LXR linux/drivers/s390/char/sclp

   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
  28static char hmc_network[OCF_LENGTH_HMC_NETWORK + 1];
  29static char cpc_name[OCF_LENGTH_CPC_NAME]; /* in EBCDIC */
  30
  31static DEFINE_SPINLOCK(sclp_ocf_lock);
  32static struct work_struct sclp_ocf_change_work;
  33
  34static struct kset *ocf_kset;
  35
  36static 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. */
  42static 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
  82static struct sclp_register sclp_ocf_event = {
  83        .receive_mask = EVTYP_OCF_MASK,
  84        .receiver_fn = sclp_ocf_handler,
  85};
  86
  87void 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}
  93EXPORT_SYMBOL(sclp_ocf_cpc_name_copy);
  94
  95static 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
 106static struct kobj_attribute cpc_name_attr =
 107        __ATTR(cpc_name, 0444, cpc_name_show, NULL);
 108
 109static 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
 120static struct kobj_attribute hmc_network_attr =
 121        __ATTR(hmc_network, 0444, hmc_network_show, NULL);
 122
 123static struct attribute *ocf_attrs[] = {
 124        &cpc_name_attr.attr,
 125        &hmc_network_attr.attr,
 126        NULL,
 127};
 128
 129static struct attribute_group ocf_attr_group = {
 130        .attrs = ocf_attrs,
 131};
 132
 133static 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
 151device_initcall(ocf_init);
 152