1/*
  2 * Purpose: Export the firmware instance and label associated with
  3 * a pci device to sysfs
 
  4 * Copyright (C) 2010 Dell Inc.
  5 * by Narendra K <Narendra_K@dell.com>,
  6 * Jordan Hargrave <Jordan_Hargrave@dell.com>
  7 *
  8 * PCI Firmware Specification Revision 3.1 section 4.6.7 (DSM for Naming a
  9 * PCI or PCI Express Device Under Operating Systems) defines an instance
 10 * number and string name. This code retrieves them and exports them to sysfs.
 11 * If the system firmware does not provide the ACPI _DSM (Device Specific
 12 * Method), then the SMBIOS type 41 instance number and string is exported to
 13 * sysfs.
 14 *
 15 * SMBIOS defines type 41 for onboard pci devices. This code retrieves
 16 * the instance number and string from the type 41 record and exports
 17 * it to sysfs.
 18 *
 19 * Please see http://linux.dell.com/wiki/index.php/Oss/libnetdevname for more
 20 * information.
 21 */
 22
 23#include <linux/dmi.h>
 24#include <linux/sysfs.h>
 25#include <linux/pci.h>
 26#include <linux/pci_ids.h>
 27#include <linux/module.h>
 28#include <linux/device.h>
 29#include <linux/nls.h>
 30#include <linux/acpi.h>
 31#include <linux/pci-acpi.h>
 32#include "pci.h"
 33
 34#define	DEVICE_LABEL_DSM	0x07
 35
 36#ifdef CONFIG_DMI
 37enum smbios_attr_enum {
 38	SMBIOS_ATTR_NONE = 0,
 39	SMBIOS_ATTR_LABEL_SHOW,
 40	SMBIOS_ATTR_INSTANCE_SHOW,
 41};
 42
 43static size_t
 44find_smbios_instance_string(struct pci_dev *pdev, char *buf,
 45			    enum smbios_attr_enum attribute)
 46{
 47	const struct dmi_device *dmi;
 48	struct dmi_dev_onboard *donboard;
 
 49	int bus;
 50	int devfn;
 51
 
 52	bus = pdev->bus->number;
 53	devfn = pdev->devfn;
 54
 55	dmi = NULL;
 56	while ((dmi = dmi_find_device(DMI_DEV_TYPE_DEV_ONBOARD,
 57				      NULL, dmi)) != NULL) {
 58		donboard = dmi->device_data;
 59		if (donboard && donboard->bus == bus &&
 60					donboard->devfn == devfn) {
 
