[PATCH v4 05/24] x86/resctrl: Label the resources with their configuration type

From: James Morse
Date: Mon Jun 14 2021 - 16:10:23 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>
Signed-off-by: James Morse <james.morse@xxxxxxx>
---
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 | 10 ++++++++++
4 files changed, 20 insertions(+)

diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index aff5d0dde6c1..9ba12c3d175a 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,
.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,
.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,
.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,
.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,
.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,
.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,
.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 f6790d03f056..e800de110230 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -364,6 +364,7 @@ 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
* @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
@@ -376,6 +377,7 @@ struct rdt_parse_data {
* msr_update and msr_base.
*/
struct rdt_hw_resource {
+ enum resctrl_conf_type conf_type;
struct rdt_resource 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 6ad9df322282..199b3035dfbf 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 425e7913dc8d..81073d0751c9 100644
--- a/include/linux/resctrl.h
+++ b/include/linux/resctrl.h
@@ -15,6 +15,14 @@ int proc_resctrl_show(struct seq_file *m,

#endif

+enum resctrl_conf_type {
+ /* No prioritisation, both code and data are controlled or monitored. */
+ CDP_NONE,
+
+ CDP_CODE,
+ CDP_DATA,
+};
+
/**
* struct rdt_domain - group of CPUs sharing a resctrl resource
* @list: all instances of this resource
@@ -158,11 +166,13 @@ 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