Commit | Line | Data |
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736759ef | 1 | // SPDX-License-Identifier: GPL-2.0+ |
1da177e4 | 2 | /* |
783c49fc | 3 | * Common ACPI functions for hot plug platforms |
1da177e4 | 4 | * |
783c49fc | 5 | * Copyright (C) 2006 Intel Corporation |
1da177e4 LT |
6 | * |
7 | * All rights reserved. | |
8 | * | |
8cf4c195 | 9 | * Send feedback to <kristen.c.accardi@intel.com> |
1da177e4 LT |
10 | */ |
11 | ||
1da177e4 | 12 | #include <linux/module.h> |
aad20cab | 13 | #include <linux/moduleparam.h> |
1da177e4 LT |
14 | #include <linux/kernel.h> |
15 | #include <linux/types.h> | |
16 | #include <linux/pci.h> | |
7a54f25c | 17 | #include <linux/pci_hotplug.h> |
9f5404d8 | 18 | #include <linux/acpi.h> |
ac9c052d | 19 | #include <linux/pci-acpi.h> |
5a0e3ad6 | 20 | #include <linux/slab.h> |
1da177e4 | 21 | |
aad20cab KK |
22 | #define MY_NAME "acpi_pcihp" |
23 | ||
ff3ce480 BS |
24 | #define dbg(fmt, arg...) do { if (debug_acpi) printk(KERN_DEBUG "%s: %s: " fmt, MY_NAME, __func__, ## arg); } while (0) |
25 | #define err(format, arg...) printk(KERN_ERR "%s: " format, MY_NAME, ## arg) | |
26 | #define info(format, arg...) printk(KERN_INFO "%s: " format, MY_NAME, ## arg) | |
27 | #define warn(format, arg...) printk(KERN_WARNING "%s: " format, MY_NAME, ## arg) | |
aad20cab | 28 | |
1da177e4 | 29 | #define METHOD_NAME__SUN "_SUN" |
1da177e4 LT |
30 | #define METHOD_NAME_OSHP "OSHP" |
31 | ||
90ab5ee9 | 32 | static bool debug_acpi; |
aad20cab | 33 | |
783c49fc KA |
34 | /* acpi_run_oshp - get control of hotplug from the firmware |
35 | * | |
36 | * @handle - the handle of the hotplug controller. | |
37 | */ | |
ac9c052d | 38 | static acpi_status acpi_run_oshp(acpi_handle handle) |
1da177e4 LT |
39 | { |
40 | acpi_status status; | |
b2e6e3ba MT |
41 | struct acpi_buffer string = { ACPI_ALLOCATE_BUFFER, NULL }; |
42 | ||
43 | acpi_get_name(handle, ACPI_FULL_PATHNAME, &string); | |
1da177e4 LT |
44 | |
45 | /* run OSHP */ | |
a8a2be94 | 46 | status = acpi_evaluate_object(handle, METHOD_NAME_OSHP, NULL, NULL); |
783c49fc | 47 | if (ACPI_FAILURE(status)) |
aad20cab KK |
48 | if (status != AE_NOT_FOUND) |
49 | printk(KERN_ERR "%s:%s OSHP fails=0x%x\n", | |
66bef8c0 | 50 | __func__, (char *)string.pointer, status); |
aad20cab KK |
51 | else |
52 | dbg("%s:%s OSHP not found\n", | |
66bef8c0 | 53 | __func__, (char *)string.pointer); |
783c49fc | 54 | else |
66bef8c0 | 55 | pr_debug("%s:%s OSHP passes\n", __func__, |
b2e6e3ba MT |
56 | (char *)string.pointer); |
57 | ||
81b26bca | 58 | kfree(string.pointer); |
783c49fc KA |
59 | return status; |
60 | } | |
783c49fc | 61 | |
ac9c052d KK |
62 | /** |
63 | * acpi_get_hp_hw_control_from_firmware | |
9b41d19a | 64 | * @pdev: the pci_dev of the bridge that has a hotplug controller |
ac9c052d KK |
65 | * |
66 | * Attempt to take hotplug control from firmware. | |
67 | */ | |
