s390/char/sclp_ocf.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  *    SCLP OCF communication parameters sysfs interface
0004  *
0005  *    Copyright IBM Corp. 2011
0006  *    Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
0007  */
0008
0009 #define KMSG_COMPONENT "sclp_ocf"
0010 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
0011
0012 #include <linux/kernel.h>
0013 #include <linux/init.h>
0014 #include <linux/stat.h>
0015 #include <linux/device.h>
0016 #include <linux/string.h>
0017 #include <linux/ctype.h>
0018 #include <linux/kmod.h>
0019 #include <linux/timer.h>
0020 #include <linux/err.h>
0021 #include <asm/ebcdic.h>
0022 #include <asm/sclp.h>
0023
0024 #include "sclp.h"
0025
0026 #define OCF_LENGTH_HMC_NETWORK 8UL
0027 #define OCF_LENGTH_CPC_NAME 8UL
0028
0029 static char hmc_network[OCF_LENGTH_HMC_NETWORK + 1];
0030 static char cpc_name[OCF_LENGTH_CPC_NAME]; /* in EBCDIC */
0031
0032 static DEFINE_SPINLOCK(sclp_ocf_lock);
0033 static struct work_struct sclp_ocf_change_work;
0034
0035 static struct kset *ocf_kset;
0036
0037 static void sclp_ocf_change_notify(struct work_struct *work)
0038 {
0039     kobject_uevent(&ocf_kset->kobj, KOBJ_CHANGE);
0040 }
0041
0042 /* Handler for OCF event. Look for the CPC image name. */
0043 static void sclp_ocf_handler(struct evbuf_header *evbuf)
0044 {
0045     struct gds_vector *v;
0046     struct gds_subvector *sv, *netid, *cpc;
0047     size_t size;
0048
0049     /* Find the 0x9f00 block. */
0050     v = sclp_find_gds_vector(evbuf + 1, (void *) evbuf + evbuf->length,
0051                  0x9f00);
0052     if (!v)
0053         return;
0054     /* Find the 0x9f22 block inside the 0x9f00 block. */
0055     v = sclp_find_gds_vector(v + 1, (void *) v + v->length, 0x9f22);
0056     if (!v)
0057         return;
0058     /* Find the 0x81 block inside the 0x9f22 block. */
0059     sv = sclp_find_gds_subvector(v + 1, (void *) v + v->length, 0x81);
0060     if (!sv)
0061         return;
0062     /* Find the 0x01 block inside the 0x81 block. */
0063     netid = sclp_find_gds_subvector(sv + 1, (void *) sv + sv->length, 1);
0064     /* Find the 0x02 block inside the 0x81 block. */
0065     cpc = sclp_find_gds_subvector(sv + 1, (void *) sv + sv->length, 2);
0066     /* Copy network name and cpc name. */
0067     spin_lock(&sclp_ocf_lock);
0068     if (netid) {
0069         size = min(OCF_LENGTH_HMC_NETWORK, (size_t) netid->length);
0070         memcpy(hmc_network, netid + 1, size);
0071         EBCASC(hmc_network, size);
0072         hmc_network[size] = 0;
0073     }
0074     if (cpc) {
0075         size = min(OCF_LENGTH_CPC_NAME, (size_t) cpc->length);
0076         memset(cpc_name, 0, OCF_LENGTH_CPC_NAME);
0077         memcpy(cpc_name, cpc + 1, size);
0078     }
0079     spin_unlock(&sclp_ocf_lock);
0080     schedule_work(&sclp_ocf_change_work);
0081 }
0082
0083 static struct sclp_register sclp_ocf_event = {
0084     .receive_mask = EVTYP_OCF_MASK,
0085     .receiver_fn = sclp_ocf_handler,
0086 };
0087
0088 void sclp_ocf_cpc_name_copy(char *dst)
0089 {
0090     spin_lock_irq(&sclp_ocf_lock);
0091     memcpy(dst, cpc_name, OCF_LENGTH_CPC_NAME);
0092     spin_unlock_irq(&sclp_ocf_lock);
0093 }
0094 EXPORT_SYMBOL(sclp_ocf_cpc_name_copy);
0095
0096 static ssize_t cpc_name_show(struct kobject *kobj,
0097                  struct kobj_attribute *attr, char *page)
0098 {
0099     char name[OCF_LENGTH_CPC_NAME + 1];
0100
0101     sclp_ocf_cpc_name_copy(name);
0102     name[OCF_LENGTH_CPC_NAME] = 0;
0103     EBCASC(name, OCF_LENGTH_CPC_NAME);
0104     return snprintf(page, PAGE_SIZE, "%s\n", name);
0105 }
0106
0107 static struct kobj_attribute cpc_name_attr =
0108     __ATTR(cpc_name, 0444, cpc_name_show, NULL);
0109
0110 static ssize_t hmc_network_show(struct kobject *kobj,
0111                 struct kobj_attribute *attr, char *page)
0112 {
0113     int rc;
0114
0115     spin_lock_irq(&sclp_ocf_lock);
0116     rc = snprintf(page, PAGE_SIZE, "%s\n", hmc_network);
0117     spin_unlock_irq(&sclp_ocf_lock);
0118     return rc;
0119 }
0120
0121 static struct kobj_attribute hmc_network_attr =
0122     __ATTR(hmc_network, 0444, hmc_network_show, NULL);
0123
0124 static struct attribute *ocf_attrs[] = {
0125     &cpc_name_attr.attr,
0126     &hmc_network_attr.attr,
0127     NULL,
0128 };
0129
0130 static const struct attribute_group ocf_attr_group = {
0131     .attrs = ocf_attrs,
0132 };
0133
0134 static int __init ocf_init(void)
0135 {
0136     int rc;
0137
0138     INIT_WORK(&sclp_ocf_change_work, sclp_ocf_change_notify);
0139     ocf_kset = kset_create_and_add("ocf", NULL, firmware_kobj);
0140     if (!ocf_kset)
0141         return -ENOMEM;
0142
0143     rc = sysfs_create_group(&ocf_kset->kobj, &ocf_attr_group);
0144     if (rc) {
0145         kset_unregister(ocf_kset);
0146         return rc;
0147     }
0148
0149     return sclp_register(&sclp_ocf_event);
0150 }
0151
0152 device_initcall(ocf_init);