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 KMSG_COMPONENT "zpci"
 11#define pr_fmt(fmt) KMSG_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 <asm/pci_debug.h>
 19#include <asm/sclp.h>
 20
 21#define SLOT_NAME_SIZE	10
 22static LIST_HEAD(s390_hotplug_slot_list);
 23
 24MODULE_AUTHOR("Jan Glauber <jang@linux.vnet.ibm.com");
 25MODULE_DESCRIPTION("Hot Plug PCI Controller for System z");
 26MODULE_LICENSE("GPL");
 27
 28static int zpci_fn_configured(enum zpci_state state)
 29{
 30	return state == ZPCI_FN_STATE_CONFIGURED ||
 31	       state == ZPCI_FN_STATE_ONLINE;
 32}
 33
 34/*
 35 * struct slot - slot information for each *physical* slot
 36 */
 37struct slot {
 38	struct list_head slot_list;
 39	struct hotplug_slot *hotplug_slot;
 40	struct zpci_dev *zdev;
 41};
 42
 43static inline int slot_configure(struct slot *slot)
 44{
 45	int ret = sclp_pci_configure(slot->zdev->fid);
 46
 47	zpci_dbg(3, "conf fid:%x, rc:%d\n", slot->zdev->fid, ret);
 48	if (!ret)
 49		slot->zdev->state = ZPCI_FN_STATE_CONFIGURED;
 50
 51	return ret;
 52}
 53
 54static inline int slot_deconfigure(struct slot *slot)
 55{
 56	int ret = sclp_pci_deconfigure(slot->zdev->fid);
 57
 58	zpci_dbg(3, "deconf fid:%x, rc:%d\n", slot->zdev->fid, ret);
 59	if (!ret)
 60		slot->zdev->state = ZPCI_FN_STATE_STANDBY;
 61
 62	return ret;
 63}
 64
 65static int enable_slot(struct hotplug_slot *hotplug_slot)
 66{
 67	struct slot *slot = hotplug_slot->private;
 68	int rc;
 69
 70	if (slot->zdev->state != ZPCI_FN_STATE_STANDBY)
 71		return -EIO;
 72
 73	rc = slot_configure(slot);
 74	if (rc)
 75		return rc;
 76
 77	rc = zpci_enable_device(slot->zdev);
 78	if (rc)
 79		goto out_deconfigure;
 80
 81	pci_scan_slot(slot->zdev->bus, ZPCI_DEVFN);
 82	pci_lock_rescan_remove();
 83	pci_bus_add_devices(slot->zdev->bus);
 84	pci_unlock_rescan_remove();
 85
 86	return rc;
 87
 88out_deconfigure:
 89	slot_deconfigure(slot);
 90	return rc;
 91}
 92
 93static int disable_slot(struct hotplug_slot *hotplug_slot)
 94{
 95	struct slot *slot = hotplug_slot->private;
 96	struct pci_dev *pdev;
 97	int rc;
 98
 99	if (!zpci_fn_configured(slot->zdev->state))
100		return -EIO;
101
102	pdev = pci_get_slot(slot->zdev->bus, ZPCI_DEVFN);
103	if (pdev) {
104		pci_stop_and_remove_bus_device_locked(pdev);
105		pci_dev_put(pdev);
106	}
107
108	rc = zpci_disable_device(slot->zdev);
109	if (rc)
110		return rc;
111
112	return slot_deconfigure(slot);
113}
114
115static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
116{
117	struct slot *slot = hotplug_slot->private;
118
119	switch (slot->zdev->state) {
120	case ZPCI_FN_STATE_STANDBY:
121		*value = 0;
122		break;
123	default:
124		*value = 1;
125		break;
126	}
127	return 0;
128}
129
130static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
131{
132	/* if the slot exits it always contains a function */
133	*value = 1;
134	return 0;
135}
136
137static void release_slot(struct hotplug_slot *hotplug_slot)
138{
139	struct slot *slot = hotplug_slot->private;
140
141	kfree(slot->hotplug_slot->info);
142	kfree(slot->hotplug_slot);
143	kfree(slot);
144}
145
146static struct hotplug_slot_ops s390_hotplug_slot_ops = {
147	.enable_slot =		enable_slot,
148	.disable_slot =		disable_slot,
149	.get_power_status =	get_power_status,
150	.get_adapter_status =	get_adapter_status,
151};
152
153int zpci_init_slot(struct zpci_dev *zdev)
154{
155	struct hotplug_slot *hotplug_slot;
156	struct hotplug_slot_info *info;
157	char name[SLOT_NAME_SIZE];
158	struct slot *slot;
159	int rc;
160
161	if (!zdev)
162		return 0;
163
164	slot = kzalloc(sizeof(*slot), GFP_KERNEL);
165	if (!slot)
166		goto error;
167
168	hotplug_slot = kzalloc(sizeof(*hotplug_slot), GFP_KERNEL);
169	if (!hotplug_slot)
170		goto error_hp;
171	hotplug_slot->private = slot;
172
173	slot->hotplug_slot = hotplug_slot;
174	slot->zdev = zdev;
175
176	info = kzalloc(sizeof(*info), GFP_KERNEL);
177	if (!info)
178		goto error_info;
179	hotplug_slot->info = info;
180
181	hotplug_slot->ops = &s390_hotplug_slot_ops;
182	hotplug_slot->release = &release_slot;
183
184	get_power_status(hotplug_slot, &info->power_status);
185	get_adapter_status(hotplug_slot, &info->adapter_status);
186
187	snprintf(name, SLOT_NAME_SIZE, "%08x", zdev->fid);
188	rc = pci_hp_register(slot->hotplug_slot, zdev->bus,
189			     ZPCI_DEVFN, name);
190	if (rc)
191		goto error_reg;
192
193	list_add(&slot->slot_list, &s390_hotplug_slot_list);
194	return 0;
195
196error_reg:
197	kfree(info);
198error_info:
199	kfree(hotplug_slot);
200error_hp:
201	kfree(slot);
202error:
203	return -ENOMEM;
204}
205
206void zpci_exit_slot(struct zpci_dev *zdev)
207{
208	struct slot *slot, *next;
209
210	list_for_each_entry_safe(slot, next, &s390_hotplug_slot_list,
211				 slot_list) {
212		if (slot->zdev != zdev)
213			continue;
214		list_del(&slot->slot_list);
215		pci_hp_deregister(slot->hotplug_slot);
216	}
217}