 61			if (buf) {
 62				if (attribute == SMBIOS_ATTR_INSTANCE_SHOW)
 63					return scnprintf(buf, PAGE_SIZE,
 64							 "%d\n",
 65							 donboard->instance);
 66				else if (attribute == SMBIOS_ATTR_LABEL_SHOW)
 67					return scnprintf(buf, PAGE_SIZE,
 68							 "%s\n",
 69							 dmi->name);
 70			}
 71			return strlen(dmi->name);
 72		}
 73	}
 74	return 0;
 75}
 76
 77static umode_t
 78smbios_instance_string_exist(struct kobject *kobj, struct attribute *attr,
 79			     int n)
 80{
 81	struct device *dev;
 82	struct pci_dev *pdev;
 83
 84	dev = container_of(kobj, struct device, kobj);
 85	pdev = to_pci_dev(dev);
 86
 87	return find_smbios_instance_string(pdev, NULL, SMBIOS_ATTR_NONE) ?
 88					   S_IRUGO : 0;
 89}
 90
 91static ssize_t
 92smbioslabel_show(struct device *dev, struct device_attribute *attr, char *buf)
 93{
 94	struct pci_dev *pdev;
 95	pdev = to_pci_dev(dev);
 96
 97	return find_smbios_instance_string(pdev, buf,
 98					   SMBIOS_ATTR_LABEL_SHOW);
 99}
100
101static ssize_t
102smbiosinstance_show(struct device *dev,
103		    struct device_attribute *attr, char *buf)
104{
105	struct pci_dev *pdev;
106	pdev = to_pci_dev(dev);
107
108	return find_smbios_instance_string(pdev, buf,
109					   SMBIOS_ATTR_INSTANCE_SHOW);
110}
111
112static struct device_attribute smbios_attr_label = {
113	.attr = {.name = "label", .mode = 0444},
114	.show = smbioslabel_show,
115};
116
117static struct device_attribute smbios_attr_instance = {
118	.attr = {.name = "index", .mode = 0444},
119	.show = smbiosinstance_show,
120};
121
122static struct attribute *smbios_attributes[] = {
123	&smbios_attr_label.attr,
124	&smbios_attr_instance.attr,
125	NULL,
126};
127
128static struct attribute_group smbios_attr_group = {
129	.attrs = smbios_attributes,
130	.is_visible = smbios_instance_string_exist,
131};
132
133static int
134pci_create_smbiosname_file(struct pci_dev *pdev)
135{
136	return sysfs_create_group(&pdev->dev.kobj, &smbios_attr_group);
137}
138
139static void
140pci_remove_smbiosname_file(struct pci_dev *pdev)
141{
142	sysfs_remove_group(&pdev->dev.kobj, &smbios_attr_group);
143}
144#else
145static inline int
146pci_create_smbiosname_file(struct pci_dev *pdev)
147{
148	return -1;
149}
150
151static inline void
152pci_remove_smbiosname_file(struct pci_dev *pdev)
153{
154}
155#endif
156
157#ifdef CONFIG_ACPI
158static const char device_label_dsm_uuid[] = {
159	0xD0, 0x37, 0xC9, 0xE5, 0x53, 0x35, 0x7A, 0x4D,
160	0x91, 0x17, 0xEA, 0x4D, 0x19, 0xC3, 0x43, 0x4D
161};
162
163enum acpi_attr_enum {
164	ACPI_ATTR_LABEL_SHOW,
165	ACPI_ATTR_INDEX_SHOW,
166};
167
168static void dsm_label_utf16s_to_utf8s(union acpi_object *obj, char *buf)
169{
170	int len;
171	len = utf16s_to_utf8s((const wchar_t *)obj->string.pointer,
172			      obj->string.length,
173			      UTF16_LITTLE_ENDIAN,
174			      buf, PAGE_SIZE);
175	buf[len] = '\n';
176}
177
178static int
179dsm_get_label(struct device *dev, char *buf, enum acpi_attr_enum attr)
180{
181	acpi_handle handle;
182	union acpi_object *obj, *tmp;
183	int len = -1;
184
185	handle = ACPI_HANDLE(dev);
186	if (!handle)
187		return -1;
188
189	obj = acpi_evaluate_dsm(handle, device_label_dsm_uuid, 0x2,
190				DEVICE_LABEL_DSM, NULL);
191	if (!obj)
192		return -1;
193
194	tmp = obj->package.elements;
195	if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 2 &&
196	    tmp[0].type == ACPI_TYPE_INTEGER &&
197	    tmp[1].type == ACPI_TYPE_STRING) {
 
198		/*
199		 * The second string element is optional even when
200		 * this _DSM is implemented; when not implemented,
201		 * this entry must return a null string.
202		 */
203		if (attr == ACPI_ATTR_INDEX_SHOW)
204			scnprintf(buf, PAGE_SIZE, "%llu\n", tmp->integer.value);
205		else if (attr == ACPI_ATTR_LABEL_SHOW)
206			dsm_label_utf16s_to_utf8s(tmp + 1, buf);
 
 
 
 
 
