s390/pci: Refactor arch_setup_msi_irqs()

jira LE-2349
Rebuild_History Non-Buildable kernel-4.18.0-553.40.1.el8_10
commit-author Gerd Bayer <gbayer@linux.ibm.com>
commit 5fd11b9
Empty-Commit: Cherry-Pick Conflicts during history rebuild.
Will be included in final tarball splat. Ref for failed cherry-pick at:
ciq/ciq_backports/kernel-4.18.0-553.40.1.el8_10/5fd11b96.failed

Factor out adapter interrupt allocation from arch_setup_msi_irqs() in
preparation for enabling registration of multiple MSIs. Code movement
only, no change of functionality intended.

	Signed-off-by: Gerd Bayer <gbayer@linux.ibm.com>
	Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
	Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
(cherry picked from commit 5fd11b9)
	Signed-off-by: Jonathan Maple <jmaple@ciq.com>

# Conflicts:
#	arch/s390/pci/pci_irq.c

Author: PlaidCat

ciq/ciq_backports/kernel-4.18.0-553.40.1.el8_10/5fd11b96.failed

@@ -0,0 +1,60 @@
+s390/pci: Refactor arch_setup_msi_irqs()
+
+jira LE-2349
+Rebuild_History Non-Buildable kernel-4.18.0-553.40.1.el8_10
+commit-author Gerd Bayer <gbayer@linux.ibm.com>
+commit 5fd11b96b43708f2f6e3964412c301c1bd20ec0f
+Empty-Commit: Cherry-Pick Conflicts during history rebuild.
+Will be included in final tarball splat. Ref for failed cherry-pick at:
+ciq/ciq_backports/kernel-4.18.0-553.40.1.el8_10/5fd11b96.failed
+
+Factor out adapter interrupt allocation from arch_setup_msi_irqs() in
+preparation for enabling registration of multiple MSIs. Code movement
+only, no change of functionality intended.
+
+	Signed-off-by: Gerd Bayer <gbayer@linux.ibm.com>
+	Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
+	Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
+(cherry picked from commit 5fd11b96b43708f2f6e3964412c301c1bd20ec0f)
+	Signed-off-by: Jonathan Maple <jmaple@ciq.com>
+
+# Conflicts:
+#	arch/s390/pci/pci_irq.c
+diff --cc arch/s390/pci/pci_irq.c
+index 192f3b104ae4,979f776b09b8..000000000000
+--- a/arch/s390/pci/pci_irq.c
++++ b/arch/s390/pci/pci_irq.c
+@@@ -269,25 -268,13 +269,29 @@@ static void zpci_floating_irq_handler(s
+  	}
+  }
+  
+- int arch_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
++ static int __alloc_airq(struct zpci_dev *zdev, int msi_vecs,
++ 			unsigned long *bit)
+  {
+++<<<<<<< HEAD
+ +	struct zpci_dev *zdev = to_zpci(pdev);
+ +	unsigned int hwirq, msi_vecs, cpu;
+ +	unsigned long bit;
+ +	struct msi_desc *msi;
+ +	struct msi_msg msg;
+ +	int rc, irq;
+ +
+ +	zdev->aisb = -1UL;
+ +	zdev->msi_first_bit = -1U;
+ +	if (type == PCI_CAP_ID_MSI && nvec > 1)
+ +		return 1;
+ +	msi_vecs = min_t(unsigned int, nvec, zdev->max_msi);
+ +
+++=======
+++>>>>>>> 5fd11b96b437 (s390/pci: Refactor arch_setup_msi_irqs())
+  	if (irq_delivery == DIRECTED) {
+  		/* Allocate cpu vector bits */
+- 		bit = airq_iv_alloc(zpci_ibv[0], msi_vecs);
+- 		if (bit == -1UL)
++ 		*bit = airq_iv_alloc(zpci_ibv[0], msi_vecs);
++ 		if (*bit == -1UL)
+  			return -EIO;
+  	} else {
+  		/* Allocate adapter summary indicator bit */
+* Unmerged path arch/s390/pci/pci_irq.c