sclp_cpi_sys.c

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/*
 *    SCLP control program identification sysfs interface
 *
 *    Copyright IBM Corp. 2001, 2007
 *    Author(s): Martin Peschke <[email protected]>
 *       Michael Ernst <[email protected]>
 */

#define KMSG_COMPONENT "sclp_cpi"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/stat.h>
#include <linux/device.h>
#include <linux/string.h>
#include <linux/ctype.h>
#include <linux/kmod.h>
#include <linux/timer.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/completion.h>
#include <linux/export.h>
#include <asm/ebcdic.h>
#include <asm/sclp.h>

#include "sclp.h"
#include "sclp_rw.h"
#include "sclp_cpi_sys.h"

#define CPI_LENGTH_NAME 8
#define CPI_LENGTH_LEVEL 16

static DEFINE_MUTEX(sclp_cpi_mutex);

struct cpi_evbuf {
    struct evbuf_header header;
    u8  id_format;
    u8  reserved0;
    u8  system_type[CPI_LENGTH_NAME];
    u64 reserved1;
    u8  system_name[CPI_LENGTH_NAME];
    u64 reserved2;
    u64 system_level;
    u64 reserved3;
    u8  sysplex_name[CPI_LENGTH_NAME];
    u8  reserved4[16];
} __attribute__((packed));

struct cpi_sccb {
    struct sccb_header header;
    struct cpi_evbuf cpi_evbuf;
} __attribute__((packed));

static struct sclp_register sclp_cpi_event = {
    .send_mask = EVTYP_CTLPROGIDENT_MASK,
};

static char system_name[CPI_LENGTH_NAME + 1];
static char sysplex_name[CPI_LENGTH_NAME + 1];
static char system_type[CPI_LENGTH_NAME + 1];
static u64 system_level;

static void set_data(char *field, char *data)
{
    memset(field, ' ', CPI_LENGTH_NAME);
    memcpy(field, data, strlen(data));
    sclp_ascebc_str(field, CPI_LENGTH_NAME);
}

static void cpi_callback(struct sclp_req *req, void *data)
{
    struct completion *completion = data;

    complete(completion);
}

static struct sclp_req *cpi_prepare_req(void)
{
    struct sclp_req *req;
    struct cpi_sccb *sccb;
    struct cpi_evbuf *evb;

    req = kzalloc(sizeof(struct sclp_req), GFP_KERNEL);
    if (!req)
        return ERR_PTR(-ENOMEM);
    sccb = (struct cpi_sccb *) get_zeroed_page(GFP_KERNEL | GFP_DMA);
    if (!sccb) {
        kfree(req);
        return ERR_PTR(-ENOMEM);
    }

    /* setup SCCB for Control-Program Identification */
    sccb->header.length = sizeof(struct cpi_sccb);
    sccb->cpi_evbuf.header.length = sizeof(struct cpi_evbuf);
    sccb->cpi_evbuf.header.type = 0x0b;
    evb = &sccb->cpi_evbuf;

    /* set system type */
    set_data(evb->system_type, system_type);

    /* set system name */
    set_data(evb->system_name, system_name);

    /* set system level */
    evb->system_level = system_level;

    /* set sysplex name */
    set_data(evb->sysplex_name, sysplex_name);

    /* prepare request data structure presented to SCLP driver */
    req->command = SCLP_CMDW_WRITE_EVENT_DATA;
    req->sccb = sccb;
    req->status = SCLP_REQ_FILLED;
    req->callback = cpi_callback;
    return req;
}

static void cpi_free_req(struct sclp_req *req)
{
    free_page((unsigned long) req->sccb);
    kfree(req);
}

static int cpi_req(void)
{
    struct completion completion;
    struct sclp_req *req;
    int rc;
    int response;

    rc = sclp_register(&sclp_cpi_event);
    if (rc)
        goto out;
    if (!(sclp_cpi_event.sclp_receive_mask & EVTYP_CTLPROGIDENT_MASK)) {
        rc = -EOPNOTSUPP;
        goto out_unregister;
    }

    req = cpi_prepare_req();
    if (IS_ERR(req)) {
        rc = PTR_ERR(req);
        goto out_unregister;
    }

    init_completion(&completion);
    req->callback_data = &completion;

    /* Add request to sclp queue */
    rc = sclp_add_request(req);
    if (rc)
        goto out_free_req;

    wait_for_completion(&completion);

    if (req->status != SCLP_REQ_DONE) {
        pr_warning("request failed (status=0x%02x)\n",
               req->status);
        rc = -EIO;
        goto out_free_req;
    }

    response = ((struct cpi_sccb *) req->sccb)->header.response_code;
    if (response != 0x0020) {
        pr_warning("request failed with response code 0x%x\n",
               response);
        rc = -EIO;
    }

out_free_req:
    cpi_free_req(req);

out_unregister:
    sclp_unregister(&sclp_cpi_event);

out:
    return rc;
}

static int check_string(const char *attr, const char *str)
{
    size_t len;
    size_t i;

    len = strlen(str);

    if ((len > 0) && (str[len - 1] == '\n'))
        len--;

    if (len > CPI_LENGTH_NAME)
        return -EINVAL;

    for (i = 0; i < len ; i++) {
        if (isalpha(str[i]) || isdigit(str[i]) ||
            strchr("$@# ", str[i]))
            continue;
        return -EINVAL;
    }

    return 0;
}

static void set_string(char *attr, const char *value)
{
    size_t len;
    size_t i;

    len = strlen(value);

    if ((len > 0) && (value[len - 1] == '\n'))
        len--;

