1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * PCI Hot Plug Controller Driver for System z
  4 *
  5 * Copyright 2012 IBM Corp.
  6 *
  7 * Author(s):
  8 *   Jan Glauber <jang@linux.vnet.ibm.com>
  9 */
 10
 11#define KMSG_COMPONENT "zpci"
 12#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
 13
 14#include <linux/kernel.h>
 15#include <linux/slab.h>
 16#include <linux/pci.h>
 17#include <linux/pci_hotplug.h>
 18#include <asm/pci_debug.h>
 19#include <asm/sclp.h>
 20
 21#define SLOT_NAME_SIZE	10
 22static LIST_HEAD(s390_hotplug_slot_list);
 23
 24static int zpci_fn_configured(enum zpci_state state)
 25{
 26	return state == ZPCI_FN_STATE_CONFIGURED ||
 27	       state == ZPCI_FN_STATE_ONLINE;
 28}
 29
 30/*
 31 * struct slot - slot information for each *physical* slot
 32 */
 33struct slot {
 34	struct list_head slot_list;
 35	struct hotplug_slot hotplug_slot;
 36	struct zpci_dev *zdev;
 37};
 38
 39static inline struct slot *to_slot(struct hotplug_slot *hotplug_slot)
 40{
 41	return container_of(hotplug_slot, struct slot, hotplug_slot);
 42}
 43
 44static inline int slot_configure(struct slot *slot)
 45{
 46	int ret = sclp_pci_configure(slot->zdev->fid);
 47
 48	zpci_dbg(3, "conf fid:%x, rc:%d\n", slot->zdev->fid, ret);
 49	if (!ret)
 50		slot->zdev->state = ZPCI_FN_STATE_CONFIGURED;
 51
 52	return ret;
 53}
 54
 55static inline int slot_deconfigure(struct slot *slot)
 56{
 57	int ret = sclp_pci_deconfigure(slot->zdev->fid);
 58
 59	zpci_dbg(3, "deconf fid:%x, rc:%d\n", slot->zdev->fid, ret);
 60	if (!ret)
 61		slot->zdev->state = ZPCI_FN_STATE_STANDBY;
 62
 63	return ret;
 64}
 65
 66static int enable_slot(struct hotplug_slot *hotplug_slot)
 67{
 68	struct slot *slot = to_slot(hotplug_slot);
 69	int rc;
 70
 71	if (slot->zdev->state != ZPCI_FN_STATE_STANDBY)
 72		return -EIO;
 73
 74	rc = slot_configure(slot);
 75	if (rc)
 76		return rc;
 77
 78	rc = zpci_enable_device(slot->zdev);
 79	if (rc)
 80		goto out_deconfigure;
 81
 82	pci_scan_slot(slot->zdev->bus, ZPCI_DEVFN);
 83	pci_lock_rescan_remove();
 84	pci_bus_add_devices(slot->zdev->bus);
 85	pci_unlock_rescan_remove();
 86
 87	return rc;
 88
 89out_deconfigure:
 90	slot_deconfigure(slot);
 91	return rc;
 92}
 93
 94static int disable_slot(struct hotplug_slot *hotplug_slot)
 95{
 96	struct slot *slot = to_slot(hotplug_slot);
 97	struct pci_dev *pdev;
 98	int rc;
 99
100	if (!zpci_fn_configured(slot->zdev->state))
101		return -EIO;
102
103	pdev = pci_get_slot(slot->zdev->bus, ZPCI_DEVFN);
104	if (pdev) {
105		pci_stop_and_remove_bus_device_locked(pdev);
106		pci_dev_put(pdev);
107	}
108
109	rc = zpci_disable_device(slot->zdev);
110	if (rc)
111		return rc;
112
113	return slot_deconfigure(slot);
114}
115
116static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
117{
118	struct slot *slot = to_slot(hotplug_slot);
119
120	switch (slot->zdev->state) {
121	case ZPCI_FN_STATE_STANDBY:
122		*value = 0;
123		break;
124	default:
125		*value = 1;
126		break;
127	}
128	return 0;
129}
130
131static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
132{
133	/* if the slot exits it always contains a function */
134	*value = 1;
135	return 0;
136}
137
138static const struct hotplug_slot_ops s390_hotplug_slot_ops = {
139	.enable_slot =		enable_slot,
140	.disable_slot =		disable_slot,
141	.get_power_status =	get_power_status,
142	.get_adapter_status =	get_adapter_status,
143};
144
145int zpci_init_slot(struct zpci_dev *zdev)
146{
147	char name[SLOT_NAME_SIZE];
148	struct slot *slot;
149	int rc;
150
151	if (!zdev)
152		return 0;
153
154	slot = kzalloc(sizeof(*slot), GFP_KERNEL);
155	if (!slot)
156		goto error;
157
158	slot->zdev = zdev;
159	slot->hotplug_slot.ops = &s390_hotplug_slot_ops;
160
161	snprintf(name, SLOT_NAME_SIZE, "%08x", zdev->fid);
162	rc = pci_hp_register(&slot->hotplug_slot, zdev->bus,
163			     ZPCI_DEVFN, name);
164	if (rc)
165		goto error_reg;
166
167	list_add(&slot->slot_list, &s390_hotplug_slot_list);
168	return 0;
169
170error_reg:
171	kfree(slot);
172error:
173	return -ENOMEM;
174}
175
176void zpci_exit_slot(struct zpci_dev *zdev)
177{
178	struct slot *slot, *next;
179
180	list_for_each_entry_safe(slot, next, &s390_hotplug_slot_list,
181				 slot_list) {
182		if (slot->zdev != zdev)
183			continue;
184		list_del(&slot->slot_list);
185		pci_hp_deregister(&slot->hotplug_slot);
186		kfree(slot);
187	}
188}