207		len = strlen(buf) > 0 ? strlen(buf) : -1;
208	}
209
210	ACPI_FREE(obj);
211
212	return len;
213}
214
215static bool
216device_has_dsm(struct device *dev)
217{
218	acpi_handle handle;
219
220	handle = ACPI_HANDLE(dev);
221	if (!handle)
222		return false;
223
224	return !!acpi_check_dsm(handle, device_label_dsm_uuid, 0x2,
225				1 << DEVICE_LABEL_DSM);
226}
227
228static umode_t
229acpi_index_string_exist(struct kobject *kobj, struct attribute *attr, int n)
230{
231	struct device *dev;
232
233	dev = container_of(kobj, struct device, kobj);
234
235	if (device_has_dsm(dev))
236		return S_IRUGO;
237
238	return 0;
239}
240
241static ssize_t
242acpilabel_show(struct device *dev, struct device_attribute *attr, char *buf)
243{
244	return dsm_get_label(dev, buf, ACPI_ATTR_LABEL_SHOW);
245}
246
247static ssize_t
248acpiindex_show(struct device *dev, struct device_attribute *attr, char *buf)
249{
250	return dsm_get_label(dev, buf, ACPI_ATTR_INDEX_SHOW);
251}
252
253static struct device_attribute acpi_attr_label = {
254	.attr = {.name = "label", .mode = 0444},
255	.show = acpilabel_show,
256};
257
258static struct device_attribute acpi_attr_index = {
259	.attr = {.name = "acpi_index", .mode = 0444},
260	.show = acpiindex_show,
261};
262
263static struct attribute *acpi_attributes[] = {
264	&acpi_attr_label.attr,
265	&acpi_attr_index.attr,
266	NULL,
267};
268
269static struct attribute_group acpi_attr_group = {
270	.attrs = acpi_attributes,
271	.is_visible = acpi_index_string_exist,
272};
273
274static int
275pci_create_acpi_index_label_files(struct pci_dev *pdev)
276{
277	return sysfs_create_group(&pdev->dev.kobj, &acpi_attr_group);
278}
279
280static int
281pci_remove_acpi_index_label_files(struct pci_dev *pdev)
282{
283	sysfs_remove_group(&pdev->dev.kobj, &acpi_attr_group);
284	return 0;
285}
286#else
287static inline int
288pci_create_acpi_index_label_files(struct pci_dev *pdev)
289{
290	return -1;
291}
292
293static inline int
294pci_remove_acpi_index_label_files(struct pci_dev *pdev)
295{
296	return -1;
297}
298
299static inline bool
300device_has_dsm(struct device *dev)
301{
302	return false;
303}
304#endif
305
306void pci_create_firmware_label_files(struct pci_dev *pdev)
307{
308	if (device_has_dsm(&pdev->dev))
309		pci_create_acpi_index_label_files(pdev);
310	else
311		pci_create_smbiosname_file(pdev);
312}
313
314void pci_remove_firmware_label_files(struct pci_dev *pdev)
315{
316	if (device_has_dsm(&pdev->dev))
317		pci_remove_acpi_index_label_files(pdev);
318	else
319		pci_remove_smbiosname_file(pdev);
320}

  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Export the firmware instance and label associated with a PCI device to
  4 * sysfs
  5 *
  6 * Copyright (C) 2010 Dell Inc.
  7 * by Narendra K <Narendra_K@dell.com>,
  8 * Jordan Hargrave <Jordan_Hargrave@dell.com>
  9 *
 10 * PCI Firmware Specification Revision 3.1 section 4.6.7 (DSM for Naming a
 11 * PCI or PCI Express Device Under Operating Systems) defines an instance
 12 * number and string name. This code retrieves them and exports them to sysfs.
 13 * If the system firmware does not provide the ACPI _DSM (Device Specific
 14 * Method), then the SMBIOS type 41 instance number and string is exported to
 15 * sysfs.
 16 *
 17 * SMBIOS defines type 41 for onboard pci devices. This code retrieves
 18 * the instance number and string from the type 41 record and exports
 19 * it to sysfs.
 20 *
 21 * Please see http://linux.dell.com/files/biosdevname/ for more
 22 * information.
 23 */
 24
 25#include <linux/dmi.h>
 26#include <linux/sysfs.h>
 27#include <linux/pci.h>
 28#include <linux/pci_ids.h>
 29#include <linux/module.h>
 30#include <linux/device.h>
 31#include <linux/nls.h>
 32#include <linux/acpi.h>
 33#include <linux/pci-acpi.h>
 34#include "pci.h"
 35
 
 
 36#ifdef CONFIG_DMI
 37enum smbios_attr_enum {
 38	SMBIOS_ATTR_NONE = 0,
 39	SMBIOS_ATTR_LABEL_SHOW,
 40	SMBIOS_ATTR_INSTANCE_SHOW,
 41};
 42
 43static size_t find_smbios_instance_string(struct pci_dev *pdev, char *buf,
 44					  enum smbios_attr_enum attribute)
 
