arch/s390/pci/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 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
  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                         if (ret)
  94                                 goto out;
  95                 }
  96
  97                 ret = zpci_enable_device(zdev);
  98                 if (ret)
  99                         goto out;
 100                 ret = zpci_dma_init_device(zdev);
 101                 if (ret) {
 102                         zpci_disable_device(zdev);
 103                         goto out;
 104                 }
 105                 pci_rescan_bus(zdev->zbus->bus);
 106         }
 107 out:
 108         pci_unlock_rescan_remove();
 109         if (kn)
 110                 sysfs_unbreak_active_protection(kn);
 111         return ret ? ret : count;
 112 }
 113 static DEVICE_ATTR_WO(recover);
 114
 115 static ssize_t util_string_read(struct file *filp, struct kobject *kobj,
 116                                 struct bin_attribute *attr, char *buf,
 117                                 loff_t off, size_t count)
 118 {
 119         struct device *dev = kobj_to_dev(kobj);
 120         struct pci_dev *pdev = to_pci_dev(dev);
 121         struct zpci_dev *zdev = to_zpci(pdev);
 122
 123         return memory_read_from_buffer(buf, count, &off, zdev->util_str,
 124                                        sizeof(zdev->util_str));
 125 }
 126 static BIN_ATTR_RO(util_string, CLP_UTIL_STR_LEN);
 127
 128 static ssize_t report_error_write(struct file *filp, struct kobject *kobj,
 129                                   struct bin_attribute *attr, char *buf,
 130                                   loff_t off, size_t count)
 131 {
 132         struct zpci_report_error_header *report = (void *) buf;
 133         struct device *dev = kobj_to_dev(kobj);
 134         struct pci_dev *pdev = to_pci_dev(dev);
 135         struct zpci_dev *zdev = to_zpci(pdev);
 136         int ret;
 137
 138         if (off || (count < sizeof(*report)))
 139                 return -EINVAL;
 140
 141         ret = sclp_pci_report(report, zdev->fh, zdev->fid);
 142
 143         return ret ? ret : count;
 144 }
 145 static BIN_ATTR(report_error, S_IWUSR, NULL, report_error_write, PAGE_SIZE);
 146
 147 static ssize_t uid_is_unique_show(struct device *dev,
 148                                   struct device_attribute *attr, char *buf)
 149 {
 150         return sysfs_emit(buf, "%d\n", zpci_unique_uid ? 1 : 0);
 151 }
 152 static DEVICE_ATTR_RO(uid_is_unique);
 153
 154 #ifndef CONFIG_DMI
 155 /* analogous to smbios index */
 156 static ssize_t index_show(struct device *dev,
 157                           struct device_attribute *attr, char *buf)
 158 {
 159         struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
 160         u32 index = ~0;
 161
 162         if (zpci_unique_uid)
 163                 index = zdev->uid;
 164
 165         return sysfs_emit(buf, "%u\n", index);
 166 }
 167 static DEVICE_ATTR_RO(index);
 168
 169 static umode_t zpci_index_is_visible(struct kobject *kobj,
 170                                      struct attribute *attr, int n)
 171 {
 172         return zpci_unique_uid ? attr->mode : 0;
 173 }
 174
 175 static struct attribute *zpci_ident_attrs[] = {
 176         &dev_attr_index.attr,
 177         NULL,
 178 };
 179
 180 static struct attribute_group zpci_ident_attr_group = {
 181         .attrs = zpci_ident_attrs,
 182         .is_visible = zpci_index_is_visible,
 183 };
 184 #endif
 185
 186 static struct bin_attribute *zpci_bin_attrs[] = {
 187         &bin_attr_util_string,
 188         &bin_attr_report_error,
 189         NULL,
 190 };
 191
 192 static struct attribute *zpci_dev_attrs[] = {
 193         &dev_attr_function_id.attr,
 194         &dev_attr_function_handle.attr,
 195         &dev_attr_pchid.attr,
 196         &dev_attr_pfgid.attr,
 197         &dev_attr_pft.attr,
 198         &dev_attr_port.attr,
 199         &dev_attr_vfn.attr,
 200         &dev_attr_uid.attr,
 201         &dev_attr_recover.attr,
 202         &dev_attr_mio_enabled.attr,
 203         &dev_attr_uid_is_unique.attr,
 204         NULL,
 205 };
 206
 207 static struct attribute_group zpci_attr_group = {
 208         .attrs = zpci_dev_attrs,
 209         .bin_attrs = zpci_bin_attrs,
 210 };
 211
 212 static struct attribute *pfip_attrs[] = {
 213         &dev_attr_segment0.attr,
 214         &dev_attr_segment1.attr,
 215         &dev_attr_segment2.attr,
 216         &dev_attr_segment3.attr,
 217         NULL,
 218 };
 219 static struct attribute_group pfip_attr_group = {
 220         .name = "pfip",
 221         .attrs = pfip_attrs,
 222 };
 223
 224 const struct attribute_group *zpci_attr_groups[] = {
 225         &zpci_attr_group,
 226         &pfip_attr_group,
 227 #ifndef CONFIG_DMI
 228         &zpci_ident_attr_group,
 229 #endif
 230         NULL,
 231 };