// SPDX-License-Identifier: GPL-2.0
/*
 * Driver for s390 chsc subchannels
 *
 * Copyright IBM Corp. 2008, 2011
 *
 * Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
 *
 */

#include <linux/slab.h>
#include <linux/compat.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/uaccess.h>
#include <linux/miscdevice.h>
#include <linux/kernel_stat.h>

#include <asm/cio.h>
#include <asm/chsc.h>
#include <asm/isc.h>

#include "cio.h"
#include "cio_debug.h"
#include "css.h"
#include "chsc_sch.h"
#include "ioasm.h"

static debug_info_t *chsc_debug_msg_id;
static debug_info_t *chsc_debug_log_id;

static struct chsc_request *on_close_request;
static struct chsc_async_area *on_close_chsc_area;
static DEFINE_MUTEX(on_close_mutex);

#define CHSC_MSG(imp, args...) do {                                     \
                debug_sprintf_event(chsc_debug_msg_id, imp , ##args);   \
        } while (0)

#define CHSC_LOG(imp, txt) do {                                 \
                debug_text_event(chsc_debug_log_id, imp , txt); \
        } while (0)

static void CHSC_LOG_HEX(int level, void *data, int length)
{
        debug_event(chsc_debug_log_id, level, data, length);
}

MODULE_AUTHOR("IBM Corporation");
MODULE_DESCRIPTION("driver for s390 chsc subchannels");
MODULE_LICENSE("GPL");

static void chsc_subchannel_irq(struct subchannel *sch)
{
        struct chsc_private *private = dev_get_drvdata(&sch->dev);
        struct chsc_request *request = private->request;
        struct irb *irb = this_cpu_ptr(&cio_irb);

        CHSC_LOG(4, "irb");
        CHSC_LOG_HEX(4, irb, sizeof(*irb));
        inc_irq_stat(IRQIO_CSC);

        /* Copy irb to provided request and set done. */
        if (!request) {
                CHSC_MSG(0, "Interrupt on sch 0.%x.%04x with no request\n",
                         sch->schid.ssid, sch->schid.sch_no);
                return;
        }
        private->request = NULL;
        memcpy(&request->irb, irb, sizeof(*irb));
        cio_update_schib(sch);
        complete(&request->completion);
        put_device(&sch->dev);
}

static int chsc_subchannel_probe(struct subchannel *sch)
{
        struct chsc_private *private;
        int ret;

        CHSC_MSG(6, "Detected chsc subchannel 0.%x.%04x\n",
                 sch->schid.ssid, sch->schid.sch_no);
        sch->isc = CHSC_SCH_ISC;
        private = kzalloc(sizeof(*private), GFP_KERNEL);
        if (!private)
                return -ENOMEM;
        dev_set_drvdata(&sch->dev, private);
        ret = cio_enable_subchannel(sch, (u32)(unsigned long)sch);
        if (ret) {
                CHSC_MSG(0, "Failed to enable 0.%x.%04x: %d\n",
                         sch->schid.ssid, sch->schid.sch_no, ret);
                dev_set_drvdata(&sch->dev, NULL);
                kfree(private);
        } else {
                if (dev_get_uevent_suppress(&sch->dev)) {
                        dev_set_uevent_suppress(&sch->dev, 0);
                        kobject_uevent(&sch->dev.kobj, KOBJ_ADD);
                }
        }
        return ret;
}

static int chsc_subchannel_remove(struct subchannel *sch)
{
        struct chsc_private *private;

        cio_disable_subchannel(sch);
        private = dev_get_drvdata(&sch->dev);
        dev_set_drvdata(&sch->dev, NULL);
        if (private->request) {
                complete(&private->request->completion);
                put_device(&sch->dev);
        }
        kfree(private);
        return 0;
}

static void chsc_subchannel_shutdown(struct subchannel *sch)
{
        cio_disable_subchannel(sch);
}

static int chsc_subchannel_prepare(struct subchannel *sch)
{
        int cc;
        struct schib schib;
        /*
         * Don't allow suspend while the subchannel is not idle
         * since we don't have a way to clear the subchannel and
         * cannot disable it with a request running.
         */
        cc = stsch(sch->schid, &schib);
        if (!cc && scsw_stctl(&schib.scsw))
                return -EAGAIN;
        return 0;
}

