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
  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
  22 static LIST_HEAD(s390_hotplug_slot_list);
  23
  24 MODULE_AUTHOR("Jan Glauber <jang@linux.vnet.ibm.com");
  25 MODULE_DESCRIPTION("Hot Plug PCI Controller for System z");
  26 MODULE_LICENSE("GPL");
  27
  28 static 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  */
  37 struct slot {
  38         struct list_head slot_list;
  39         struct hotplug_slot *hotplug_slot;
  40         struct zpci_dev *zdev;
  41 };
  42
  43 static 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
  54 static 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
  65 static 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
  88 out_deconfigure:
  89         slot_deconfigure(slot);
  90         return rc;
  91 }
  92
  93 static 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
 115 static 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
 130 static 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
 137 static 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
 146 static 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
 153 int 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
 196 error_reg:
 197         kfree(info);
 198 error_info:
 199         kfree(hotplug_slot);
 200 error_hp:
 201         kfree(slot);
 202 error:
 203         return -ENOMEM;
 204 }
 205
 206 void 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 }