[PATCH v14 02/32] x86/resctrl: Move L3 initialization into new helper function

Tony Luck
2025-11-24T18:54:45Z

Carve out the resource monitoring domain init code into a separate helper in
order to be able to initialize new types of monitoring domains besides the
usual L3 ones.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
---
arch/x86/kernel/cpu/resctrl/core.c | 64 ++++++++++++++++--------------
1 file changed, 34 insertions(+), 30 deletions(-)

diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index 0b8b7b8697a7..2a568b316711 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -501,37 +501,13 @@ static void domain_add_cpu_ctrl(int cpu, struct rdt_resource *r)
}
}

-static void domain_add_cpu_mon(int cpu, struct rdt_resource *r)
+static void l3_mon_domain_setup(int cpu, int id, struct rdt_resource *r, struct list_head *add_pos)
{
- int id = get_domain_id_from_scope(cpu, r->mon_scope);
- struct list_head *add_pos = NULL;
struct rdt_hw_mon_domain *hw_dom;
- struct rdt_domain_hdr *hdr;
struct rdt_mon_domain *d;
struct cacheinfo *ci;
int err;

- lockdep_assert_held(&domain_list_lock);
-
- if (id < 0) {
- pr_warn_once("Can't find monitor domain id for CPU:%d scope:%d for resource %s\n",
- cpu, r->mon_scope, r->name);
- return;
- }
-
- hdr = resctrl_find_domain(&r->mon_domains, id, &add_pos);
- if (hdr) {
- if (!domain_header_is_valid(hdr, RESCTRL_MON_DOMAIN, r->rid))
- return;
- d = container_of(hdr, struct rdt_mon_domain, hdr);
-
- cpumask_set_cpu(cpu, &d->hdr.cpu_mask);
- /* Update the mbm_assign_mode state for the CPU if supported */
- if (r->mon.mbm_cntr_assignable)
- resctrl_arch_mbm_cntr_assign_set_one(r);
- return;
- }
-
hw_dom = kzalloc_node(sizeof(*hw_dom), GFP_KERNEL, cpu_to_node(cpu));
if (!hw_dom)
return;
@@ -539,7 +515,7 @@ static void domain_add_cpu_mon(int cpu, struct rdt_resource *r)
d = &hw_dom->d_resctrl;
d->hdr.id = id;
d->hdr.type = RESCTRL_MON_DOMAIN;
- d->hdr.rid = r->rid;
+ d->hdr.rid = RDT_RESOURCE_L3;
ci = get_cpu_cacheinfo_level(cpu, RESCTRL_L3_CACHE);
if (!ci) {
pr_warn_once("Can't find L3 cache for CPU:%d resource %s\n", cpu, r->name);
@@ -549,10 +525,6 @@ static void domain_add_cpu_mon(int cpu, struct rdt_resource *r)
d->ci_id = ci->id;
cpumask_set_cpu(cpu, &d->hdr.cpu_mask);

- /* Update the mbm_assign_mode state for the CPU if supported */
- if (r->mon.mbm_cntr_assignable)
- resctrl_arch_mbm_cntr_assign_set_one(r);
-
arch_mon_domain_online(r, d);

if (arch_domain_mbm_alloc(r->mon.num_rmid, hw_dom)) {
@@ -570,6 +542,38 @@ static void domain_add_cpu_mon(int cpu, struct rdt_resource *r)
}
}

+static void domain_add_cpu_mon(int cpu, struct rdt_resource *r)
+{
+ int id = get_domain_id_from_scope(cpu, r->mon_scope);
+ struct list_head *add_pos = NULL;
+ struct rdt_domain_hdr *hdr;
+
+ lockdep_assert_held(&domain_list_lock);
+
+ if (id < 0) {
+ pr_warn_once("Can't find monitor domain id for CPU:%d scope:%d for resource %s\n",
+ cpu, r->mon_scope, r->name);
+ return;
+ }
+
+ hdr = resctrl_find_domain(&r->mon_domains, id, &add_pos);
+ if (hdr)
+ cpumask_set_cpu(cpu, &hdr->cpu_mask);
+
+ switch (r->rid) {
+ case RDT_RESOURCE_L3:
+ /* Update the mbm_assign_mode state for the CPU if supported */
+ if (r->mon.mbm_cntr_assignable)
+ resctrl_arch_mbm_cntr_assign_set_one(r);
+ if (!hdr)
+ l3_mon_domain_setup(cpu, id, r, add_pos);
+ break;
+ default:
+ pr_warn_once("Unknown resource rid=%d\n", r->rid);
+ break;
+ }
+}
+
static void domain_add_cpu(int cpu, struct rdt_resource *r)
{
if (r->alloc_capable)
--
2.51.1