1/*
2 *  pci_slot.c - ACPI PCI Slot Driver
3 *
4 *  The code here is heavily leveraged from the acpiphp module.
5 *  Thanks to Matthew Wilcox <matthew@wil.cx> for much guidance.
6 *  Thanks to Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> for code
7 *  review and fixes.
8 *
9 *  Copyright (C) 2007-2008 Hewlett-Packard Development Company, L.P.
10 *  	Alex Chiang <achiang@hp.com>
11 *
12 *  Copyright (C) 2013 Huawei Tech. Co., Ltd.
13 *	Jiang Liu <jiang.liu@huawei.com>
14 *
15 *  This program is free software; you can redistribute it and/or modify it
16 *  under the terms and conditions of the GNU General Public License,
17 *  version 2, as published by the Free Software Foundation.
18 *
19 *  This program is distributed in the hope that it will be useful, but
20 *  WITHOUT ANY WARRANTY; without even the implied warranty of
21 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
22 *  General Public License for more details.
23 */
24
25#include <linux/kernel.h>
26#include <linux/module.h>
27#include <linux/init.h>
28#include <linux/slab.h>
29#include <linux/types.h>
30#include <linux/list.h>
31#include <linux/pci.h>
32#include <linux/acpi.h>
33#include <linux/dmi.h>
34#include <linux/pci-acpi.h>
35
36static bool debug;
37static int check_sta_before_sun;
38
39#define DRIVER_VERSION 	"0.1"
40#define DRIVER_AUTHOR	"Alex Chiang <achiang@hp.com>"
41#define DRIVER_DESC	"ACPI PCI Slot Detection Driver"
42MODULE_AUTHOR(DRIVER_AUTHOR);
43MODULE_DESCRIPTION(DRIVER_DESC);
44MODULE_LICENSE("GPL");
45MODULE_PARM_DESC(debug, "Debugging mode enabled or not");
46module_param(debug, bool, 0644);
47
48#define _COMPONENT		ACPI_PCI_COMPONENT
49ACPI_MODULE_NAME("pci_slot");
50
51#define MY_NAME "pci_slot"
52#define err(format, arg...) pr_err("%s: " format , MY_NAME , ## arg)
53#define info(format, arg...) pr_info("%s: " format , MY_NAME , ## arg)
54#define dbg(format, arg...)					\
55	do {							\
56		if (debug)					\
57			pr_debug("%s: " format,	MY_NAME , ## arg); \
58	} while (0)
59
60#define SLOT_NAME_SIZE 21		/* Inspired by #define in acpiphp.h */
61
62struct acpi_pci_slot {
63	struct pci_slot *pci_slot;	/* corresponding pci_slot */
64	struct list_head list;		/* node in the list of slots */
65};
66
67static LIST_HEAD(slot_list);
68static DEFINE_MUTEX(slot_list_lock);
69
70static int
71check_slot(acpi_handle handle, unsigned long long *sun)
72{
73	int device = -1;
74	unsigned long long adr, sta;
75	acpi_status status;
76	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
77
78	acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
79	dbg("Checking slot on path: %s\n", (char *)buffer.pointer);
80
81	if (check_sta_before_sun) {
82		/* If SxFy doesn't have _STA, we just assume it's there */
83		status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
84		if (ACPI_SUCCESS(status) && !(sta & ACPI_STA_DEVICE_PRESENT))
85			goto out;
86	}
87
88	status = acpi_evaluate_integer(handle, "_ADR", NULL, &adr);
89	if (ACPI_FAILURE(status)) {
90		dbg("_ADR returned %d on %s\n", status, (char *)buffer.pointer);
91		goto out;
92	}
93
94	/* No _SUN == not a slot == bail */
95	status = acpi_evaluate_integer(handle, "_SUN", NULL, sun);
96	if (ACPI_FAILURE(status)) {
97		dbg("_SUN returned %d on %s\n", status, (char *)buffer.pointer);
98		goto out;
99	}
100
101	device = (adr >> 16) & 0xffff;
102out:
103	kfree(buffer.pointer);
104	return device;
105}
106
107/*
108 * Check whether handle has an associated slot and create PCI slot if it has.
