pci_sysfs.c

  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 pr_fmt(fmt) "zpci: " fmt
 10
 11#include <linux/kernel.h>
 12#include <linux/stat.h>
 13#include <linux/pci.h>
 14
 15#include "../../../drivers/pci/pci.h"
 16
 17#include <asm/sclp.h>
 18
 19#define zpci_attr(name, fmt, member)					\
 20static ssize_t name##_show(struct device *dev,				\
 21			   struct device_attribute *attr, char *buf)	\
 22{									\
 23	struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));		\
 24									\
 25	return sysfs_emit(buf, fmt, zdev->member);				\
 26}									\
 27static DEVICE_ATTR_RO(name)
 28
 29zpci_attr(function_id, "0x%08x\n", fid);
 30zpci_attr(function_handle, "0x%08x\n", fh);
 31zpci_attr(pchid, "0x%04x\n", pchid);
 32zpci_attr(pfgid, "0x%02x\n", pfgid);
 33zpci_attr(vfn, "0x%04x\n", vfn);
 34zpci_attr(pft, "0x%02x\n", pft);
 35zpci_attr(port, "%d\n", port);
 36zpci_attr(fidparm, "0x%02x\n", fidparm);
 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
 43#define ZPCI_FW_ATTR_RO(_name)						\
 44	static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
 45
 46static ssize_t mio_enabled_show(struct device *dev,
 47				struct device_attribute *attr, char *buf)
 48{
 49	struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
 50
 51	return sysfs_emit(buf, zpci_use_mio(zdev) ? "1\n" : "0\n");
 52}
 53static DEVICE_ATTR_RO(mio_enabled);
 54
 55static int _do_recover(struct pci_dev *pdev, struct zpci_dev *zdev)
 56{
 57	int ret;
 58
 59	pci_stop_and_remove_bus_device(pdev);
 60	if (zdev_enabled(zdev)) {
 61		ret = zpci_disable_device(zdev);
 62		/*
 63		 * Due to a z/VM vs LPAR inconsistency in the error
 64		 * state the FH may indicate an enabled device but
 65		 * disable says the device is already disabled don't
 66		 * treat it as an error here.
 67		 */
 68		if (ret == -EINVAL)
 69			ret = 0;
 70		if (ret)
 71			return ret;
 72	}
 73
 74	ret = zpci_reenable_device(zdev);
 75
 76	return ret;
 77}
 78
 79static ssize_t recover_store(struct device *dev, struct device_attribute *attr,
 80			     const char *buf, size_t count)
 81{
 82	struct kernfs_node *kn;
 83	struct pci_dev *pdev = to_pci_dev(dev);
 84	struct zpci_dev *zdev = to_zpci(pdev);
 85	int ret = 0;
 86
 87	/* Can't use device_remove_self() here as that would lead us to lock
 88	 * the pci_rescan_remove_lock while holding the device' kernfs lock.
 89	 * This would create a possible deadlock with disable_slot() which is
 90	 * not directly protected by the device' kernfs lock but takes it
 91	 * during the device removal which happens under
 92	 * pci_rescan_remove_lock.
 93	 *
 94	 * This is analogous to sdev_store_delete() in
 95	 * drivers/scsi/scsi_sysfs.c
 96	 */
 97	kn = sysfs_break_active_protection(&dev->kobj, &attr->attr);
 98	WARN_ON_ONCE(!kn);
 99
100	/* Device needs to be configured and state must not change */
101	mutex_lock(&zdev->state_lock);
102	if (zdev->state != ZPCI_FN_STATE_CONFIGURED)
103		goto out;
104
105	/* device_remove_file() serializes concurrent calls ignoring all but
106	 * the first
107	 */
108	device_remove_file(dev, attr);
109
110	/* A concurrent call to recover_store() may slip between
111	 * sysfs_break_active_protection() and the sysfs file removal.
112	 * Once it unblocks from pci_lock_rescan_remove() the original pdev
113	 * will already be removed.