 45{
 46	const struct dmi_device *dmi;
 47	struct dmi_dev_onboard *donboard;
 48	int domain_nr;
 49	int bus;
 50	int devfn;
 51
 52	domain_nr = pci_domain_nr(pdev->bus);
 53	bus = pdev->bus->number;
 54	devfn = pdev->devfn;
 55
 56	dmi = NULL;
 57	while ((dmi = dmi_find_device(DMI_DEV_TYPE_DEV_ONBOARD,
 58				      NULL, dmi)) != NULL) {
 59		donboard = dmi->device_data;
 60		if (donboard && donboard->segment == domain_nr &&
 61				donboard->bus == bus &&
 62				donboard->devfn == devfn) {
 63			if (buf) {
 64				if (attribute == SMBIOS_ATTR_INSTANCE_SHOW)
 65					return scnprintf(buf, PAGE_SIZE,
 66							 "%d\n",
 67							 donboard->instance);
 68				else if (attribute == SMBIOS_ATTR_LABEL_SHOW)
 69					return scnprintf(buf, PAGE_SIZE,
 70							 "%s\n",
 71							 dmi->name);
 72			}
 73			return strlen(dmi->name);
 74		}
 75	}
 76	return 0;
 77}
 78
 79static umode_t smbios_instance_string_exist(struct kobject *kobj,
 80					    struct attribute *attr, int n)
 
 81{
 82	struct device *dev;
 83	struct pci_dev *pdev;
 84
 85	dev = kobj_to_dev(kobj);
 86	pdev = to_pci_dev(dev);
 87
 88	return find_smbios_instance_string(pdev, NULL, SMBIOS_ATTR_NONE) ?
 89					   S_IRUGO : 0;
 90}
 91
 92static ssize_t smbioslabel_show(struct device *dev,
 93				struct device_attribute *attr, char *buf)
 94{
 95	struct pci_dev *pdev;
 96	pdev = to_pci_dev(dev);
 97
 98	return find_smbios_instance_string(pdev, buf,
 99					   SMBIOS_ATTR_LABEL_SHOW);
100}
101
102static ssize_t smbiosinstance_show(struct device *dev,
103				   struct device_attribute *attr, char *buf)
 
104{
105	struct pci_dev *pdev;
106	pdev = to_pci_dev(dev);
107
108	return find_smbios_instance_string(pdev, buf,
109					   SMBIOS_ATTR_INSTANCE_SHOW);
110}
111
112static struct device_attribute smbios_attr_label = {
113	.attr = {.name = "label", .mode = 0444},
114	.show = smbioslabel_show,
115};
116
117static struct device_attribute smbios_attr_instance = {
118	.attr = {.name = "index", .mode = 0444},
119	.show = smbiosinstance_show,
120};
121
122static struct attribute *smbios_attributes[] = {
123	&smbios_attr_label.attr,
124	&smbios_attr_instance.attr,
125	NULL,
126};
127
128static const struct attribute_group smbios_attr_group = {
129	.attrs = smbios_attributes,
130	.is_visible = smbios_instance_string_exist,
131};
132
133static int pci_create_smbiosname_file(struct pci_dev *pdev)
 
134{
135	return sysfs_create_group(&pdev->dev.kobj, &smbios_attr_group);
136}
137
138static void pci_remove_smbiosname_file(struct pci_dev *pdev)
 
139{
140	sysfs_remove_group(&pdev->dev.kobj, &smbios_attr_group);
141}
142#else
143static inline int pci_create_smbiosname_file(struct pci_dev *pdev)
 
144{
145	return -1;
146}
147
148static inline void pci_remove_smbiosname_file(struct pci_dev *pdev)
 
149{
150}
151#endif
152
153#ifdef CONFIG_ACPI
 
 
 
 
 
