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	if (zdev->state != ZPCI_FN_STATE_STANDBY)
 30		return -EIO;
 31
 32	rc = sclp_pci_configure(zdev->fid);
 33	zpci_dbg(3, "conf fid:%x, rc:%d\n", zdev->fid, rc);
 34	if (rc)
 35		return rc;
 36	zdev->state = ZPCI_FN_STATE_CONFIGURED;
 37
 38	return zpci_scan_configured_device(zdev, zdev->fh);
 39}
 40
 41static int disable_slot(struct hotplug_slot *hotplug_slot)
 42{
 43	struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
 44					     hotplug_slot);
 45	struct pci_dev *pdev;
 46
 47	if (zdev->state != ZPCI_FN_STATE_CONFIGURED)
 48		return -EIO;
 49
 50	pdev = pci_get_slot(zdev->zbus->bus, zdev->devfn);
 51	if (pdev && pci_num_vf(pdev)) {
 52		pci_dev_put(pdev);
 53		return -EBUSY;
 54	}
 55	pci_dev_put(pdev);
 56
 57	return zpci_deconfigure_device(zdev);
 58}
 59
 60static int reset_slot(struct hotplug_slot *hotplug_slot, bool probe)
 61{
 62	struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
 63					     hotplug_slot);
 64
 65	if (zdev->state != ZPCI_FN_STATE_CONFIGURED)
 66		return -EIO;
 67	/*
 68	 * We can't take the zdev->lock as reset_slot may be called during
 69	 * probing and/or device removal which already happens under the
 70	 * zdev->lock. Instead the user should use the higher level
 71	 * pci_reset_function() or pci_bus_reset() which hold the PCI device
 72	 * lock preventing concurrent removal. If not using these functions
 73	 * holding the PCI device lock is required.
 74	 */
 75
 76	/* As long as the function is configured we can reset */
 77	if (probe)
 78		return 0;
 79
 80	return zpci_hot_reset_device(zdev);
 81}
 82
 83static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
 84{
 85	struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
 86					     hotplug_slot);
 87
 88	*value = zpci_is_device_configured(zdev) ? 1 : 0;
 89	return 0;
 90}
 91
 92static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
 93{
 94	/* if the slot exits it always contains a function */
 95	*value = 1;
 96	return 0;
 97}
 98
 99static const struct hotplug_slot_ops s390_hotplug_slot_ops = {
100	.enable_slot =		enable_slot,
101	.disable_slot =		disable_slot,
102	.reset_slot =		reset_slot,
103	.get_power_status =	get_power_status,
104	.get_adapter_status =	get_adapter_status,
105};
106
107int zpci_init_slot(struct zpci_dev *zdev)
108{
109	char name[SLOT_NAME_SIZE];
110	struct zpci_bus *zbus = zdev->zbus;
111
112	zdev->hotplug_slot.ops = &s390_hotplug_slot_ops;
113
114	snprintf(name, SLOT_NAME_SIZE, "%08x", zdev->fid);
115	return pci_hp_register(&zdev->hotplug_slot, zbus->bus,
116			       zdev->devfn, name);
117}
118
119void zpci_exit_slot(struct zpci_dev *zdev)
120{
121	pci_hp_deregister(&zdev->hotplug_slot);
122}