    for (i = 0; i < CPI_LENGTH_NAME; i++) {
        if (i < len)
            attr[i] = toupper(value[i]);
        else
            attr[i] = ' ';
    }
}

static ssize_t system_name_show(struct kobject *kobj,
                struct kobj_attribute *attr, char *page)
{
    int rc;

    mutex_lock(&sclp_cpi_mutex);
    rc = snprintf(page, PAGE_SIZE, "%s\n", system_name);
    mutex_unlock(&sclp_cpi_mutex);
    return rc;
}

static ssize_t system_name_store(struct kobject *kobj,
                 struct kobj_attribute *attr,
                 const char *buf,
    size_t len)
{
    int rc;

    rc = check_string("system_name", buf);
    if (rc)
        return rc;

    mutex_lock(&sclp_cpi_mutex);
    set_string(system_name, buf);
    mutex_unlock(&sclp_cpi_mutex);

    return len;
}

static struct kobj_attribute system_name_attr =
    __ATTR(system_name, 0644, system_name_show, system_name_store);

static ssize_t sysplex_name_show(struct kobject *kobj,
                 struct kobj_attribute *attr, char *page)
{
    int rc;

    mutex_lock(&sclp_cpi_mutex);
    rc = snprintf(page, PAGE_SIZE, "%s\n", sysplex_name);
    mutex_unlock(&sclp_cpi_mutex);
    return rc;
}

static ssize_t sysplex_name_store(struct kobject *kobj,
                  struct kobj_attribute *attr,
                  const char *buf,
    size_t len)
{
    int rc;

    rc = check_string("sysplex_name", buf);
    if (rc)
        return rc;

    mutex_lock(&sclp_cpi_mutex);
    set_string(sysplex_name, buf);
    mutex_unlock(&sclp_cpi_mutex);

    return len;
}

static struct kobj_attribute sysplex_name_attr =
    __ATTR(sysplex_name, 0644, sysplex_name_show, sysplex_name_store);

static ssize_t system_type_show(struct kobject *kobj,
                struct kobj_attribute *attr, char *page)
{
    int rc;

    mutex_lock(&sclp_cpi_mutex);
    rc = snprintf(page, PAGE_SIZE, "%s\n", system_type);
    mutex_unlock(&sclp_cpi_mutex);
    return rc;
}

static ssize_t system_type_store(struct kobject *kobj,
                 struct kobj_attribute *attr,
                 const char *buf,
    size_t len)
{
    int rc;

    rc = check_string("system_type", buf);
    if (rc)
        return rc;

    mutex_lock(&sclp_cpi_mutex);
    set_string(system_type, buf);
    mutex_unlock(&sclp_cpi_mutex);

    return len;
}

static struct kobj_attribute system_type_attr =
    __ATTR(system_type, 0644, system_type_show, system_type_store);

static ssize_t system_level_show(struct kobject *kobj,
                 struct kobj_attribute *attr, char *page)
{
    unsigned long long level;

    mutex_lock(&sclp_cpi_mutex);
    level = system_level;
    mutex_unlock(&sclp_cpi_mutex);
    return snprintf(page, PAGE_SIZE, "%#018llx\n", level);
}

static ssize_t system_level_store(struct kobject *kobj,
                  struct kobj_attribute *attr,
                  const char *buf,
    size_t len)
{
    unsigned long long level;
    char *endp;

    level = simple_strtoull(buf, &endp, 16);

    if (endp == buf)
        return -EINVAL;
    if (*endp == '\n')
        endp++;
    if (*endp)
        return -EINVAL;

    mutex_lock(&sclp_cpi_mutex);
    system_level = level;
    mutex_unlock(&sclp_cpi_mutex);
    return len;
}

static struct kobj_attribute system_level_attr =
    __ATTR(system_level, 0644, system_level_show, system_level_store);

static ssize_t set_store(struct kobject *kobj,
             struct kobj_attribute *attr,
             const char *buf, size_t len)
{
    int rc;

    mutex_lock(&sclp_cpi_mutex);
    rc = cpi_req();
    mutex_unlock(&sclp_cpi_mutex);
    if (rc)
        return rc;

    return len;
}

static struct kobj_attribute set_attr = __ATTR(set, 0200, NULL, set_store);

static struct attribute *cpi_attrs[] = {
    &system_name_attr.attr,
    &sysplex_name_attr.attr,
    &system_type_attr.attr,
    &system_level_attr.attr,
    &set_attr.attr,
    NULL,
};

static struct attribute_group cpi_attr_group = {
    .attrs = cpi_attrs,
};

static struct kset *cpi_kset;

int sclp_cpi_set_data(const char *system, const char *sysplex, const char *type,
              const u64 level)
{
    int rc;

    rc = check_string("system_name", system);
    if (rc)
        return rc;
    rc = check_string("sysplex_name", sysplex);
    if (rc)
        return rc;
    rc = check_string("system_type", type);
    if (rc)
        return rc;

    mutex_lock(&sclp_cpi_mutex);
    set_string(system_name, system);
    set_string(sysplex_name, sysplex);
    set_string(system_type, type);
    system_level = level;

    rc = cpi_req();
    mutex_unlock(&sclp_cpi_mutex);

    return rc;
}
EXPORT_SYMBOL(sclp_cpi_set_data);

static int __init cpi_init(void)
{
    int rc;

    cpi_kset = kset_create_and_add("cpi", NULL, firmware_kobj);
    if (!cpi_kset)
        return -ENOMEM;

    rc = sysfs_create_group(&cpi_kset->kobj, &cpi_attr_group);
    if (rc)
        kset_unregister(cpi_kset);

    return rc;
}

__initcall(cpi_init);