109 */
110static acpi_status
111register_slot(acpi_handle handle, u32 lvl, void *context, void **rv)
112{
113	int device;
114	unsigned long long sun;
115	char name[SLOT_NAME_SIZE];
116	struct acpi_pci_slot *slot;
117	struct pci_slot *pci_slot;
118	struct pci_bus *pci_bus = context;
119
120	device = check_slot(handle, &sun);
121	if (device < 0)
122		return AE_OK;
123
124	/*
125	 * There may be multiple PCI functions associated with the same slot.
126	 * Check whether PCI slot has already been created for this PCI device.
127	 */
128	list_for_each_entry(slot, &slot_list, list) {
129		pci_slot = slot->pci_slot;
130		if (pci_slot->bus == pci_bus && pci_slot->number == device)
131			return AE_OK;
132	}
133
134	slot = kmalloc(sizeof(*slot), GFP_KERNEL);
135	if (!slot) {
136		err("%s: cannot allocate memory\n", __func__);
137		return AE_OK;
138	}
139
140	snprintf(name, sizeof(name), "%llu", sun);
141	pci_slot = pci_create_slot(pci_bus, device, name, NULL);
142	if (IS_ERR(pci_slot)) {
143		err("pci_create_slot returned %ld\n", PTR_ERR(pci_slot));
144		kfree(slot);
145		return AE_OK;
146	}
147
148	slot->pci_slot = pci_slot;
149	list_add(&slot->list, &slot_list);
150
151	get_device(&pci_bus->dev);
152
153	dbg("pci_slot: %p, pci_bus: %x, device: %d, name: %s\n",
154		pci_slot, pci_bus->number, device, name);
155
156	return AE_OK;
157}
158
159void acpi_pci_slot_enumerate(struct pci_bus *bus)
160{
161	acpi_handle handle = ACPI_HANDLE(bus->bridge);
162
163	if (handle) {
164		mutex_lock(&slot_list_lock);
165		acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
166				    register_slot, NULL, bus, NULL);
167		mutex_unlock(&slot_list_lock);
168	}
169}
170
171void acpi_pci_slot_remove(struct pci_bus *bus)
172{
173	struct acpi_pci_slot *slot, *tmp;
174
175	mutex_lock(&slot_list_lock);
176	list_for_each_entry_safe(slot, tmp, &slot_list, list) {
177		if (slot->pci_slot->bus == bus) {
178			list_del(&slot->list);
179			pci_destroy_slot(slot->pci_slot);
180			put_device(&bus->dev);
181			kfree(slot);
182		}
183	}
184	mutex_unlock(&slot_list_lock);
185}
186
187static int do_sta_before_sun(const struct dmi_system_id *d)
188{
189	info("%s detected: will evaluate _STA before calling _SUN\n", d->ident);
190	check_sta_before_sun = 1;
191	return 0;
192}
193
194static struct dmi_system_id acpi_pci_slot_dmi_table[] __initdata = {
195	/*
196	 * Fujitsu Primequest machines will return 1023 to indicate an
197	 * error if the _SUN method is evaluated on SxFy objects that
198	 * are not present (as indicated by _STA), so for those machines,
199	 * we want to check _STA before evaluating _SUN.
200	 */
201	{
202	 .callback = do_sta_before_sun,
203	 .ident = "Fujitsu PRIMEQUEST",
204	 .matches = {
205		DMI_MATCH(DMI_BIOS_VENDOR, "FUJITSU LIMITED"),
206		DMI_MATCH(DMI_BIOS_VERSION, "PRIMEQUEST"),
207		},
208	},
209	{}
210};
211
212void __init acpi_pci_slot_init(void)
213{
214	dmi_check_system(acpi_pci_slot_dmi_table);
215}
216