MSI fixes for 6.2:

- Return MSI_XA_DOMAIN_SIZE as the maximum MSI index when the architecture
   does not make use of irq domains instead of returning 0, which is pretty
   limiting.
 
 - Check for the presence of an irq domain when validating the MSI iterator,
   as s390/powerpc won't have one.
 
 - Fix powerpc's MSI backends which fail to clear the descriptor's IRQ field
   on teardown, leading to a splat and leaked descriptors.
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Merge tag 'msi-fixes-6.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms

Pull MSI fixes from Marc Zyngier:
 "Thomas tasked me with sending out a few urgent fixes after the giant
  MSI rework that landed in 6.2, as both s390 and powerpc ended-up
  suffering from it (they do not use the full core code infrastructure,
  leading to these previously undetected issues):

   - Return MSI_XA_DOMAIN_SIZE as the maximum MSI index when the
     architecture does not make use of irq domains instead of returning
     0, which is pretty limiting.

   - Check for the presence of an irq domain when validating the MSI
     iterator, as s390/powerpc won't have one.

   - Fix powerpc's MSI backends which fail to clear the descriptor's IRQ
     field on teardown, leading to a splat and leaked descriptors"

* tag 'msi-fixes-6.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms:
  powerpc/msi: Fix deassociation of MSI descriptors
  genirq/msi: Return MSI_XA_DOMAIN_SIZE as the maximum MSI index when no domain is present
  genirq/msi: Check for the presence of an irq domain when validating msi_ctrl

arch/powerpc/platforms/4xx/hsta_msi.c

@@ -115,6 +115,7 @@ static void hsta_teardown_msi_irqs(struct pci_dev *dev)
 		msi_bitmap_free_hwirqs(&ppc4xx_hsta_msi.bmp, irq, 1);
 		pr_debug("%s: Teardown IRQ %u (index %u)\n", __func__,
 			 entry->irq, irq);
+		entry->irq = 0;
 	}
 }
 

arch/powerpc/platforms/cell/axon_msi.c

@@ -289,6 +289,7 @@ static void axon_msi_teardown_msi_irqs(struct pci_dev *dev)
 	msi_for_each_desc(entry, &dev->dev, MSI_DESC_ASSOCIATED) {
 		irq_set_msi_desc(entry->irq, NULL);
 		irq_dispose_mapping(entry->irq);
+		entry->irq = 0;
 	}
 }
 

arch/powerpc/platforms/pasemi/msi.c

@@ -66,6 +66,7 @@ static void pasemi_msi_teardown_msi_irqs(struct pci_dev *pdev)
 		hwirq = virq_to_hw(entry->irq);
 		irq_set_msi_desc(entry->irq, NULL);
 		irq_dispose_mapping(entry->irq);
+		entry->irq = 0;
 		msi_bitmap_free_hwirqs(&msi_mpic->msi_bitmap, hwirq, ALLOC_CHUNK);
 	}
 }

arch/powerpc/sysdev/fsl_msi.c

@@ -132,6 +132,7 @@ static void fsl_teardown_msi_irqs(struct pci_dev *pdev)
 		msi_data = irq_get_chip_data(entry->irq);
 		irq_set_msi_desc(entry->irq, NULL);
 		irq_dispose_mapping(entry->irq);
+		entry->irq = 0;
 		msi_bitmap_free_hwirqs(&msi_data->bitmap, hwirq, 1);
 	}
 }

arch/powerpc/sysdev/mpic_u3msi.c

@@ -108,6 +108,7 @@ static void u3msi_teardown_msi_irqs(struct pci_dev *pdev)
 		hwirq = virq_to_hw(entry->irq);
 		irq_set_msi_desc(entry->irq, NULL);
 		irq_dispose_mapping(entry->irq);
+		entry->irq = 0;
 		msi_bitmap_free_hwirqs(&msi_mpic->msi_bitmap, hwirq, 1);
 	}
 }

kernel/irq/msi.c

@@ -165,7 +165,8 @@ static bool msi_ctrl_valid(struct device *dev, struct msi_ctrl *ctrl)
 	unsigned int hwsize;
 
 	if (WARN_ON_ONCE(ctrl->domid >= MSI_MAX_DEVICE_IRQDOMAINS ||
-			 !dev->msi.data->__domains[ctrl->domid].domain))
+			 (dev->msi.domain &&
+			  !dev->msi.data->__domains[ctrl->domid].domain)))
 		return false;
 
 	hwsize = msi_domain_get_hwsize(dev, ctrl->domid);
@@ -609,8 +610,8 @@ static unsigned int msi_domain_get_hwsize(struct device *dev, unsigned int domid
 		info = domain->host_data;
 		return info->hwsize;
 	}
-	/* No domain, no size... */
-	return 0;
+	/* No domain, default to MSI_XA_DOMAIN_SIZE */
+	return MSI_XA_DOMAIN_SIZE;
 }
 
 static inline void irq_chip_write_msi_msg(struct irq_data *data,