tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * ACPI related functions for PCI Express Hot Plug driver.
3 *
4 * Copyright (C) 2008 Kenji Kaneshige
5 * Copyright (C) 2008 Fujitsu Limited.
6 *
7 * All rights reserved.
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or (at
12 * your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
17 * NON INFRINGEMENT. See the GNU General Public License for more
18 * details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
23 *
24 */
25
26#include <linux/acpi.h>
27#include <linux/pci.h>
28#include <linux/pci_hotplug.h>
29#include <linux/slab.h>
30#include "pciehp.h"
31
32#define PCIEHP_DETECT_PCIE (0)
33#define PCIEHP_DETECT_ACPI (1)
34#define PCIEHP_DETECT_AUTO (2)
35#define PCIEHP_DETECT_DEFAULT PCIEHP_DETECT_AUTO
36
37struct dummy_slot {
38 u32 number;
39 struct list_head list;
40};
41
42static int slot_detection_mode;
43static char *pciehp_detect_mode;
44module_param(pciehp_detect_mode, charp, 0444);
45MODULE_PARM_DESC(pciehp_detect_mode,
46 "Slot detection mode: pcie, acpi, auto\n"
47 " pcie - Use PCIe based slot detection\n"
48 " acpi - Use ACPI for slot detection\n"
49 " auto(default) - Auto select mode. Use acpi option if duplicate\n"
50 " slot ids are found. Otherwise, use pcie option\n");
51
52int pciehp_acpi_slot_detection_check(struct pci_dev *dev)
53{
54 if (slot_detection_mode != PCIEHP_DETECT_ACPI)
55 return 0;
56 if (acpi_pci_detect_ejectable(DEVICE_ACPI_HANDLE(&dev->dev)))
57 return 0;
58 return -ENODEV;
59}
60
61static int __init parse_detect_mode(void)
62{
63 if (!pciehp_detect_mode)
64 return PCIEHP_DETECT_DEFAULT;
65 if (!strcmp(pciehp_detect_mode, "pcie"))
66 return PCIEHP_DETECT_PCIE;
67 if (!strcmp(pciehp_detect_mode, "acpi"))
68 return PCIEHP_DETECT_ACPI;
69 if (!strcmp(pciehp_detect_mode, "auto"))
70 return PCIEHP_DETECT_AUTO;
71 warn("bad specifier '%s' for pciehp_detect_mode. Use default\n",
72 pciehp_detect_mode);
73 return PCIEHP_DETECT_DEFAULT;
74}
75
76static int __initdata dup_slot_id;
77static int __initdata acpi_slot_detected;
78static struct list_head __initdata dummy_slots = LIST_HEAD_INIT(dummy_slots);
79
80/* Dummy driver for dumplicate name detection */
81static int __init dummy_probe(struct pcie_device *dev)
82{
83 int pos;
84 u32 slot_cap;
85 acpi_handle handle;
86 struct dummy_slot *slot, *tmp;
87 struct pci_dev *pdev = dev->port;
88 /* Note: pciehp_detect_mode != PCIEHP_DETECT_ACPI here */
89 if (pciehp_get_hp_hw_control_from_firmware(pdev))
90 return -ENODEV;
91 pos = pci_pcie_cap(pdev);
92 if (!pos)
93 return -ENODEV;
94 pci_read_config_dword(pdev, pos + PCI_EXP_SLTCAP, &slot_cap);
95 slot = kzalloc(sizeof(*slot), GFP_KERNEL);
96 if (!slot)
97 return -ENOMEM;
98 slot->number = slot_cap >> 19;
99 list_for_each_entry(tmp, &dummy_slots, list) {
100 if (tmp->number == slot->number)
101 dup_slot_id++;
102 }
103 list_add_tail(&slot->list, &dummy_slots);
104 handle = DEVICE_ACPI_HANDLE(&pdev->dev);
105 if (!acpi_slot_detected && acpi_pci_detect_ejectable(handle))
106 acpi_slot_detected = 1;
107 return -ENODEV; /* dummy driver always returns error */
108}
109
110static struct pcie_port_service_driver __initdata dummy_driver = {
111 .name = "pciehp_dummy",
112 .port_type = PCIE_ANY_PORT,
113 .service = PCIE_PORT_SERVICE_HP,
114 .probe = dummy_probe,
115};
116
117static int __init select_detection_mode(void)
118{
119 struct dummy_slot *slot, *tmp;
120 pcie_port_service_register(&dummy_driver);
121 pcie_port_service_unregister(&dummy_driver);
122 list_for_each_entry_safe(slot, tmp, &dummy_slots, list) {
123 list_del(&slot->list);
124 kfree(slot);
125 }
126 if (acpi_slot_detected && dup_slot_id)
127 return PCIEHP_DETECT_ACPI;
128 return PCIEHP_DETECT_PCIE;
129}
130
131void __init pciehp_acpi_slot_detection_init(void)
132{
133 slot_detection_mode = parse_detect_mode();
134 if (slot_detection_mode != PCIEHP_DETECT_AUTO)
135 goto out;
136 slot_detection_mode = select_detection_mode();
137out:
138 if (slot_detection_mode == PCIEHP_DETECT_ACPI)
139 info("Using ACPI for slot detection.\n");
140}