xref: /kernel/linux/linux-6.6/arch/s390/pci/pci_sysfs.c (revision 62306a36)
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright IBM Corp. 2012
4 *
5 * Author(s):
6 *   Jan Glauber <jang@linux.vnet.ibm.com>
7 */
8
9#define KMSG_COMPONENT "zpci"
10#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
11
12#include <linux/kernel.h>
13#include <linux/stat.h>
14#include <linux/pci.h>
15
16#include "../../../drivers/pci/pci.h"
17
18#include <asm/sclp.h>
19
20#define zpci_attr(name, fmt, member)					\
21static ssize_t name##_show(struct device *dev,				\
22			   struct device_attribute *attr, char *buf)	\
23{									\
24	struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));		\
25									\
26	return sprintf(buf, fmt, zdev->member);				\
27}									\
28static DEVICE_ATTR_RO(name)
29
30zpci_attr(function_id, "0x%08x\n", fid);
31zpci_attr(function_handle, "0x%08x\n", fh);
32zpci_attr(pchid, "0x%04x\n", pchid);
33zpci_attr(pfgid, "0x%02x\n", pfgid);
34zpci_attr(vfn, "0x%04x\n", vfn);
35zpci_attr(pft, "0x%02x\n", pft);
36zpci_attr(port, "%d\n", port);
37zpci_attr(uid, "0x%x\n", uid);
38zpci_attr(segment0, "0x%02x\n", pfip[0]);
39zpci_attr(segment1, "0x%02x\n", pfip[1]);
40zpci_attr(segment2, "0x%02x\n", pfip[2]);
41zpci_attr(segment3, "0x%02x\n", pfip[3]);
42
43static ssize_t mio_enabled_show(struct device *dev,
44				struct device_attribute *attr, char *buf)
45{
46	struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
47
48	return sprintf(buf, zpci_use_mio(zdev) ? "1\n" : "0\n");
49}
50static DEVICE_ATTR_RO(mio_enabled);
51
52static ssize_t recover_store(struct device *dev, struct device_attribute *attr,
53			     const char *buf, size_t count)
54{
55	struct kernfs_node *kn;
56	struct pci_dev *pdev = to_pci_dev(dev);
57	struct zpci_dev *zdev = to_zpci(pdev);
58	int ret = 0;
59
60	/* Can't use device_remove_self() here as that would lead us to lock
61	 * the pci_rescan_remove_lock while holding the device' kernfs lock.
62	 * This would create a possible deadlock with disable_slot() which is
63	 * not directly protected by the device' kernfs lock but takes it
64	 * during the device removal which happens under
65	 * pci_rescan_remove_lock.
66	 *
67	 * This is analogous to sdev_store_delete() in
68	 * drivers/scsi/scsi_sysfs.c
69	 */
70	kn = sysfs_break_active_protection(&dev->kobj, &attr->attr);
71	WARN_ON_ONCE(!kn);
72	/* device_remove_file() serializes concurrent calls ignoring all but
73	 * the first
74	 */
75	device_remove_file(dev, attr);
76
77	/* A concurrent call to recover_store() may slip between
78	 * sysfs_break_active_protection() and the sysfs file removal.
79	 * Once it unblocks from pci_lock_rescan_remove() the original pdev
80	 * will already be removed.
81	 */
82	pci_lock_rescan_remove();
83	if (pci_dev_is_added(pdev)) {
84		pci_stop_and_remove_bus_device(pdev);
85		if (zdev->dma_table) {
86			ret = zpci_dma_exit_device(zdev);
87			if (ret)
88				goto out;
89		}
90
91		if (zdev_enabled(zdev)) {
92			ret = zpci_disable_device(zdev);
93			/*
94			 * Due to a z/VM vs LPAR inconsistency in the error
95			 * state the FH may indicate an enabled device but
96			 * disable says the device is already disabled don't
97			 * treat it as an error here.