static int chsc_subchannel_freeze(struct subchannel *sch)
{
        return cio_disable_subchannel(sch);
}

static int chsc_subchannel_restore(struct subchannel *sch)
{
        return cio_enable_subchannel(sch, (u32)(unsigned long)sch);
}

static struct css_device_id chsc_subchannel_ids[] = {
        { .match_flags = 0x1, .type =SUBCHANNEL_TYPE_CHSC, },
        { /* end of list */ },
};
MODULE_DEVICE_TABLE(css, chsc_subchannel_ids);

static struct css_driver chsc_subchannel_driver = {
        .drv = {
                .owner = THIS_MODULE,
                .name = "chsc_subchannel",
        },
        .subchannel_type = chsc_subchannel_ids,
        .irq = chsc_subchannel_irq,
        .probe = chsc_subchannel_probe,
        .remove = chsc_subchannel_remove,
        .shutdown = chsc_subchannel_shutdown,
        .prepare = chsc_subchannel_prepare,
        .freeze = chsc_subchannel_freeze,
        .thaw = chsc_subchannel_restore,
        .restore = chsc_subchannel_restore,
};

static int __init chsc_init_dbfs(void)
{
        chsc_debug_msg_id = debug_register("chsc_msg", 8, 1, 4 * sizeof(long));
        if (!chsc_debug_msg_id)
                goto out;
        debug_register_view(chsc_debug_msg_id, &debug_sprintf_view);
        debug_set_level(chsc_debug_msg_id, 2);
        chsc_debug_log_id = debug_register("chsc_log", 16, 1, 16);
        if (!chsc_debug_log_id)
                goto out;
        debug_register_view(chsc_debug_log_id, &debug_hex_ascii_view);
        debug_set_level(chsc_debug_log_id, 2);
        return 0;
out:
        debug_unregister(chsc_debug_msg_id);
        return -ENOMEM;
}

static void chsc_remove_dbfs(void)
{
        debug_unregister(chsc_debug_log_id);
        debug_unregister(chsc_debug_msg_id);
}

static int __init chsc_init_sch_driver(void)
{
        return css_driver_register(&chsc_subchannel_driver);
}

static void chsc_cleanup_sch_driver(void)
{
        css_driver_unregister(&chsc_subchannel_driver);
}

static DEFINE_SPINLOCK(chsc_lock);

static int chsc_subchannel_match_next_free(struct device *dev, const void *data)
{
        struct subchannel *sch = to_subchannel(dev);

        return sch->schib.pmcw.ena && !scsw_fctl(&sch->schib.scsw);
}

static struct subchannel *chsc_get_next_subchannel(struct subchannel *sch)
{
        struct device *dev;

        dev = driver_find_device(&chsc_subchannel_driver.drv,
                                 sch ? &sch->dev : NULL, NULL,
                                 chsc_subchannel_match_next_free);
        return dev ? to_subchannel(dev) : NULL;
}

/**
 * chsc_async() - try to start a chsc request asynchronously
 * @chsc_area: request to be started
 * @request: request structure to associate
 *
 * Tries to start a chsc request on one of the existing chsc subchannels.
 * Returns:
 *  %0 if the request was performed synchronously
 *  %-EINPROGRESS if the request was successfully started
 *  %-EBUSY if all chsc subchannels are busy
 *  %-ENODEV if no chsc subchannels are available
 * Context:
 *  interrupts disabled, chsc_lock held
 */
static int chsc_async(struct chsc_async_area *chsc_area,
                      struct chsc_request *request)
{
        int cc;
        struct chsc_private *private;
        struct subchannel *sch = NULL;
        int ret = -ENODEV;
        char dbf[10];

