summaryrefslogtreecommitdiffstats
path: root/kernel/drivers/pci/hotplug/pciehp_acpi.c
blob: 93cc9266e8cb8caa38075e044849413116ed9b71 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
/*
 * ACPI related functions for PCI Express Hot Plug driver.
 *
 * Copyright (C) 2008 Kenji Kaneshige
 * Copyright (C) 2008 Fujitsu Limited.
 *
 * All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or (at
 * your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 * NON INFRINGEMENT.  See the GNU General Public License for more
 * details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#include <linux/acpi.h>
#include <linux/pci.h>
#include <linux/pci_hotplug.h>
#include <linux/slab.h>
#include <linux/module.h>
#include "pciehp.h"

#define PCIEHP_DETECT_PCIE	(0)
#define PCIEHP_DETECT_ACPI	(1)
#define PCIEHP_DETECT_AUTO	(2)
#define PCIEHP_DETECT_DEFAULT	PCIEHP_DETECT_AUTO

struct dummy_slot {
	u32 number;
	struct list_head list;
};

static int slot_detection_mode;
static char *pciehp_detect_mode;
module_param(pciehp_detect_mode, charp, 0444);
MODULE_PARM_DESC(pciehp_detect_mode,
	 "Slot detection mode: pcie, acpi, auto\n"
	 "  pcie          - Use PCIe based slot detection\n"
	 "  acpi          - Use ACPI for slot detection\n"
	 "  auto(default) - Auto select mode. Use acpi option if duplicate\n"
	 "                  slot ids are found. Otherwise, use pcie option\n");

int pciehp_acpi_slot_detection_check(struct pci_dev *dev)
{
	if (slot_detection_mode != PCIEHP_DETECT_ACPI)
		return 0;
	if (acpi_pci_detect_ejectable(ACPI_HANDLE(&dev->dev)))
		return 0;
	return -ENODEV;
}

static int __init parse_detect_mode(void)
{
	if (!pciehp_detect_mode)
		return PCIEHP_DETECT_DEFAULT;
	if (!strcmp(pciehp_detect_mode, "pcie"))
		return PCIEHP_DETECT_PCIE;
	if (!strcmp(pciehp_detect_mode, "acpi"))
		return PCIEHP_DETECT_ACPI;
	if (!strcmp(pciehp_detect_mode, "auto"))
		return PCIEHP_DETECT_AUTO;
	warn("bad specifier '%s' for pciehp_detect_mode. Use default\n",
	     pciehp_detect_mode);
	return PCIEHP_DETECT_DEFAULT;
}

static int __initdata dup_slot_id;
static int __initdata acpi_slot_detected;
static struct list_head __initdata dummy_slots = LIST_HEAD_INIT(dummy_slots);

/* Dummy driver for duplicate name detection */
static int __init dummy_probe(struct pcie_device *dev)
{
	u32 slot_cap;
	acpi_handle handle;
	struct dummy_slot *slot, *tmp;
	struct pci_dev *pdev = dev->port;

	pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP, &slot_cap);
	slot = kzalloc(sizeof(*slot), GFP_KERNEL);
	if (!slot)
		return -ENOMEM;
	slot->number = (slot_cap & PCI_EXP_SLTCAP_PSN) >> 19;
	list_for_each_entry(tmp, &dummy_slots, list) {
		if (tmp->number == slot->number)
			dup_slot_id++;
	}
	list_add_tail(&slot->list, &dummy_slots);
	handle = ACPI_HANDLE(&pdev->dev);
	if (!acpi_slot_detected && acpi_pci_detect_ejectable(handle))
		acpi_slot_detected = 1;
	return -ENODEV;         /* dummy driver always returns error */
}

static struct pcie_port_service_driver __initdata dummy_driver = {
	.name		= "pciehp_dummy",
	.port_type	= PCIE_ANY_PORT,
	.service	= PCIE_PORT_SERVICE_HP,
	.probe		= dummy_probe,
};

static int __init select_detection_mode(void)
{
	struct dummy_slot *slot, *tmp;

	if (pcie_port_service_register(&dummy_driver))
		return PCIEHP_DETECT_ACPI;
	pcie_port_service_unregister(&dummy_driver);
	list_for_each_entry_safe(slot, tmp, &dummy_slots, list) {
		list_del(&slot->list);
		kfree(slot);
	}
	if (acpi_slot_detected && dup_slot_id)
		return PCIEHP_DETECT_ACPI;
	return PCIEHP_DETECT_PCIE;
}

void __init pciehp_acpi_slot_detection_init(void)
{
	slot_detection_mode = parse_detect_mode();
	if (slot_detection_mode != PCIEHP_DETECT_AUTO)
		goto out;
	slot_detection_mode = select_detection_mode();
out:
	if (slot_detection_mode == PCIEHP_DETECT_ACPI)
		info("Using ACPI for slot detection.\n");
}