drivers/s390/char/sclp_ocf.c

   1 /*
   2  *  drivers/s390/char/sclp_ocf.c
   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 + 1];
  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                 memcpy(cpc_name, cpc + 1, size);
  77                 EBCASC(cpc_name, size);
  78                 cpc_name[size] = 0;
  79         }
  80         spin_unlock(&sclp_ocf_lock);
  81         schedule_work(&sclp_ocf_change_work);
  82 }
  83
  84 static struct sclp_register sclp_ocf_event = {
  85         .receive_mask = EVTYP_OCF_MASK,
  86         .receiver_fn = sclp_ocf_handler,
  87 };
  88
  89 static ssize_t cpc_name_show(struct kobject *kobj,
  90                              struct kobj_attribute *attr, char *page)
  91 {
  92         int rc;
  93
  94         spin_lock_irq(&sclp_ocf_lock);
  95         rc = snprintf(page, PAGE_SIZE, "%s\n", cpc_name);
  96         spin_unlock_irq(&sclp_ocf_lock);
  97         return rc;
  98 }
  99
 100 static struct kobj_attribute cpc_name_attr =
 101         __ATTR(cpc_name, 0444, cpc_name_show, NULL);
 102
 103 static ssize_t hmc_network_show(struct kobject *kobj,
 104                                 struct kobj_attribute *attr, char *page)
 105 {
 106         int rc;
 107
 108         spin_lock_irq(&sclp_ocf_lock);
 109         rc = snprintf(page, PAGE_SIZE, "%s\n", hmc_network);
 110         spin_unlock_irq(&sclp_ocf_lock);
 111         return rc;
 112 }
 113
 114 static struct kobj_attribute hmc_network_attr =
 115         __ATTR(hmc_network, 0444, hmc_network_show, NULL);
 116
 117 static struct attribute *ocf_attrs[] = {
 118         &cpc_name_attr.attr,
 119         &hmc_network_attr.attr,
 120         NULL,
 121 };
 122
 123 static struct attribute_group ocf_attr_group = {
 124         .attrs = ocf_attrs,
 125 };
 126
 127 static int __init ocf_init(void)
 128 {
 129         int rc;
 130
 131         INIT_WORK(&sclp_ocf_change_work, sclp_ocf_change_notify);
 132         ocf_kset = kset_create_and_add("ocf", NULL, firmware_kobj);
 133         if (!ocf_kset)
 134                 return -ENOMEM;
 135
 136         rc = sysfs_create_group(&ocf_kset->kobj, &ocf_attr_group);
 137         if (rc) {
 138                 kset_unregister(ocf_kset);
 139                 return rc;
 140         }
 141
 142         return sclp_register(&sclp_ocf_event);
 143 }
 144
 145 device_initcall(ocf_init);