        chsc_area->header.key = PAGE_DEFAULT_KEY >> 4;
        while ((sch = chsc_get_next_subchannel(sch))) {
                spin_lock(sch->lock);
                private = dev_get_drvdata(&sch->dev);
                if (private->request) {
                        spin_unlock(sch->lock);
                        ret = -EBUSY;
                        continue;
                }
                chsc_area->header.sid = sch->schid;
                CHSC_LOG(2, "schid");
                CHSC_LOG_HEX(2, &sch->schid, sizeof(sch->schid));
                cc = chsc(chsc_area);
                snprintf(dbf, sizeof(dbf), "cc:%d", cc);
                CHSC_LOG(2, dbf);
                switch (cc) {
                case 0:
                        ret = 0;
                        break;
                case 1:
                        sch->schib.scsw.cmd.fctl |= SCSW_FCTL_START_FUNC;
                        ret = -EINPROGRESS;
                        private->request = request;
                        break;
                case 2:
                        ret = -EBUSY;
                        break;
                default:
                        ret = -ENODEV;
                }
                spin_unlock(sch->lock);
                CHSC_MSG(2, "chsc on 0.%x.%04x returned cc=%d\n",
                         sch->schid.ssid, sch->schid.sch_no, cc);
                if (ret == -EINPROGRESS)
                        return -EINPROGRESS;
                put_device(&sch->dev);
                if (ret == 0)
                        return 0;
        }
        return ret;
}

static void chsc_log_command(void *chsc_area)
{
        char dbf[10];

        snprintf(dbf, sizeof(dbf), "CHSC:%x", ((uint16_t *)chsc_area)[1]);
        CHSC_LOG(0, dbf);
        CHSC_LOG_HEX(0, chsc_area, 32);
}

static int chsc_examine_irb(struct chsc_request *request)
{
        int backed_up;

        if (!(scsw_stctl(&request->irb.scsw) & SCSW_STCTL_STATUS_PEND))
                return -EIO;
        backed_up = scsw_cstat(&request->irb.scsw) & SCHN_STAT_CHAIN_CHECK;
        request->irb.scsw.cmd.cstat &= ~SCHN_STAT_CHAIN_CHECK;
        if (scsw_cstat(&request->irb.scsw) == 0)
                return 0;
        if (!backed_up)
                return 0;
        if (scsw_cstat(&request->irb.scsw) & SCHN_STAT_PROG_CHECK)
                return -EIO;
        if (scsw_cstat(&request->irb.scsw) & SCHN_STAT_PROT_CHECK)
                return -EPERM;
        if (scsw_cstat(&request->irb.scsw) & SCHN_STAT_CHN_DATA_CHK)
                return -EAGAIN;
        if (scsw_cstat(&request->irb.scsw) & SCHN_STAT_CHN_CTRL_CHK)
                return -EAGAIN;
        return -EIO;
}

static int chsc_ioctl_start(void __user *user_area)
{
        struct chsc_request *request;
        struct chsc_async_area *chsc_area;
        int ret;
        char dbf[10];

        if (!css_general_characteristics.dynio)
                /* It makes no sense to try. */
                return -EOPNOTSUPP;
        chsc_area = (void *)get_zeroed_page(GFP_DMA | GFP_KERNEL);
        if (!chsc_area)
                return -ENOMEM;
        request = kzalloc(sizeof(*request), GFP_KERNEL);
        if (!request) {
                ret = -ENOMEM;
                goto out_free;
        }
        init_completion(&request->completion);
        if (copy_from_user(chsc_area, user_area, PAGE_SIZE)) {
                ret = -EFAULT;
                goto out_free;
        }
        chsc_log_command(chsc_area);
        spin_lock_irq(&chsc_lock);
        ret = chsc_async(chsc_area, request);
        spin_unlock_irq(&chsc_lock);
        if (ret == -EINPROGRESS) {
                wait_for_completion(&request->completion);
                ret = chsc_examine_irb(request);
        }
        /* copy area back to user */
        if (!ret)
                if (copy_to_user(user_area, chsc_area, PAGE_SIZE))
                        ret = -EFAULT;
out_free:
        snprintf(dbf, sizeof(dbf), "ret:%d", ret);
        CHSC_LOG(0, dbf);
        kfree(request);
        free_page((unsigned long)chsc_area);
        return ret;
}

static int chsc_ioctl_on_close_set(void __user *user_area)
{
        char dbf[13];
        int ret;

