xref: /linux/arch/s390/pci/pci_sysfs.c (revision e7d759f31ca295d589f7420719c311870bb3166f)
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)					\
21 static 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 }									\
28 static DEVICE_ATTR_RO(name)
29 
30 zpci_attr(function_id, "0x%08x\n", fid);
31 zpci_attr(function_handle, "0x%08x\n", fh);
32 zpci_attr(pchid, "0x%04x\n", pchid);
33 zpci_attr(pfgid, "0x%02x\n", pfgid);
34 zpci_attr(vfn, "0x%04x\n", vfn);
35 zpci_attr(pft, "0x%02x\n", pft);
36 zpci_attr(port, "%d\n", port);
37 zpci_attr(uid, "0x%x\n", uid);
38 zpci_attr(segment0, "0x%02x\n", pfip[0]);
39 zpci_attr(segment1, "0x%02x\n", pfip[1]);
40 zpci_attr(segment2, "0x%02x\n", pfip[2]);
41 zpci_attr(segment3, "0x%02x\n", pfip[3]);
42 
43 static 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 }
50 static DEVICE_ATTR_RO(mio_enabled);
51 
52 static 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 	u8 status;
60 
61 	/* Can't use device_remove_self() here as that would lead us to lock
62 	 * the pci_rescan_remove_lock while holding the device' kernfs lock.
63 	 * This would create a possible deadlock with disable_slot() which is
64 	 * not directly protected by the device' kernfs lock but takes it
65 	 * during the device removal which happens under
66 	 * pci_rescan_remove_lock.
67 	 *
68 	 * This is analogous to sdev_store_delete() in
69 	 * drivers/scsi/scsi_sysfs.c
70 	 */
71 	kn = sysfs_break_active_protection(&dev->kobj, &attr->attr);
72 	WARN_ON_ONCE(!kn);
73 	/* device_remove_file() serializes concurrent calls ignoring all but
74 	 * the first
75 	 */
76 	device_remove_file(dev, attr);
77 
78 	/* A concurrent call to recover_store() may slip between
79 	 * sysfs_break_active_protection() and the sysfs file removal.
80 	 * Once it unblocks from pci_lock_rescan_remove() the original pdev
81 	 * will already be removed.
82 	 */
83 	pci_lock_rescan_remove();
84 	if (pci_dev_is_added(pdev)) {
85 		pci_stop_and_remove_bus_device(pdev);
86 		if (zdev_enabled(zdev)) {
87 			ret = zpci_disable_device(zdev);
88 			/*
89 			 * Due to a z/VM vs LPAR inconsistency in the error
90 			 * state the FH may indicate an enabled device but
91 			 * disable says the device is already disabled don't
92 			 * treat it as an error here.
93 			 */
94 			if (ret == -EINVAL)
95 				ret = 0;
96 			if (ret)
97 				goto out;
98 		}
99 
100 		ret = zpci_enable_device(zdev);
101 		if (ret)
102 			goto out;
103 
104 		if (zdev->dma_table) {
105 			ret = zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma,
106 						 virt_to_phys(zdev->dma_table), &status);
107 			if (ret)
108 				zpci_disable_device(zdev);
109 		}
110 	}
111 out:
112 	pci_rescan_bus(zdev->zbus->bus);
113 	pci_unlock_rescan_remove();
114 	if (kn)
115 		sysfs_unbreak_active_protection(kn);
116 	return ret ? ret : count;
117 }
118 static DEVICE_ATTR_WO(recover);
119 
120 static ssize_t util_string_read(struct file *filp, struct kobject *kobj,
121 				struct bin_attribute *attr, char *buf,
122 				loff_t off, size_t count)
123 {
124 	struct device *dev = kobj_to_dev(kobj);
