// SPDX-License-Identifier: GPL-2.0
/*
 * Author(s)......: Holger Smolinski <Holger.Smolinski@de.ibm.com>
 *                  Horst Hummel <Horst.Hummel@de.ibm.com>
 *                  Carsten Otte <Cotte@de.ibm.com>
 *                  Martin Schwidefsky <schwidefsky@de.ibm.com>
 * Bugreports.to..: <Linux390@de.ibm.com>
 * Copyright IBM Corp. 1999, 2001
 *
 * i/o controls for the dasd driver.
 */

#include <linux/interrupt.h>
#include <linux/export.h>
#include <linux/major.h>
#include <linux/fs.h>
#include <linux/blkpg.h>
#include <linux/slab.h>
#include <asm/ccwdev.h>
#include <asm/schid.h>
#include <asm/cmb.h>
#include <linux/uaccess.h>
#include <linux/dasd_mod.h>

#include "dasd_int.h"

static int
dasd_ioctl_api_version(void __user *argp)
{
        int ver = DASD_API_VERSION;
        return put_user(ver, (int __user *)argp);
}

/*
 * Enable device.
 * used by dasdfmt after BIODASDDISABLE to retrigger blocksize detection
 */
static int
dasd_ioctl_enable(struct block_device *bdev)
{
        struct dasd_device *base;

        if (!capable(CAP_SYS_ADMIN))
                return -EACCES;

        base = dasd_device_from_gendisk(bdev->bd_disk);
        if (!base)
                return -ENODEV;

        dasd_enable_device(base);
        dasd_put_device(base);
        return 0;
}

/*
 * Disable device.
 * Used by dasdfmt. Disable I/O operations but allow ioctls.
 */
static int
dasd_ioctl_disable(struct block_device *bdev)
{
        struct dasd_device *base;

        if (!capable(CAP_SYS_ADMIN))
                return -EACCES;

        base = dasd_device_from_gendisk(bdev->bd_disk);
        if (!base)
                return -ENODEV;
        /*
         * Man this is sick. We don't do a real disable but only downgrade
         * the device to DASD_STATE_BASIC. The reason is that dasdfmt uses
         * BIODASDDISABLE to disable accesses to the device via the block
         * device layer but it still wants to do i/o on the device by
         * using the BIODASDFMT ioctl. Therefore the correct state for the
         * device is DASD_STATE_BASIC that allows to do basic i/o.
         */
        dasd_set_target_state(base, DASD_STATE_BASIC);
        /*
         * Set i_size to zero, since read, write, etc. check against this
         * value.
         */
        set_capacity(bdev->bd_disk, 0);
        dasd_put_device(base);
        return 0;
}

/*
 * Quiesce device.
 */
static int dasd_ioctl_quiesce(struct dasd_block *block)
{
        unsigned long flags;
        struct dasd_device *base;

        base = block->base;
        if (!capable (CAP_SYS_ADMIN))
                return -EACCES;

        pr_info("%s: The DASD has been put in the quiesce "
                "state\n", dev_name(&base->cdev->dev));
        spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
        dasd_device_set_stop_bits(base, DASD_STOPPED_QUIESCE);
        spin_unlock_irqrestore(get_ccwdev_lock(base->cdev), flags);
        return 0;
}


/*
 * Resume device.
 */
static int dasd_ioctl_resume(struct dasd_block *block)
{
        unsigned long flags;
        struct dasd_device *base;

        base = block->base;
        if (!capable (CAP_SYS_ADMIN))
                return -EACCES;

        pr_info("%s: I/O operations have been resumed "
                "on the DASD\n", dev_name(&base->cdev->dev));
        spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
        dasd_device_remove_stop_bits(base, DASD_STOPPED_QUIESCE);
        spin_unlock_irqrestore(get_ccwdev_lock(base->cdev), flags);

        dasd_schedule_block_bh(block);
        dasd_schedule_device_bh(base);
        return 0;
}

