drivers/pci/hotplug/s390_pci_hpc.c

   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  * License: GPL
  10  */
  11
  12 #define KMSG_COMPONENT "zpci"
  13 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  14
  15 #include <linux/kernel.h>
  16 #include <linux/slab.h>
  17 #include <linux/pci.h>
  18 #include <linux/pci_hotplug.h>
  19 #include <asm/pci_debug.h>
  20 #include <asm/sclp.h>
  21
  22 #define SLOT_NAME_SIZE  10
  23 static LIST_HEAD(s390_hotplug_slot_list);
  24
  25 static int zpci_fn_configured(enum zpci_state state)
  26 {
  27         return state == ZPCI_FN_STATE_CONFIGURED ||
  28                state == ZPCI_FN_STATE_ONLINE;
  29 }
  30
  31 /*
  32  * struct slot - slot information for each *physical* slot
  33  */
  34 struct slot {
  35         struct list_head slot_list;
  36         struct hotplug_slot *hotplug_slot;
  37         struct zpci_dev *zdev;
  38 };
  39
  40 static inline int slot_configure(struct slot *slot)
  41 {
  42         int ret = sclp_pci_configure(slot->zdev->fid);
  43
  44         zpci_dbg(3, "conf fid:%x, rc:%d\n", slot->zdev->fid, ret);
  45         if (!ret)
  46                 slot->zdev->state = ZPCI_FN_STATE_CONFIGURED;
  47
  48         return ret;
  49 }
  50
  51 static inline int slot_deconfigure(struct slot *slot)
  52 {
  53         int ret = sclp_pci_deconfigure(slot->zdev->fid);
  54
  55         zpci_dbg(3, "deconf fid:%x, rc:%d\n", slot->zdev->fid, ret);
  56         if (!ret)
  57                 slot->zdev->state = ZPCI_FN_STATE_STANDBY;
  58
  59         return ret;
  60 }
  61
  62 static int enable_slot(struct hotplug_slot *hotplug_slot)
  63 {
  64         struct slot *slot = hotplug_slot->private;
  65         int rc;
  66
  67         if (slot->zdev->state != ZPCI_FN_STATE_STANDBY)
  68                 return -EIO;
  69
  70         rc = slot_configure(slot);
  71         if (rc)
  72                 return rc;
  73
  74         rc = zpci_enable_device(slot->zdev);
  75         if (rc)
  76                 goto out_deconfigure;
  77
  78         pci_scan_slot(slot->zdev->bus, ZPCI_DEVFN);
  79         pci_lock_rescan_remove();
  80         pci_bus_add_devices(slot->zdev->bus);
  81         pci_unlock_rescan_remove();
  82
  83         return rc;
  84
  85 out_deconfigure:
  86         slot_deconfigure(slot);
  87         return rc;
  88 }
  89
  90 static int disable_slot(struct hotplug_slot *hotplug_slot)
  91 {
  92         struct slot *slot = hotplug_slot->private;
  93         struct pci_dev *pdev;
  94         int rc;
  95
  96         if (!zpci_fn_configured(slot->zdev->state))
  97                 return -EIO;
  98
  99         pdev = pci_get_slot(slot->zdev->bus, ZPCI_DEVFN);
 100         if (pdev) {
 101                 pci_stop_and_remove_bus_device_locked(pdev);
 102                 pci_dev_put(pdev);
 103         }
 104
 105         rc = zpci_disable_device(slot->zdev);
 106         if (rc)
 107                 return rc;
 108
 109         return slot_deconfigure(slot);
 110 }
 111
 112 static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
 113 {
 114         struct slot *slot = hotplug_slot->private;
 115
 116         switch (slot->zdev->state) {
 117         case ZPCI_FN_STATE_STANDBY:
 118                 *value = 0;
 119                 break;
 120         default:
 121                 *value = 1;
 122                 break;
 123         }
 124         return 0;
 125 }
 126
 127 static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
 128 {
 129         /* if the slot exits it always contains a function */
 130         *value = 1;
 131         return 0;
 132 }
 133
 134 static void release_slot(struct hotplug_slot *hotplug_slot)
 135 {
 136         struct slot *slot = hotplug_slot->private;
 137
 138         kfree(slot->hotplug_slot->info);
 139         kfree(slot->hotplug_slot);
 140         kfree(slot);
 141 }
 142
 143 static struct hotplug_slot_ops s390_hotplug_slot_ops = {
 144         .enable_slot =          enable_slot,
 145         .disable_slot =         disable_slot,
 146         .get_power_status =     get_power_status,
 147         .get_adapter_status =   get_adapter_status,
 148 };
 149
 150 int zpci_init_slot(struct zpci_dev *zdev)
 151 {
 152         struct hotplug_slot *hotplug_slot;
 153         struct hotplug_slot_info *info;
 154         char name[SLOT_NAME_SIZE];
 155         struct slot *slot;
 156         int rc;
 157
 158         if (!zdev)
 159                 return 0;
 160
 161         slot = kzalloc(sizeof(*slot), GFP_KERNEL);
 162         if (!slot)
 163                 goto error;
 164
 165         hotplug_slot = kzalloc(sizeof(*hotplug_slot), GFP_KERNEL);
 166         if (!hotplug_slot)
 167                 goto error_hp;
 168         hotplug_slot->private = slot;
 169
 170         slot->hotplug_slot = hotplug_slot;
 171         slot->zdev = zdev;
 172
 173         info = kzalloc(sizeof(*info), GFP_KERNEL);
 174         if (!info)
 175                 goto error_info;
 176         hotplug_slot->info = info;
 177
 178         hotplug_slot->ops = &s390_hotplug_slot_ops;
 179         hotplug_slot->release = &release_slot;
 180
 181         get_power_status(hotplug_slot, &info->power_status);
 182         get_adapter_status(hotplug_slot, &info->adapter_status);
 183
 184         snprintf(name, SLOT_NAME_SIZE, "%08x", zdev->fid);
 185         rc = pci_hp_register(slot->hotplug_slot, zdev->bus,
 186                              ZPCI_DEVFN, name);
 187         if (rc)
 188                 goto error_reg;
 189
 190         list_add(&slot->slot_list, &s390_hotplug_slot_list);
 191         return 0;
 192
 193 error_reg:
 194         kfree(info);
 195 error_info:
 196         kfree(hotplug_slot);
 197 error_hp:
 198         kfree(slot);
 199 error:
 200         return -ENOMEM;
 201 }
 202
 203 void zpci_exit_slot(struct zpci_dev *zdev)
 204 {
 205         struct slot *slot, *next;
 206
 207         list_for_each_entry_safe(slot, next, &s390_hotplug_slot_list,
 208                                  slot_list) {
 209                 if (slot->zdev != zdev)
 210                         continue;
 211                 list_del(&slot->slot_list);
 212                 pci_hp_deregister(slot->hotplug_slot);
 213         }
 214 }