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(uid, "0x%x\n", uid);
  37 zpci_attr(segment0, "0x%02x\n", pfip[0]);
  38 zpci_attr(segment1, "0x%02x\n", pfip[1]);
  39 zpci_attr(segment2, "0x%02x\n", pfip[2]);
  40 zpci_attr(segment3, "0x%02x\n", pfip[3]);
  41
  42 static ssize_t mio_enabled_show(struct device *dev,
  43                                 struct device_attribute *attr, char *buf)
  44 {
  45         struct zpci_dev *zdev = to_zpci(to_pci_dev(dev));
  46
  47         return sprintf(buf, zpci_use_mio(zdev) ? "1\n" : "0\n");
  48 }
  49 static DEVICE_ATTR_RO(mio_enabled);
  50
  51 static ssize_t recover_store(struct device *dev, struct device_attribute *attr,
  52                              const char *buf, size_t count)
  53 {
  54         struct kernfs_node *kn;
  55         struct pci_dev *pdev = to_pci_dev(dev);
  56         struct zpci_dev *zdev = to_zpci(pdev);
  57         int ret = 0;
  58
  59         /* Can't use device_remove_self() here as that would lead us to lock
  60          * the pci_rescan_remove_lock while holding the device' kernfs lock.
  61          * This would create a possible deadlock with disable_slot() which is
  62          * not directly protected by the device' kernfs lock but takes it
  63          * during the device removal which happens under
  64          * pci_rescan_remove_lock.
  65          *
  66          * This is analogous to sdev_store_delete() in
  67          * drivers/scsi/scsi_sysfs.c
  68          */
  69         kn = sysfs_break_active_protection(&dev->kobj, &attr->attr);
  70         WARN_ON_ONCE(!kn);
  71         /* device_remove_file() serializes concurrent calls ignoring all but
  72          * the first
  73          */
  74         device_remove_file(dev, attr);
  75
  76         /* A concurrent call to recover_store() may slip between
  77          * sysfs_break_active_protection() and the sysfs file removal.
  78          * Once it unblocks from pci_lock_rescan_remove() the original pdev
  79          * will already be removed.
  80          */
  81         pci_lock_rescan_remove();
  82         if (pci_dev_is_added(pdev)) {
  83                 pci_stop_and_remove_bus_device(pdev);
  84                 ret = zpci_disable_device(zdev);
  85                 if (ret)
  86                         goto out;
  87
  88                 ret = zpci_enable_device(zdev);
  89                 if (ret)
  90                         goto out;
  91                 pci_rescan_bus(zdev->bus);
  92         }
  93 out:
  94         pci_unlock_rescan_remove();
  95         if (kn)
  96                 sysfs_unbreak_active_protection(kn);
  97         return ret ? ret : count;
  98 }
  99 static DEVICE_ATTR_WO(recover);
 100
 101 static ssize_t util_string_read(struct file *filp, struct kobject *kobj,
 102                                 struct bin_attribute *attr, char *buf,
 103                                 loff_t off, size_t count)
 104 {
 105         struct device *dev = kobj_to_dev(kobj);
 106         struct pci_dev *pdev = to_pci_dev(dev);
 107         struct zpci_dev *zdev = to_zpci(pdev);
 108
 109         return memory_read_from_buffer(buf, count, &off, zdev->util_str,
 110                                        sizeof(zdev->util_str));
 111 }
 112 static BIN_ATTR_RO(util_string, CLP_UTIL_STR_LEN);
 113
 114 static ssize_t report_error_write(struct file *filp, struct kobject *kobj,
 115                                   struct bin_attribute *attr, char *buf,
 116                                   loff_t off, size_t count)
 117 {
 118         struct zpci_report_error_header *report = (void *) buf;
 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         int ret;
 123
 124         if (off || (count < sizeof(*report)))
 125                 return -EINVAL;
 126
 127         ret = sclp_pci_report(report, zdev->fh, zdev->fid);
 128
 129         return ret ? ret : count;
 130 }
 131 static BIN_ATTR(report_error, S_IWUSR, NULL, report_error_write, PAGE_SIZE);
 132
 133 static struct bin_attribute *zpci_bin_attrs[] = {
 134         &bin_attr_util_string,
 135         &bin_attr_report_error,
 136         NULL,
 137 };
 138
 139 static struct attribute *zpci_dev_attrs[] = {
 140         &dev_attr_function_id.attr,
 141         &dev_attr_function_handle.attr,
 142         &dev_attr_pchid.attr,
 143         &dev_attr_pfgid.attr,
 144         &dev_attr_pft.attr,
 145         &dev_attr_vfn.attr,
 146         &dev_attr_uid.attr,
 147         &dev_attr_recover.attr,
 148         &dev_attr_mio_enabled.attr,
 149         NULL,
 150 };
 151 static struct attribute_group zpci_attr_group = {
 152         .attrs = zpci_dev_attrs,
 153         .bin_attrs = zpci_bin_attrs,
 154 };
 155
 156 static struct attribute *pfip_attrs[] = {
 157         &dev_attr_segment0.attr,
 158         &dev_attr_segment1.attr,
 159         &dev_attr_segment2.attr,
 160         &dev_attr_segment3.attr,
 161         NULL,
 162 };
 163 static struct attribute_group pfip_attr_group = {
 164         .name = "pfip",
 165         .attrs = pfip_attrs,
 166 };
 167
 168 const struct attribute_group *zpci_attr_groups[] = {
 169         &zpci_attr_group,
 170         &pfip_attr_group,
 171         NULL,
 172 };