/*
 * Abort all failfast I/O on a device.
 */
static int dasd_ioctl_abortio(struct dasd_block *block)
{
        unsigned long flags;
        struct dasd_device *base;
        struct dasd_ccw_req *cqr, *n;

        base = block->base;
        if (!capable(CAP_SYS_ADMIN))
                return -EACCES;

        if (test_and_set_bit(DASD_FLAG_ABORTALL, &base->flags))
                return 0;
        DBF_DEV_EVENT(DBF_NOTICE, base, "%s", "abortall flag set");

        spin_lock_irqsave(&block->request_queue_lock, flags);
        spin_lock(&block->queue_lock);
        list_for_each_entry_safe(cqr, n, &block->ccw_queue, blocklist) {
                if (test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) &&
                    cqr->callback_data &&
                    cqr->callback_data != DASD_SLEEPON_START_TAG &&
                    cqr->callback_data != DASD_SLEEPON_END_TAG) {
                        spin_unlock(&block->queue_lock);
                        blk_abort_request(cqr->callback_data);
                        spin_lock(&block->queue_lock);
                }
        }
        spin_unlock(&block->queue_lock);
        spin_unlock_irqrestore(&block->request_queue_lock, flags);

        dasd_schedule_block_bh(block);
        return 0;
}

/*
 * Allow I/O on a device
 */
static int dasd_ioctl_allowio(struct dasd_block *block)
{
        struct dasd_device *base;

        base = block->base;
        if (!capable(CAP_SYS_ADMIN))
                return -EACCES;

        if (test_and_clear_bit(DASD_FLAG_ABORTALL, &base->flags))
                DBF_DEV_EVENT(DBF_NOTICE, base, "%s", "abortall flag unset");

        return 0;
}

/*
 * performs formatting of _device_ according to _fdata_
 * Note: The discipline's format_function is assumed to deliver formatting
 * commands to format multiple units of the device. In terms of the ECKD
 * devices this means CCWs are generated to format multiple tracks.
 */
static int
dasd_format(struct dasd_block *block, struct format_data_t *fdata)
{
        struct dasd_device *base;
        int rc;

        base = block->base;
        if (base->discipline->format_device == NULL)
                return -EPERM;

        if (base->state != DASD_STATE_BASIC) {
                pr_warn("%s: The DASD cannot be formatted while it is enabled\n",
                        dev_name(&base->cdev->dev));
                return -EBUSY;
        }

        DBF_DEV_EVENT(DBF_NOTICE, base,
                      "formatting units %u to %u (%u B blocks) flags %u",
                      fdata->start_unit,
                      fdata->stop_unit, fdata->blksize, fdata->intensity);

        /* Since dasdfmt keeps the device open after it was disabled,
         * there still exists an inode for this device.
         * We must update i_blkbits, otherwise we might get errors when
         * enabling the device later.
         */
        if (fdata->start_unit == 0) {
                block->gdp->part0->bd_mapping->host->i_blkbits =
                        blksize_bits(fdata->blksize);
        }

        rc = base->discipline->format_device(base, fdata, 1);
        if (rc == -EAGAIN)
                rc = base->discipline->format_device(base, fdata, 0);

        return rc;
}

static int dasd_check_format(struct dasd_block *block,
                             struct format_check_t *cdata)
{
        struct dasd_device *base;
        int rc;

        base = block->base;
        if (!base->discipline->check_device_format)
                return -ENOTTY;

        rc = base->discipline->check_device_format(base, cdata, 1);
        if (rc == -EAGAIN)
                rc = base->discipline->check_device_format(base, cdata, 0);

        return rc;
}

/*
 * Format device.
 */
static int
dasd_ioctl_format(struct block_device *bdev, void __user *argp)
{
        struct dasd_device *base;
        struct format_data_t fdata;
        int rc;

        if (!capable(CAP_SYS_ADMIN))
                return -EACCES;
        if (!argp)
                return -EINVAL;
        base = dasd_device_from_gendisk(bdev->bd_disk);
        if (!base)
                return -ENODEV;
        if (base->features & DASD_FEATURE_READONLY ||
            test_bit(DASD_FLAG_DEVICE_RO, &base->flags)) {
                dasd_put_device(base);
                return -EROFS;
        }
        if (copy_from_user(&fdata, argp, sizeof(struct format_data_t))) {
                dasd_put_device(base);
                return -EFAULT;
        }
        if (bdev_is_partition(bdev)) {
                pr_warn("%s: The specified DASD is a partition and cannot be formatted\n",
                        dev_name(&base->cdev->dev));
                dasd_put_device(base);
                return -EINVAL;
        }
        rc = dasd_format(base->block, &fdata);
        dasd_put_device(base);

        return rc;
}

/*
 * Check device format
 */
static int dasd_ioctl_check_format(struct block_device *bdev, void __user *argp)
{
        struct format_check_t cdata;
        struct dasd_device *base;
        int rc = 0;

        if (!argp)
                return -EINVAL;

