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
 22
 23static int enable_slot(struct hotplug_slot *hotplug_slot)
 24{
 25	struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
 26					     hotplug_slot);
 27	int rc;
 28
 29	mutex_lock(&zdev->state_lock);
 30	if (zdev->state != ZPCI_FN_STATE_STANDBY) {
 31		rc = -EIO;
 32		goto out;
 33	}
 34
 35	rc = sclp_pci_configure(zdev->fid);
 36	zpci_dbg(3, "conf fid:%x, rc:%d\n", zdev->fid, rc);
 37	if (rc)
 38		goto out;
 39	zdev->state = ZPCI_FN_STATE_CONFIGURED;
 40
 41	rc = zpci_scan_configured_device(zdev, zdev->fh);
 42out:
 43	mutex_unlock(&zdev->state_lock);
 44	return rc;
 45}
 46
 47static int disable_slot(struct hotplug_slot *hotplug_slot)
 48{
 49	struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
 50					     hotplug_slot);
 51	struct pci_dev *pdev = NULL;
 52	int rc;
 53
 54	mutex_lock(&zdev->state_lock);
 55	if (zdev->state != ZPCI_FN_STATE_CONFIGURED) {
 56		rc = -EIO;
 57		goto out;
 58	}
 59
 60	pdev = pci_get_slot(zdev->zbus->bus, zdev->devfn);
 61	if (pdev && pci_num_vf(pdev)) {
 62		pci_dev_put(pdev);
 63		rc = -EBUSY;
 64		goto out;
 65	}
 66
 67	rc = zpci_deconfigure_device(zdev);
 68out:
 69	mutex_unlock(&zdev->state_lock);
 70	if (pdev)
 71		pci_dev_put(pdev);
 72	return rc;
 73}
 74
 75static int reset_slot(struct hotplug_slot *hotplug_slot, bool probe)
 76{
 77	struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
 78					     hotplug_slot);
 79	int rc = -EIO;
 80
 81	/*
 82	 * If we can't get the zdev->state_lock the device state is
 83	 * currently undergoing a transition and we bail out - just
 84	 * the same as if the device's state is not configured at all.
 85	 */
 86	if (!mutex_trylock(&zdev->state_lock))
 87		return rc;
 88
 89	/* We can reset only if the function is configured */
 90	if (zdev->state != ZPCI_FN_STATE_CONFIGURED)
 91		goto out;
 92
 93	if (probe) {
 94		rc = 0;
 95		goto out;
 96	}
 97
 98	rc = zpci_hot_reset_device(zdev);
 99out:
100	mutex_unlock(&zdev->state_lock);
101	return rc;
102}
103
104static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
105{
106	struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
107					     hotplug_slot);
108
109	*value = zpci_is_device_configured(zdev) ? 1 : 0;
110	return 0;
111}
112
113static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
114{
115	/* if the slot exits it always contains a function */
116	*value = 1;
117	return 0;
118}
119
120static const struct hotplug_slot_ops s390_hotplug_slot_ops = {
121	.enable_slot =		enable_slot,
122	.disable_slot =		disable_slot,
123	.reset_slot =		reset_slot,
124	.get_power_status =	get_power_status,
125	.get_adapter_status =	get_adapter_status,
126};
127
128int zpci_init_slot(struct zpci_dev *zdev)
129{
130	char name[SLOT_NAME_SIZE];
131	struct zpci_bus *zbus = zdev->zbus;
132
133	zdev->hotplug_slot.ops = &s390_hotplug_slot_ops;
134
135	snprintf(name, SLOT_NAME_SIZE, "%08x", zdev->fid);
136	return pci_hp_register(&zdev->hotplug_slot, zbus->bus,
137			       zdev->devfn, name);
138}
139
140void zpci_exit_slot(struct zpci_dev *zdev)
141{
142	pci_hp_deregister(&zdev->hotplug_slot);
143}