x86/resctrl: Store the effective num_closid in the schema

Struct resctrl_schema holds properties that vary with the style of
configuration that resctrl applies to a resource. There are already
two values for the hardware's num_closid, depending on whether the
architecture presents the L3 or L3CODE/L3DATA resources.

As the way CDP changes the number of control groups that resctrl can
create is part of the user-space interface, it should be managed by the
filesystem parts of resctrl. This allows the architecture code to only
describe the value the hardware supports.

Add num_closid to resctrl_schema. This is the value seen by the
filesystem, which may be different to the maximum value described by the
arch code when CDP is enabled.

These functions operate on the num_closid value that is exposed to
user-space:

  * rdtgroup_parse_resource()
  * rdtgroup_schemata_show()
  * rdt_num_closids_show()
  * closid_init()

Change them to use the schema value instead. schemata_list_create() sets
this value, and reaches into the architecture-specific structure to get
the value. This will eventually be replaced with a helper.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Jamie Iles <jamie@nuviainc.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://lkml.kernel.org/r/20210728170637.25610-8-james.morse@arm.com

1 files changed, 4 insertions, 9 deletions

diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 7502b7de3916..2f29b7d7d602 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -103,15 +103,12 @@ int closids_supported(void)
 
 static void closid_init(void)
 {
-	struct rdt_hw_resource *hw_res;
 	struct resctrl_schema *s;
 	int rdt_min_closid = 32;
 
 	/* Compute rdt_min_closid across all resources */
-	list_for_each_entry(s, &resctrl_schema_all, list) {
-		hw_res = resctrl_to_arch_res(s->res);
-		rdt_min_closid = min(rdt_min_closid, hw_res->num_closid);
-	}
+	list_for_each_entry(s, &resctrl_schema_all, list)
+		rdt_min_closid = min(rdt_min_closid, s->num_closid);
 
 	closid_free_map = BIT_MASK(rdt_min_closid) - 1;
 
@@ -849,11 +846,8 @@ static int rdt_num_closids_show(struct kernfs_open_file *of,
 				struct seq_file *seq, void *v)
 {
 	struct resctrl_schema *s = of->kn->parent->priv;
-	struct rdt_resource *r = s->res;
-	struct rdt_hw_resource *hw_res;
 
-	hw_res = resctrl_to_arch_res(r);
-	seq_printf(seq, "%d\n", hw_res->num_closid);
+	seq_printf(seq, "%u\n", s->num_closid);
 	return 0;
 }
 
@@ -2140,6 +2134,7 @@ static int schemata_list_create(void)
 
 		s->res = r;
 		s->conf_type = resctrl_to_arch_res(r)->conf_type;
+		s->num_closid = resctrl_to_arch_res(r)->num_closid;
 
 		INIT_LIST_HEAD(&s->list);
 		list_add(&s->list, &resctrl_schema_all);