        base = dasd_device_from_gendisk(bdev->bd_disk);
        if (!base)
                return -ENODEV;
        if (bdev_is_partition(bdev)) {
                pr_warn("%s: The specified DASD is a partition and cannot be checked\n",
                        dev_name(&base->cdev->dev));
                rc = -EINVAL;
                goto out_err;
        }

        if (copy_from_user(&cdata, argp, sizeof(cdata))) {
                rc = -EFAULT;
                goto out_err;
        }

        rc = dasd_check_format(base->block, &cdata);
        if (rc)
                goto out_err;

        if (copy_to_user(argp, &cdata, sizeof(cdata)))
                rc = -EFAULT;

out_err:
        dasd_put_device(base);

        return rc;
}

static int dasd_release_space(struct dasd_device *device,
                              struct format_data_t *rdata)
{
        if (!device->discipline->is_ese && !device->discipline->is_ese(device))
                return -ENOTSUPP;
        if (!device->discipline->release_space)
                return -ENOTSUPP;

        return device->discipline->release_space(device, rdata);
}

/*
 * Release allocated space
 */
static int dasd_ioctl_release_space(struct block_device *bdev, void __user *argp)
{
        struct format_data_t rdata;
        struct dasd_device *base;
        int rc = 0;

        if (!capable(CAP_SYS_ADMIN))
                return -EACCES;
        if (!argp)
                return -EINVAL;

        base = dasd_device_from_gendisk(bdev->bd_disk);
        if (!base)
                return -ENODEV;
        if (base->features & DASD_FEATURE_READONLY ||
            test_bit(DASD_FLAG_DEVICE_RO, &base->flags)) {
                rc = -EROFS;
                goto out_err;
        }
        if (bdev_is_partition(bdev)) {
                pr_warn("%s: The specified DASD is a partition and tracks cannot be released\n",
                        dev_name(&base->cdev->dev));
                rc = -EINVAL;
                goto out_err;
        }

        if (copy_from_user(&rdata, argp, sizeof(rdata))) {
                rc = -EFAULT;
                goto out_err;
        }

        rc = dasd_release_space(base, &rdata);

out_err:
        dasd_put_device(base);

        return rc;
}

/*
 * Swap driver iternal copy relation.
 */
static int
dasd_ioctl_copy_pair_swap(struct block_device *bdev, void __user *argp)
{
        struct dasd_copypair_swap_data_t data;
        struct dasd_device *device;
        int rc;

        if (!capable(CAP_SYS_ADMIN))
                return -EACCES;

        device = dasd_device_from_gendisk(bdev->bd_disk);
        if (!device)
                return -ENODEV;

        if (copy_from_user(&data, argp, sizeof(struct dasd_copypair_swap_data_t))) {
                dasd_put_device(device);
                return -EFAULT;
        }
        if (memchr_inv(data.reserved, 0, sizeof(data.reserved))) {
                pr_warn("%s: Invalid swap data specified\n",
                        dev_name(&device->cdev->dev));
                dasd_put_device(device);
                return DASD_COPYPAIRSWAP_INVALID;
        }
        if (bdev_is_partition(bdev)) {
                pr_warn("%s: The specified DASD is a partition and cannot be swapped\n",
                        dev_name(&device->cdev->dev));
                dasd_put_device(device);
                return DASD_COPYPAIRSWAP_INVALID;
        }
        if (!device->copy) {
                pr_warn("%s: The specified DASD has no copy pair set up\n",
                        dev_name(&device->cdev->dev));
                dasd_put_device(device);
                return -ENODEV;
        }
        if (!device->discipline->copy_pair_swap) {
                dasd_put_device(device);
                return -EOPNOTSUPP;
        }
        rc = device->discipline->copy_pair_swap(device, data.primary,
                                                data.secondary);
        dasd_put_device(device);

        return rc;
}

#ifdef CONFIG_DASD_PROFILE
/*
 * Reset device profile information
 */
static int dasd_ioctl_reset_profile(struct dasd_block *block)
{
        dasd_profile_reset(&block->profile);
        return 0;
}

