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		ret = zpci_disable_device(zdev);
86		if (ret)
87			goto out;
88
89		ret = zpci_enable_device(zdev);
90		if (ret)
91			goto out;
92		pci_rescan_bus(zdev->zbus->bus);
93	}
94out:
95	pci_unlock_rescan_remove();
96	if (kn)
97		sysfs_unbreak_active_protection(kn);
98	return ret ? ret : count;
99}
100static DEVICE_ATTR_WO(recover);
101
102static ssize_t util_string_read(struct file *filp, struct kobject *kobj,
103				struct bin_attribute *attr, char *buf,
104				loff_t off, size_t count)
105{
106	struct device *dev = kobj_to_dev(kobj);
107	struct pci_dev *pdev = to_pci_dev(dev);
108	struct zpci_dev *zdev = to_zpci(pdev);
109
110	return memory_read_from_buffer(buf, count, &off, zdev->util_str,
111				       sizeof(zdev->util_str));
112}
113static BIN_ATTR_RO(util_string, CLP_UTIL_STR_LEN);
114
115static ssize_t report_error_write(struct file *filp, struct kobject *kobj,
116				  struct bin_attribute *attr, char *buf,
117				  loff_t off, size_t count)
118{
119	struct zpci_report_error_header *report = (void *) buf;
120	struct device *dev = kobj_to_dev(kobj);
121	struct pci_dev *pdev = to_pci_dev(dev);
122	struct zpci_dev *zdev = to_zpci(pdev);
123	int ret;
124
125	if (off || (count < sizeof(*report)))
126		return -EINVAL;
127
128	ret = sclp_pci_report(report, zdev->fh, zdev->fid);
129
130	return ret ? ret : count;
131}
132static BIN_ATTR(report_error, S_IWUSR, NULL, report_error_write, PAGE_SIZE);
133
134static struct bin_attribute *zpci_bin_attrs[] = {
135	&bin_attr_util_string,
136	&bin_attr_report_error,
137	NULL,
138};
139
140static struct attribute *zpci_dev_attrs[] = {
141	&dev_attr_function_id.attr,
142	&dev_attr_function_handle.attr,
143	&dev_attr_pchid.attr,
144	&dev_attr_pfgid.attr,
145	&dev_attr_pft.attr,
146	&dev_attr_port.attr,
147	&dev_attr_vfn.attr,
148	&dev_attr_uid.attr,
149	&dev_attr_recover.attr,
150	&dev_attr_mio_enabled.attr,
151	NULL,
152};
153static struct attribute_group zpci_attr_group = {
154	.attrs = zpci_dev_attrs,
155	.bin_attrs = zpci_bin_attrs,
156};
157
158static struct attribute *pfip_attrs[] = {
159	&dev_attr_segment0.attr,
160	&dev_attr_segment1.attr,
161	&dev_attr_segment2.attr,
162	&dev_attr_segment3.attr,
163	NULL,
164};
165static struct attribute_group pfip_attr_group = {
166	.name = "pfip",
167	.attrs = pfip_attrs,
168};
169
170const struct attribute_group *zpci_attr_groups[] = {
171	&zpci_attr_group,
172	&pfip_attr_group,
173	NULL,
174};
175