Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull smp hotplug updates from Thomas Gleixner:
 "This is the final round of converting the notifier mess to the state
  machine. The removal of the notifiers and the related infrastructure
  will happen around rc1, as there are conversions outstanding in other
  trees.

  The whole exercise removed about 2000 lines of code in total and in
  course of the conversion several dozen bugs got fixed. The new
  mechanism allows to test almost every hotplug step standalone, so
  usage sites can exercise all transitions extensively.

  There is more room for improvement, like integrating all the
  pointlessly different architecture mechanisms of synchronizing,
  setting cpus online etc into the core code"

* 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (60 commits)
  tracing/rb: Init the CPU mask on allocation
  soc/fsl/qbman: Convert to hotplug state machine
  soc/fsl/qbman: Convert to hotplug state machine
  zram: Convert to hotplug state machine
  KVM/PPC/Book3S HV: Convert to hotplug state machine
  arm64/cpuinfo: Convert to hotplug state machine
  arm64/cpuinfo: Make hotplug notifier symmetric
  mm/compaction: Convert to hotplug state machine
  iommu/vt-d: Convert to hotplug state machine
  mm/zswap: Convert pool to hotplug state machine
  mm/zswap: Convert dst-mem to hotplug state machine
  mm/zsmalloc: Convert to hotplug state machine
  mm/vmstat: Convert to hotplug state machine
  mm/vmstat: Avoid on each online CPU loops
  mm/vmstat: Drop get_online_cpus() from init_cpu_node_state/vmstat_cpu_dead()
  tracing/rb: Convert to hotplug state machine
  oprofile/nmi timer: Convert to hotplug state machine
  net/iucv: Use explicit clean up labels in iucv_init()
  x86/pci/amd-bus: Convert to hotplug state machine
  x86/oprofile/nmi: Convert to hotplug state machine
  ...

1 files changed, 19 insertions, 50 deletions

diff --git a/drivers/pci/host/pci-xgene-msi.c b/drivers/pci/host/pci-xgene-msi.c
index a6456b578269..1f38d0836751 100644
--- a/drivers/pci/host/pci-xgene-msi.c
+++ b/drivers/pci/host/pci-xgene-msi.c
@@ -360,16 +360,16 @@ static void xgene_msi_isr(struct irq_desc *desc)
 	chained_irq_exit(chip, desc);
 }
 
+static enum cpuhp_state pci_xgene_online;
+
 static int xgene_msi_remove(struct platform_device *pdev)
 {
-	int virq, i;
 	struct xgene_msi *msi = platform_get_drvdata(pdev);
 
-	for (i = 0; i < NR_HW_IRQS; i++) {
-		virq = msi->msi_groups[i].gic_irq;
-		if (virq != 0)
-			irq_set_chained_handler_and_data(virq, NULL, NULL);
-	}
+	if (pci_xgene_online)
+		cpuhp_remove_state(pci_xgene_online);
+	cpuhp_remove_state(CPUHP_PCI_XGENE_DEAD);
+
 	kfree(msi->msi_groups);
 
 	kfree(msi->bitmap);
@@ -427,7 +427,7 @@ static int xgene_msi_hwirq_alloc(unsigned int cpu)
 	return 0;
 }
 
-static void xgene_msi_hwirq_free(unsigned int cpu)
+static int xgene_msi_hwirq_free(unsigned int cpu)
 {
 	struct xgene_msi *msi = &xgene_msi_ctrl;
 	struct xgene_msi_group *msi_group;
@@ -441,33 +441,9 @@ static void xgene_msi_hwirq_free(unsigned int cpu)
 		irq_set_chained_handler_and_data(msi_group->gic_irq, NULL,
 						 NULL);
 	}
+	return 0;
 }
 
-static int xgene_msi_cpu_callback(struct notifier_block *nfb,
-				  unsigned long action, void *hcpu)
-{
-	unsigned cpu = (unsigned long)hcpu;
-
-	switch (action) {
-	case CPU_ONLINE:
-	case CPU_ONLINE_FROZEN:
-		xgene_msi_hwirq_alloc(cpu);
-		break;
-	case CPU_DEAD:
-	case CPU_DEAD_FROZEN:
-		xgene_msi_hwirq_free(cpu);
-		break;
-	default:
-		break;
-	}
-
-	return NOTIFY_OK;
-}
-
-static struct notifier_block xgene_msi_cpu_notifier = {
-	.notifier_call = xgene_msi_cpu_callback,
-};
-
 static const struct of_device_id xgene_msi_match_table[] = {
 	{.compatible = "apm,xgene1-msi"},
 	{},
@@ -478,7 +454,6 @@ static int xgene_msi_probe(struct platform_device *pdev)
 	struct resource *res;
 	int rc, irq_index;
 	struct xgene_msi *xgene_msi;
-	unsigned int cpu;
 	int virt_msir;
 	u32 msi_val, msi_idx;
 
@@ -540,28 +515,22 @@ static int xgene_msi_probe(struct platform_device *pdev)
 		}
 	}
 
-	cpu_notifier_register_begin();
-
-	for_each_online_cpu(cpu)
-		if (xgene_msi_hwirq_alloc(cpu)) {
-			dev_err(&pdev->dev, "failed to register MSI handlers\n");
-			cpu_notifier_register_done();
-			goto error;
-		}
-
-	rc = __register_hotcpu_notifier(&xgene_msi_cpu_notifier);
-	if (rc) {
-		dev_err(&pdev->dev, "failed to add CPU MSI notifier\n");
-		cpu_notifier_register_done();
-		goto error;
-	}
-
-	cpu_notifier_register_done();
+	rc = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "pci/xgene:online",
+			       xgene_msi_hwirq_alloc, NULL);
+	if (rc)
+		goto err_cpuhp;
+	pci_xgene_online = rc;
+	rc = cpuhp_setup_state(CPUHP_PCI_XGENE_DEAD, "pci/xgene:dead", NULL,
+			       xgene_msi_hwirq_free);
+	if (rc)
+		goto err_cpuhp;
 
 	dev_info(&pdev->dev, "APM X-Gene PCIe MSI driver loaded\n");
 
 	return 0;
 
+err_cpuhp:
+	dev_err(&pdev->dev, "failed to add CPU MSI notifier\n");
 error:
 	xgene_msi_remove(pdev);
 	return rc;