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
  23 static int zpci_fn_configured(enum zpci_state state)
  24 {
  25         return state == ZPCI_FN_STATE_CONFIGURED ||
  26                state == ZPCI_FN_STATE_ONLINE;
  27 }
  28
  29 static inline int zdev_configure(struct zpci_dev *zdev)
  30 {
  31         int ret = sclp_pci_configure(zdev->fid);
  32
  33         zpci_dbg(3, "conf fid:%x, rc:%d\n", zdev->fid, ret);
  34         if (!ret)
  35                 zdev->state = ZPCI_FN_STATE_CONFIGURED;
  36
  37         return ret;
  38 }
  39
  40 static inline int zdev_deconfigure(struct zpci_dev *zdev)
  41 {
  42         int ret = sclp_pci_deconfigure(zdev->fid);
  43
  44         zpci_dbg(3, "deconf fid:%x, rc:%d\n", zdev->fid, ret);
  45         if (!ret)
  46                 zdev->state = ZPCI_FN_STATE_STANDBY;
  47
  48         return ret;
  49 }
  50
  51 static int enable_slot(struct hotplug_slot *hotplug_slot)
  52 {
  53         struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
  54                                              hotplug_slot);
  55         int rc;
  56
  57         if (zdev->state != ZPCI_FN_STATE_STANDBY)
  58                 return -EIO;
  59
  60         rc = zdev_configure(zdev);
  61         if (rc)
  62                 return rc;
  63
  64         rc = zpci_enable_device(zdev);
  65         if (rc)
  66                 goto out_deconfigure;
  67
  68         pci_scan_slot(zdev->bus, ZPCI_DEVFN);
  69         pci_lock_rescan_remove();
  70         pci_bus_add_devices(zdev->bus);
  71         pci_unlock_rescan_remove();
  72
  73         return rc;
  74
  75 out_deconfigure:
  76         zdev_deconfigure(zdev);
  77         return rc;
  78 }
  79
  80 static int disable_slot(struct hotplug_slot *hotplug_slot)
  81 {
  82         struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
  83                                              hotplug_slot);
  84         struct pci_dev *pdev;
  85         int rc;
  86
  87         if (!zpci_fn_configured(zdev->state))
  88                 return -EIO;
  89
  90         pdev = pci_get_slot(zdev->bus, ZPCI_DEVFN);
  91         if (pdev) {
  92                 pci_stop_and_remove_bus_device_locked(pdev);
  93                 pci_dev_put(pdev);
  94         }
  95
  96         rc = zpci_disable_device(zdev);
  97         if (rc)
  98                 return rc;
  99
 100         return zdev_deconfigure(zdev);
 101 }
 102
 103 static int get_power_status(struct hotplug_slot *hotplug_slot, u8 *value)
 104 {
 105         struct zpci_dev *zdev = container_of(hotplug_slot, struct zpci_dev,
 106                                              hotplug_slot);
 107
 108         switch (zdev->state) {
 109         case ZPCI_FN_STATE_STANDBY:
 110                 *value = 0;
 111                 break;
 112         default:
 113                 *value = 1;
 114                 break;
 115         }
 116         return 0;
 117 }
 118
 119 static int get_adapter_status(struct hotplug_slot *hotplug_slot, u8 *value)
 120 {
 121         /* if the slot exits it always contains a function */
 122         *value = 1;
 123         return 0;
 124 }
 125
 126 static const struct hotplug_slot_ops s390_hotplug_slot_ops = {
 127         .enable_slot =          enable_slot,
 128         .disable_slot =         disable_slot,
 129         .get_power_status =     get_power_status,
 130         .get_adapter_status =   get_adapter_status,
 131 };
 132
 133 int zpci_init_slot(struct zpci_dev *zdev)
 134 {
 135         char name[SLOT_NAME_SIZE];
 136
 137         zdev->hotplug_slot.ops = &s390_hotplug_slot_ops;
 138
 139         snprintf(name, SLOT_NAME_SIZE, "%08x", zdev->fid);
 140         return pci_hp_register(&zdev->hotplug_slot, zdev->bus,
 141                                ZPCI_DEVFN, name);
 142 }
 143
 144 void zpci_exit_slot(struct zpci_dev *zdev)
 145 {
 146         pci_hp_deregister(&zdev->hotplug_slot);
 147 }