98			 */
99			if (ret == -EINVAL)
100				ret = 0;
101			if (ret)
102				goto out;
103		}
104
105		ret = zpci_enable_device(zdev);
106		if (ret)
107			goto out;
108		ret = zpci_dma_init_device(zdev);
109		if (ret) {
110			zpci_disable_device(zdev);
111			goto out;
112		}
113		pci_rescan_bus(zdev->zbus->bus);
114	}
115out:
116	pci_unlock_rescan_remove();
117	if (kn)
118		sysfs_unbreak_active_protection(kn);
119	return ret ? ret : count;
120}
121static DEVICE_ATTR_WO(recover);
122
123static ssize_t util_string_read(struct file *filp, struct kobject *kobj,
124				struct bin_attribute *attr, char *buf,
125				loff_t off, size_t count)
126{
127	struct device *dev = kobj_to_dev(kobj);
128	struct pci_dev *pdev = to_pci_dev(dev);
129	struct zpci_dev *zdev = to_zpci(pdev);
130
131	return memory_read_from_buffer(buf, count, &off, zdev->util_str,
132				       sizeof(zdev->util_str));
133}
134static BIN_ATTR_RO(util_string, CLP_UTIL_STR_LEN);
135
136static ssize_t report_error_write(struct file *filp, struct kobject *kobj,
137				  struct bin_attribute *attr, char *buf,
138				  loff_t off, size_t count)
139{
140	struct zpci_report_error_header *report = (void *) buf;
141	struct device *dev = kobj_to_dev(kobj);
142	struct pci_dev *pdev = to_pci_dev(dev);
143	struct zpci_dev *zdev = to_zpci(pdev);
144	int ret;
145
146	if (off || (count < sizeof(*report)))
147		return -EINVAL;
148
149	ret = sclp_pci_report(report, zdev->fh, zdev->fid);
150
151	return ret ? ret : count;
152}
153static BIN_ATTR(report_error, S_IWUSR, NULL, report_error_write, PAGE_SIZE);
154
155static ssize_t uid_is_unique_show(struct device *dev,
156				  struct device_attribute *attr, char *buf)
157{
158	return sysfs_emit(buf, "%d\n", zpci_unique_uid ? 1 : 0);
159}
160static DEVICE_ATTR_RO(uid_is_unique);
161
162#ifndef CONFIG_DMI
163/* analogous to smbios index */
164static ssize_t index_show(struct device *dev,
165			  struct device_attribute *attr, char *buf)
166{
167	struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
168	u32 index = ~0;
169
170	if (zpci_unique_uid)
171		index = zdev->uid;
172
173	return sysfs_emit(buf, "%u\n", index);
174}
175static DEVICE_ATTR_RO(index);
176
177static umode_t zpci_index_is_visible(struct kobject *kobj,
178				     struct attribute *attr, int n)
179{
180	return zpci_unique_uid ? attr->mode : 0;
181}
182
183static struct attribute *zpci_ident_attrs[] = {
184	&dev_attr_index.attr,
185	NULL,
186};
187
188static struct attribute_group zpci_ident_attr_group = {
189	.attrs = zpci_ident_attrs,
190	.is_visible = zpci_index_is_visible,
191};
192#endif
193
194static struct bin_attribute *zpci_bin_attrs[] = {
195	&bin_attr_util_string,
196	&bin_attr_report_error,
197	NULL,
198};
199
200static struct attribute *zpci_dev_attrs[] = {
201	&dev_attr_function_id.attr,
202	&dev_attr_function_handle.attr,
203	&dev_attr_pchid.attr,
204	&dev_attr_pfgid.attr,
205	&dev_attr_pft.attr,
206	&dev_attr_port.attr,
207	&dev_attr_vfn.attr,
208	&dev_attr_uid.attr,
209	&dev_attr_recover.attr,
210	&dev_attr_mio_enabled.attr,
211	&dev_attr_uid_is_unique.attr,
212	NULL,
213};
214
215static struct attribute_group zpci_attr_group = {
216	.attrs = zpci_dev_attrs,
217	.bin_attrs = zpci_bin_attrs,
218};
219
220static struct attribute *pfip_attrs[] = {
221	&dev_attr_segment0.attr,
222	&dev_attr_segment1.attr,
223	&dev_attr_segment2.attr,
224	&dev_attr_segment3.attr,
225	NULL,
226};
227static struct attribute_group pfip_attr_group = {
228	.name = "pfip",
229	.attrs = pfip_attrs,
230};
231
232const struct attribute_group *zpci_attr_groups[] = {
233	&zpci_attr_group,
234	&pfip_attr_group,
235#ifndef CONFIG_DMI
236	&zpci_ident_attr_group,
237#endif
238	NULL,
239};
240