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