[PATCH v6 05/24] x86/resctrl: Label the resources with their configuration type

From: James Morse
Date: Thu Jul 15 2021 - 13:31:24 EST


The names of resources are used for the schema name presented to
user-space. The name used is rooted in a structure provided by
the architecture code because the names are different when CDP
is enabled. x86 implements this by swapping between two sets of
resource structures based on their alloc_enabled flag. The type
of configuration in-use is encoded in the name (and cbm_idx_offset).

Once the CDP behaviour is moved into the parts of resctrl that will
move to /fs/, there will be two struct resctrl_schema for one
struct rdt_resource. The schema describes the type of configuration
being applied to the resource. The name of the schema should be
generated by resctrl, base on the type of configuration. To do this
struct resctrl_schema needs to store the type of configuration in use
for a schema.

Create an enum resctrl_conf_type describing the options, and add
it to struct resctrl_schema. The underlying resources are still
separate, as cbm_idx_offset is still in use.
Temporarily label all the entries in rdt_resources_all[] and copy
that value to struct resctrl_schema. Copying the value ensures there
is no mismatch while the filesystem parts of resctrl are modified
to use the schema. Once the resources are merged, the filesystem
code can assign this value based on the schema being created.

Reviewed-by: Jamie Iles <jamie@xxxxxxxxxxxx>
Reviewed-by: Reinette Chatre <reinette.chatre@xxxxxxxxx>
Tested-by: Babu Moger <babu.moger@xxxxxxx>
Signed-off-by: James Morse <james.morse@xxxxxxx>
---
Changes since v4:
* Padded the comment for CDP_NONE into kernel doc.

Changes since v3:
* Removed a space.

Changes since v2:
* Renamed CDP_BOTH as CDP_NONE and described as 'no prioritisation'
* Shuffled commit message,

Changes since v1:
* {cdp,conf}_type typo
* Added kerneldoc comment
---
arch/x86/kernel/cpu/resctrl/core.c | 7 +++++++
arch/x86/kernel/cpu/resctrl/internal.h | 2 ++
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 1 +
include/linux/resctrl.h | 14 ++++++++++++++
4 files changed, 24 insertions(+)

diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index 10fbbc3cf40a..c5b5c7227837 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -62,6 +62,7 @@ mba_wrmsr_amd(struct rdt_domain *d, struct msr_param *m,
struct rdt_hw_resource rdt_resources_all[] = {
[RDT_RESOURCE_L3] =
{
+ .conf_type = CDP_NONE,
.r_resctrl = {
.rid = RDT_RESOURCE_L3,
.name = "L3",
@@ -81,6 +82,7 @@ struct rdt_hw_resource rdt_resources_all[] = {
},
[RDT_RESOURCE_L3DATA] =
{
+ .conf_type = CDP_DATA,
.r_resctrl = {
.rid = RDT_RESOURCE_L3DATA,
.name = "L3DATA",
@@ -100,6 +102,7 @@ struct rdt_hw_resource rdt_resources_all[] = {
},
[RDT_RESOURCE_L3CODE] =
{
+ .conf_type = CDP_CODE,
.r_resctrl = {
.rid = RDT_RESOURCE_L3CODE,
.name = "L3CODE",
@@ -119,6 +122,7 @@ struct rdt_hw_resource rdt_resources_all[] = {
},
[RDT_RESOURCE_L2] =
{
+ .conf_type = CDP_NONE,
.r_resctrl = {
.rid = RDT_RESOURCE_L2,
.name = "L2",
@@ -138,6 +142,7 @@ struct rdt_hw_resource rdt_resources_all[] = {
},
[RDT_RESOURCE_L2DATA] =
{
+ .conf_type = CDP_DATA,
.r_resctrl = {
.rid = RDT_RESOURCE_L2DATA,
.name = "L2DATA",
@@ -157,6 +162,7 @@ struct rdt_hw_resource rdt_resources_all[] = {
},
[RDT_RESOURCE_L2CODE] =
{
+ .conf_type = CDP_CODE,
.r_resctrl = {
.rid = RDT_RESOURCE_L2CODE,
.name = "L2CODE",
@@ -176,6 +182,7 @@ struct rdt_hw_resource rdt_resources_all[] = {
},
[RDT_RESOURCE_MBA] =
{
+ .conf_type = CDP_NONE,
.r_resctrl = {
.rid = RDT_RESOURCE_MBA,
.name = "MB",
diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index 94f4c683b7c3..b757928f9a46 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -369,6 +369,7 @@ struct rdt_parse_data {

/**
* struct rdt_hw_resource - arch private attributes of a resctrl resource
+ * @conf_type: The type that should be used when configuring. temporary
* @r_resctrl: Attributes of the resource used directly by resctrl.
* @num_closid: Maximum number of closid this hardware can support.
* @msr_base: Base MSR address for CBMs
@@ -381,6 +382,7 @@ struct rdt_parse_data {
* msr_update and msr_base.
*/
struct rdt_hw_resource {
+ enum resctrl_conf_type conf_type;
struct rdt_resource r_resctrl;
int num_closid;
unsigned int msr_base;
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 1fc40dbce85d..d7fd0712e76c 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -2135,6 +2135,7 @@ static int schemata_list_create(void)
return -ENOMEM;

s->res = r;
+ s->conf_type = resctrl_to_arch_res(r)->conf_type;

INIT_LIST_HEAD(&s->list);
list_add(&s->list, &resctrl_schema_all);
diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
index 5a21d483da6a..095ed48168d7 100644
--- a/include/linux/resctrl.h
+++ b/include/linux/resctrl.h
@@ -15,6 +15,18 @@ int proc_resctrl_show(struct seq_file *m,

#endif

+/**
+ * enum resctrl_conf_type - The type of configuration.
+ * @CDP_NONE: No prioritisation, both code and data are controlled or monitored.
+ * @CDP_CODE: Configuration applies to instruction fetches.
+ * @CDP_DATA: Configuration applies to reads and writes.
+ */
+enum resctrl_conf_type {
+ CDP_NONE,
+ CDP_CODE,
+ CDP_DATA,
+};
+
/**
* struct rdt_domain - group of CPUs sharing a resctrl resource
* @list: all instances of this resource
@@ -157,11 +169,13 @@ struct rdt_resource {
* struct resctrl_schema - configuration abilities of a resource presented to
* user-space
* @list: Member of resctrl_schema_all.
+ * @conf_type: Whether this schema is specific to code/data.
* @res: The resource structure exported by the architecture to describe
* the hardware that is configured by this schema.
*/
struct resctrl_schema {
struct list_head list;
+ enum resctrl_conf_type conf_type;
struct rdt_resource *res;
};
#endif /* _RESCTRL_H */
--
2.30.2