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/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 int enable_slot(struct hotplug_slot *hotplug_slot)
  44 {
  45         struct slot *slot = hotplug_slot->private;
  46         int rc;
  47
  48         if (slot->zdev->state != ZPCI_FN_STATE_STANDBY)
  49                 return -EIO;
  50
  51         rc = sclp_pci_configure(slot->zdev->fid);
  52         if (!rc) {
  53                 slot->zdev->state = ZPCI_FN_STATE_CONFIGURED;
  54                 /* automatically scan the device after is was configured */
  55                 zpci_enable_device(slot->zdev);
  56                 zpci_scan_device(slot->zdev);
  57         }
  58         return rc;
  59 }
  60
  61 static int disable_slot(struct hotplug_slot *hotplug_slot)
  62 {
  63         struct slot *slot = hotplug_slot->private;
  64         int rc;
  65
  66         if (!zpci_fn_configured(slot->zdev->state))
  67                 return -EIO;
  68
  69         /* TODO: we rely on the user to unbind/remove the device, is that plausible
  70          *       or do we need to trigger that here?
  71          */
  72         rc = sclp_pci_deconfigure(slot->zdev->fid);
  73         if (!rc) {
  74                 /* Fixme: better call List-PCI to find the disabled FH
  75                    for the FID since the FH should be opaque... */
  76                 slot->zdev->fh &= 0x7fffffff;
  77                 slot->zdev->state = ZPCI_FN_STATE_STANDBY;
  78         }
  79         return rc;
  80 }
  81
  82 static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
  83 {
  84         struct slot *slot = hotplug_slot->private;
  85
  86         switch (slot->zdev->state) {
  87         case ZPCI_FN_STATE_STANDBY:
  88                 *value = 0;
  89                 break;
  90         default:
  91                 *value = 1;
  92                 break;
  93         }
  94         return 0;
  95 }
  96
  97 static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
  98 {
  99         /* if the slot exits it always contains a function */
 100         *value = 1;
 101         return 0;
 102 }
 103
 104 static void release_slot(struct hotplug_slot *hotplug_slot)
 105 {
 106         struct slot *slot = hotplug_slot->private;
 107
 108         pr_debug("%s - physical_slot = %s\n", __func__, hotplug_slot_name(hotplug_slot));
 109         kfree(slot->hotplug_slot->info);
 110         kfree(slot->hotplug_slot);
 111         kfree(slot);
 112 }
 113
 114 static struct hotplug_slot_ops s390_hotplug_slot_ops = {
 115         .enable_slot =          enable_slot,
 116         .disable_slot =         disable_slot,
 117         .get_power_status =     get_power_status,
 118         .get_adapter_status =   get_adapter_status,
 119 };
 120
 121 static int init_pci_slot(struct zpci_dev *zdev)
 122 {
 123         struct hotplug_slot *hotplug_slot;
 124         struct hotplug_slot_info *info;
 125         char name[SLOT_NAME_SIZE];
 126         struct slot *slot;
 127         int rc;
 128
 129         if (!zdev)
 130                 return 0;
 131
 132         slot = kzalloc(sizeof(*slot), GFP_KERNEL);
 133         if (!slot)
 134                 goto error;
 135
 136         hotplug_slot = kzalloc(sizeof(*hotplug_slot), GFP_KERNEL);
 137         if (!hotplug_slot)
 138                 goto error_hp;
 139         hotplug_slot->private = slot;
 140
 141         slot->hotplug_slot = hotplug_slot;
 142         slot->zdev = zdev;
 143
 144         info = kzalloc(sizeof(*info), GFP_KERNEL);
 145         if (!info)
 146                 goto error_info;
 147         hotplug_slot->info = info;
 148
 149         hotplug_slot->ops = &s390_hotplug_slot_ops;
 150         hotplug_slot->release = &release_slot;
 151
 152         get_power_status(hotplug_slot, &info->power_status);
 153         get_adapter_status(hotplug_slot, &info->adapter_status);
 154
 155         snprintf(name, SLOT_NAME_SIZE, "%08x", zdev->fid);
 156         rc = pci_hp_register(slot->hotplug_slot, zdev->bus,
 157                              ZPCI_DEVFN, name);
 158         if (rc) {
 159                 pr_err("pci_hp_register failed with error %d\n", rc);
 160                 goto error_reg;
 161         }
 162         list_add(&slot->slot_list, &s390_hotplug_slot_list);
 163         return 0;
 164
 165 error_reg:
 166         kfree(info);
 167 error_info:
 168         kfree(hotplug_slot);
 169 error_hp:
 170         kfree(slot);
 171 error:
 172         return -ENOMEM;
 173 }
 174
 175 static int __init init_pci_slots(void)
 176 {
 177         struct zpci_dev *zdev;
 178         int device = 0;
 179
 180         /*
 181          * Create a structure for each slot, and register that slot
 182          * with the pci_hotplug subsystem.
 183          */
 184         mutex_lock(&zpci_list_lock);
 185         list_for_each_entry(zdev, &zpci_list, entry) {
 186                 init_pci_slot(zdev);
 187                 device++;
 188         }
 189
 190         mutex_unlock(&zpci_list_lock);
 191         return (device) ? 0 : -ENODEV;
 192 }
 193
 194 static void exit_pci_slot(struct zpci_dev *zdev)
 195 {
 196         struct list_head *tmp, *n;
 197         struct slot *slot;
 198
 199         list_for_each_safe(tmp, n, &s390_hotplug_slot_list) {
 200                 slot = list_entry(tmp, struct slot, slot_list);
 201                 if (slot->zdev != zdev)
 202                         continue;
 203                 list_del(&slot->slot_list);
 204                 pci_hp_deregister(slot->hotplug_slot);
 205         }
 206 }
 207
 208 static void __exit exit_pci_slots(void)
 209 {
 210         struct list_head *tmp, *n;
 211         struct slot *slot;
 212
 213         /*
 214          * Unregister all of our slots with the pci_hotplug subsystem.
 215          * Memory will be freed in release_slot() callback after slot's
 216          * lifespan is finished.
 217          */
 218         list_for_each_safe(tmp, n, &s390_hotplug_slot_list) {
 219                 slot = list_entry(tmp, struct slot, slot_list);
 220                 list_del(&slot->slot_list);
 221                 pci_hp_deregister(slot->hotplug_slot);
 222         }
 223 }
 224
 225 static int __init pci_hotplug_s390_init(void)
 226 {
 227         /*
 228          * Do specific initialization stuff for your driver here
 229          * like initializing your controller hardware (if any) and
 230          * determining the number of slots you have in the system
 231          * right now.
 232          */
 233
 234         if (!pci_probe)
 235                 return -EOPNOTSUPP;
 236
 237         /* register callbacks for slot handling from arch code */
 238         mutex_lock(&zpci_list_lock);
 239         hotplug_ops.create_slot = init_pci_slot;
 240         hotplug_ops.remove_slot = exit_pci_slot;
 241         mutex_unlock(&zpci_list_lock);
 242         pr_info("registered hotplug slot callbacks\n");
 243         return init_pci_slots();
 244 }
 245
 246 static void __exit pci_hotplug_s390_exit(void)
 247 {
 248         exit_pci_slots();
 249 }
 250
 251 module_init(pci_hotplug_s390_init);
 252 module_exit(pci_hotplug_s390_exit);