0f713531754279dc09921aeffbf51017476557b3
[linux-2.6.git] / drivers / pci / hotplug / acpi_pcihp.c
1 /*
2  * Common ACPI functions for hot plug platforms
3  *
4  * Copyright (C) 2006 Intel Corporation
5  *
6  * All rights reserved.
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or (at
11  * your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful, but
14  * WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
16  * NON INFRINGEMENT.  See the GNU General Public License for more
17  * details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22  *
23  * Send feedback to <kristen.c.accardi@intel.com>
24  *
25  */
26
27 #include <linux/module.h>
28 #include <linux/kernel.h>
29 #include <linux/types.h>
30 #include <linux/pci.h>
31 #include <acpi/acpi.h>
32 #include <acpi/acpi_bus.h>
33 #include <acpi/actypes.h>
34 #include "pci_hotplug.h"
35
36 #define METHOD_NAME__SUN        "_SUN"
37 #define METHOD_NAME__HPP        "_HPP"
38 #define METHOD_NAME_OSHP        "OSHP"
39
40 /* acpi_path_name
41  *
42  * @handle - the acpi_handle of the object who's name you want.
43  *
44  * Caller must free buffer.
45  */
46 u8 * acpi_path_name(acpi_handle handle)
47 {
48         acpi_status status;
49         struct acpi_buffer ret_buf = {ACPI_ALLOCATE_BUFFER, NULL};
50         union acpi_object *obj;
51
52         status = acpi_get_name(handle, ACPI_FULL_PATHNAME, &ret_buf);
53         if (ACPI_FAILURE(status)) {
54                 return NULL;
55         }
56         obj = ret_buf.pointer;
57         return obj->string.pointer;
58 }
59 EXPORT_SYMBOL_GPL(acpi_path_name);
60
61
62
63 static acpi_status
64 acpi_run_hpp(acpi_handle handle, struct hotplug_params *hpp)
65 {
66         acpi_status             status;
67         u8                      nui[4];
68         struct acpi_buffer      ret_buf = { 0, NULL};
69         union acpi_object       *ext_obj, *package;
70         u8                      *path_name = acpi_path_name(handle);
71         int                     i, len = 0;
72
73         /* get _hpp */
74         status = acpi_evaluate_object(handle, METHOD_NAME__HPP, NULL, &ret_buf);
75         switch (status) {
76         case AE_BUFFER_OVERFLOW:
77                 ret_buf.pointer = kmalloc (ret_buf.length, GFP_KERNEL);
78                 if (!ret_buf.pointer) {
79                         printk(KERN_ERR "%s:%s alloc for _HPP fail\n",
80                                 __FUNCTION__, path_name);
81                         acpi_os_free(path_name);
82                         return AE_NO_MEMORY;
83                 }
84                 status = acpi_evaluate_object(handle, METHOD_NAME__HPP,
85                                 NULL, &ret_buf);
86                 if (ACPI_SUCCESS(status))
87                         break;
88         default:
89                 if (ACPI_FAILURE(status)) {
90                         pr_debug("%s:%s _HPP fail=0x%x\n", __FUNCTION__,
91                                         path_name, status);
92                         acpi_os_free(path_name);
93                         return status;
94                 }
95         }
96
97         ext_obj = (union acpi_object *) ret_buf.pointer;
98         if (ext_obj->type != ACPI_TYPE_PACKAGE) {
99                 printk(KERN_ERR "%s:%s _HPP obj not a package\n", __FUNCTION__,
100                                 path_name);
101                 status = AE_ERROR;
102                 goto free_and_return;
103         }
104
105         len = ext_obj->package.count;
106         package = (union acpi_object *) ret_buf.pointer;
107         for ( i = 0; (i < len) || (i < 4); i++) {
108                 ext_obj = (union acpi_object *) &package->package.elements[i];
109                 switch (ext_obj->type) {
110                 case ACPI_TYPE_INTEGER:
111                         nui[i] = (u8)ext_obj->integer.value;
112                         break;
113                 default:
114                         printk(KERN_ERR "%s:%s _HPP obj type incorrect\n",
115                                 __FUNCTION__, path_name);
116                         status = AE_ERROR;
117                         goto free_and_return;
118                 }
119         }
120
121         hpp->cache_line_size = nui[0];
122         hpp->latency_timer = nui[1];
123         hpp->enable_serr = nui[2];
124         hpp->enable_perr = nui[3];
125
126         pr_debug("  _HPP: cache_line_size=0x%x\n", hpp->cache_line_size);
127         pr_debug("  _HPP: latency timer  =0x%x\n", hpp->latency_timer);
128         pr_debug("  _HPP: enable SERR    =0x%x\n", hpp->enable_serr);
129         pr_debug("  _HPP: enable PERR    =0x%x\n", hpp->enable_perr);
130
131 free_and_return:
132         acpi_os_free(path_name);
133         kfree(ret_buf.pointer);
134         return status;
135 }
136
137
138
139 /* acpi_run_oshp - get control of hotplug from the firmware
140  *
141  * @handle - the handle of the hotplug controller.
