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 }
120