drivers/s390/char/sclp_config.c

   1 /*
   2  *    Copyright IBM Corp. 2007
   3  *    Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
   4  */
   5
   6 #define KMSG_COMPONENT "sclp_config"
   7 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
   8
   9 #include <linux/init.h>
  10 #include <linux/errno.h>
  11 #include <linux/cpu.h>
  12 #include <linux/device.h>
  13 #include <linux/workqueue.h>
  14 #include <linux/slab.h>
  15 #include <linux/sysfs.h>
  16 #include <asm/smp.h>
  17
  18 #include "sclp.h"
  19
  20 struct conf_mgm_data {
  21         u8 reserved;
  22         u8 ev_qualifier;
  23 } __attribute__((packed));
  24
  25 #define OFB_DATA_MAX 64
  26
  27 struct sclp_ofb_evbuf {
  28         struct evbuf_header header;
  29         struct conf_mgm_data cm_data;
  30         char ev_data[OFB_DATA_MAX];
  31 } __packed;
  32
  33 struct sclp_ofb_sccb {
  34         struct sccb_header header;
  35         struct sclp_ofb_evbuf ofb_evbuf;
  36 } __packed;
  37
  38 #define EV_QUAL_CPU_CHANGE      1
  39 #define EV_QUAL_CAP_CHANGE      3
  40 #define EV_QUAL_OPEN4BUSINESS   5
  41
  42 static struct work_struct sclp_cpu_capability_work;
  43 static struct work_struct sclp_cpu_change_work;
  44
  45 static void sclp_cpu_capability_notify(struct work_struct *work)
  46 {
  47         int cpu;
  48         struct device *dev;
  49
  50         s390_update_cpu_mhz();
  51         pr_info("CPU capability may have changed\n");
  52         get_online_cpus();
  53         for_each_online_cpu(cpu) {
  54                 dev = get_cpu_device(cpu);
  55                 kobject_uevent(&dev->kobj, KOBJ_CHANGE);
  56         }
  57         put_online_cpus();
  58 }
  59
  60 static void __ref sclp_cpu_change_notify(struct work_struct *work)
  61 {
  62         smp_rescan_cpus();
  63 }
  64
  65 static void sclp_conf_receiver_fn(struct evbuf_header *evbuf)
  66 {
  67         struct conf_mgm_data *cdata;
  68
  69         cdata = (struct conf_mgm_data *)(evbuf + 1);
  70         switch (cdata->ev_qualifier) {
  71         case EV_QUAL_CPU_CHANGE:
  72                 schedule_work(&sclp_cpu_change_work);
  73                 break;
  74         case EV_QUAL_CAP_CHANGE:
  75                 schedule_work(&sclp_cpu_capability_work);
  76                 break;
  77         }
  78 }
  79
  80 static struct sclp_register sclp_conf_register =
  81 {
  82 #ifdef CONFIG_SCLP_OFB
  83         .send_mask    = EVTYP_CONFMGMDATA_MASK,
  84 #endif
  85         .receive_mask = EVTYP_CONFMGMDATA_MASK,
  86         .receiver_fn  = sclp_conf_receiver_fn,
  87 };
  88
  89 #ifdef CONFIG_SCLP_OFB
  90 static int sclp_ofb_send_req(char *ev_data, size_t len)
  91 {
  92         static DEFINE_MUTEX(send_mutex);
  93         struct sclp_ofb_sccb *sccb;
  94         int rc, response;
  95
  96         if (len > OFB_DATA_MAX)
  97                 return -EINVAL;
  98         sccb = (struct sclp_ofb_sccb *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
  99         if (!sccb)
 100                 return -ENOMEM;
 101         /* Setup SCCB for Control-Program Identification */
 102         sccb->header.length = sizeof(struct sclp_ofb_sccb);
 103         sccb->ofb_evbuf.header.length = sizeof(struct sclp_ofb_evbuf);
 104         sccb->ofb_evbuf.header.type = EVTYP_CONFMGMDATA;
 105         sccb->ofb_evbuf.cm_data.ev_qualifier = EV_QUAL_OPEN4BUSINESS;
 106         memcpy(sccb->ofb_evbuf.ev_data, ev_data, len);
 107
 108         if (!(sclp_conf_register.sclp_receive_mask & EVTYP_CONFMGMDATA_MASK))
 109                 pr_warn("SCLP receiver did not register to receive "
 110                         "Configuration Management Data Events.\n");
 111
 112         mutex_lock(&send_mutex);
 113         rc = sclp_sync_request(SCLP_CMDW_WRITE_EVENT_DATA, sccb);
 114         mutex_unlock(&send_mutex);
 115         if (rc)
 116                 goto out;
 117         response = sccb->header.response_code;
 118         if (response != 0x0020) {
 119                 pr_err("Open for Business request failed with response code "
 120                        "0x%04x\n", response);
 121                 rc = -EIO;
 122         }
 123 out:
 124         free_page((unsigned long)sccb);
 125         return rc;
 126 }
 127
 128 static ssize_t sysfs_ofb_data_write(struct file *filp, struct kobject *kobj,
 129                                     struct bin_attribute *bin_attr,
 130                                     char *buf, loff_t off, size_t count)
 131 {
 132         int rc;
 133
 134         rc = sclp_ofb_send_req(buf, count);
 135         return rc ?: count;
 136 }
 137
 138 static struct bin_attribute ofb_bin_attr = {
 139         .attr = {
 140                 .name = "event_data",
 141                 .mode = S_IWUSR,
 142         },
 143         .write = sysfs_ofb_data_write,
 144 };
 145 #endif
 146
 147 static int __init sclp_ofb_setup(void)
 148 {
 149 #ifdef CONFIG_SCLP_OFB
 150         struct kset *ofb_kset;
 151         int rc;
 152
 153         ofb_kset = kset_create_and_add("ofb", NULL, firmware_kobj);
 154         if (!ofb_kset)
 155                 return -ENOMEM;
 156         rc = sysfs_create_bin_file(&ofb_kset->kobj, &ofb_bin_attr);
 157         if (rc) {
 158                 kset_unregister(ofb_kset);
 159                 return rc;
 160         }
 161 #endif
 162         return 0;
 163 }
 164
 165 static int __init sclp_conf_init(void)
 166 {
 167         int rc;
 168
 169         INIT_WORK(&sclp_cpu_capability_work, sclp_cpu_capability_notify);
 170         INIT_WORK(&sclp_cpu_change_work, sclp_cpu_change_notify);
 171         rc = sclp_register(&sclp_conf_register);
 172         if (rc)
 173                 return rc;
 174         return sclp_ofb_setup();
 175 }
 176
 177 __initcall(sclp_conf_init);