LXR linux/drivers/s390/char/sclp

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   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]; /* in EBCDIC */
  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                memset(cpc_name, 0, OCF_LENGTH_CPC_NAME);
  77                memcpy(cpc_name, cpc + 1, size);
  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
  88void sclp_ocf_cpc_name_copy(char *dst)
  89{
  90        spin_lock_irq(&sclp_ocf_lock);
  91        memcpy(dst, cpc_name, OCF_LENGTH_CPC_NAME);
  92        spin_unlock_irq(&sclp_ocf_lock);
  93}
  94EXPORT_SYMBOL(sclp_ocf_cpc_name_copy);
  95
  96static ssize_t cpc_name_show(struct kobject *kobj,
  97                             struct kobj_attribute *attr, char *page)
  98{
  99        char name[OCF_LENGTH_CPC_NAME + 1];
 100
 101        sclp_ocf_cpc_name_copy(name);
 102        name[OCF_LENGTH_CPC_NAME] = 0;
 103        EBCASC(name, OCF_LENGTH_CPC_NAME);
 104        return snprintf(page, PAGE_SIZE, "%s\n", name);
 105}
 106
 107static struct kobj_attribute cpc_name_attr =
 108        __ATTR(cpc_name, 0444, cpc_name_show, NULL);
 109
 110static ssize_t hmc_network_show(struct kobject *kobj,
 111                                struct kobj_attribute *attr, char *page)
 112{
 113        int rc;
 114
 115        spin_lock_irq(&sclp_ocf_lock);
 116        rc = snprintf(page, PAGE_SIZE, "%s\n", hmc_network);
 117        spin_unlock_irq(&sclp_ocf_lock);
 118        return rc;
 119}
 120
 121static struct kobj_attribute hmc_network_attr =
 122        __ATTR(hmc_network, 0444, hmc_network_show, NULL);
 123
 124static struct attribute *ocf_attrs[] = {
 125        &cpc_name_attr.attr,
 126        &hmc_network_attr.attr,
 127        NULL,
 128};
 129
 130static const struct attribute_group ocf_attr_group = {
 131        .attrs = ocf_attrs,
 132};
 133
 134static int __init ocf_init(void)
 135{
 136        int rc;
 137
 138        INIT_WORK(&sclp_ocf_change_work, sclp_ocf_change_notify);
 139        ocf_kset = kset_create_and_add("ocf", NULL, firmware_kobj);
 140        if (!ocf_kset)
 141                return -ENOMEM;
 142
 143        rc = sysfs_create_group(&ocf_kset->kobj, &ocf_attr_group);
 144        if (rc) {
 145                kset_unregister(ocf_kset);
 146                return rc;
 147        }
 148
 149        return sclp_register(&sclp_ocf_event);
 150}
 151
 152device_initcall(ocf_init);
 153