125 	struct pci_dev *pdev = to_pci_dev(dev);
126 	struct zpci_dev *zdev = to_zpci(pdev);
127 
128 	return memory_read_from_buffer(buf, count, &off, zdev->util_str,
129 				       sizeof(zdev->util_str));
130 }
131 static BIN_ATTR_RO(util_string, CLP_UTIL_STR_LEN);
132 
133 static ssize_t report_error_write(struct file *filp, struct kobject *kobj,
134 				  struct bin_attribute *attr, char *buf,
135 				  loff_t off, size_t count)
136 {
137 	struct zpci_report_error_header *report = (void *) buf;
138 	struct device *dev = kobj_to_dev(kobj);
139 	struct pci_dev *pdev = to_pci_dev(dev);
140 	struct zpci_dev *zdev = to_zpci(pdev);
141 	int ret;
142 
143 	if (off || (count < sizeof(*report)))
144 		return -EINVAL;
145 
146 	ret = sclp_pci_report(report, zdev->fh, zdev->fid);
147 
148 	return ret ? ret : count;
149 }
150 static BIN_ATTR(report_error, S_IWUSR, NULL, report_error_write, PAGE_SIZE);
151 
152 static ssize_t uid_is_unique_show(struct device *dev,
153 				  struct device_attribute *attr, char *buf)
154 {
155 	return sysfs_emit(buf, "%d\n", zpci_unique_uid ? 1 : 0);
156 }
157 static DEVICE_ATTR_RO(uid_is_unique);
158 
159 #ifndef CONFIG_DMI
160 /* analogous to smbios index */
161 static ssize_t index_show(struct device *dev,
162 			  struct device_attribute *attr, char *buf)
163 {
164 	struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
165 	u32 index = ~0;
166 
167 	if (zpci_unique_uid)
168 		index = zdev->uid;
169 
170 	return sysfs_emit(buf, "%u\n", index);
171 }
172 static DEVICE_ATTR_RO(index);
173 
174 static umode_t zpci_index_is_visible(struct kobject *kobj,
175 				     struct attribute *attr, int n)
176 {
177 	return zpci_unique_uid ? attr->mode : 0;
178 }
179 
180 static struct attribute *zpci_ident_attrs[] = {
181 	&dev_attr_index.attr,
182 	NULL,
183 };
184 
185 static struct attribute_group zpci_ident_attr_group = {
186 	.attrs = zpci_ident_attrs,
187 	.is_visible = zpci_index_is_visible,
188 };
189 #endif
190 
191 static struct bin_attribute *zpci_bin_attrs[] = {
192 	&bin_attr_util_string,
193 	&bin_attr_report_error,
194 	NULL,
195 };
196 
197 static struct attribute *zpci_dev_attrs[] = {
198 	&dev_attr_function_id.attr,
199 	&dev_attr_function_handle.attr,
200 	&dev_attr_pchid.attr,
201 	&dev_attr_pfgid.attr,
202 	&dev_attr_pft.attr,
203 	&dev_attr_port.attr,
204 	&dev_attr_vfn.attr,
205 	&dev_attr_uid.attr,
206 	&dev_attr_recover.attr,
207 	&dev_attr_mio_enabled.attr,
208 	&dev_attr_uid_is_unique.attr,
209 	NULL,
210 };
211 
212 static struct attribute_group zpci_attr_group = {
213 	.attrs = zpci_dev_attrs,
214 	.bin_attrs = zpci_bin_attrs,
215 };
216 
217 static struct attribute *pfip_attrs[] = {
218 	&dev_attr_segment0.attr,
219 	&dev_attr_segment1.attr,
220 	&dev_attr_segment2.attr,
221 	&dev_attr_segment3.attr,
222 	NULL,
223 };
224 static struct attribute_group pfip_attr_group = {
225 	.name = "pfip",
226 	.attrs = pfip_attrs,
227 };
228 
229 const struct attribute_group *zpci_attr_groups[] = {
230 	&zpci_attr_group,
231 	&pfip_attr_group,
232 #ifndef CONFIG_DMI
233 	&zpci_ident_attr_group,
234 #endif
235 	NULL,
236 };
237