perf/x86/intel/uncore: Register the PMU only if the uncore pci device exists

[linux-drm-fsl-dcu.git] / arch / x86 / kernel / cpu / perf_event_intel_uncore.c

diff --git a/arch/x86/kernel/cpu/perf_event_intel_uncore.c b/arch/x86/kernel/cpu/perf_event_intel_uncore.c
index 2b0fa02268b77fc19107eafbafb3e685b2f4ea71..42d00e53175dd21e46379772553af91e1393004b 100644 (file)
--- a/arch/x86/kernel/cpu/perf_event_intel_uncore.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_uncore.c
@@ -793,6 +793,7 @@ static int uncore_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id
        struct intel_uncore_box *box;
        struct intel_uncore_type *type;
        int phys_id;
+       bool first_box = false;
 
        phys_id = uncore_pcibus_to_physid[pdev->bus->number];
        if (phys_id < 0)
@@ -827,9 +828,13 @@ static int uncore_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id
        pci_set_drvdata(pdev, box);
 
        raw_spin_lock(&uncore_box_lock);
+       if (list_empty(&pmu->box_list))
+               first_box = true;
        list_add_tail(&box->list, &pmu->box_list);
        raw_spin_unlock(&uncore_box_lock);
 
+       if (first_box)
+               uncore_pmu_register(pmu);
        return 0;
 }
 
@@ -838,6 +843,7 @@ static void uncore_pci_remove(struct pci_dev *pdev)
        struct intel_uncore_box *box = pci_get_drvdata(pdev);
        struct intel_uncore_pmu *pmu;
        int i, cpu, phys_id = uncore_pcibus_to_physid[pdev->bus->number];
+       bool last_box = false;
 
        box = pci_get_drvdata(pdev);
        if (!box) {
@@ -859,6 +865,8 @@ static void uncore_pci_remove(struct pci_dev *pdev)
 
        raw_spin_lock(&uncore_box_lock);
        list_del(&box->list);
+       if (list_empty(&pmu->box_list))
+               last_box = true;
        raw_spin_unlock(&uncore_box_lock);
 
        for_each_possible_cpu(cpu) {
@@ -870,6 +878,9 @@ static void uncore_pci_remove(struct pci_dev *pdev)
 
        WARN_ON_ONCE(atomic_read(&box->refcnt) != 1);
        kfree(box);
+
+       if (last_box)
+               perf_pmu_unregister(&pmu->pmu);
 }
 
 static int __init uncore_pci_init(void)
@@ -1221,14 +1232,6 @@ static int __init uncore_pmus_register(void)
                }
        }
 
-       for (i = 0; uncore_pci_uncores[i]; i++) {
-               type = uncore_pci_uncores[i];
-               for (j = 0; j < type->num_boxes; j++) {
-                       pmu = &type->pmus[j];
-                       uncore_pmu_register(pmu);
-               }
-       }
-
        return 0;
 }