iommu/vt-d: Clean up cpumask and hotplug for perfmon

The iommu PMU is system-wide scope, which is supported by the generic
perf_event subsystem now.

Set the scope for the iommu PMU and remove all the cpumask and hotplug
codes.

Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20240802151643.1691631-5-kan.liang@linux.intel.com

diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h
index b67c14da12408b22c0907215629244b61fa6e8ea..bd2c5a4ca11a736b4de014d77892582c39752a2f 100644 (file)
--- a/drivers/iommu/intel/iommu.h
+++ b/drivers/iommu/intel/iommu.h
@@ -687,8 +687,6 @@ struct iommu_pmu {
        DECLARE_BITMAP(used_mask, IOMMU_PMU_IDX_MAX);
        struct perf_event       *event_list[IOMMU_PMU_IDX_MAX];
        unsigned char           irq_name[16];
-       struct hlist_node       cpuhp_node;
-       int                     cpu;
 };
 
 #define IOMMU_IRQ_ID_OFFSET_PRQ                (DMAR_UNITS_SUPPORTED)

diff --git a/drivers/iommu/intel/perfmon.c b/drivers/iommu/intel/perfmon.c
index 44083d01852dbf997f8cc4001f3b278ea5d7fa07..75f493bcb353ed0ccf0e744f1e71261d36947acd 100644 (file)
--- a/drivers/iommu/intel/perfmon.c
+++ b/drivers/iommu/intel/perfmon.c
@@ -34,28 +34,9 @@ static struct attribute_group iommu_pmu_events_attr_group = {
        .attrs = attrs_empty,
 };
 
-static cpumask_t iommu_pmu_cpu_mask;
-
-static ssize_t
-cpumask_show(struct device *dev, struct device_attribute *attr, char *buf)
-{
-       return cpumap_print_to_pagebuf(true, buf, &iommu_pmu_cpu_mask);
-}
-static DEVICE_ATTR_RO(cpumask);
-
-static struct attribute *iommu_pmu_cpumask_attrs[] = {
-       &dev_attr_cpumask.attr,
-       NULL
-};
-
-static struct attribute_group iommu_pmu_cpumask_attr_group = {
-       .attrs = iommu_pmu_cpumask_attrs,
-};
-
 static const struct attribute_group *iommu_pmu_attr_groups[] = {
        &iommu_pmu_format_attr_group,
        &iommu_pmu_events_attr_group,
-       &iommu_pmu_cpumask_attr_group,
        NULL
 };
 
@@ -565,6 +546,7 @@ static int __iommu_pmu_register(struct intel_iommu *iommu)
        iommu_pmu->pmu.attr_groups      = iommu_pmu_attr_groups;
        iommu_pmu->pmu.attr_update      = iommu_pmu_attr_update;
        iommu_pmu->pmu.capabilities     = PERF_PMU_CAP_NO_EXCLUDE;
+       iommu_pmu->pmu.scope            = PERF_PMU_SCOPE_SYS_WIDE;
        iommu_pmu->pmu.module           = THIS_MODULE;
 
        return perf_pmu_register(&iommu_pmu->pmu, iommu_pmu->pmu.name, -1);
@@ -773,89 +755,6 @@ static void iommu_pmu_unset_interrupt(struct intel_iommu *iommu)
        iommu->perf_irq = 0;
 }
 
-static int iommu_pmu_cpu_online(unsigned int cpu, struct hlist_node *node)
-{
-       struct iommu_pmu *iommu_pmu = hlist_entry_safe(node, typeof(*iommu_pmu), cpuhp_node);
-
-       if (cpumask_empty(&iommu_pmu_cpu_mask))
-               cpumask_set_cpu(cpu, &iommu_pmu_cpu_mask);
-
-       if (cpumask_test_cpu(cpu, &iommu_pmu_cpu_mask))
-               iommu_pmu->cpu = cpu;
-
-       return 0;
-}
-
-static int iommu_pmu_cpu_offline(unsigned int cpu, struct hlist_node *node)
-{
-       struct iommu_pmu *iommu_pmu = hlist_entry_safe(node, typeof(*iommu_pmu), cpuhp_node);
-       int target = cpumask_first(&iommu_pmu_cpu_mask);
-
-       /*
-        * The iommu_pmu_cpu_mask has been updated when offline the CPU
-        * for the first iommu_pmu. Migrate the other iommu_pmu to the
-        * new target.
-        */
-       if (target < nr_cpu_ids && target != iommu_pmu->cpu) {
-               perf_pmu_migrate_context(&iommu_pmu->pmu, cpu, target);
-               iommu_pmu->cpu = target;
-               return 0;
-       }
-
-       if (!cpumask_test_and_clear_cpu(cpu, &iommu_pmu_cpu_mask))
-               return 0;
-
-       target = cpumask_any_but(cpu_online_mask, cpu);
-
-       if (target < nr_cpu_ids)
-               cpumask_set_cpu(target, &iommu_pmu_cpu_mask);
-       else
-               return 0;
-
-       perf_pmu_migrate_context(&iommu_pmu->pmu, cpu, target);
-       iommu_pmu->cpu = target;
-
-       return 0;
-}
-
-static int nr_iommu_pmu;
-static enum cpuhp_state iommu_cpuhp_slot;
-
-static int iommu_pmu_cpuhp_setup(struct iommu_pmu *iommu_pmu)
-{
-       int ret;
-
-       if (!nr_iommu_pmu) {
-               ret = cpuhp_setup_state_multi(CPUHP_AP_ONLINE_DYN,
-                                             "driver/iommu/intel/perfmon:online",
-                                             iommu_pmu_cpu_online,
-                                             iommu_pmu_cpu_offline);
-               if (ret < 0)
-                       return ret;
-               iommu_cpuhp_slot = ret;
-       }
-
-       ret = cpuhp_state_add_instance(iommu_cpuhp_slot, &iommu_pmu->cpuhp_node);
-       if (ret) {
-               if (!nr_iommu_pmu)
-                       cpuhp_remove_multi_state(iommu_cpuhp_slot);
-               return ret;
-       }
-       nr_iommu_pmu++;
-
-       return 0;
-}
-
-static void iommu_pmu_cpuhp_free(struct iommu_pmu *iommu_pmu)
-{
-       cpuhp_state_remove_instance(iommu_cpuhp_slot, &iommu_pmu->cpuhp_node);
-
-       if (--nr_iommu_pmu)
-               return;
-
-       cpuhp_remove_multi_state(iommu_cpuhp_slot);
-}
-
 void iommu_pmu_register(struct intel_iommu *iommu)
 {
        struct iommu_pmu *iommu_pmu = iommu->pmu;
@@ -866,17 +765,12 @@ void iommu_pmu_register(struct intel_iommu *iommu)
        if (__iommu_pmu_register(iommu))
                goto err;
 
-       if (iommu_pmu_cpuhp_setup(iommu_pmu))
-               goto unregister;
-
        /* Set interrupt for overflow */
        if (iommu_pmu_set_interrupt(iommu))
-               goto cpuhp_free;
+               goto unregister;
 
        return;
 
-cpuhp_free:
-       iommu_pmu_cpuhp_free(iommu_pmu);
 unregister:
        perf_pmu_unregister(&iommu_pmu->pmu);
 err:
@@ -892,6 +786,5 @@ void iommu_pmu_unregister(struct intel_iommu *iommu)
                return;
 
        iommu_pmu_unset_interrupt(iommu);
-       iommu_pmu_cpuhp_free(iommu_pmu);
        perf_pmu_unregister(&iommu_pmu->pmu);
 }