drivers/pci/hotplug/rpaphp_slot.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * RPA Virtual I/O device functions
   4  * Copyright (C) 2004 Linda Xie <lxie@us.ibm.com>
   5  *
   6  * All rights reserved.
   7  *
   8  * Send feedback to <lxie@us.ibm.com>
   9  *
  10  */
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/sysfs.h>
  14 #include <linux/of.h>
  15 #include <linux/pci.h>
  16 #include <linux/string.h>
  17 #include <linux/slab.h>
  18
  19 #include <asm/rtas.h>
  20 #include "rpaphp.h"
  21
  22 /* free up the memory used by a slot */
  23 void dealloc_slot_struct(struct slot *slot)
  24 {
  25         of_node_put(slot->dn);
  26         kfree(slot->name);
  27         kfree(slot);
  28 }
  29
  30 struct slot *alloc_slot_struct(struct device_node *dn,
  31                 int drc_index, char *drc_name, int power_domain)
  32 {
  33         struct slot *slot;
  34
  35         slot = kzalloc(sizeof(struct slot), GFP_KERNEL);
  36         if (!slot)
  37                 goto error_nomem;
  38         slot->name = kstrdup(drc_name, GFP_KERNEL);
  39         if (!slot->name)
  40                 goto error_slot;
  41         slot->dn = of_node_get(dn);
  42         slot->index = drc_index;
  43         slot->power_domain = power_domain;
  44         slot->hotplug_slot.ops = &rpaphp_hotplug_slot_ops;
  45
  46         return (slot);
  47
  48 error_slot:
  49         kfree(slot);
  50 error_nomem:
  51         return NULL;
  52 }
  53
  54 static int is_registered(struct slot *slot)
  55 {
  56         struct slot *tmp_slot;
  57
  58         list_for_each_entry(tmp_slot, &rpaphp_slot_head, rpaphp_slot_list) {
  59                 if (!strcmp(tmp_slot->name, slot->name))
  60                         return 1;
  61         }
  62         return 0;
  63 }
  64
  65 int rpaphp_deregister_slot(struct slot *slot)
  66 {
  67         int retval = 0;
  68         struct hotplug_slot *php_slot = &slot->hotplug_slot;
  69
  70          dbg("%s - Entry: deregistering slot=%s\n",
  71                 __func__, slot->name);
  72
  73         list_del(&slot->rpaphp_slot_list);
  74         pci_hp_deregister(php_slot);
  75         dealloc_slot_struct(slot);
  76
  77         dbg("%s - Exit: rc[%d]\n", __func__, retval);
  78         return retval;
  79 }
  80 EXPORT_SYMBOL_GPL(rpaphp_deregister_slot);
  81
  82 int rpaphp_register_slot(struct slot *slot)
  83 {
  84         struct hotplug_slot *php_slot = &slot->hotplug_slot;
  85         struct device_node *child;
  86         u32 my_index;
  87         int retval;
  88         int slotno = -1;
  89
  90         dbg("%s registering slot:path[%pOF] index[%x], name[%s] pdomain[%x] type[%d]\n",
  91                 __func__, slot->dn, slot->index, slot->name,
  92                 slot->power_domain, slot->type);
  93
  94         /* should not try to register the same slot twice */
  95         if (is_registered(slot)) {
  96                 err("rpaphp_register_slot: slot[%s] is already registered\n", slot->name);
  97                 return -EAGAIN;
  98         }
  99
 100         for_each_child_of_node(slot->dn, child) {
 101                 retval = of_property_read_u32(child, "ibm,my-drc-index", &my_index);
 102                 if (my_index == slot->index) {
 103                         slotno = PCI_SLOT(PCI_DN(child)->devfn);
 104                         of_node_put(child);
 105                         break;
 106                 }
 107         }
 108
 109         retval = pci_hp_register(php_slot, slot->bus, slotno, slot->name);
 110         if (retval) {
 111                 err("pci_hp_register failed with error %d\n", retval);
 112                 return retval;
 113         }
 114
 115         /* add slot to our internal list */
 116         list_add(&slot->rpaphp_slot_list, &rpaphp_slot_head);
 117         info("Slot [%s] registered\n", slot->name);
 118         return 0;
 119 }