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" : "\n");
49 }
50 static DEVICE_ATTR_RO(mio_enabled);
51
52 static int _do_recover(struct pci_dev *pdev, struct zpci_dev *zdev)
53 {
54 u8 status;
55 int ret;
56
57 pci_stop_and_remove_bus_device(pdev);
58 if (zdev_enabled(zdev)) {
59 ret = zpci_disable_device(zdev);
60 /*
61 * Due to a z/VM vs LPAR inconsistency in the error
62 * state the FH may indicate an enabled device but
63 * disable says the device is already disabled don't
64 * treat it as an error here.
65 */
66 if (ret == -EINVAL)
67 ret = 0;
68 if (ret)
69 return ret;
70 }
71
72 ret = zpci_enable_device(zdev);
73 if (ret)
74 return ret;
75
76 if (zdev->dma_table) {
77 ret = zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma,
78 virt_to_phys(zdev->dma_table), &status);
79 if (ret)
80 zpci_disable_device(zdev);
81 }
82 return ret;
83 }
84
85 static ssize_t recover_store(struct device *dev, struct device_attribute *attr,
86 const char *buf, size_t count)
87 {
88 struct kernfs_node *kn;
89 struct pci_dev *pdev = to_pci_dev(dev);
90 struct zpci_dev *zdev = to_zpci(pdev);
91 int ret = 0;
92
93 /* Can't use device_remove_self() here as that would lead us to lock
94 * the pci_rescan_remove_lock while holding the device' kernfs lock.
95 * This would create a possible deadlock with disable_slot() which is
96 * not directly protected by the device' kernfs lock but takes it
97 * during the device removal which happens under
98 * pci_rescan_remove_lock.
99 *
100 * This is analogous to sdev_store_delete() in
101 * drivers/scsi/scsi_sysfs.c
102 */
103 kn = sysfs_break_active_protection(&dev->kobj, &attr->attr);
104 WARN_ON_ONCE(!kn);
105
106 /* Device needs to be configured and state must not change */
107 mutex_lock(&zdev->state_lock);
108 if (zdev->state != ZPCI_FN_STATE_CONFIGURED)
109 goto out;
110
111 /* device_remove_file() serializes concurrent calls ignoring all but
112 * the first
113 */
114 device_remove_file(dev, attr);
115
116 /* A concurrent call to recover_store() may slip between
117 * sysfs_break_active_protection() and the sysfs file removal.
118 * Once it unblocks from pci_lock_rescan_remove() the original pdev
119 * will already be removed.
120 */
121 pci_lock_rescan_remove();
122 if (pci_dev_is_added(pdev)) {
123 ret = _do_recover(pdev, zdev);
124 }
125 pci_rescan_bus(zdev->zbus->bus);
126 pci_unlock_rescan_remove();
127
128 out:
129 mutex_unlock(&zdev->state_lock);
130 if (kn)
131 sysfs_unbreak_active_protection(kn);
132 return ret ? ret : count;
133 }
134 static DEVICE_ATTR_WO(recover);
135
136 static ssize_t util_string_read(struct file *filp, struct kobject *kobj,
137 struct bin_attribute *attr, char *buf,
138 loff_t off, size_t count)
139 {
140 struct device *dev = kobj_to_dev(kobj);
141 struct pci_dev *pdev = to_pci_dev(dev);
142 struct zpci_dev *zdev = to_zpci(pdev);
143
144 return memory_read_from_buffer(buf, count, &off, zdev->util_str,
145 sizeof(zdev->util_str));
146 }
147 static BIN_ATTR_RO(util_string, CLP_UTIL_STR_LEN);
148
149 static ssize_t report_error_write(struct file *filp, struct kobject *kobj,
150 struct bin_attribute *attr, char *buf,
151 loff_t off, size_t count)
152 {
153 struct zpci_report_error_header *report = (void *) buf;
154 struct device *dev = kobj_to_dev(kobj);
155 struct pci_dev *pdev = to_pci_dev(dev);
156 struct zpci_dev *zdev = to_zpci(pdev);
157 int ret;
158
159 if (off || (count < sizeof(*report)))
160 return -EINVAL;
161
162 ret = sclp_pci_report(report, zdev->fh, zdev->fid);
163
164 return ret ? ret : count;
165 }
166 static BIN_ATTR(report_error, S_IWUSR, NULL, report_error_write, PAGE_SIZE);
167
168 static ssize_t uid_is_unique_show(struct device *dev,
169 struct device_attribute *attr, char *buf)
170 {
171 return sysfs_emit(buf, "%d\n", zpci_unique_uid ? 1 : 0);
172 }
173 static DEVICE_ATTR_RO(uid_is_unique);
174
175 /* analogous to smbios index */
176 static ssize_t index_show(struct device *dev,
177 struct device_attribute *attr, char *buf)
178 {
179 struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
180 u32 index = ~0;
181
182 if (zpci_unique_uid)
183 index = zdev->uid;
184
185 return sysfs_emit(buf, "%u\n", index);
186 }
187 static DEVICE_ATTR_RO(index);
188
189 static umode_t zpci_index_is_visible(struct kobject *kobj,
190 struct attribute *attr, int n)
191 {
192 return zpci_unique_uid ? attr->mode : 0;
193 }
194
195 static struct attribute *zpci_ident_attrs[] = {
196 &dev_attr_index.attr,
197 NULL,
198 };
199
200 static struct attribute_group zpci_ident_attr_group = {
201 .attrs = zpci_ident_attrs,
202 .is_visible = zpci_index_is_visible,
203 };
204
205 static struct bin_attribute *zpci_bin_attrs[] = {
206 &bin_attr_util_string,
207 &bin_attr_report_error,
208 NULL,
209 };
210
211 static struct attribute *zpci_dev_attrs[] = {
212 &dev_attr_function_id.attr,
213 &dev_attr_function_handle.attr,
214 &dev_attr_pchid.attr,
215 &dev_attr_pfgid.attr,
216 &dev_attr_pft.attr,
217 &dev_attr_port.attr,
218 &dev_attr_vfn.attr,
219 &dev_attr_uid.attr,
220 &dev_attr_recover.attr,
221 &dev_attr_mio_enabled.attr,
222 &dev_attr_uid_is_unique.attr,
223 NULL,
224 };
225
226 static struct attribute_group zpci_attr_group = {
227 .attrs = zpci_dev_attrs,
228 .bin_attrs = zpci_bin_attrs,
229 };
230
231 static struct attribute *pfip_attrs[] = {
232 &dev_attr_segment0.attr,
233 &dev_attr_segment1.attr,
234 &dev_attr_segment2.attr,
235 &dev_attr_segment3.attr,
236 NULL,
237 };
238 static struct attribute_group pfip_attr_group = {
239 .name = "pfip",
240 .attrs = pfip_attrs,
241 };
242
243 const struct attribute_group *zpci_attr_groups[] = {
244 &zpci_attr_group,
245 &pfip_attr_group,
246 &zpci_ident_attr_group,
247 NULL,
248 };
249
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