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 + 1];
  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                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
  83static struct sclp_register sclp_ocf_event = {
  84        .receive_mask = EVTYP_OCF_MASK,
  85        .receiver_fn = sclp_ocf_handler,
  86};
  87
  88static 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
  99static struct kobj_attribute cpc_name_attr =
 100        __ATTR(cpc_name, 0444, cpc_name_show, NULL);
 101
 102static 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
 113static struct kobj_attribute hmc_network_attr =
 114        __ATTR(hmc_network, 0444, hmc_network_show, NULL);
 115
 116static struct attribute *ocf_attrs[] = {
 117        &cpc_name_attr.attr,
 118        &hmc_network_attr.attr,
 119        NULL,
 120};
 121
 122static struct attribute_group ocf_attr_group = {
 123        .attrs = ocf_attrs,
 124};
 125
 126static 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
 144device_initcall(ocf_init);
 145