LXR linux/drivers/s390/char/sclp

   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
  29static char hmc_network[OCF_LENGTH_HMC_NETWORK + 1];
  30static char cpc_name[OCF_LENGTH_CPC_NAME + 1];
  31
  32static DEFINE_SPINLOCK(sclp_ocf_lock);
  33static struct work_struct sclp_ocf_change_work;
  34
  35static struct kset *ocf_kset;
  36
  37static 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. */
  43static 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
  84static struct sclp_register sclp_ocf_event = {
  85        .receive_mask = EVTYP_OCF_MASK,
  86        .receiver_fn = sclp_ocf_handler,
  87};
  88
  89static 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
 100static struct kobj_attribute cpc_name_attr =
 101        __ATTR(cpc_name, 0444, cpc_name_show, NULL);
 102
 103static 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
 114static struct kobj_attribute hmc_network_attr =
 115        __ATTR(hmc_network, 0444, hmc_network_show, NULL);
 116
 117static struct attribute *ocf_attrs[] = {
 118        &cpc_name_attr.attr,
 119        &hmc_network_attr.attr,
 120        NULL,
 121};
 122
 123static struct attribute_group ocf_attr_group = {
 124        .attrs = ocf_attrs,
 125};
 126
 127static 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
 145device_initcall(ocf_init);
 146