/*
 * Return device profile information
 */
static int dasd_ioctl_read_profile(struct dasd_block *block, void __user *argp)
{
        struct dasd_profile_info_t *data;
        int rc = 0;

        data = kmalloc_obj(*data);
        if (!data)
                return -ENOMEM;

        spin_lock_bh(&block->profile.lock);
        if (block->profile.data) {
                data->dasd_io_reqs = block->profile.data->dasd_io_reqs;
                data->dasd_io_sects = block->profile.data->dasd_io_sects;
                memcpy(data->dasd_io_secs, block->profile.data->dasd_io_secs,
                       sizeof(data->dasd_io_secs));
                memcpy(data->dasd_io_times, block->profile.data->dasd_io_times,
                       sizeof(data->dasd_io_times));
                memcpy(data->dasd_io_timps, block->profile.data->dasd_io_timps,
                       sizeof(data->dasd_io_timps));
                memcpy(data->dasd_io_time1, block->profile.data->dasd_io_time1,
                       sizeof(data->dasd_io_time1));
                memcpy(data->dasd_io_time2, block->profile.data->dasd_io_time2,
                       sizeof(data->dasd_io_time2));
                memcpy(data->dasd_io_time2ps,
                       block->profile.data->dasd_io_time2ps,
                       sizeof(data->dasd_io_time2ps));
                memcpy(data->dasd_io_time3, block->profile.data->dasd_io_time3,
                       sizeof(data->dasd_io_time3));
                memcpy(data->dasd_io_nr_req,
                       block->profile.data->dasd_io_nr_req,
                       sizeof(data->dasd_io_nr_req));
                spin_unlock_bh(&block->profile.lock);
        } else {
                spin_unlock_bh(&block->profile.lock);
                rc = -EIO;
                goto out;
        }
        if (copy_to_user(argp, data, sizeof(*data)))
                rc = -EFAULT;
out:
        kfree(data);
        return rc;
}
#else
static int dasd_ioctl_reset_profile(struct dasd_block *block)
{
        return -ENOTTY;
}

static int dasd_ioctl_read_profile(struct dasd_block *block, void __user *argp)
{
        return -ENOTTY;
}
#endif

/*
 * Return dasd information. Used for BIODASDINFO and BIODASDINFO2.
 */
static int __dasd_ioctl_information(struct dasd_block *block,
                struct dasd_information2_t *dasd_info)
{
        struct subchannel_id sch_id;
        struct ccw_dev_id dev_id;
        struct dasd_device *base;
        struct ccw_device *cdev;
        struct list_head *l;
        unsigned long flags;
        int rc;

        base = block->base;
        if (!base->discipline || !base->discipline->fill_info)
                return -EINVAL;

        rc = base->discipline->fill_info(base, dasd_info);
        if (rc)
                return rc;

        cdev = base->cdev;
        ccw_device_get_id(cdev, &dev_id);
        ccw_device_get_schid(cdev, &sch_id);

        dasd_info->devno = dev_id.devno;
        dasd_info->schid = sch_id.sch_no;
        dasd_info->cu_type = cdev->id.cu_type;
        dasd_info->cu_model = cdev->id.cu_model;
        dasd_info->dev_type = cdev->id.dev_type;
        dasd_info->dev_model = cdev->id.dev_model;
        dasd_info->status = base->state;
        /*
         * The open_count is increased for every opener, that includes
         * the blkdev_get in dasd_scan_partitions.
         * This must be hidden from user-space.
         */
        dasd_info->open_count = atomic_read(&block->open_count);
        if (!block->bdev_file)
                dasd_info->open_count++;

        /*
         * check if device is really formatted
         * LDL / CDL was returned by 'fill_info'
         */
        if ((base->state < DASD_STATE_READY) ||
            (dasd_check_blocksize(block->bp_block)))
                dasd_info->format = DASD_FORMAT_NONE;

        dasd_info->features |=
                ((base->features & DASD_FEATURE_READONLY) != 0);

        memcpy(dasd_info->type, base->discipline->name, 4);

        spin_lock_irqsave(get_ccwdev_lock(base->cdev), flags);
        list_for_each(l, &base->ccw_queue)
                dasd_info->chanq_len++;
        spin_unlock_irqrestore(get_ccwdev_lock(base->cdev), flags);
        return 0;
}

static int dasd_ioctl_information(struct dasd_block *block, void __user *argp,
                size_t copy_size)
{
        struct dasd_information2_t *dasd_info;
        int error;

        dasd_info = kzalloc_obj(*dasd_info);
        if (!dasd_info)
                return -ENOMEM;

        error = __dasd_ioctl_information(block, dasd_info);
        if (!error && copy_to_user(argp, dasd_info, copy_size))
                error = -EFAULT;
        kfree(dasd_info);
        return error;
}

/*
 * Set read only
 */
int dasd_set_read_only(struct block_device *bdev, bool ro)
{
        struct dasd_device *base;
        int rc;

