device_ops.c

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/*
 * Copyright IBM Corp. 2002, 2009
 *
 * Author(s): Martin Schwidefsky ([email protected])
 *        Cornelia Huck ([email protected])
 */
#include <linux/module.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/device.h>
#include <linux/delay.h>
#include <linux/completion.h>

#include <asm/ccwdev.h>
#include <asm/idals.h>
#include <asm/chpid.h>
#include <asm/fcx.h>

#include "cio.h"
#include "cio_debug.h"
#include "css.h"
#include "chsc.h"
#include "device.h"
#include "chp.h"

int ccw_device_set_options_mask(struct ccw_device *cdev, unsigned long flags)
{
       /*
    * The flag usage is mutal exclusive ...
    */
    if ((flags & CCWDEV_EARLY_NOTIFICATION) &&
        (flags & CCWDEV_REPORT_ALL))
        return -EINVAL;
    cdev->private->options.fast = (flags & CCWDEV_EARLY_NOTIFICATION) != 0;
    cdev->private->options.repall = (flags & CCWDEV_REPORT_ALL) != 0;
    cdev->private->options.pgroup = (flags & CCWDEV_DO_PATHGROUP) != 0;
    cdev->private->options.force = (flags & CCWDEV_ALLOW_FORCE) != 0;
    cdev->private->options.mpath = (flags & CCWDEV_DO_MULTIPATH) != 0;
    return 0;
}

int ccw_device_set_options(struct ccw_device *cdev, unsigned long flags)
{
       /*
    * The flag usage is mutal exclusive ...
    */
    if (((flags & CCWDEV_EARLY_NOTIFICATION) &&
        (flags & CCWDEV_REPORT_ALL)) ||
        ((flags & CCWDEV_EARLY_NOTIFICATION) &&
         cdev->private->options.repall) ||
        ((flags & CCWDEV_REPORT_ALL) &&
         cdev->private->options.fast))
        return -EINVAL;
    cdev->private->options.fast |= (flags & CCWDEV_EARLY_NOTIFICATION) != 0;
    cdev->private->options.repall |= (flags & CCWDEV_REPORT_ALL) != 0;
    cdev->private->options.pgroup |= (flags & CCWDEV_DO_PATHGROUP) != 0;
    cdev->private->options.force |= (flags & CCWDEV_ALLOW_FORCE) != 0;
    cdev->private->options.mpath |= (flags & CCWDEV_DO_MULTIPATH) != 0;
    return 0;
}

void ccw_device_clear_options(struct ccw_device *cdev, unsigned long flags)
{
    cdev->private->options.fast &= (flags & CCWDEV_EARLY_NOTIFICATION) == 0;
    cdev->private->options.repall &= (flags & CCWDEV_REPORT_ALL) == 0;
    cdev->private->options.pgroup &= (flags & CCWDEV_DO_PATHGROUP) == 0;
    cdev->private->options.force &= (flags & CCWDEV_ALLOW_FORCE) == 0;
    cdev->private->options.mpath &= (flags & CCWDEV_DO_MULTIPATH) == 0;
}

int ccw_device_is_pathgroup(struct ccw_device *cdev)
{
    return cdev->private->flags.pgroup;
}
EXPORT_SYMBOL(ccw_device_is_pathgroup);

int ccw_device_is_multipath(struct ccw_device *cdev)
{
    return cdev->private->flags.mpath;
}
EXPORT_SYMBOL(ccw_device_is_multipath);

int ccw_device_clear(struct ccw_device *cdev, unsigned long intparm)
{
    struct subchannel *sch;
    int ret;

    if (!cdev || !cdev->dev.parent)
        return -ENODEV;
    sch = to_subchannel(cdev->dev.parent);
    if (!sch->schib.pmcw.ena)
        return -EINVAL;
    if (cdev->private->state == DEV_STATE_NOT_OPER)
        return -ENODEV;
    if (cdev->private->state != DEV_STATE_ONLINE &&
        cdev->private->state != DEV_STATE_W4SENSE)
        return -EINVAL;

    ret = cio_clear(sch);
    if (ret == 0)
        cdev->private->intparm = intparm;
    return ret;
}

int ccw_device_start_key(struct ccw_device *cdev, struct ccw1 *cpa,
             unsigned long intparm, __u8 lpm, __u8 key,
             unsigned long flags)
{
    struct subchannel *sch;
    int ret;

    if (!cdev || !cdev->dev.parent)
        return -ENODEV;
    sch = to_subchannel(cdev->dev.parent);
    if (!sch->schib.pmcw.ena)
        return -EINVAL;
    if (cdev->private->state == DEV_STATE_NOT_OPER)
        return -ENODEV;
    if (cdev->private->state == DEV_STATE_VERIFY) {
        /* Remember to fake irb when finished. */
        if (!cdev->private->flags.fake_irb) {
            cdev->private->flags.fake_irb = FAKE_CMD_IRB;
            cdev->private->intparm = intparm;
            return 0;
        } else
            /* There's already a fake I/O around. */
            return -EBUSY;
    }
    if (cdev->private->state != DEV_STATE_ONLINE ||
        ((sch->schib.scsw.cmd.stctl & SCSW_STCTL_PRIM_STATUS) &&
         !(sch->schib.scsw.cmd.stctl & SCSW_STCTL_SEC_STATUS)) ||
        cdev->private->flags.doverify)
        return -EBUSY;
    ret = cio_set_options (sch, flags);
    if (ret)
        return ret;
    /* Adjust requested path mask to exclude unusable paths. */
    if (lpm) {
        lpm &= sch->lpm;
        if (lpm == 0)
            return -EACCES;
    }
    ret = cio_start_key (sch, cpa, lpm, key);
    switch (ret) {
    case 0:
        cdev->private->intparm = intparm;
        break;
    case -EACCES:
    case -ENODEV:
        dev_fsm_event(cdev, DEV_EVENT_VERIFY);
        break;
    }
    return ret;
}