114	 */
115	pci_lock_rescan_remove();
116	if (pci_dev_is_added(pdev)) {
117		ret = _do_recover(pdev, zdev);
118	}
119	pci_rescan_bus(zdev->zbus->bus);
120	pci_unlock_rescan_remove();
121
122out:
123	mutex_unlock(&zdev->state_lock);
124	if (kn)
125		sysfs_unbreak_active_protection(kn);
126	return ret ? ret : count;
127}
128static DEVICE_ATTR_WO(recover);
129
130static ssize_t util_string_read(struct file *filp, struct kobject *kobj,
131				const struct bin_attribute *attr, char *buf,
132				loff_t off, size_t count)
133{
134	struct device *dev = kobj_to_dev(kobj);
135	struct pci_dev *pdev = to_pci_dev(dev);
136	struct zpci_dev *zdev = to_zpci(pdev);
137
138	return memory_read_from_buffer(buf, count, &off, zdev->util_str,
139				       sizeof(zdev->util_str));
140}
141static const BIN_ATTR_RO(util_string, CLP_UTIL_STR_LEN);
142
143static ssize_t report_error_write(struct file *filp, struct kobject *kobj,
144				  const struct bin_attribute *attr, char *buf,
145				  loff_t off, size_t count)
146{
147	struct zpci_report_error_header *report = (void *) buf;
148	struct device *dev = kobj_to_dev(kobj);
149	struct pci_dev *pdev = to_pci_dev(dev);
150	struct zpci_dev *zdev = to_zpci(pdev);
151	int ret;
152
153	if (off || (count < sizeof(*report)))
154		return -EINVAL;
155
156	ret = sclp_pci_report(report, zdev->fh, zdev->fid);
157
158	return ret ? ret : count;
159}
160static const BIN_ATTR(report_error, S_IWUSR, NULL, report_error_write, PAGE_SIZE);
161
162static ssize_t uid_is_unique_show(struct device *dev,
163				  struct device_attribute *attr, char *buf)
164{
165	return sysfs_emit(buf, "%d\n", zpci_unique_uid ? 1 : 0);
166}
167static DEVICE_ATTR_RO(uid_is_unique);
168
169static ssize_t uid_checking_show(struct kobject *kobj,
170				 struct kobj_attribute *attr, char *buf)
171{
172	return sysfs_emit(buf, "%d\n", zpci_unique_uid ? 1 : 0);
173}
174ZPCI_FW_ATTR_RO(uid_checking);
175
176/* analogous to smbios index */
177static ssize_t index_show(struct device *dev,
178			  struct device_attribute *attr, char *buf)
179{
180	struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
181	u32 index = ~0;
182
183	if (zpci_unique_uid)
184		index = zdev->uid;
185
186	return sysfs_emit(buf, "%u\n", index);
187}
188static DEVICE_ATTR_RO(index);
189
190static umode_t zpci_index_is_visible(struct kobject *kobj,
191				     struct attribute *attr, int n)
192{
193	return zpci_unique_uid ? attr->mode : 0;
194}
195
196static struct attribute *zpci_ident_attrs[] = {
197	&dev_attr_index.attr,
198	NULL,
199};
200
201const struct attribute_group zpci_ident_attr_group = {
202	.attrs = zpci_ident_attrs,
203	.is_visible = zpci_index_is_visible,
204};
205
206static const struct bin_attribute *const zpci_bin_attrs[] = {
207	&bin_attr_util_string,
208	&bin_attr_report_error,
209	NULL,
210};
211
212static struct attribute *zpci_dev_attrs[] = {
213	&dev_attr_function_id.attr,
214	&dev_attr_function_handle.attr,
215	&dev_attr_pchid.attr,
216	&dev_attr_pfgid.attr,
217	&dev_attr_pft.attr,
218	&dev_attr_port.attr,
219	&dev_attr_fidparm.attr,
220	&dev_attr_vfn.attr,
221	&dev_attr_uid.attr,
222	&dev_attr_recover.attr,
223	&dev_attr_mio_enabled.attr,
224	&dev_attr_uid_is_unique.attr,
225	NULL,
226};
227
228const struct attribute_group zpci_attr_group = {
229	.attrs = zpci_dev_attrs,
230	.bin_attrs = zpci_bin_attrs,
231};
232
233static struct attribute *pfip_attrs[] = {
234	&dev_attr_segment0.attr,
235	&dev_attr_segment1.attr,
236	&dev_attr_segment2.attr,
237	&dev_attr_segment3.attr,
238	NULL,
239};
240
241const struct attribute_group pfip_attr_group = {
242	.name = "pfip",
243	.attrs = pfip_attrs,
244};
245
246static struct attribute *clp_fw_attrs[] = {
247	&uid_checking_attr.attr,
248	NULL,
249};
250
251static struct attribute_group clp_fw_attr_group = {
252	.name = "clp",
253	.attrs = clp_fw_attrs,
254};
255
256int __init __zpci_fw_sysfs_init(void)
257{
258	return sysfs_create_group(firmware_kobj, &clp_fw_attr_group);
259}