s390/pci: fix handling of PEC 306

In contrast to other hotplug events PEC 0x306 isn't about a single
but multiple devices. Also there's no information on what happened
to these devices. We correctly handled hotplug that way but failed
to handle hot-unplug. This patch addresses that and implements
hot-unplug of multiple devices via PEC 306.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

3 files changed, 24 insertions, 32 deletions

diff --git a/arch/s390/include/asm/pci.h b/arch/s390/include/asm/pci.h
index 280458c82104..f36b4b726057 100644
--- a/arch/s390/include/asm/pci.h
+++ b/arch/s390/include/asm/pci.h
@@ -161,9 +161,9 @@ int zpci_create_device(struct zpci_dev *);
 void zpci_remove_device(struct zpci_dev *zdev);
 int zpci_enable_device(struct zpci_dev *);
 int zpci_disable_device(struct zpci_dev *);
-void zpci_stop_device(struct zpci_dev *);
 int zpci_register_ioat(struct zpci_dev *, u8, u64, u64, u64);
 int zpci_unregister_ioat(struct zpci_dev *, u8);
+void zpci_remove_reserved_devices(void);
 
 /* CLP */
 int clp_scan_pci_devices(void);
diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
index f4928bc57773..114b390d80f9 100644
--- a/arch/s390/pci/pci.c
+++ b/arch/s390/pci/pci.c
@@ -86,6 +86,25 @@ struct zpci_dev *get_zdev_by_fid(u32 fid)
         return zdev;
 }
 
+void zpci_remove_reserved_devices(void)
+{
+        struct zpci_dev *tmp, *zdev;
+        enum zpci_state state;
+        LIST_HEAD(remove);
+
+        spin_lock(&zpci_list_lock);
+        list_for_each_entry_safe(zdev, tmp, &zpci_list, entry) {
+                if (zdev->state == ZPCI_FN_STATE_STANDBY &&
+                    !clp_get_state(zdev->fid, &state) &&
+                    state == ZPCI_FN_STATE_RESERVED)
+                        list_move_tail(&zdev->entry, &remove);
+        }
+        spin_unlock(&zpci_list_lock);
+
+        list_for_each_entry_safe(zdev, tmp, &remove, entry)
+                zpci_remove_device(zdev);
+}
+
 static struct zpci_dev *get_zdev_by_bus(struct pci_bus *bus)
 {
         return (bus && bus->sysdata) ? (struct zpci_dev *) bus->sysdata : NULL;
@@ -845,16 +864,6 @@ out:
         return rc;
 }
 
-void zpci_stop_device(struct zpci_dev *zdev)
-{
-        zpci_dma_exit_device(zdev);
-        /*
-         * Note: SCLP disables fh via set-pci-fn so don't
-         * do that here.
-         */
-}
-EXPORT_SYMBOL_GPL(zpci_stop_device);
-
 void zpci_remove_device(struct zpci_dev *zdev)
 {
         if (!zdev->bus)
diff --git a/arch/s390/pci/pci_clp.c b/arch/s390/pci/pci_clp.c
index 267cdd69e6da..3a5cd84e5a3b 100644
--- a/arch/s390/pci/pci_clp.c
+++ b/arch/s390/pci/pci_clp.c
@@ -335,33 +335,14 @@ out:
 
 static void __clp_add(struct clp_fh_list_entry *entry, void *data)
 {
-        if (!entry->vendor_id)
-                return;
-
-        clp_add_pci_device(entry->fid, entry->fh, entry->config_state);
-}
-
-static void __clp_rescan(struct clp_fh_list_entry *entry, void *data)
-{
         struct zpci_dev *zdev;
 
         if (!entry->vendor_id)
                 return;
 
         zdev = get_zdev_by_fid(entry->fid);
-        if (!zdev) {
+        if (!zdev)
                 clp_add_pci_device(entry->fid, entry->fh, entry->config_state);
-                return;
-        }
-
-        if (!entry->config_state) {
-                /*
-                 * The handle is already disabled, that means no iota/irq freeing via
-                 * the firmware interfaces anymore. Need to free resources manually
-                 * (DMA memory, debug, sysfs)...
-                 */
-                zpci_stop_device(zdev);
-        }
 }
 
 static void __clp_update(struct clp_fh_list_entry *entry, void *data)
@@ -398,11 +379,13 @@ int clp_rescan_pci_devices(void)
         struct clp_req_rsp_list_pci *rrb;
         int rc;
 
+        zpci_remove_reserved_devices();
+
         rrb = clp_alloc_block(GFP_KERNEL);
         if (!rrb)
                 return -ENOMEM;
 
-        rc = clp_list_pci(rrb, NULL, __clp_rescan);
+        rc = clp_list_pci(rrb, NULL, __clp_add);
 
         clp_free_block(rrb);
         return rc;