diff options
| -rw-r--r-- | arch/s390/pci/pci.c | 32 | ||||
| -rw-r--r-- | arch/s390/pci/pci_bus.h | 7 | ||||
| -rw-r--r-- | arch/s390/pci/pci_event.c | 22 |
3 files changed, 45 insertions, 16 deletions
diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c index 9fcc6d3180f2..4602abd0c6f1 100644 --- a/arch/s390/pci/pci.c +++ b/arch/s390/pci/pci.c @@ -70,6 +70,13 @@ EXPORT_SYMBOL_GPL(zpci_aipb); struct airq_iv *zpci_aif_sbv; EXPORT_SYMBOL_GPL(zpci_aif_sbv); +void zpci_zdev_put(struct zpci_dev *zdev) +{ + if (!zdev) + return; + kref_put_lock(&zdev->kref, zpci_release_device, &zpci_list_lock); +} + struct zpci_dev *get_zdev_by_fid(u32 fid) { struct zpci_dev *tmp, *zdev = NULL; @@ -925,21 +932,20 @@ int zpci_deconfigure_device(struct zpci_dev *zdev) * @zdev: the zpci_dev that was reserved * * Handle the case that a given zPCI function was reserved by another system. - * After a call to this function the zpci_dev can not be found via - * get_zdev_by_fid() anymore but may still be accessible via existing - * references though it will not be functional anymore. */ void zpci_device_reserved(struct zpci_dev *zdev) { - /* - * Remove device from zpci_list as it is going away. This also - * makes sure we ignore subsequent zPCI events for this device. - */ - spin_lock(&zpci_list_lock); - list_del(&zdev->entry); - spin_unlock(&zpci_list_lock); + lockdep_assert_held(&zdev->state_lock); + /* We may declare the device reserved multiple times */ + if (zdev->state == ZPCI_FN_STATE_RESERVED) + return; zdev->state = ZPCI_FN_STATE_RESERVED; zpci_dbg(3, "rsv fid:%x\n", zdev->fid); + /* + * The underlying device is gone. Allow the zdev to be freed + * as soon as all other references are gone by accounting for + * the removal as a dropped reference. + */ zpci_zdev_put(zdev); } @@ -948,6 +954,12 @@ void zpci_release_device(struct kref *kref) struct zpci_dev *zdev = container_of(kref, struct zpci_dev, kref); WARN_ON(zdev->state != ZPCI_FN_STATE_RESERVED); + /* + * We already hold zpci_list_lock thanks to kref_put_lock(). + * This makes sure no new reference can be taken from the list. + */ + list_del(&zdev->entry); + spin_unlock(&zpci_list_lock); if (zdev->has_hp_slot) zpci_exit_slot(zdev); diff --git a/arch/s390/pci/pci_bus.h b/arch/s390/pci/pci_bus.h index e86a9419d233..ae3d7a9159bd 100644 --- a/arch/s390/pci/pci_bus.h +++ b/arch/s390/pci/pci_bus.h @@ -21,11 +21,8 @@ int zpci_bus_scan_device(struct zpci_dev *zdev); void zpci_bus_remove_device(struct zpci_dev *zdev, bool set_error); void zpci_release_device(struct kref *kref); -static inline void zpci_zdev_put(struct zpci_dev *zdev) -{ - if (zdev) - kref_put(&zdev->kref, zpci_release_device); -} + +void zpci_zdev_put(struct zpci_dev *zdev); static inline void zpci_zdev_get(struct zpci_dev *zdev) { diff --git a/arch/s390/pci/pci_event.c b/arch/s390/pci/pci_event.c index 7bd7721c1239..2fbee3887d13 100644 --- a/arch/s390/pci/pci_event.c +++ b/arch/s390/pci/pci_event.c @@ -335,6 +335,22 @@ static void zpci_event_hard_deconfigured(struct zpci_dev *zdev, u32 fh) zdev->state = ZPCI_FN_STATE_STANDBY; } +static void zpci_event_reappear(struct zpci_dev *zdev) +{ + lockdep_assert_held(&zdev->state_lock); + /* + * The zdev is in the reserved state. This means that it was presumed to + * go away but there are still undropped references. Now, the platform + * announced its availability again. Bring back the lingering zdev + * to standby. This is safe because we hold a temporary reference + * now so that it won't go away. Account for the re-appearance of the + * underlying device by incrementing the reference count. + */ + zdev->state = ZPCI_FN_STATE_STANDBY; + zpci_zdev_get(zdev); + zpci_dbg(1, "rea fid:%x, fh:%x\n", zdev->fid, zdev->fh); +} + static void __zpci_event_availability(struct zpci_ccdf_avail *ccdf) { struct zpci_dev *zdev = get_zdev_by_fid(ccdf->fid); @@ -358,8 +374,10 @@ static void __zpci_event_availability(struct zpci_ccdf_avail *ccdf) break; } } else { + if (zdev->state == ZPCI_FN_STATE_RESERVED) + zpci_event_reappear(zdev); /* the configuration request may be stale */ - if (zdev->state != ZPCI_FN_STATE_STANDBY) + else if (zdev->state != ZPCI_FN_STATE_STANDBY) break; zdev->state = ZPCI_FN_STATE_CONFIGURED; } @@ -375,6 +393,8 @@ static void __zpci_event_availability(struct zpci_ccdf_avail *ccdf) break; } } else { + if (zdev->state == ZPCI_FN_STATE_RESERVED) + zpci_event_reappear(zdev); zpci_update_fh(zdev, ccdf->fh); } break; |