diff options
Diffstat (limited to 'arch/s390/pci')
| -rw-r--r-- | arch/s390/pci/pci.c | 45 | ||||
| -rw-r--r-- | arch/s390/pci/pci_bus.h | 7 | ||||
| -rw-r--r-- | arch/s390/pci/pci_event.c | 22 | ||||
| -rw-r--r-- | arch/s390/pci/pci_mmio.c | 2 |
4 files changed, 53 insertions, 23 deletions
diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c index 88f72745fa59..9e19d6076d3e 100644 --- a/arch/s390/pci/pci.c +++ b/arch/s390/pci/pci.c @@ -44,6 +44,7 @@ /* list of all detected zpci devices */ static LIST_HEAD(zpci_list); static DEFINE_SPINLOCK(zpci_list_lock); +static DEFINE_MUTEX(zpci_add_remove_lock); static DECLARE_BITMAP(zpci_domain, ZPCI_DOMAIN_BITMAP_SIZE); static DEFINE_SPINLOCK(zpci_domain_lock); @@ -69,6 +70,15 @@ 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; + mutex_lock(&zpci_add_remove_lock); + kref_put_lock(&zdev->kref, zpci_release_device, &zpci_list_lock); + mutex_unlock(&zpci_add_remove_lock); +} + struct zpci_dev *get_zdev_by_fid(u32 fid) { struct zpci_dev *tmp, *zdev = NULL; @@ -831,6 +841,7 @@ int zpci_add_device(struct zpci_dev *zdev) { int rc; + mutex_lock(&zpci_add_remove_lock); zpci_dbg(1, "add fid:%x, fh:%x, c:%d\n", zdev->fid, zdev->fh, zdev->state); rc = zpci_init_iommu(zdev); if (rc) @@ -844,12 +855,14 @@ int zpci_add_device(struct zpci_dev *zdev) spin_lock(&zpci_list_lock); list_add_tail(&zdev->entry, &zpci_list); spin_unlock(&zpci_list_lock); + mutex_unlock(&zpci_add_remove_lock); return 0; error_destroy_iommu: zpci_destroy_iommu(zdev); error: zpci_dbg(0, "add fid:%x, rc:%d\n", zdev->fid, rc); + mutex_unlock(&zpci_add_remove_lock); return rc; } @@ -919,21 +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); } @@ -941,13 +953,14 @@ void zpci_release_device(struct kref *kref) { struct zpci_dev *zdev = container_of(kref, struct zpci_dev, kref); + lockdep_assert_held(&zpci_add_remove_lock); WARN_ON(zdev->state != ZPCI_FN_STATE_RESERVED); - - if (zdev->zbus->bus) - zpci_bus_remove_device(zdev, false); - - if (zdev_enabled(zdev)) - zpci_disable_device(zdev); + /* + * 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 af9f0ac79a1b..3febb3b297c0 100644 --- a/arch/s390/pci/pci_bus.h +++ b/arch/s390/pci/pci_bus.h @@ -17,11 +17,8 @@ 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 7f7b732b3f3e..6f48a1073c6e 100644 --- a/arch/s390/pci/pci_event.c +++ b/arch/s390/pci/pci_event.c @@ -322,6 +322,22 @@ 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); @@ -345,8 +361,10 @@ 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; } @@ -362,6 +380,8 @@ 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; diff --git a/arch/s390/pci/pci_mmio.c b/arch/s390/pci/pci_mmio.c index 4779c3cb6cfa..0fa34c501296 100644 --- a/arch/s390/pci/pci_mmio.c +++ b/arch/s390/pci/pci_mmio.c @@ -228,7 +228,7 @@ static inline int __pcilg_mio_inuser( [ioaddr_len] "+&d" (ioaddr_len.pair), [cc] "+d" (cc), [val] "=d" (val), [dst] "+a" (dst), [cnt] "+d" (cnt), [tmp] "=d" (tmp), - [shift] "+d" (shift) + [shift] "+a" (shift) :: "cc", "memory"); /* did we write everything to the user space buffer? */ |