[PATCH v6 23/30] x86/resctrl: Handle domain creation/deletion for RDT_RESOURCE_PERF_PKG

[Tony Luck <tony.luck@intel.com>]

The L3 resource has several requirements for domains. There are structures
that hold the 64-bit values of counters, and elements to keep track of
the overflow and limbo threads.

None of these are needed for the PERF_PKG resource. The hardware counters
are wide enough that they do not wrap around for decades.

Define a new rdt_perf_pkg_mon_domain structure which just consists of
the standard rdt_domain_hdr to keep track of domain id and CPU mask.

Change domain_add_cpu_mon(), domain_remove_cpu_mon(),
resctrl_offline_mon_domain(), and resctrl_online_mon_domain() to check
resource type and perform only the operations needed for domains in the
PERF_PKG resource.

Signed-off-by: Tony Luck <tony.luck@intel.com>
---
 arch/x86/kernel/cpu/resctrl/core.c | 41 ++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index f3144fe918dd..f857f92e7b8b 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -547,6 +547,38 @@ static void l3_mon_domain_setup(int cpu, int id, struct rdt_resource *r, struct
 	}
 }
 
+/**
+ * struct rdt_perf_pkg_mon_domain - CPUs sharing an Intel-PMT-scoped resctrl monitor resource
+ * @hdr:	common header for different domain types
+ */
+struct rdt_perf_pkg_mon_domain {
+	struct rdt_domain_hdr   hdr;
+};
+
+static void setup_intel_aet_mon_domain(int cpu, int id, struct rdt_resource *r,
+				       struct list_head *add_pos)
+{
+	struct rdt_perf_pkg_mon_domain *d;
+	int err;
+
+	d = kzalloc_node(sizeof(*d), GFP_KERNEL, cpu_to_node(cpu));
+	if (!d)
+		return;
+
+	d->hdr.id = id;
+	d->hdr.type = RESCTRL_MON_DOMAIN;
+	d->hdr.rid = r->rid;
+	cpumask_set_cpu(cpu, &d->hdr.cpu_mask);
+	list_add_tail_rcu(&d->hdr.list, add_pos);
+
+	err = resctrl_online_mon_domain(r, &d->hdr);
+	if (err) {
+		list_del_rcu(&d->hdr.list);
+		synchronize_rcu();
+		kfree(d);
+	}
+}
+
 static void domain_add_cpu_mon(int cpu, struct rdt_resource *r)
 {
 	int id = get_domain_id_from_scope(cpu, r->mon_scope);
@@ -574,6 +606,9 @@ static void domain_add_cpu_mon(int cpu, struct rdt_resource *r)
 	case RDT_RESOURCE_L3:
 		l3_mon_domain_setup(cpu, id, r, add_pos);
 		break;
+	case RDT_RESOURCE_PERF_PKG:
+		setup_intel_aet_mon_domain(cpu, id, r, add_pos);
+		break;
 	default:
 		WARN_ON_ONCE(1);
 	}
@@ -670,6 +705,12 @@ static void domain_remove_cpu_mon(int cpu, struct rdt_resource *r)
 		synchronize_rcu();
 		l3_mon_domain_free(hw_dom);
 		break;
+	case RDT_RESOURCE_PERF_PKG:
+		resctrl_offline_mon_domain(r, hdr);
+		list_del_rcu(&hdr->list);
+		synchronize_rcu();
+		kfree(container_of(hdr, struct rdt_perf_pkg_mon_domain, hdr));
+		break;
 	default:
 		pr_warn_once("Unknown resource rid=%d\n", r->rid);
 		break;
-- 
2.49.0