drivers/s390/char/sclp_ocf.c

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