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 COMPONENT "zPCI hpc"
  11 #define pr_fmt(fmt) 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 <linux/init.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 MODULE_AUTHOR("Jan Glauber <jang@linux.vnet.ibm.com");
  26 MODULE_DESCRIPTION("Hot Plug PCI Controller for System z");
  27 MODULE_LICENSE("GPL");
  28
  29 static int zpci_fn_configured(enum zpci_state state)
  30 {
  31         return state == ZPCI_FN_STATE_CONFIGURED ||
  32                state == ZPCI_FN_STATE_ONLINE;
  33 }
  34
  35 /*
  36  * struct slot - slot information for each *physical* slot
  37  */
  38 struct slot {
  39         struct list_head slot_list;
  40         struct hotplug_slot *hotplug_slot;
  41         struct zpci_dev *zdev;
  42 };
  43
  44 static 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
  55 static 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
  66 static int enable_slot(struct hotplug_slot *hotplug_slot)
  67 {
  68         struct slot *slot = hotplug_slot->private;
  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
  89 out_deconfigure:
  90         slot_deconfigure(slot);
  91         return rc;
  92 }
  93
  94 static int disable_slot(struct hotplug_slot *hotplug_slot)
  95 {
  96         struct slot *slot = hotplug_slot->private;
  97         int rc;
  98
  99         if (!zpci_fn_configured(slot->zdev->state))
 100                 return -EIO;
 101
 102         if (slot->zdev->pdev)
 103                 pci_stop_and_remove_bus_device_locked(slot->zdev->pdev);
 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 list_head *tmp, *n;
 206         struct slot *slot;
 207
 208         list_for_each_safe(tmp, n, &s390_hotplug_slot_list) {
 209                 slot = list_entry(tmp, struct slot, slot_list);
 210                 if (slot->zdev != zdev)
 211                         continue;
 212                 list_del(&slot->slot_list);
 213                 pci_hp_deregister(slot->hotplug_slot);
 214         }
 215 }