drivers/s390/char/sclp_ocf.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *    SCLP OCF communication parameters sysfs interface
   4  *
   5  *    Copyright IBM Corp. 2011
   6  *    Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
   7  */
   8
   9 #define KMSG_COMPONENT "sclp_ocf"
  10 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  11
  12 #include <linux/kernel.h>
  13 #include <linux/init.h>
  14 #include <linux/stat.h>
  15 #include <linux/device.h>
  16 #include <linux/string.h>
  17 #include <linux/ctype.h>
  18 #include <linux/kmod.h>
  19 #include <linux/timer.h>
  20 #include <linux/err.h>
  21 #include <asm/ebcdic.h>
  22 #include <asm/sclp.h>
  23
  24 #include "sclp.h"
  25
  26 #define OCF_LENGTH_HMC_NETWORK 8UL
  27 #define OCF_LENGTH_CPC_NAME 8UL
  28
  29 static char hmc_network[OCF_LENGTH_HMC_NETWORK + 1];
  30 static char cpc_name[OCF_LENGTH_CPC_NAME]; /* in EBCDIC */
  31
  32 static DEFINE_SPINLOCK(sclp_ocf_lock);
  33 static struct work_struct sclp_ocf_change_work;
  34
  35 static struct kset *ocf_kset;
  36
  37 static void sclp_ocf_change_notify(struct work_struct *work)
  38 {
  39         kobject_uevent(&ocf_kset->kobj, KOBJ_CHANGE);
  40 }
  41
  42 /* Handler for OCF event. Look for the CPC image name. */
  43 static void sclp_ocf_handler(struct evbuf_header *evbuf)
  44 {
  45         struct gds_vector *v;
  46         struct gds_subvector *sv, *netid, *cpc;
  47         size_t size;
  48
  49         /* Find the 0x9f00 block. */
  50         v = sclp_find_gds_vector(evbuf + 1, (void *) evbuf + evbuf->length,
  51                                  0x9f00);
  52         if (!v)
  53                 return;
  54         /* Find the 0x9f22 block inside the 0x9f00 block. */
  55         v = sclp_find_gds_vector(v + 1, (void *) v + v->length, 0x9f22);
  56         if (!v)
  57                 return;
  58         /* Find the 0x81 block inside the 0x9f22 block. */
  59         sv = sclp_find_gds_subvector(v + 1, (void *) v + v->length, 0x81);
  60         if (!sv)
  61                 return;
  62         /* Find the 0x01 block inside the 0x81 block. */
  63         netid = sclp_find_gds_subvector(sv + 1, (void *) sv + sv->length, 1);
  64         /* Find the 0x02 block inside the 0x81 block. */
  65         cpc = sclp_find_gds_subvector(sv + 1, (void *) sv + sv->length, 2);
  66         /* Copy network name and cpc name. */
  67         spin_lock(&sclp_ocf_lock);
  68         if (netid) {
  69                 size = min(OCF_LENGTH_HMC_NETWORK, (size_t) netid->length);
  70                 memcpy(hmc_network, netid + 1, size);
  71                 EBCASC(hmc_network, size);
  72                 hmc_network[size] = 0;
  73         }
  74         if (cpc) {
  75                 size = min(OCF_LENGTH_CPC_NAME, (size_t) cpc->length);
  76                 memset(cpc_name, 0, OCF_LENGTH_CPC_NAME);
  77                 memcpy(cpc_name, cpc + 1, size);
  78         }
  79         spin_unlock(&sclp_ocf_lock);
  80         schedule_work(&sclp_ocf_change_work);
  81 }
  82
  83 static struct sclp_register sclp_ocf_event = {
  84         .receive_mask = EVTYP_OCF_MASK,
  85         .receiver_fn = sclp_ocf_handler,
  86 };
  87
  88 void sclp_ocf_cpc_name_copy(char *dst)
  89 {
  90         spin_lock_irq(&sclp_ocf_lock);
  91         memcpy(dst, cpc_name, OCF_LENGTH_CPC_NAME);
  92         spin_unlock_irq(&sclp_ocf_lock);
  93 }
  94 EXPORT_SYMBOL(sclp_ocf_cpc_name_copy);
  95
  96 static ssize_t cpc_name_show(struct kobject *kobj,
  97                              struct kobj_attribute *attr, char *page)
  98 {
  99         char name[OCF_LENGTH_CPC_NAME + 1];
 100
 101         sclp_ocf_cpc_name_copy(name);
 102         name[OCF_LENGTH_CPC_NAME] = 0;
 103         EBCASC(name, OCF_LENGTH_CPC_NAME);
 104         return snprintf(page, PAGE_SIZE, "%s\n", name);
 105 }
 106
 107 static struct kobj_attribute cpc_name_attr =
 108         __ATTR(cpc_name, 0444, cpc_name_show, NULL);
 109
 110 static ssize_t hmc_network_show(struct kobject *kobj,
 111                                 struct kobj_attribute *attr, char *page)
 112 {
 113         int rc;
 114
 115         spin_lock_irq(&sclp_ocf_lock);
 116         rc = snprintf(page, PAGE_SIZE, "%s\n", hmc_network);
 117         spin_unlock_irq(&sclp_ocf_lock);
 118         return rc;
 119 }
 120
 121 static struct kobj_attribute hmc_network_attr =
 122         __ATTR(hmc_network, 0444, hmc_network_show, NULL);
 123
 124 static struct attribute *ocf_attrs[] = {
 125         &cpc_name_attr.attr,
 126         &hmc_network_attr.attr,
 127         NULL,
 128 };
 129
 130 static const struct attribute_group ocf_attr_group = {
 131         .attrs = ocf_attrs,
 132 };
 133
 134 static int __init ocf_init(void)
 135 {
 136         int rc;
 137
 138         INIT_WORK(&sclp_ocf_change_work, sclp_ocf_change_notify);
 139         ocf_kset = kset_create_and_add("ocf", NULL, firmware_kobj);
 140         if (!ocf_kset)
 141                 return -ENOMEM;
 142
 143         rc = sysfs_create_group(&ocf_kset->kobj, &ocf_attr_group);
 144         if (rc) {
 145                 kset_unregister(ocf_kset);
 146                 return rc;
 147         }
 148
 149         return sclp_register(&sclp_ocf_event);
 150 }
 151
 152 device_initcall(ocf_init);