Merge tag 's390-6.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull more s390 updates from Heiko Carstens:

 - Add swap entry for hugetlbfs support

 - Add PTE_MARKER support for hugetlbs mappings; this fixes a regression
   (possible page fault loop) which was introduced when support for
   UFFDIO_POISON for hugetlbfs was added

 - Add ARCH_HAS_PREEMPT_LAZY and PREEMPT_DYNAMIC support

 - Mark IRQ entries in entry code, so that stack tracers can filter out
   the non-IRQ parts of stack traces. This fixes stack depot capacity
   limit warnings, since without filtering the number of unique stack
   traces is huge

 - In PCI code fix leak of struct zpci_dev object, and fix potential
   double remove of hotplug slot

 - Fix pagefault_disable() / pagefault_enable() unbalance in
   arch_stack_user_walk_common()

 - A couple of inline assembly optimizations, more cmpxchg() to
   try_cmpxchg() conversions, and removal of usages of xchg() and
   cmpxchg() on one and two byte memory areas

 - Various other small improvements and cleanups

* tag 's390-6.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (27 commits)
  Revert "s390/mm: Allow large pages for KASAN shadow mapping"
  s390/spinlock: Use flag output constraint for arch_cmpxchg_niai8()
  s390/spinlock: Use R constraint for arch_load_niai4()
  s390/spinlock: Generate shorter code for arch_spin_unlock()
  s390/spinlock: Remove condition code clobber from arch_spin_unlock()
  s390/spinlock: Use symbolic names in inline assemblies
  s390: Support PREEMPT_DYNAMIC
  s390/pci: Fix potential double remove of hotplug slot
  s390/pci: Fix leak of struct zpci_dev when zpci_add_device() fails
  s390/mm/hugetlbfs: Add missing includes
  s390/mm: Add PTE_MARKER support for hugetlbfs mappings
  s390/mm: Introduce region-third and segment table swap entries
  s390/mm: Introduce region-third and segment table entry present bits
  s390/mm: Rearrange region-third and segment table entry SW bits
  KVM: s390: Increase size of union sca_utility to four bytes
  KVM: s390: Remove one byte cmpxchg() usage
  KVM: s390: Use try_cmpxchg() instead of cmpxchg() loops
  s390/ap: Replace xchg() with WRITE_ONCE()
  s390/mm: Allow large pages for KASAN shadow mapping
  s390: Add ARCH_HAS_PREEMPT_LAZY support
  ...

2 files changed, 34 insertions, 31 deletions

diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
index cbff587dc4e3..88f72745fa59 100644
--- a/arch/s390/pci/pci.c
+++ b/arch/s390/pci/pci.c
@@ -779,8 +779,9 @@ int zpci_hot_reset_device(struct zpci_dev *zdev)
  * @fh: Current Function Handle of the device to be created
  * @state: Initial state after creation either Standby or Configured
  *
- * Creates a new zpci device and adds it to its, possibly newly created, zbus
- * as well as zpci_list.
+ * Allocates a new struct zpci_dev and queries the platform for its details.
+ * If successful the device can subsequently be added to the zPCI subsystem
+ * using zpci_add_device().
  *
  * Returns: the zdev on success or an error pointer otherwise
  */
@@ -803,7 +804,6 @@ struct zpci_dev *zpci_create_device(u32 fid, u32 fh, enum zpci_state state)
 		goto error;
 	zdev->state =  state;
 
-	kref_init(&zdev->kref);
 	mutex_init(&zdev->state_lock);
 	mutex_init(&zdev->fmb_lock);
 	mutex_init(&zdev->kzdev_lock);
@@ -816,6 +816,17 @@ error:
 	return ERR_PTR(rc);
 }
 
+/**
+ * zpci_add_device() - Add a previously created zPCI device to the zPCI subsystem
+ * @zdev: The zPCI device to be added
+ *
+ * A struct zpci_dev is added to the zPCI subsystem and to a virtual PCI bus creating
+ * a new one as necessary. A hotplug slot is created and events start to be handled.
+ * If successful from this point on zpci_zdev_get() and zpci_zdev_put() must be used.
+ * If adding the struct zpci_dev fails the device was not added and should be freed.
+ *
+ * Return: 0 on success, or an error code otherwise
+ */
 int zpci_add_device(struct zpci_dev *zdev)
 {
 	int rc;
@@ -829,6 +840,7 @@ int zpci_add_device(struct zpci_dev *zdev)
 	if (rc)
 		goto error_destroy_iommu;
 