6f77fa49 | 68 | int acpi_get_hp_hw_control_from_firmware(struct pci_dev *pdev) |
ac9c052d | 69 | { |
aa6be07c MW |
70 | const struct pci_host_bridge *host; |
71 | const struct acpi_pci_root *root; | |
ac9c052d | 72 | acpi_status status; |
e0d94bee | 73 | acpi_handle chandle, handle; |
ac9c052d KK |
74 | struct acpi_buffer string = { ACPI_ALLOCATE_BUFFER, NULL }; |
75 | ||
6f6f4246 BH |
76 | /* |
77 | * If there's no ACPI host bridge (i.e., ACPI support is compiled | |
78 | * into the kernel but the hardware platform doesn't support ACPI), | |
79 | * there's nothing to do here. | |
80 | */ | |
90cc0c3c | 81 | host = pci_find_host_bridge(pdev->bus); |
aa6be07c | 82 | root = acpi_pci_find_root(ACPI_HANDLE(&host->dev)); |
6f6f4246 BH |
83 | if (!root) |
84 | return 0; | |
85 | ||
b03799b0 BH |
86 | /* |
87 | * If _OSC exists, it determines whether we're allowed to manage | |
88 | * the SHPC. We executed it while enumerating the host bridge. | |
89 | */ | |
90 | if (root->osc_support_set) { | |
91 | if (host->native_shpc_hotplug) | |
92 | return 0; | |
93 | return -ENODEV; | |
94 | } | |
e0d94bee | 95 | |
b03799b0 BH |
96 | /* |
97 | * In the absence of _OSC, we're always allowed to manage the SHPC. | |
98 | * However, if an OSHP method is present, we must execute it so the | |
99 | * firmware can transfer control to the OS, e.g., direct interrupts | |
100 | * to the OS instead of to the firmware. | |
101 | * | |
102 | * N.B. The PCI Firmware Spec (r3.2, sec 4.8) does not endorse | |
103 | * searching up the ACPI hierarchy, so the loops below are suspect. | |
104 | */ | |
3a83f992 | 105 | handle = ACPI_HANDLE(&pdev->dev); |
d391f00f | 106 | if (!handle) { |
ac9c052d KK |
107 | /* |
108 | * This hotplug controller was not listed in the ACPI name | |
f2b775f5 | 109 | * space at all. Try to get ACPI handle of parent PCI bus. |
ac9c052d | 110 | */ |
d391f00f KK |
111 | struct pci_bus *pbus; |
112 | for (pbus = pdev->bus; pbus; pbus = pbus->parent) { | |
113 | handle = acpi_pci_get_bridge_handle(pbus); | |
114 | if (handle) | |
115 | break; | |
116 | } | |
ac9c052d KK |
117 | } |
118 | ||
119 | while (handle) { | |
120 | acpi_get_name(handle, ACPI_FULL_PATHNAME, &string); | |
f2b775f5 BH |
121 | pci_info(pdev, "Requesting control of SHPC hotplug via OSHP (%s)\n", |
122 | (char *)string.pointer); | |
e0d94bee JS |
123 | status = acpi_run_oshp(handle); |
124 | if (ACPI_SUCCESS(status)) | |
125 | goto got_one; | |
27558203 | 126 | if (acpi_is_root_bridge(handle)) |
ac9c052d KK |
127 | break; |
128 | chandle = handle; | |
129 | status = acpi_get_parent(chandle, &handle); | |
130 | if (ACPI_FAILURE(status)) | |
131 | break; | |
132 | } | |
b03799b0 | 133 | |
f2b775f5 | 134 | pci_info(pdev, "Cannot get control of SHPC hotplug\n"); |
ac9c052d KK |
135 | kfree(string.pointer); |
136 | return -ENODEV; | |
e0d94bee | 137 | got_one: |
f2b775f5 BH |