154enum acpi_attr_enum {
155	ACPI_ATTR_LABEL_SHOW,
156	ACPI_ATTR_INDEX_SHOW,
157};
158
159static void dsm_label_utf16s_to_utf8s(union acpi_object *obj, char *buf)
160{
161	int len;
162	len = utf16s_to_utf8s((const wchar_t *)obj->buffer.pointer,
163			      obj->buffer.length,
164			      UTF16_LITTLE_ENDIAN,
165			      buf, PAGE_SIZE);
166	buf[len] = '\n';
167}
168
169static int dsm_get_label(struct device *dev, char *buf,
170			 enum acpi_attr_enum attr)
171{
172	acpi_handle handle;
173	union acpi_object *obj, *tmp;
174	int len = -1;
175
176	handle = ACPI_HANDLE(dev);
177	if (!handle)
178		return -1;
179
180	obj = acpi_evaluate_dsm(handle, &pci_acpi_dsm_guid, 0x2,
181				DEVICE_LABEL_DSM, NULL);
182	if (!obj)
183		return -1;
184
185	tmp = obj->package.elements;
186	if (obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 2 &&
187	    tmp[0].type == ACPI_TYPE_INTEGER &&
188	    (tmp[1].type == ACPI_TYPE_STRING ||
189	     tmp[1].type == ACPI_TYPE_BUFFER)) {
190		/*
191		 * The second string element is optional even when
192		 * this _DSM is implemented; when not implemented,
193		 * this entry must return a null string.
194		 */
195		if (attr == ACPI_ATTR_INDEX_SHOW) {
196			scnprintf(buf, PAGE_SIZE, "%llu\n", tmp->integer.value);
197		} else if (attr == ACPI_ATTR_LABEL_SHOW) {
198			if (tmp[1].type == ACPI_TYPE_STRING)
199				scnprintf(buf, PAGE_SIZE, "%s\n",
200					  tmp[1].string.pointer);
201			else if (tmp[1].type == ACPI_TYPE_BUFFER)
202				dsm_label_utf16s_to_utf8s(tmp + 1, buf);
203		}
204		len = strlen(buf) > 0 ? strlen(buf) : -1;
205	}
206
207	ACPI_FREE(obj);
208
209	return len;
210}
211
212static bool device_has_dsm(struct device *dev)
 
213{
214	acpi_handle handle;
215
216	handle = ACPI_HANDLE(dev);
217	if (!handle)
218		return false;
219
220	return !!acpi_check_dsm(handle, &pci_acpi_dsm_guid, 0x2,
221				1 << DEVICE_LABEL_DSM);
222}
223
224static umode_t acpi_index_string_exist(struct kobject *kobj,
225				       struct attribute *attr, int n)
226{
227	struct device *dev;
228
229	dev = kobj_to_dev(kobj);
230
231	if (device_has_dsm(dev))
232		return S_IRUGO;
233
234	return 0;
235}
236
237static ssize_t acpilabel_show(struct device *dev,
238			      struct device_attribute *attr, char *buf)
239{
240	return dsm_get_label(dev, buf, ACPI_ATTR_LABEL_SHOW);
241}
242
243static ssize_t acpiindex_show(struct device *dev,
244			      struct device_attribute *attr, char *buf)
245{
246	return dsm_get_label(dev, buf, ACPI_ATTR_INDEX_SHOW);
247}
248
249static struct device_attribute acpi_attr_label = {
250	.attr = {.name = "label", .mode = 0444},
251	.show = acpilabel_show,
252};
253
254static struct device_attribute acpi_attr_index = {
255	.attr = {.name = "acpi_index", .mode = 0444},
256	.show = acpiindex_show,
257};
258
259static struct attribute *acpi_attributes[] = {
260	&acpi_attr_label.attr,
261	&acpi_attr_index.attr,
262	NULL,
263};
264
265static const struct attribute_group acpi_attr_group = {
266	.attrs = acpi_attributes,
267	.is_visible = acpi_index_string_exist,
268};
269
270static int pci_create_acpi_index_label_files(struct pci_dev *pdev)
 
271{
272	return sysfs_create_group(&pdev->dev.kobj, &acpi_attr_group);
273}
274
275static int pci_remove_acpi_index_label_files(struct pci_dev *pdev)
 
276{
277	sysfs_remove_group(&pdev->dev.kobj, &acpi_attr_group);
278	return 0;
279}
280#else
281static inline int pci_create_acpi_index_label_files(struct pci_dev *pdev)
 
282{
283	return -1;
284}
285
286static inline int pci_remove_acpi_index_label_files(struct pci_dev *pdev)
 
287{
288	return -1;
289}
290
291static inline bool device_has_dsm(struct device *dev)
 
292{
293	return false;
294}
295#endif
296
297void pci_create_firmware_label_files(struct pci_dev *pdev)
298{
299	if (device_has_dsm(&pdev->dev))
300		pci_create_acpi_index_label_files(pdev);
301	else
302		pci_create_smbiosname_file(pdev);
303}
304
305void pci_remove_firmware_label_files(struct pci_dev *pdev)
306{
307	if (device_has_dsm(&pdev->dev))
308		pci_remove_acpi_index_label_files(pdev);
309	else
310		pci_remove_smbiosname_file(pdev);
311}