.

Use the type as an index to the array to ensure that a schema
configuration string can't specify the same domain twice. This will
allow two schemata to apply configuration changes to one resource.

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/20210728170637.25610-15-james.morse@arm.com

x86/resctrl: Group staged configuration into a separate struct

2021-08-11T14:32:32+00:00

When configuration changes are made, the new value is written to struct
rdt_domain's new_ctrl field and the have_new_ctrl flag is set. Later
new_ctrl is copied to hardware by a call to update_domains().

Once the CDP resources are merged, there will be one new_ctrl field in
use by two struct resctrl_schema requiring a per-schema IPI to copy the
value to hardware.

Move new_ctrl and have_new_ctrl into a new struct resctrl_staged_config.
Before the CDP resources can be merged, struct rdt_domain will need an
array of these, one per type of configuration. Using the type as an
index to the array will ensure that a schema configuration string can't
specify the same domain twice.

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/20210728170637.25610-14-james.morse@arm.com

x86/resctrl: Move the schemata names into struct resctrl_schema

2021-08-11T14:21:35+00:00

resctrl 'info' directories and schema parsing use the schema name.
This lives in the struct rdt_resource, and is specified by the
architecture code.

Once the CDP resources are merged, there will only be one resource (and
one name) in use by two schemata. To allow the CDP CODE/DATA property to
be the type of configuration the schema uses, the name should also be
per-schema.

Add a name field to struct resctrl_schema, and use this wherever
the schema name is exposed (or read from) user-space. Calculating
max_name_width for padding the schemata file also moves as this is
visible to user-space. As the names in struct rdt_resource already
include the CDP information, schemata_list_create() copies them.

schemata_list_create() includes the length of the CDP suffix when
calculating max_name_width in preparation for CDP resources being
merged.

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/20210728170637.25610-13-james.morse@arm.com