[PATCH 4/7] perf/x86/intel/uncore: Factor out box setup code

[Zide Chen]

The PCI uncore PMU path already implements a lazy registration model:
the PMU is registered when the first active box appears and
unregistered when the last active box is removed.

Factor this registration management into a shared helper, so the same
code can be reused by the MSR and MMIO paths in later changes.

No functional change intended.

Signed-off-by: Zide Chen <zide.chen@xxxxxxxxx>
---
 arch/x86/events/intel/uncore.c | 39 ++++++++++++++++++++++++----------
 1 file changed, 28 insertions(+), 11 deletions(-)

diff --git a/arch/x86/events/intel/uncore.c b/arch/x86/events/intel/uncore.c
index 8d5170788af2..00ed4e5047ac 100644
--- a/arch/x86/events/intel/uncore.c
+++ b/arch/x86/events/intel/uncore.c
@@ -1148,6 +1148,29 @@ uncore_pci_find_dev_pmu(struct pci_dev *pdev, const struct pci_device_id *ids)
 	return pmu;
 }
 
+static int uncore_box_setup(struct intel_uncore_pmu *pmu,
+			    struct intel_uncore_box *box)
+{
+	int dies, ret;
+
+	/* die_refcnt tracks online dies, not only functioning boxes. */
+	dies = atomic_inc_return(&pmu->die_refcnt);
+	uncore_box_init(box);
+
+	/* First active box registers the pmu. */
+	if (dies > 1)
+		return 0;
+
+	ret = uncore_pmu_register(pmu);
+	if (ret)
+		goto err;
+
+	return 0;
+err:
+	uncore_box_exit(box);
+	return ret;
+}
+
 /*
  * Register the PMU for a PCI device
  * @pdev: The PCI device.
@@ -1173,19 +1196,13 @@ static int uncore_pci_pmu_register(struct pci_dev *pdev,
 	box->dieid = die;
 	box->pci_dev = pdev;
 	box->pmu = pmu;
-	uncore_box_init(box);
 
-	pmu->boxes[die] = box;
-	if (atomic_inc_return(&pmu->die_refcnt) > 1)
-		return 0;
-
-	/* First active box registers the pmu */
-	ret = uncore_pmu_register(pmu);
-	if (ret) {
-		pmu->boxes[die] = NULL;
-		uncore_box_exit(box);
+	ret = uncore_box_setup(pmu, box);
+	if (!ret)
+		pmu->boxes[die] = box;
+	else
 		kfree(box);
-	}
+
 	return ret;
 }
 
-- 
2.54.0