        mutex_lock(&on_close_mutex);
        if (on_close_chsc_area) {
                ret = -EBUSY;
                goto out_unlock;
        }
        on_close_request = kzalloc(sizeof(*on_close_request), GFP_KERNEL);
        if (!on_close_request) {
                ret = -ENOMEM;
                goto out_unlock;
        }
        on_close_chsc_area = (void *)get_zeroed_page(GFP_DMA | GFP_KERNEL);
        if (!on_close_chsc_area) {
                ret = -ENOMEM;
                goto out_free_request;
        }
        if (copy_from_user(on_close_chsc_area, user_area, PAGE_SIZE)) {
                ret = -EFAULT;
                goto out_free_chsc;
        }
        ret = 0;
        goto out_unlock;

out_free_chsc:
        free_page((unsigned long)on_close_chsc_area);
        on_close_chsc_area = NULL;
out_free_request:
        kfree(on_close_request);
        on_close_request = NULL;
out_unlock:
        mutex_unlock(&on_close_mutex);
        snprintf(dbf, sizeof(dbf), "ocsret:%d", ret);
        CHSC_LOG(0, dbf);
        return ret;
}

static int chsc_ioctl_on_close_remove(void)
{
        char dbf[13];
        int ret;

        mutex_lock(&on_close_mutex);
        if (!on_close_chsc_area) {
                ret = -ENOENT;
                goto out_unlock;
        }
        free_page((unsigned long)on_close_chsc_area);
        on_close_chsc_area = NULL;
        kfree(on_close_request);
        on_close_request = NULL;
        ret = 0;
out_unlock:
        mutex_unlock(&on_close_mutex);
        snprintf(dbf, sizeof(dbf), "ocrret:%d", ret);
        CHSC_LOG(0, dbf);
        return ret;
}

static int chsc_ioctl_start_sync(void __user *user_area)
{
        struct chsc_sync_area *chsc_area;
        int ret, ccode;

        chsc_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
        if (!chsc_area)
                return -ENOMEM;
        if (copy_from_user(chsc_area, user_area, PAGE_SIZE)) {
                ret = -EFAULT;
                goto out_free;
        }
        if (chsc_area->header.code & 0x4000) {
                ret = -EINVAL;
                goto out_free;
        }
        chsc_log_command(chsc_area);
        ccode = chsc(chsc_area);
        if (ccode != 0) {
                ret = -EIO;
                goto out_free;
        }
        if (copy_to_user(user_area, chsc_area, PAGE_SIZE))
                ret = -EFAULT;
        else
                ret = 0;
out_free:
        free_page((unsigned long)chsc_area);
        return ret;
}

static int chsc_ioctl_info_channel_path(void __user *user_cd)
{
        struct chsc_chp_cd *cd;
        int ret, ccode;
        struct {
                struct chsc_header request;
                u32 : 2;
                u32 m : 1;
                u32 : 1;
                u32 fmt1 : 4;
                u32 cssid : 8;
                u32 : 8;
                u32 first_chpid : 8;
                u32 : 24;
                u32 last_chpid : 8;
                u32 : 32;
                struct chsc_header response;
                u8 data[PAGE_SIZE - 20];
        } __attribute__ ((packed)) *scpcd_area;

        scpcd_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
        if (!scpcd_area)
                return -ENOMEM;
        cd = kzalloc(sizeof(*cd), GFP_KERNEL);
        if (!cd) {
                ret = -ENOMEM;
                goto out_free;
        }
        if (copy_from_user(cd, user_cd, sizeof(*cd))) {
                ret = -EFAULT;
                goto out_free;
        }
        scpcd_area->request.length = 0x0010;
        scpcd_area->request.code = 0x0028;
        scpcd_area->m = cd->m;
        scpcd_area->fmt1 = cd->fmt;
        scpcd_area->cssid = cd->chpid.cssid;
        scpcd_area->first_chpid = cd->chpid.id;
        scpcd_area->last_chpid = cd->chpid.id;

