summaryrefslogtreecommitdiffstats
path: root/drivers/pci/hotplug/pciehprm_acpi.c
blob: 4d013f86b1a59462ff96431c2e22a46445f36659 (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
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
/*
 * PCIEHPRM ACPI: PHP Resource Manager for ACPI platform
 *
 * Copyright (C) 2003-2004 Intel Corporation
 *
 * 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.
 *
 * Send feedback to <kristen.c.accardi@intel.com>
 *
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/acpi.h>
#include <linux/pci-acpi.h>
#include <acpi/acpi_bus.h>
#include <acpi/actypes.h>
#include "pciehp.h"

#define	METHOD_NAME__SUN	"_SUN"
#define	METHOD_NAME__HPP	"_HPP"
#define	METHOD_NAME_OSHP	"OSHP"

static u8 * acpi_path_name( acpi_handle	handle)
{
	acpi_status		status;
	static u8		path_name[ACPI_PATHNAME_MAX];
	struct acpi_buffer	ret_buf = { ACPI_PATHNAME_MAX, path_name };

	memset(path_name, 0, sizeof (path_name));
	status = acpi_get_name(handle, ACPI_FULL_PATHNAME, &ret_buf);

	if (ACPI_FAILURE(status))
		return NULL;
	else
		return path_name;	
}

static acpi_status
acpi_run_hpp(acpi_handle handle, struct hotplug_params *hpp)
{
	acpi_status		status;
	u8			nui[4];
	struct acpi_buffer	ret_buf = { 0, NULL};
	union acpi_object	*ext_obj, *package;
	u8			*path_name = acpi_path_name(handle);
	int			i, len = 0;

	/* get _hpp */
	status = acpi_evaluate_object(handle, METHOD_NAME__HPP, NULL, &ret_buf);
	switch (status) {
	case AE_BUFFER_OVERFLOW:
		ret_buf.pointer = kmalloc (ret_buf.length, GFP_KERNEL);
		if (!ret_buf.pointer) {
			err ("%s:%s alloc for _HPP fail\n", __FUNCTION__,
					path_name);
			return AE_NO_MEMORY;
		}
		status = acpi_evaluate_object(handle, METHOD_NAME__HPP,
				NULL, &ret_buf);
		if (ACPI_SUCCESS(status))
			break;
	default:
		if (ACPI_FAILURE(status)) {
			dbg("%s:%s _HPP fail=0x%x\n", __FUNCTION__,
					path_name, status);
			return status;
		}
	}

	ext_obj = (union acpi_object *) ret_buf.pointer;
	if (ext_obj->type != ACPI_TYPE_PACKAGE) {
		err ("%s:%s _HPP obj not a package\n", __FUNCTION__,
				path_name);
		status = AE_ERROR;
		goto free_and_return;
	}

	len = ext_obj->package.count;
	package = (union acpi_object *) ret_buf.pointer;
	for ( i = 0; (i < len) || (i < 4); i++) {
		ext_obj = (union acpi_object *) &package->package.elements[i];
		switch (ext_obj->type) {
		case ACPI_TYPE_INTEGER:
			nui[i] = (u8)ext_obj->integer.value;
			break;
		default:
			err ("%s:%s _HPP obj type incorrect\n", __FUNCTION__,
					path_name);
			status = AE_ERROR;
			goto free_and_return;
		}
	}

	hpp->cache_line_size = nui[0];
	hpp->latency_timer = nui[1];
	hpp->enable_serr = nui[2];
	hpp->enable_perr = nui[3];

	dbg("  _HPP: cache_line_size=0x%x\n", hpp->cache_line_size);
	dbg("  _HPP: latency timer  =0x%x\n", hpp->latency_timer);
	dbg("  _HPP: enable SERR    =0x%x\n", hpp->enable_serr);
	dbg("  _HPP: enable PERR    =0x%x\n", hpp->enable_perr);

free_and_return:
	kfree(ret_buf.pointer);
	return status;
}

static acpi_status acpi_run_oshp(acpi_handle handle)
{
	acpi_status		status;
	u8			*path_name = acpi_path_name(handle);