+	kref_init(&zdev->kref);
 	spin_lock(&zpci_list_lock);
 	list_add_tail(&zdev->entry, &zpci_list);
 	spin_unlock(&zpci_list_lock);
@@ -928,10 +940,8 @@ void zpci_device_reserved(struct zpci_dev *zdev)
 void zpci_release_device(struct kref *kref)
 {
 	struct zpci_dev *zdev = container_of(kref, struct zpci_dev, kref);
-	int ret;
 
-	if (zdev->has_hp_slot)
-		zpci_exit_slot(zdev);
+	WARN_ON(zdev->state != ZPCI_FN_STATE_RESERVED);
 
 	if (zdev->zbus->bus)
 		zpci_bus_remove_device(zdev, false);
@@ -939,28 +949,14 @@ void zpci_release_device(struct kref *kref)
 	if (zdev_enabled(zdev))
 		zpci_disable_device(zdev);
 
-	switch (zdev->state) {
-	case ZPCI_FN_STATE_CONFIGURED:
-		ret = sclp_pci_deconfigure(zdev->fid);
-		zpci_dbg(3, "deconf fid:%x, rc:%d\n", zdev->fid, ret);
-		fallthrough;
-	case ZPCI_FN_STATE_STANDBY:
-		if (zdev->has_hp_slot)
-			zpci_exit_slot(zdev);
-		spin_lock(&zpci_list_lock);
-		list_del(&zdev->entry);
-		spin_unlock(&zpci_list_lock);
-		zpci_dbg(3, "rsv fid:%x\n", zdev->fid);
-		fallthrough;
-	case ZPCI_FN_STATE_RESERVED:
-		if (zdev->has_resources)
-			zpci_cleanup_bus_resources(zdev);
-		zpci_bus_device_unregister(zdev);
-		zpci_destroy_iommu(zdev);
-		fallthrough;
-	default:
-		break;
-	}
+	if (zdev->has_hp_slot)
+		zpci_exit_slot(zdev);
+
+	if (zdev->has_resources)
+		zpci_cleanup_bus_resources(zdev);
+
+	zpci_bus_device_unregister(zdev);
+	zpci_destroy_iommu(zdev);
 	zpci_dbg(3, "rem fid:%x\n", zdev->fid);
 	kfree_rcu(zdev, rcu);
 }
@@ -1121,7 +1117,8 @@ static void zpci_add_devices(struct list_head *scan_list)
 	list_sort(NULL, scan_list, &zpci_cmp_rid);
 	list_for_each_entry_safe(zdev, tmp, scan_list, entry) {
 		list_del_init(&zdev->entry);
-		zpci_add_device(zdev);
+		if (zpci_add_device(zdev))
+			kfree(zdev);
 	}
 }
 
diff --git a/arch/s390/pci/pci_event.c b/arch/s390/pci/pci_event.c
index 47f934f4e828..7f7b732b3f3e 100644
--- a/arch/s390/pci/pci_event.c
+++ b/arch/s390/pci/pci_event.c
@@ -340,7 +340,10 @@ static void __zpci_event_availability(struct zpci_ccdf_avail *ccdf)
 			zdev = zpci_create_device(ccdf->fid, ccdf->fh, ZPCI_FN_STATE_CONFIGURED);
 			if (IS_ERR(zdev))
 				break;
-			zpci_add_device(zdev);
+			if (zpci_add_device(zdev)) {
+				kfree(zdev);
+				break;
+			}
 		} else {
 			/* the configuration request may be stale */
 			if (zdev->state != ZPCI_FN_STATE_STANDBY)
@@ -354,7 +357,10 @@ static void __zpci_event_availability(struct zpci_ccdf_avail *ccdf)
 			zdev = zpci_create_device(ccdf->fid, ccdf->fh, ZPCI_FN_STATE_STANDBY);
 			if (IS_ERR(zdev))
 				break;
-			zpci_add_device(zdev);
+			if (zpci_add_device(zdev)) {
+				kfree(zdev);
+				break;
+			}
 		} else {
 			zpci_update_fh(zdev, ccdf->fh);
 		}