1/*
  2 * PCI Hot Plug Controller Driver for System z
  3 *
  4 * Copyright 2012 IBM Corp.
  5 *
  6 * Author(s):
  7 *   Jan Glauber <jang@linux.vnet.ibm.com>
  8 */
  9
 10#define COMPONENT "zPCI hpc"
 11#define pr_fmt(fmt) COMPONENT ": " fmt
 12
 13#include <linux/module.h>
 14#include <linux/kernel.h>
 15#include <linux/slab.h>
 16#include <linux/pci.h>
 17#include <linux/pci_hotplug.h>
 18#include <linux/init.h>
 19#include <asm/pci_debug.h>
 20#include <asm/sclp.h>
 21
 22#define SLOT_NAME_SIZE	10
 23static LIST_HEAD(s390_hotplug_slot_list);
 24
 25MODULE_AUTHOR("Jan Glauber <jang@linux.vnet.ibm.com");
 26MODULE_DESCRIPTION("Hot Plug PCI Controller for System z");
 27MODULE_LICENSE("GPL");
 28
 29static int zpci_fn_configured(enum zpci_state state)
 30{
 31	return state == ZPCI_FN_STATE_CONFIGURED ||
 32	       state == ZPCI_FN_STATE_ONLINE;
 33}
 34
 35/*
 36 * struct slot - slot information for each *physical* slot
 37 */
 38struct slot {
 39	struct list_head slot_list;
 40	struct hotplug_slot *hotplug_slot;
 41	struct zpci_dev *zdev;
 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 = hotplug_slot->private;
 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 = hotplug_slot->private;
 97	int rc;
 98
 99	if (!zpci_fn_configured(slot->zdev->state))
100		return -EIO;
101
102	if (slot->zdev->pdev)
103		pci_stop_and_remove_bus_device_locked(slot->zdev->pdev);
104
105	rc = zpci_disable_device(slot->zdev);
106	if (rc)
107		return rc;
108
109	return slot_deconfigure(slot);
110}
111
112static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
113{
114	struct slot *slot = hotplug_slot->private;
115
116	switch (slot->zdev->state) {
117	case ZPCI_FN_STATE_STANDBY:
118		*value = 0;
119		break;
120	default:
121		*value = 1;
122		break;
123	}
124	return 0;
125}
126
127static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
128{
129	/* if the slot exits it always contains a function */
130	*value = 1;
131	return 0;
132}
133
134static void release_slot(struct hotplug_slot *hotplug_slot)
135{
136	struct slot *slot = hotplug_slot->private;
137
138	kfree(slot->hotplug_slot->info);
139	kfree(slot->hotplug_slot);
140	kfree(slot);
141}
142
143static struct hotplug_slot_ops s390_hotplug_slot_ops = {
144	.enable_slot =		enable_slot,
145	.disable_slot =		disable_slot,
146	.get_power_status =	get_power_status,
147	.get_adapter_status =	get_adapter_status,
148};
149
150int zpci_init_slot(struct zpci_dev *zdev)
151{
152	struct hotplug_slot *hotplug_slot;
153	struct hotplug_slot_info *info;
154	char name[SLOT_NAME_SIZE];
155	struct slot *slot;
156	int rc;
157
158	if (!zdev)
159		return 0;
160
161	slot = kzalloc(sizeof(*slot), GFP_KERNEL);
162	if (!slot)
163		goto error;
164
165	hotplug_slot = kzalloc(sizeof(*hotplug_slot), GFP_KERNEL);
166	if (!hotplug_slot)
167		goto error_hp;
168	hotplug_slot->private = slot;
169
170	slot->hotplug_slot = hotplug_slot;
171	slot->zdev = zdev;
172
173	info = kzalloc(sizeof(*info), GFP_KERNEL);
174	if (!info)
175		goto error_info;
176	hotplug_slot->info = info;
177
178	hotplug_slot->ops = &s390_hotplug_slot_ops;
179	hotplug_slot->release = &release_slot;
180
181	get_power_status(hotplug_slot, &info->power_status);
182	get_adapter_status(hotplug_slot, &info->adapter_status);
183
184	snprintf(name, SLOT_NAME_SIZE, "%08x", zdev->fid);
185	rc = pci_hp_register(slot->hotplug_slot, zdev->bus,
186			     ZPCI_DEVFN, name);
187	if (rc)
188		goto error_reg;
189
190	list_add(&slot->slot_list, &s390_hotplug_slot_list);
191	return 0;
192
193error_reg:
194	kfree(info);
195error_info:
196	kfree(hotplug_slot);
197error_hp:
198	kfree(slot);
199error:
200	return -ENOMEM;
201}
202
203void zpci_exit_slot(struct zpci_dev *zdev)
204{
205	struct list_head *tmp, *n;
206	struct slot *slot;
207
208	list_for_each_safe(tmp, n, &s390_hotplug_slot_list) {
209		slot = list_entry(tmp, struct slot, slot_list);
210		if (slot->zdev != zdev)
211			continue;
212		list_del(&slot->slot_list);
213		pci_hp_deregister(slot->hotplug_slot);
214	}
215}