	/* run OSHP */
	status = acpi_evaluate_object(handle, METHOD_NAME_OSHP, NULL, NULL);
	if (ACPI_FAILURE(status)) {
		dbg("%s:%s OSHP fails=0x%x\n", __FUNCTION__, path_name,
				status);
	} else {
		dbg("%s:%s OSHP passes\n", __FUNCTION__, path_name);
	}
	return status;
}

static int is_root_bridge(acpi_handle handle)
{
	acpi_status status;
	struct acpi_device_info *info;
	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
	int i;

	status = acpi_get_object_info(handle, &buffer);
	if (ACPI_SUCCESS(status)) {
		info = buffer.pointer;
		if ((info->valid & ACPI_VALID_HID) &&
			!strcmp(PCI_ROOT_HID_STRING,
					info->hardware_id.value)) {
			acpi_os_free(buffer.pointer);
			return 1;
		}
		if (info->valid & ACPI_VALID_CID) {
			for (i=0; i < info->compatibility_id.count; i++) {
				if (!strcmp(PCI_ROOT_HID_STRING,
					info->compatibility_id.id[i].value)) {
					acpi_os_free(buffer.pointer);
					return 1;
				}
			}
		}
	}
	return 0;
}

int get_hp_hw_control_from_firmware(struct pci_dev *dev)
{
	acpi_status status;
	acpi_handle chandle, handle = DEVICE_ACPI_HANDLE(&(dev->dev));
	struct pci_dev *pdev = dev;
	u8 *path_name;
	/*
	 * Per PCI firmware specification, we should run the ACPI _OSC
	 * method to get control of hotplug hardware before using it.
	 * If an _OSC is missing, we look for an OSHP to do the same thing.
	 * To handle different BIOS behavior, we look for _OSC and OSHP
	 * within the scope of the hotplug controller and its parents, upto
	 * the host bridge under which this controller exists.
	 */
	while (!handle) {
		/*
		 * This hotplug controller was not listed in the ACPI name
		 * space at all. Try to get acpi handle of parent pci bus.
		 */
		if (!pdev || !pdev->bus->parent)
			break;
		dbg("Could not find %s in acpi namespace, trying parent\n",
				pci_name(pdev));
		if (!pdev->bus->parent->self)
			/* Parent must be a host bridge */
			handle = acpi_get_pci_rootbridge_handle(
					pci_domain_nr(pdev->bus->parent),
					pdev->bus->parent->number);
		else
			handle = DEVICE_ACPI_HANDLE(
					&(pdev->bus->parent->self->dev));
		pdev = pdev->bus->parent->self;
	}

	while (handle) {
		path_name = acpi_path_name(handle);
		dbg("Trying to get hotplug control for %s \n", path_name);
		status = pci_osc_control_set(handle,
				OSC_PCI_EXPRESS_NATIVE_HP_CONTROL);
		if (status == AE_NOT_FOUND)
			status = acpi_run_oshp(handle);
		if (ACPI_SUCCESS(status)) {
			dbg("Gained control for hotplug HW for pci %s (%s)\n",
				pci_name(dev), path_name);
			return 0;
		}
		if (is_root_bridge(handle))
			break;
		chandle = handle;
		status = acpi_get_parent(chandle, &handle);
		if (ACPI_FAILURE(status))
			break;
	}

	err("Cannot get control of hotplug hardware for pci %s\n",
			pci_name(dev));
	return -1;
}

void get_hp_params_from_firmware(struct pci_dev *dev,
		struct hotplug_params *hpp)
{
	acpi_status status = AE_NOT_FOUND;
	struct pci_dev *pdev = dev;

	/*
	 * _HPP settings apply to all child buses, until another _HPP is
	 * encountered. If we don't find an _HPP for the input pci dev,
	 * look for it in the parent device scope since that would apply to
	 * this pci dev. If we don't find any _HPP, use hardcoded defaults
	 */
	while (pdev && (ACPI_FAILURE(status))) {
		acpi_handle handle = DEVICE_ACPI_HANDLE(&(pdev->dev));
		if (!handle)
			break;
		status = acpi_run_hpp(handle, hpp);
		if (!(pdev->bus->parent))
			break;
		/* Check if a parent object supports _HPP */
		pdev = pdev->bus->parent->self;
	}
}