        ccode = chsc(scpcd_area);
        if (ccode != 0) {
                ret = -EIO;
                goto out_free;
        }
        if (scpcd_area->response.code != 0x0001) {
                ret = -EIO;
                CHSC_MSG(0, "scpcd: response code=%x\n",
                         scpcd_area->response.code);
                goto out_free;
        }
        memcpy(&cd->cpcb, &scpcd_area->response, scpcd_area->response.length);
        if (copy_to_user(user_cd, cd, sizeof(*cd)))
                ret = -EFAULT;
        else
                ret = 0;
out_free:
        kfree(cd);
        free_page((unsigned long)scpcd_area);
        return ret;
}

static int chsc_ioctl_info_cu(void __user *user_cd)
{
        struct chsc_cu_cd *cd;
        int ret, ccode;
        struct {
                struct chsc_header request;
                u32 : 2;
                u32 m : 1;
                u32 : 1;
                u32 fmt1 : 4;
                u32 cssid : 8;
                u32 : 8;
                u32 first_cun : 8;
                u32 : 24;
                u32 last_cun : 8;
                u32 : 32;
                struct chsc_header response;
                u8 data[PAGE_SIZE - 20];
        } __attribute__ ((packed)) *scucd_area;

        scucd_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
        if (!scucd_area)
                return -ENOMEM;
        cd = kzalloc(sizeof(*cd), GFP_KERNEL);
        if (!cd) {
                ret = -ENOMEM;
                goto out_free;
        }
        if (copy_from_user(cd, user_cd, sizeof(*cd))) {
                ret = -EFAULT;
                goto out_free;
        }
        scucd_area->request.length = 0x0010;
        scucd_area->request.code = 0x0026;
        scucd_area->m = cd->m;
        scucd_area->fmt1 = cd->fmt;
        scucd_area->cssid = cd->cssid;
        scucd_area->first_cun = cd->cun;
        scucd_area->last_cun = cd->cun;

        ccode = chsc(scucd_area);
        if (ccode != 0) {
                ret = -EIO;
                goto out_free;
        }
        if (scucd_area->response.code != 0x0001) {
                ret = -EIO;
                CHSC_MSG(0, "scucd: response code=%x\n",
                         scucd_area->response.code);
                goto out_free;
        }
        memcpy(&cd->cucb, &scucd_area->response, scucd_area->response.length);
        if (copy_to_user(user_cd, cd, sizeof(*cd)))
                ret = -EFAULT;
        else
                ret = 0;
out_free:
        kfree(cd);
        free_page((unsigned long)scucd_area);
        return ret;
}

static int chsc_ioctl_info_sch_cu(void __user *user_cud)
{
        struct chsc_sch_cud *cud;
        int ret, ccode;
        struct {
                struct chsc_header request;
                u32 : 2;
                u32 m : 1;
                u32 : 5;
                u32 fmt1 : 4;
                u32 : 2;
                u32 ssid : 2;
                u32 first_sch : 16;
                u32 : 8;
                u32 cssid : 8;
                u32 last_sch : 16;
                u32 : 32;
                struct chsc_header response;
                u8 data[PAGE_SIZE - 20];
        } __attribute__ ((packed)) *sscud_area;

        sscud_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
        if (!sscud_area)
                return -ENOMEM;
        cud = kzalloc(sizeof(*cud), GFP_KERNEL);
        if (!cud) {
                ret = -ENOMEM;
                goto out_free;
        }
        if (copy_from_user(cud, user_cud, sizeof(*cud))) {
                ret = -EFAULT;
                goto out_free;
        }
        sscud_area->request.length = 0x0010;
        sscud_area->request.code = 0x0006;
        sscud_area->m = cud->schid.m;
        sscud_area->fmt1 = cud->fmt;
        sscud_area->ssid = cud->schid.ssid;
        sscud_area->first_sch = cud->schid.sch_no;
        sscud_area->cssid = cud->schid.cssid;
        sscud_area->last_sch = cud->schid.sch_no;

