linux/drivers/pci/hotplug/s390_pci_hpc.c
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   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}
 218