s390/pci: embedding hotplug_slot in zdev

Embedding the hotplug_slot in zdev structure allows to
greatly simplify the hotplug handling by eliminating
the handling of the slot_list.
Signed-off-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

arch/s390/include/asm/pci.h

@@ -5,6 +5,7 @@
 #include <linux/pci.h>
 #include <linux/mutex.h>
 #include <linux/iommu.h>
+#include <linux/pci_hotplug.h>
 #include <asm-generic/pci.h>
 #include <asm/pci_clp.h>
 #include <asm/pci_debug.h>
@@ -96,6 +97,7 @@ struct s390_domain;
 struct zpci_dev {
 	struct pci_bus	*bus;
 	struct list_head entry;		/* list of all zpci_devices, needed for hotplug, etc. */
+	struct hotplug_slot hotplug_slot;
 
 	enum zpci_state state;
 	u32		fid;		/* function ID, used by sclp */

drivers/pci/hotplug/s390_pci_hpc.c

@@ -19,7 +19,6 @@
 #include <asm/sclp.h>
 
 #define SLOT_NAME_SIZE	10
-static LIST_HEAD(s390_hotplug_slot_list);
 
 static int zpci_fn_configured(enum zpci_state state)
 {
@@ -27,97 +26,86 @@ static int zpci_fn_configured(enum zpci_state state)
 	       state == ZPCI_FN_STATE_ONLINE;
 }
 
-/*
- * struct slot - slot information for each *physical* slot
- */
-struct slot {
-	struct list_head slot_list;
-	struct hotplug_slot hotplug_slot;
-	struct zpci_dev *zdev;
-};
-
-static inline struct slot *to_slot(struct hotplug_slot *hotplug_slot)
+static inline int zdev_configure(struct zpci_dev *zdev)
 {
-	return container_of(hotplug_slot, struct slot, hotplug_slot);
-}
-
-static inline int slot_configure(struct slot *slot)
-{
-	int ret = sclp_pci_configure(slot->zdev->fid);
+	int ret = sclp_pci_configure(zdev->fid);
 
-	zpci_dbg(3, "conf fid:%x, rc:%d\n", slot->zdev->fid, ret);
+	zpci_dbg(3, "conf fid:%x, rc:%d\n", zdev->fid, ret);
 	if (!ret)
-		slot->zdev->state = ZPCI_FN_STATE_CONFIGURED;
+		zdev->state = ZPCI_FN_STATE_CONFIGURED;
 
 	return ret;
 }
 
-static inline int slot_deconfigure(struct slot *slot)
+static inline int zdev_deconfigure(struct zpci_dev *zdev)
 {
-	int ret = sclp_pci_deconfigure(slot->zdev->fid);
+	int ret = sclp_pci_deconfigure(zdev->fid);
 
-	zpci_dbg(3, "deconf fid:%x, rc:%d\n", slot->zdev->fid, ret);
+	zpci_dbg(3, "deconf fid:%x, rc:%d\n", zdev->fid, ret);
 	if (!ret)
-		slot->zdev->state = ZPCI_FN_STATE_STANDBY;
+		zdev->state = ZPCI_FN_STATE_STANDBY;
 
 	return ret;
 }
 
 static int enable_slot(struct hotplug_slot *hotplug_slot)
 {
-	struct slot *slot = to_slot(hotplug_slot);
+	struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
+					     hotplug_slot);
 	int rc;
 
-	if (slot->zdev->state != ZPCI_FN_STATE_STANDBY)
+	if (zdev->state != ZPCI_FN_STATE_STANDBY)
 		return -EIO;
 
-	rc = slot_configure(slot);
+	rc = zdev_configure(zdev);
 	if (rc)
 		return rc;
 
-	rc = zpci_enable_device(slot->zdev);
+	rc = zpci_enable_device(zdev);
 	if (rc)
 		goto out_deconfigure;
 
-	pci_scan_slot(slot->zdev->bus, ZPCI_DEVFN);
+	pci_scan_slot(zdev->bus, ZPCI_DEVFN);
 	pci_lock_rescan_remove();
-	pci_bus_add_devices(slot->zdev->bus);
+	pci_bus_add_devices(zdev->bus);
 	pci_unlock_rescan_remove();
 
 	return rc;
 
 out_deconfigure:
-	slot_deconfigure(slot);
+	zdev_deconfigure(zdev);
 	return rc;
 }
 
 static int disable_slot(struct hotplug_slot *hotplug_slot)
 {
-	struct slot *slot = to_slot(hotplug_slot);
+	struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
+					     hotplug_slot);
 	struct pci_dev *pdev;
 	int rc;
 
-	if (!zpci_fn_configured(slot->zdev->state))
+	if (!zpci_fn_configured(zdev->state))
 		return -EIO;
 
-	pdev = pci_get_slot(slot->zdev->bus, ZPCI_DEVFN);
+	pdev = pci_get_slot(zdev->bus, ZPCI_DEVFN);
 	if (pdev) {
 		pci_stop_and_remove_bus_device_locked(pdev);
 		pci_dev_put(pdev);
 	}
 
-	rc = zpci_disable_device(slot->zdev);
+	rc = zpci_disable_device(zdev);
 	if (rc)
 		return rc;
 
-	return slot_deconfigure(slot);
+	return zdev_deconfigure(zdev);
 }
 
 static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
 {
-	struct slot *slot = to_slot(hotplug_slot);
+	struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
+					     hotplug_slot);
 
-	switch (slot->zdev->state) {
+	switch (zdev->state) {
 	case ZPCI_FN_STATE_STANDBY:
 		*value = 0;
 		break;
@@ -145,44 +133,15 @@ static const struct hotplug_slot_ops s390_hotplug_slot_ops = {
 int zpci_init_slot(struct zpci_dev *zdev)
 {
 	char name[SLOT_NAME_SIZE];
-	struct slot *slot;
-	int rc;
 
-	if (!zdev)
-		return 0;
-
-	slot = kzalloc(sizeof(*slot), GFP_KERNEL);
-	if (!slot)
-		goto error;
-
-	slot->zdev = zdev;
-	slot->hotplug_slot.ops = &s390_hotplug_slot_ops;
+	zdev->hotplug_slot.ops = &s390_hotplug_slot_ops;
 
 	snprintf(name, SLOT_NAME_SIZE, "%08x", zdev->fid);
-	rc = pci_hp_register(&slot->hotplug_slot, zdev->bus,
+	return pci_hp_register(&zdev->hotplug_slot, zdev->bus,
 			       ZPCI_DEVFN, name);
-	if (rc)
-		goto error_reg;
-
-	list_add(&slot->slot_list, &s390_hotplug_slot_list);
-	return 0;
-
-error_reg:
-	kfree(slot);
-error:
-	return -ENOMEM;
 }
 
 void zpci_exit_slot(struct zpci_dev *zdev)
 {
-	struct slot *slot, *next;
-
-	list_for_each_entry_safe(slot, next, &s390_hotplug_slot_list,
-				 slot_list) {
-		if (slot->zdev != zdev)
-			continue;
-		list_del(&slot->slot_list);
-		pci_hp_deregister(&slot->hotplug_slot);
-		kfree(slot);
-	}
+	pci_hp_deregister(&zdev->hotplug_slot);
 }