        ccode = chsc(sscud_area);
        if (ccode != 0) {
                ret = -EIO;
                goto out_free;
        }
        if (sscud_area->response.code != 0x0001) {
                ret = -EIO;
                CHSC_MSG(0, "sscud: response code=%x\n",
                         sscud_area->response.code);
                goto out_free;
        }
        memcpy(&cud->scub, &sscud_area->response, sscud_area->response.length);
        if (copy_to_user(user_cud, cud, sizeof(*cud)))
                ret = -EFAULT;
        else
                ret = 0;
out_free:
        kfree(cud);
        free_page((unsigned long)sscud_area);
        return ret;
}

static int chsc_ioctl_conf_info(void __user *user_ci)
{
        struct chsc_conf_info *ci;
        int ret, ccode;
        struct {
                struct chsc_header request;
                u32 : 2;
                u32 m : 1;
                u32 : 1;
                u32 fmt1 : 4;
                u32 cssid : 8;
                u32 : 6;
                u32 ssid : 2;
                u32 : 8;
                u64 : 64;
                struct chsc_header response;
                u8 data[PAGE_SIZE - 20];
        } __attribute__ ((packed)) *sci_area;

        sci_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
        if (!sci_area)
                return -ENOMEM;
        ci = kzalloc(sizeof(*ci), GFP_KERNEL);
        if (!ci) {
                ret = -ENOMEM;
                goto out_free;
        }
        if (copy_from_user(ci, user_ci, sizeof(*ci))) {
                ret = -EFAULT;
                goto out_free;
        }
        sci_area->request.length = 0x0010;
        sci_area->request.code = 0x0012;
        sci_area->m = ci->id.m;
        sci_area->fmt1 = ci->fmt;
        sci_area->cssid = ci->id.cssid;
        sci_area->ssid = ci->id.ssid;

        ccode = chsc(sci_area);
        if (ccode != 0) {
                ret = -EIO;
                goto out_free;
        }
        if (sci_area->response.code != 0x0001) {
                ret = -EIO;
                CHSC_MSG(0, "sci: response code=%x\n",
                         sci_area->response.code);
                goto out_free;
        }
        memcpy(&ci->scid, &sci_area->response, sci_area->response.length);
        if (copy_to_user(user_ci, ci, sizeof(*ci)))
                ret = -EFAULT;
        else
                ret = 0;
out_free:
        kfree(ci);
        free_page((unsigned long)sci_area);
        return ret;
}

static int chsc_ioctl_conf_comp_list(void __user *user_ccl)
{
        struct chsc_comp_list *ccl;
        int ret, ccode;
        struct {
                struct chsc_header request;
                u32 ctype : 8;
                u32 : 4;
                u32 fmt : 4;
                u32 : 16;
                u64 : 64;
                u32 list_parm[2];
                u64 : 64;
                struct chsc_header response;
                u8 data[PAGE_SIZE - 36];
        } __attribute__ ((packed)) *sccl_area;
        struct {
                u32 m : 1;
                u32 : 31;
                u32 cssid : 8;
                u32 : 16;
                u32 chpid : 8;
        } __attribute__ ((packed)) *chpid_parm;
        struct {
                u32 f_cssid : 8;
                u32 l_cssid : 8;
                u32 : 16;
                u32 res;
        } __attribute__ ((packed)) *cssids_parm;

        sccl_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
        if (!sccl_area)
                return -ENOMEM;
        ccl = kzalloc(sizeof(*ccl), GFP_KERNEL);
        if (!ccl) {
                ret = -ENOMEM;
                goto out_free;
        }
        if (copy_from_user(ccl, user_ccl, sizeof(*ccl))) {
                ret = -EFAULT;
                goto out_free;
        }
        sccl_area->request.length = 0x0020;
        sccl_area->request.code = 0x0030;
        sccl_area->fmt = ccl->req.fmt;
        sccl_area->ctype = ccl->req.ctype;
        switch (sccl_area->ctype) {
        case CCL_CU_ON_CHP:
        case CCL_IOP_CHP:
                chpid_parm = (void *)&sccl_area->list_parm;
                chpid_parm->m = ccl->req.chpid.m;
                chpid_parm->cssid = ccl->req.chpid.chp.cssid;
                chpid_parm->chpid = ccl->req.chpid.chp.id;
                break;
        case CCL_CSS_IMG:
        case CCL_CSS_IMG_CONF_CHAR:
                cssids_parm = (void *)&sccl_area->list_parm;
                cssids_parm->f_cssid = ccl->req.cssids.f_cssid;
                cssids_parm->l_cssid = ccl->req.cssids.l_cssid;
                break;
        }
        ccode = chsc(sccl_area);
        if (ccode != 0) {
                ret = -EIO;
                goto out_free;
        }
        if (sccl_area->response.code != 0x0001) {
                ret = -EIO;
                CHSC_MSG(0, "sccl: response code=%x\n",
                         sccl_area->response.code);
                goto out_free;
        }
        memcpy(&ccl->sccl, &sccl_area->response, sccl_area->response.length);
        if (copy_to_user(user_ccl, ccl, sizeof(*ccl)))
                ret = -EFAULT;
        else
                ret = 0;
out_free:
        kfree(ccl);
        free_page((unsigned long)sccl_area);
        return ret;
}

