5acdae3d52b18bb98789908ad191209bdd319b1a
[linux-2.6.git] / drivers / pci / hotplug / pciehprm_acpi.c
1 /*
2  * PCIEHPRM ACPI: PHP Resource Manager for ACPI platform
3  *
4  * Copyright (C) 2003-2004 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 <linux/acpi.h>
32 #include <linux/pci-acpi.h>
33 #include <acpi/acpi_bus.h>
34 #include <acpi/actypes.h>
35 #include "pciehp.h"
36
37 #define METHOD_NAME__SUN        "_SUN"
38 #define METHOD_NAME__HPP        "_HPP"
39 #define METHOD_NAME_OSHP        "OSHP"
40
41 static u8 * acpi_path_name( acpi_handle handle)
42 {
43         acpi_status             status;
44         static u8               path_name[ACPI_PATHNAME_MAX];
45         struct acpi_buffer      ret_buf = { ACPI_PATHNAME_MAX, path_name };
46
47         memset(path_name, 0, sizeof (path_name));
48         status = acpi_get_name(handle, ACPI_FULL_PATHNAME, &ret_buf);
49
50         if (ACPI_FAILURE(status))
51                 return NULL;
52         else
53                 return path_name;       
54 }
55
56 static acpi_status
57 acpi_run_hpp(acpi_handle handle, struct hotplug_params *hpp)
58 {
59         acpi_status             status;
60         u8                      nui[4];
61         struct acpi_buffer      ret_buf = { 0, NULL};
62         union acpi_object       *ext_obj, *package;
63         u8                      *path_name = acpi_path_name(handle);
64         int                     i, len = 0;
65
66         /* get _hpp */
67         status = acpi_evaluate_object(handle, METHOD_NAME__HPP, NULL, &ret_buf);
68         switch (status) {
69         case AE_BUFFER_OVERFLOW:
70                 ret_buf.pointer = kmalloc (ret_buf.length, GFP_KERNEL);
71                 if (!ret_buf.pointer) {
72                         err ("%s:%s alloc for _HPP fail\n", __FUNCTION__,
73                                         path_name);
74                         return AE_NO_MEMORY;
75                 }
76                 status = acpi_evaluate_object(handle, METHOD_NAME__HPP,
77                                 NULL, &ret_buf);
78                 if (ACPI_SUCCESS(status))
79                         break;
80         default:
81                 if (ACPI_FAILURE(status)) {
82                         dbg("%s:%s _HPP fail=0x%x\n", __FUNCTION__,
83                                         path_name, status);
84                         return status;
85                 }
86         }
87
88         ext_obj = (union acpi_object *) ret_buf.pointer;
89         if (ext_obj->type != ACPI_TYPE_PACKAGE) {
90                 err ("%s:%s _HPP obj not a package\n", __FUNCTION__,
91                                 path_name);
92                 status = AE_ERROR;
93                 goto free_and_return;
94         }
95
96         len = ext_obj->package.count;
97         package = (union acpi_object *) ret_buf.pointer;
98         for ( i = 0; (i < len) || (i < 4); i++) {
99                 ext_obj = (union acpi_object *) &package->package.elements[i];
100                 switch (ext_obj->type) {
101                 case ACPI_TYPE_INTEGER:
102                         nui[i] = (u8)ext_obj->integer.value;
103                         break;
104                 default:
105                         err ("%s:%s _HPP obj type incorrect\n", __FUNCTION__,
106                                         path_name);
107                         status = AE_ERROR;
108                         goto free_and_return;
109                 }
110         }
111
112         hpp->cache_line_size = nui[0];
113         hpp->latency_timer = nui[1];
114         hpp->enable_serr = nui[2];
115         hpp->enable_perr = nui[3];
116
117         dbg("  _HPP: cache_line_size=0x%x\n", hpp->cache_line_size);
118         dbg("  _HPP: latency timer  =0x%x\n", hpp->latency_timer);
119         dbg("  _HPP: enable SERR    =0x%x\n", hpp->enable_serr);
120         dbg("  _HPP: enable PERR    =0x%x\n", hpp->enable_perr);
121
122 free_and_return:
123         kfree(ret_buf.pointer);
124         return status;
125 }
126
127 static acpi_status acpi_run_oshp(acpi_handle handle)
128 {
129         acpi_status             status;
130         u8                      *path_name = acpi_path_name(handle);
131
132         /* run OSHP */
133         status = acpi_evaluate_object(handle, METHOD_NAME_OSHP, NULL, NULL);
134         if (ACPI_FAILURE(status)) {
135                 err("%s:%s OSHP fails=0x%x\n", __FUNCTION__, path_name,
136                                 status);
137         } else {
138                 dbg("%s:%s OSHP passes\n", __FUNCTION__, path_name);
139         }
140         return status;
141 }
142
143 int get_hp_hw_control_from_firmware(struct pci_dev *dev)
144 {
145         acpi_status status;
146         acpi_handle handle = DEVICE_ACPI_HANDLE(&(dev->dev));
147         /*
148          * Per PCI firmware specification, we should run the ACPI _OSC
149          * method to get control of hotplug hardware before using it
150          */
151         status = pci_osc_control_set(handle,
152                         OSC_PCI_EXPRESS_NATIVE_HP_CONTROL);
153
154         /* Fixme: fail native hotplug if _OSC does not exist for root ports */
155         if (status == AE_NOT_FOUND) {
156                 /*
157                  * Some older BIOS's don't support _OSC but support
158                  * OSHP to do the same thing
159                  */
160                 status = acpi_run_oshp(handle);
161         }
162         if (ACPI_FAILURE(status)) {
163                 err("Cannot get control of hotplug hardware\n");
164                 return -1;
165         }
166
167         dbg("Sucess getting control of hotplug hardware\n");
168         return 0;
169 }
170
171 void get_hp_params_from_firmware(struct pci_dev *dev,
172                 struct hotplug_params *hpp)
173 {
174         acpi_status status = AE_NOT_FOUND;
175         struct pci_dev *pdev = dev;
176
177         /*
178          * _HPP settings apply to all child buses, until another _HPP is
179          * encountered. If we don't find an _HPP for the input pci dev,
180          * look for it in the parent device scope since that would apply to
181          * this pci dev. If we don't find any _HPP, use hardcoded defaults
182          */
183         while (pdev && (ACPI_FAILURE(status))) {
184                 acpi_handle handle = DEVICE_ACPI_HANDLE(&(pdev->dev));
185                 if (!handle)
186                         break;
187                 status = acpi_run_hpp(handle, hpp);
188                 if (!(pdev->bus->parent))
189                         break;
190                 /* Check if a parent object supports _HPP */
191                 pdev = pdev->bus->parent->self;
192         }
193 }
194