138 | pci_info(pdev, "Gained control of SHPC hotplug (%s)\n", |
139 | (char *)string.pointer); | |
e0d94bee JS |
140 | kfree(string.pointer); |
141 | return 0; | |
ac9c052d KK |
142 | } |
143 | EXPORT_SYMBOL(acpi_get_hp_hw_control_from_firmware); | |
1da177e4 | 144 | |
efe6d727 | 145 | static int pcihp_is_ejectable(acpi_handle handle) |
e8c331e9 KK |
146 | { |
147 | acpi_status status; | |
e8c331e9 | 148 | unsigned long long removable; |
2fd6f9c3 | 149 | if (!acpi_has_method(handle, "_ADR")) |
e8c331e9 | 150 | return 0; |
2fd6f9c3 | 151 | if (acpi_has_method(handle, "_EJ0")) |
e8c331e9 KK |
152 | return 1; |
153 | status = acpi_evaluate_integer(handle, "_RMV", NULL, &removable); | |
154 | if (ACPI_SUCCESS(status) && removable) | |
155 | return 1; | |
156 | return 0; | |
157 | } | |
158 | ||
159 | /** | |
43395d9e | 160 | * acpi_pci_check_ejectable - check if handle is ejectable ACPI PCI slot |
e8c331e9 KK |
161 | * @pbus: the PCI bus of the PCI slot corresponding to 'handle' |
162 | * @handle: ACPI handle to check | |
163 | * | |
164 | * Return 1 if handle is ejectable PCI slot, 0 otherwise. | |
165 | */ | |
166 | int acpi_pci_check_ejectable(struct pci_bus *pbus, acpi_handle handle) | |
167 | { | |
168 | acpi_handle bridge_handle, parent_handle; | |
169 | ||
79e50e72 QL |
170 | bridge_handle = acpi_pci_get_bridge_handle(pbus); |
171 | if (!bridge_handle) | |
e8c331e9 KK |
172 | return 0; |
173 | if ((ACPI_FAILURE(acpi_get_parent(handle, &parent_handle)))) | |
174 | return 0; | |
175 | if (bridge_handle != parent_handle) | |
176 | return 0; | |
efe6d727 | 177 | return pcihp_is_ejectable(handle); |
e8c331e9 KK |
178 | } |
179 | EXPORT_SYMBOL_GPL(acpi_pci_check_ejectable); | |
180 | ||
181 | static acpi_status | |
182 | check_hotplug(acpi_handle handle, u32 lvl, void *context, void **rv) | |
183 | { | |
184 | int *found = (int *)context; | |
efe6d727 | 185 | if (pcihp_is_ejectable(handle)) { |
e8c331e9 KK |
186 | *found = 1; |
187 | return AE_CTRL_TERMINATE; | |
188 | } | |
189 | return AE_OK; | |
190 | } | |
191 | ||
192 | /** | |
193 | * acpi_pci_detect_ejectable - check if the PCI bus has ejectable slots | |
9b41d19a | 194 | * @handle: handle of the PCI bus to scan |
e8c331e9 KK |
195 | * |
196 | * Returns 1 if the PCI bus has ACPI based ejectable slots, 0 otherwise. | |
197 | */ | |
7f538669 | 198 | int acpi_pci_detect_ejectable(acpi_handle handle) |
e8c331e9 | 199 | { |
e8c331e9 KK |
200 | int found = 0; |
201 | ||
7f538669 AC |
202 | if (!handle) |
203 | return found; | |
204 | ||
205 | acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1, | |
2263576c | 206 | check_hotplug, NULL, (void *)&found, NULL); |
e8c331e9 KK |
207 | return found; |
208 | } | |
209 | EXPORT_SYMBOL_GPL(acpi_pci_detect_ejectable); | |
210 | ||
aad20cab KK |
211 | module_param(debug_acpi, bool, 0644); |
212 | MODULE_PARM_DESC(debug_acpi, "Debugging mode for ACPI enabled or not"); |