drivers/pci/hotplug/s390_pci_hpc.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * PCI Hot Plug Controller Driver for System z
   4  *
   5  * Copyright 2012 IBM Corp.
   6  *
   7  * Author(s):
   8  *   Jan Glauber <jang@linux.vnet.ibm.com>
   9  */
  10
  11 #define KMSG_COMPONENT "zpci"
  12 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  13
  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 static int zpci_fn_configured(enum zpci_state state)
  25 {
  26         return state == ZPCI_FN_STATE_CONFIGURED ||
  27                state == ZPCI_FN_STATE_ONLINE;
  28 }
  29
  30 /*
  31  * struct slot - slot information for each *physical* slot
  32  */
  33 struct slot {
  34         struct list_head slot_list;
  35         struct hotplug_slot *hotplug_slot;
  36         struct zpci_dev *zdev;
  37 };
  38
  39 static inline int slot_configure(struct slot *slot)
  40 {
  41         int ret = sclp_pci_configure(slot->zdev->fid);
  42
  43         zpci_dbg(3, "conf fid:%x, rc:%d\n", slot->zdev->fid, ret);
  44         if (!ret)
  45                 slot->zdev->state = ZPCI_FN_STATE_CONFIGURED;
  46
  47         return ret;
  48 }
  49
  50 static inline int slot_deconfigure(struct slot *slot)
  51 {
  52         int ret = sclp_pci_deconfigure(slot->zdev->fid);
  53
  54         zpci_dbg(3, "deconf fid:%x, rc:%d\n", slot->zdev->fid, ret);
  55         if (!ret)
  56                 slot->zdev->state = ZPCI_FN_STATE_STANDBY;
  57
  58         return ret;
  59 }
  60
  61 static int enable_slot(struct hotplug_slot *hotplug_slot)
  62 {
  63         struct slot *slot = hotplug_slot->private;
  64         int rc;
  65
  66         if (slot->zdev->state != ZPCI_FN_STATE_STANDBY)
  67                 return -EIO;
  68
  69         rc = slot_configure(slot);
  70         if (rc)
  71                 return rc;
  72
  73         rc = zpci_enable_device(slot->zdev);
  74         if (rc)
  75                 goto out_deconfigure;
  76
  77         pci_scan_slot(slot->zdev->bus, ZPCI_DEVFN);
  78         pci_lock_rescan_remove();
  79         pci_bus_add_devices(slot->zdev->bus);
  80         pci_unlock_rescan_remove();
  81
  82         return rc;
  83
  84 out_deconfigure:
  85         slot_deconfigure(slot);
  86         return rc;
  87 }
  88
  89 static int disable_slot(struct hotplug_slot *hotplug_slot)
  90 {
  91         struct slot *slot = hotplug_slot->private;
  92         struct pci_dev *pdev;
  93         int rc;
  94
  95         if (!zpci_fn_configured(slot->zdev->state))
  96                 return -EIO;
  97
  98         pdev = pci_get_slot(slot->zdev->bus, ZPCI_DEVFN);
  99         if (pdev) {
 100                 pci_stop_and_remove_bus_device_locked(pdev);
 101                 pci_dev_put(pdev);
 102         }
 103
 104         rc = zpci_disable_device(slot->zdev);
 105         if (rc)
 106                 return rc;
 107
 108         return slot_deconfigure(slot);
 109 }
 110
 111 static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
 112 {
 113         struct slot *slot = hotplug_slot->private;
 114
 115         switch (slot->zdev->state) {
 116         case ZPCI_FN_STATE_STANDBY:
 117                 *value = 0;
 118                 break;
 119         default:
 120                 *value = 1;
 121                 break;
 122         }
 123         return 0;
 124 }
 125
 126 static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
 127 {
 128         /* if the slot exits it always contains a function */
 129         *value = 1;
 130         return 0;
 131 }
 132
 133 static void release_slot(struct hotplug_slot *hotplug_slot)
 134 {
 135         struct slot *slot = hotplug_slot->private;
 136
 137         kfree(slot->hotplug_slot->info);
 138         kfree(slot->hotplug_slot);
 139         kfree(slot);
 140 }
 141
 142 static struct hotplug_slot_ops s390_hotplug_slot_ops = {
 143         .enable_slot =          enable_slot,
 144         .disable_slot =         disable_slot,
 145         .get_power_status =     get_power_status,
 146         .get_adapter_status =   get_adapter_status,
 147 };
 148
 149 int zpci_init_slot(struct zpci_dev *zdev)
 150 {
 151         struct hotplug_slot *hotplug_slot;
 152         struct hotplug_slot_info *info;
 153         char name[SLOT_NAME_SIZE];
 154         struct slot *slot;
 155         int rc;
 156
 157         if (!zdev)
 158                 return 0;
 159
 160         slot = kzalloc(sizeof(*slot), GFP_KERNEL);
 161         if (!slot)
 162                 goto error;
 163
 164         hotplug_slot = kzalloc(sizeof(*hotplug_slot), GFP_KERNEL);
 165         if (!hotplug_slot)
 166                 goto error_hp;
 167         hotplug_slot->private = slot;
 168
 169         slot->hotplug_slot = hotplug_slot;
 170         slot->zdev = zdev;
 171
 172         info = kzalloc(sizeof(*info), GFP_KERNEL);
 173         if (!info)
 174                 goto error_info;
 175         hotplug_slot->info = info;
 176
 177         hotplug_slot->ops = &s390_hotplug_slot_ops;
 178         hotplug_slot->release = &release_slot;
 179
 180         get_power_status(hotplug_slot, &info->power_status);
 181         get_adapter_status(hotplug_slot, &info->adapter_status);
 182
 183         snprintf(name, SLOT_NAME_SIZE, "%08x", zdev->fid);
 184         rc = pci_hp_register(slot->hotplug_slot, zdev->bus,
 185                              ZPCI_DEVFN, name);
 186         if (rc)
 187                 goto error_reg;
 188
 189         list_add(&slot->slot_list, &s390_hotplug_slot_list);
 190         return 0;
 191
 192 error_reg:
 193         kfree(info);
 194 error_info:
 195         kfree(hotplug_slot);
 196 error_hp:
 197         kfree(slot);
 198 error:
 199         return -ENOMEM;
 200 }
 201
 202 void zpci_exit_slot(struct zpci_dev *zdev)
 203 {
 204         struct slot *slot, *next;
 205
 206         list_for_each_entry_safe(slot, next, &s390_hotplug_slot_list,
 207                                  slot_list) {
 208                 if (slot->zdev != zdev)
 209                         continue;
 210                 list_del(&slot->slot_list);
 211                 pci_hp_deregister(slot->hotplug_slot);
 212         }
 213 }