static int chsc_ioctl_chpd(void __user *user_chpd)
{
        struct chsc_scpd *scpd_area;
        struct chsc_cpd_info *chpd;
        int ret;

        chpd = kzalloc(sizeof(*chpd), GFP_KERNEL);
        scpd_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
        if (!scpd_area || !chpd) {
                ret = -ENOMEM;
                goto out_free;
        }
        if (copy_from_user(chpd, user_chpd, sizeof(*chpd))) {
                ret = -EFAULT;
                goto out_free;
        }
        ret = chsc_determine_channel_path_desc(chpd->chpid, chpd->fmt,
                                               chpd->rfmt, chpd->c, chpd->m,
                                               scpd_area);
        if (ret)
                goto out_free;
        memcpy(&chpd->chpdb, &scpd_area->response, scpd_area->response.length);
        if (copy_to_user(user_chpd, chpd, sizeof(*chpd)))
                ret = -EFAULT;
out_free:
        kfree(chpd);
        free_page((unsigned long)scpd_area);
        return ret;
}

static int chsc_ioctl_dcal(void __user *user_dcal)
{
        struct chsc_dcal *dcal;
        int ret, ccode;
        struct {
                struct chsc_header request;
                u32 atype : 8;
                u32 : 4;
                u32 fmt : 4;
                u32 : 16;
                u32 res0[2];
                u32 list_parm[2];
                u32 res1[2];
                struct chsc_header response;
                u8 data[PAGE_SIZE - 36];
        } __attribute__ ((packed)) *sdcal_area;

        sdcal_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
        if (!sdcal_area)
                return -ENOMEM;
        dcal = kzalloc(sizeof(*dcal), GFP_KERNEL);
        if (!dcal) {
                ret = -ENOMEM;
                goto out_free;
        }
        if (copy_from_user(dcal, user_dcal, sizeof(*dcal))) {
                ret = -EFAULT;
                goto out_free;
        }
        sdcal_area->request.length = 0x0020;
        sdcal_area->request.code = 0x0034;
        sdcal_area->atype = dcal->req.atype;
        sdcal_area->fmt = dcal->req.fmt;
        memcpy(&sdcal_area->list_parm, &dcal->req.list_parm,
               sizeof(sdcal_area->list_parm));

        ccode = chsc(sdcal_area);
        if (ccode != 0) {
                ret = -EIO;
                goto out_free;
        }
        if (sdcal_area->response.code != 0x0001) {
                ret = -EIO;
                CHSC_MSG(0, "sdcal: response code=%x\n",
                         sdcal_area->response.code);
                goto out_free;
        }
        memcpy(&dcal->sdcal, &sdcal_area->response,
               sdcal_area->response.length);
        if (copy_to_user(user_dcal, dcal, sizeof(*dcal)))
                ret = -EFAULT;
        else
                ret = 0;
out_free:
        kfree(dcal);
        free_page((unsigned long)sdcal_area);
        return ret;
}

static long chsc_ioctl(struct file *filp, unsigned int cmd,
                       unsigned long arg)
{
        void __user *argp;

