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         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 };