142  */
143 acpi_status acpi_run_oshp(acpi_handle handle)
144 {
145         acpi_status             status;
146         u8                      *path_name = acpi_path_name(handle);
147
148         /* run OSHP */
149         status = acpi_evaluate_object(handle, METHOD_NAME_OSHP, NULL, NULL);
150         if (ACPI_FAILURE(status))
151                 printk(KERN_ERR "%s:%s OSHP fails=0x%x\n", __FUNCTION__,
152                         path_name, status);
153         else
154                 pr_debug("%s:%s OSHP passes\n", __FUNCTION__, path_name);
155         acpi_os_free(path_name);
156         return status;
157 }
158 EXPORT_SYMBOL_GPL(acpi_run_oshp);
159
160
161
162 /* acpi_get_hp_params_from_firmware
163  *
164  * @dev - the pci_dev of the newly added device
165  * @hpp - allocated by the caller
166  */
167 acpi_status acpi_get_hp_params_from_firmware(struct pci_dev *dev,
168                 struct hotplug_params *hpp)
169 {
170         acpi_status status = AE_NOT_FOUND;
171         struct pci_dev *pdev = dev;
172
173         /*
174          * _HPP settings apply to all child buses, until another _HPP is
175          * encountered. If we don't find an _HPP for the input pci dev,
176          * look for it in the parent device scope since that would apply to
177          * this pci dev. If we don't find any _HPP, use hardcoded defaults
178          */
179         while (pdev && (ACPI_FAILURE(status))) {
180                 acpi_handle handle = DEVICE_ACPI_HANDLE(&(pdev->dev));
181                 if (!handle)
182                         break;
183                 status = acpi_run_hpp(handle, hpp);
184                 if (!(pdev->bus->parent))
185                         break;
186                 /* Check if a parent object supports _HPP */
187                 pdev = pdev->bus->parent->self;
188         }
189         return status;
190 }
191 EXPORT_SYMBOL_GPL(acpi_get_hp_params_from_firmware);
192
193
194 /* acpi_root_bridge - check to see if this acpi object is a root bridge
195  *
196  * @handle - the acpi object in question.
197  */
198 int acpi_root_bridge(acpi_handle handle)
199 {
200         acpi_status status;
201         struct acpi_device_info *info;
202         struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
203         int i;
204
205         status = acpi_get_object_info(handle, &buffer);
206         if (ACPI_SUCCESS(status)) {
207                 info = buffer.pointer;
208                 if ((info->valid & ACPI_VALID_HID) &&
209                         !strcmp(PCI_ROOT_HID_STRING,
210                                         info->hardware_id.value)) {
211                         acpi_os_free(buffer.pointer);
212                         return 1;
213                 }
214                 if (info->valid & ACPI_VALID_CID) {
215                         for (i=0; i < info->compatibility_id.count; i++) {
216                                 if (!strcmp(PCI_ROOT_HID_STRING,
217                                         info->compatibility_id.id[i].value)) {
218                                         acpi_os_free(buffer.pointer);
219                                         return 1;
220                                 }
221                         }
222                 }
223                 acpi_os_free(buffer.pointer);
224         }
225         return 0;
226 }
227 EXPORT_SYMBOL_GPL(acpi_root_bridge);