        /* do not manipulate hardware state for partitions */
        if (bdev_is_partition(bdev))
                return 0;

        base = dasd_device_from_gendisk(bdev->bd_disk);
        if (!base)
                return -ENODEV;
        if (!ro && test_bit(DASD_FLAG_DEVICE_RO, &base->flags))
                rc = -EROFS;
        else
                rc = dasd_set_feature(base->cdev, DASD_FEATURE_READONLY, ro);
        dasd_put_device(base);
        return rc;
}

static int dasd_ioctl_readall_cmb(struct dasd_block *block, unsigned int cmd,
                                  struct cmbdata __user *argp)
{
        size_t size = _IOC_SIZE(cmd);
        struct cmbdata data;
        int ret;

        ret = cmf_readall(block->base->cdev, &data);
        if (!ret && copy_to_user(argp, &data, min(size, sizeof(*argp))))
                return -EFAULT;
        return ret;
}

int dasd_ioctl(struct block_device *bdev, blk_mode_t mode,
               unsigned int cmd, unsigned long arg)
{
        struct dasd_block *block;
        struct dasd_device *base;
        void __user *argp;
        int rc;

        argp = (void __user *)arg;

        if ((_IOC_DIR(cmd) != _IOC_NONE) && !arg)
                return -EINVAL;

        base = dasd_device_from_gendisk(bdev->bd_disk);
        if (!base)
                return -ENODEV;
        block = base->block;
        rc = 0;
        switch (cmd) {
        case BIODASDDISABLE:
                rc = dasd_ioctl_disable(bdev);
                break;
        case BIODASDENABLE:
                rc = dasd_ioctl_enable(bdev);
                break;
        case BIODASDQUIESCE:
                rc = dasd_ioctl_quiesce(block);
                break;
        case BIODASDRESUME:
                rc = dasd_ioctl_resume(block);
                break;
        case BIODASDABORTIO:
                rc = dasd_ioctl_abortio(block);
                break;
        case BIODASDALLOWIO:
                rc = dasd_ioctl_allowio(block);
                break;
        case BIODASDFMT:
                rc = dasd_ioctl_format(bdev, argp);
                break;
        case BIODASDCHECKFMT:
                rc = dasd_ioctl_check_format(bdev, argp);
                break;
        case BIODASDINFO:
                rc = dasd_ioctl_information(block, argp,
                                sizeof(struct dasd_information_t));
                break;
        case BIODASDINFO2:
                rc = dasd_ioctl_information(block, argp,
                                sizeof(struct dasd_information2_t));
                break;
        case BIODASDPRRD:
                rc = dasd_ioctl_read_profile(block, argp);
                break;
        case BIODASDPRRST:
                rc = dasd_ioctl_reset_profile(block);
                break;
        case DASDAPIVER:
                rc = dasd_ioctl_api_version(argp);
                break;
        case BIODASDCMFENABLE:
                rc = enable_cmf(base->cdev);
                break;
        case BIODASDCMFDISABLE:
                rc = disable_cmf(base->cdev);
                break;
        case BIODASDREADALLCMB:
                rc = dasd_ioctl_readall_cmb(block, cmd, argp);
                break;
        case BIODASDRAS:
                rc = dasd_ioctl_release_space(bdev, argp);
                break;
        case BIODASDCOPYPAIRSWAP:
                rc = dasd_ioctl_copy_pair_swap(bdev, argp);
                break;
        default:
                /* if the discipline has an ioctl method try it. */
                rc = -ENOTTY;
                if (base->discipline->ioctl)
                        rc = base->discipline->ioctl(block, cmd, argp);
        }
        dasd_put_device(base);
        return rc;
}


/**
 * dasd_biodasdinfo() - fill out the dasd information structure
 * @disk: [in] pointer to gendisk structure that references a DASD
 * @info: [out] pointer to the dasd_information2_t structure
 *
 * Provide access to DASD specific information.
 * The gendisk structure is checked if it belongs to the DASD driver by
 * comparing the gendisk->fops pointer.
 * If it does not belong to the DASD driver -EINVAL is returned.
 * Otherwise the provided dasd_information2_t structure is filled out.
 *
 * Returns:
 *   %0 on success and a negative error value on failure.
 */
int dasd_biodasdinfo(struct gendisk *disk, struct dasd_information2_t *info)
{
        struct dasd_device *base;
        int error;

        if (disk->fops != &dasd_device_operations)
                return -EINVAL;

        base = dasd_device_from_gendisk(disk);
        if (!base)
                return -ENODEV;
        error = __dasd_ioctl_information(base->block, info);
        dasd_put_device(base);
        return error;
}
/* export that symbol_get in partition detection is possible */
EXPORT_SYMBOL_GPL(dasd_biodasdinfo);