        CHSC_MSG(2, "chsc_ioctl called, cmd=%x\n", cmd);
        if (is_compat_task())
                argp = compat_ptr(arg);
        else
                argp = (void __user *)arg;
        switch (cmd) {
        case CHSC_START:
                return chsc_ioctl_start(argp);
        case CHSC_START_SYNC:
                return chsc_ioctl_start_sync(argp);
        case CHSC_INFO_CHANNEL_PATH:
                return chsc_ioctl_info_channel_path(argp);
        case CHSC_INFO_CU:
                return chsc_ioctl_info_cu(argp);
        case CHSC_INFO_SCH_CU:
                return chsc_ioctl_info_sch_cu(argp);
        case CHSC_INFO_CI:
                return chsc_ioctl_conf_info(argp);
        case CHSC_INFO_CCL:
                return chsc_ioctl_conf_comp_list(argp);
        case CHSC_INFO_CPD:
                return chsc_ioctl_chpd(argp);
        case CHSC_INFO_DCAL:
                return chsc_ioctl_dcal(argp);
        case CHSC_ON_CLOSE_SET:
                return chsc_ioctl_on_close_set(argp);
        case CHSC_ON_CLOSE_REMOVE:
                return chsc_ioctl_on_close_remove();
        default: /* unknown ioctl number */
                return -ENOIOCTLCMD;
        }
}

static atomic_t chsc_ready_for_use = ATOMIC_INIT(1);

static int chsc_open(struct inode *inode, struct file *file)
{
        if (!atomic_dec_and_test(&chsc_ready_for_use)) {
                atomic_inc(&chsc_ready_for_use);
                return -EBUSY;
        }
        return nonseekable_open(inode, file);
}

static int chsc_release(struct inode *inode, struct file *filp)
{
        char dbf[13];
        int ret;

        mutex_lock(&on_close_mutex);
        if (!on_close_chsc_area)
                goto out_unlock;
        init_completion(&on_close_request->completion);
        CHSC_LOG(0, "on_close");
        chsc_log_command(on_close_chsc_area);
        spin_lock_irq(&chsc_lock);
        ret = chsc_async(on_close_chsc_area, on_close_request);
        spin_unlock_irq(&chsc_lock);
        if (ret == -EINPROGRESS) {
                wait_for_completion(&on_close_request->completion);
                ret = chsc_examine_irb(on_close_request);
        }
        snprintf(dbf, sizeof(dbf), "relret:%d", ret);
        CHSC_LOG(0, dbf);
        free_page((unsigned long)on_close_chsc_area);
        on_close_chsc_area = NULL;
        kfree(on_close_request);
        on_close_request = NULL;
out_unlock:
        mutex_unlock(&on_close_mutex);
        atomic_inc(&chsc_ready_for_use);
        return 0;
}

static const struct file_operations chsc_fops = {
        .owner = THIS_MODULE,
        .open = chsc_open,
        .release = chsc_release,
        .unlocked_ioctl = chsc_ioctl,
        .compat_ioctl = chsc_ioctl,
        .llseek = no_llseek,
};

static struct miscdevice chsc_misc_device = {
        .minor = MISC_DYNAMIC_MINOR,
        .name = "chsc",
        .fops = &chsc_fops,
};

static int __init chsc_misc_init(void)
{
        return misc_register(&chsc_misc_device);
}

static void chsc_misc_cleanup(void)
{
        misc_deregister(&chsc_misc_device);
}

static int __init chsc_sch_init(void)
{
        int ret;

        ret = chsc_init_dbfs();
        if (ret)
                return ret;
        isc_register(CHSC_SCH_ISC);
        ret = chsc_init_sch_driver();
        if (ret)
                goto out_dbf;
        ret = chsc_misc_init();
        if (ret)
                goto out_driver;
        return ret;
out_driver:
        chsc_cleanup_sch_driver();
out_dbf:
        isc_unregister(CHSC_SCH_ISC);
        chsc_remove_dbfs();
        return ret;

}

static void __exit chsc_sch_exit(void)
{
        chsc_misc_cleanup();
        chsc_cleanup_sch_driver();
        isc_unregister(CHSC_SCH_ISC);
        chsc_remove_dbfs();
}

module_init(chsc_sch_init);
module_exit(chsc_sch_exit);