s390_pci_hpc.c

  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 pr_fmt(fmt) "zpci: " fmt
 12
 13#include <linux/kernel.h>
 14#include <linux/slab.h>
 15#include <linux/pci.h>
 16#include <linux/pci_hotplug.h>
 17#include <asm/pci_debug.h>
 18#include <asm/sclp.h>
 19
 20#define SLOT_NAME_SIZE	10
 21
 22static int enable_slot(struct hotplug_slot *hotplug_slot)
 23{
 24	struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
 25					     hotplug_slot);
 26	int rc;
 27
 28	mutex_lock(&zdev->state_lock);
 29	if (zdev->state != ZPCI_FN_STATE_STANDBY) {
 30		rc = -EIO;
 31		goto out;
 32	}
 33
 34	rc = sclp_pci_configure(zdev->fid);
 35	zpci_dbg(3, "conf fid:%x, rc:%d\n", zdev->fid, rc);
 36	if (rc)
 37		goto out;
 38	zdev->state = ZPCI_FN_STATE_CONFIGURED;
 39
 40	rc = zpci_scan_configured_device(zdev, zdev->fh);
 41out:
 42	mutex_unlock(&zdev->state_lock);
 43	return rc;
 44}
 45
 46static int disable_slot(struct hotplug_slot *hotplug_slot)
 47{
 48	struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
 49					     hotplug_slot);
 50	struct pci_dev *pdev = NULL;
 51	int rc;
 52
 53	mutex_lock(&zdev->state_lock);
 54	if (zdev->state != ZPCI_FN_STATE_CONFIGURED) {
 55		rc = -EIO;
 56		goto out;
 57	}
 58
 59	pdev = pci_get_slot(zdev->zbus->bus, zdev->devfn);
 60	if (pdev && pci_num_vf(pdev)) {
 61		rc = -EBUSY;
 62		goto out;
 63	}
 64
 65	rc = zpci_deconfigure_device(zdev);
 66out:
 67	if (pdev)
 68		pci_dev_put(pdev);
 69	mutex_unlock(&zdev->state_lock);
 70	return rc;
 71}
 72
 73static int reset_slot(struct hotplug_slot *hotplug_slot, bool probe)
 74{
 75	struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
 76					     hotplug_slot);
 77	int rc = -EIO;
 78
 79	/*
 80	 * If we can't get the zdev->state_lock the device state is
 81	 * currently undergoing a transition and we bail out - just
 82	 * the same as if the device's state is not configured at all.
 83	 */
 84	if (!mutex_trylock(&zdev->state_lock))
 85		return rc;
 86
 87	/* We can reset only if the function is configured */
 88	if (zdev->state != ZPCI_FN_STATE_CONFIGURED)
 89		goto out;
 90
 91	if (probe) {
 92		rc = 0;
 93		goto out;
 94	}
 95
 96	rc = zpci_hot_reset_device(zdev);
 97out:
 98	mutex_unlock(&zdev->state_lock);
 99	return rc;
100}
101
102static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
103{
104	struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
105					     hotplug_slot);
106
107	*value = zpci_is_device_configured(zdev) ? 1 : 0;
108	return 0;
109}
110
111static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
112{
113	/* if the slot exists it always contains a function */
114	*value = 1;
115	return 0;
116}
117
118static const struct hotplug_slot_ops s390_hotplug_slot_ops = {
119	.enable_slot =		enable_slot,
120	.disable_slot =		disable_slot,
121	.reset_slot =		reset_slot,
122	.get_power_status =	get_power_status,
123	.get_adapter_status =	get_adapter_status,
124};
125
126int zpci_init_slot(struct zpci_dev *zdev)
127{
128	char name[SLOT_NAME_SIZE];
129	struct zpci_bus *zbus = zdev->zbus;
130
131	zdev->hotplug_slot.ops = &s390_hotplug_slot_ops;
132
133	snprintf(name, SLOT_NAME_SIZE, "%08x", zdev->fid);
134	return pci_hp_register(&zdev->hotplug_slot, zbus->bus,
135			       zdev->devfn, name);
136}
137
138void zpci_exit_slot(struct zpci_dev *zdev)
139{
140	pci_hp_deregister(&zdev->hotplug_slot);
141}