LXR linux/drivers/pci/hotplug/s390_pci

   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
  22static LIST_HEAD(s390_hotplug_slot_list);
  23
  24static int zpci_fn_configured(enum zpci_state state)
  25{
  26        return state == ZPCI_FN_STATE_CONFIGURED ||
  27               state == ZPCI_FN_STATE_ONLINE;
  28}
  29
  30/*
  31 * struct slot - slot information for each *physical* slot
  32 */
  33struct slot {
  34        struct list_head slot_list;
  35        struct hotplug_slot hotplug_slot;
  36        struct zpci_dev *zdev;
  37};
  38
  39static inline struct slot *to_slot(struct hotplug_slot *hotplug_slot)
  40{
  41        return container_of(hotplug_slot, struct slot, hotplug_slot);
  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 = to_slot(hotplug_slot);
  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 = to_slot(hotplug_slot);
  97        struct pci_dev *pdev;
  98        int rc;
  99
 100        if (!zpci_fn_configured(slot->zdev->state))
 101                return -EIO;
 102
 103        pdev = pci_get_slot(slot->zdev->bus, ZPCI_DEVFN);
 104        if (pdev) {
 105                pci_stop_and_remove_bus_device_locked(pdev);
 106                pci_dev_put(pdev);
 107        }
 108
 109        rc = zpci_disable_device(slot->zdev);
 110        if (rc)
 111                return rc;
 112
 113        return slot_deconfigure(slot);
 114}
 115
 116static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
 117{
 118        struct slot *slot = to_slot(hotplug_slot);
 119
 120        switch (slot->zdev->state) {
 121        case ZPCI_FN_STATE_STANDBY:
 122                *value = 0;
 123                break;
 124        default:
 125                *value = 1;
 126                break;
 127        }
 128        return 0;
 129}
 130
 131static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
 132{
 133        /* if the slot exits it always contains a function */
 134        *value = 1;
 135        return 0;
 136}
 137
 138static const struct hotplug_slot_ops s390_hotplug_slot_ops = {
 139        .enable_slot =          enable_slot,
 140        .disable_slot =         disable_slot,
 141        .get_power_status =     get_power_status,
 142        .get_adapter_status =   get_adapter_status,
 143};
 144
 145int zpci_init_slot(struct zpci_dev *zdev)
 146{
 147        char name[SLOT_NAME_SIZE];
 148        struct slot *slot;
 149        int rc;
 150
 151        if (!zdev)
 152                return 0;
 153
 154        slot = kzalloc(sizeof(*slot), GFP_KERNEL);
 155        if (!slot)
 156                goto error;
 157
 158        slot->zdev = zdev;
 159        slot->hotplug_slot.ops = &s390_hotplug_slot_ops;
 160
 161        snprintf(name, SLOT_NAME_SIZE, "%08x", zdev->fid);
 162        rc = pci_hp_register(&slot->hotplug_slot, zdev->bus,
 163                             ZPCI_DEVFN, name);
 164        if (rc)
 165                goto error_reg;
 166
 167        list_add(&slot->slot_list, &s390_hotplug_slot_list);
 168        return 0;
 169
 170error_reg:
 171        kfree(slot);
 172error:
 173        return -ENOMEM;
 174}
 175
 176void zpci_exit_slot(struct zpci_dev *zdev)
 177{
 178        struct slot *slot, *next;
 179
 180        list_for_each_entry_safe(slot, next, &s390_hotplug_slot_list,
 181                                 slot_list) {
 182                if (slot->zdev != zdev)
 183                        continue;
 184                list_del(&slot->slot_list);
 185                pci_hp_deregister(&slot->hotplug_slot);
 186                kfree(slot);
 187        }
 188}
 189