int ccw_device_start_timeout_key(struct ccw_device *cdev, struct ccw1 *cpa,
                 unsigned long intparm, __u8 lpm, __u8 key,
                 unsigned long flags, int expires)
{
    int ret;

    if (!cdev)
        return -ENODEV;
    ccw_device_set_timeout(cdev, expires);
    ret = ccw_device_start_key(cdev, cpa, intparm, lpm, key, flags);
    if (ret != 0)
        ccw_device_set_timeout(cdev, 0);
    return ret;
}

int ccw_device_start(struct ccw_device *cdev, struct ccw1 *cpa,
             unsigned long intparm, __u8 lpm, unsigned long flags)
{
    return ccw_device_start_key(cdev, cpa, intparm, lpm,
                    PAGE_DEFAULT_KEY, flags);
}

int ccw_device_start_timeout(struct ccw_device *cdev, struct ccw1 *cpa,
                 unsigned long intparm, __u8 lpm,
                 unsigned long flags, int expires)
{
    return ccw_device_start_timeout_key(cdev, cpa, intparm, lpm,
                        PAGE_DEFAULT_KEY, flags,
                        expires);
}


int ccw_device_halt(struct ccw_device *cdev, unsigned long intparm)
{
    struct subchannel *sch;
    int ret;

    if (!cdev || !cdev->dev.parent)
        return -ENODEV;
    sch = to_subchannel(cdev->dev.parent);
    if (!sch->schib.pmcw.ena)
        return -EINVAL;
    if (cdev->private->state == DEV_STATE_NOT_OPER)
        return -ENODEV;
    if (cdev->private->state != DEV_STATE_ONLINE &&
        cdev->private->state != DEV_STATE_W4SENSE)
        return -EINVAL;

    ret = cio_halt(sch);
    if (ret == 0)
        cdev->private->intparm = intparm;
    return ret;
}

int ccw_device_resume(struct ccw_device *cdev)
{
    struct subchannel *sch;

    if (!cdev || !cdev->dev.parent)
        return -ENODEV;
    sch = to_subchannel(cdev->dev.parent);
    if (!sch->schib.pmcw.ena)
        return -EINVAL;
    if (cdev->private->state == DEV_STATE_NOT_OPER)
        return -ENODEV;
    if (cdev->private->state != DEV_STATE_ONLINE ||
        !(sch->schib.scsw.cmd.actl & SCSW_ACTL_SUSPENDED))
        return -EINVAL;
    return cio_resume(sch);
}

/*
 * Pass interrupt to device driver.
 */
int
ccw_device_call_handler(struct ccw_device *cdev)
{
    unsigned int stctl;
    int ending_status;

    /*
     * we allow for the device action handler if .
     *  - we received ending status
     *  - the action handler requested to see all interrupts
     *  - we received an intermediate status
     *  - fast notification was requested (primary status)
     *  - unsolicited interrupts
     */
    stctl = scsw_stctl(&cdev->private->irb.scsw);
    ending_status = (stctl & SCSW_STCTL_SEC_STATUS) ||
        (stctl == (SCSW_STCTL_ALERT_STATUS | SCSW_STCTL_STATUS_PEND)) ||
        (stctl == SCSW_STCTL_STATUS_PEND);
    if (!ending_status &&
        !cdev->private->options.repall &&
        !(stctl & SCSW_STCTL_INTER_STATUS) &&
        !(cdev->private->options.fast &&
          (stctl & SCSW_STCTL_PRIM_STATUS)))
        return 0;

    /* Clear pending timers for device driver initiated I/O. */
    if (ending_status)
        ccw_device_set_timeout(cdev, 0);
    /*
     * Now we are ready to call the device driver interrupt handler.
     */
    if (cdev->handler)
        cdev->handler(cdev, cdev->private->intparm,
                  &cdev->private->irb);

    /*
     * Clear the old and now useless interrupt response block.
     */
    memset(&cdev->private->irb, 0, sizeof(struct irb));

    return 1;
}

struct ciw *ccw_device_get_ciw(struct ccw_device *cdev, __u32 ct)
{
    int ciw_cnt;

    if (cdev->private->flags.esid == 0)
        return NULL;
    for (ciw_cnt = 0; ciw_cnt < MAX_CIWS; ciw_cnt++)
        if (cdev->private->senseid.ciw[ciw_cnt].ct == ct)
            return cdev->private->senseid.ciw + ciw_cnt;
    return NULL;
}

__u8 ccw_device_get_path_mask(struct ccw_device *cdev)
{
    struct subchannel *sch;

    if (!cdev->dev.parent)
        return 0;

    sch = to_subchannel(cdev->dev.parent);
    return sch->lpm;
}

struct stlck_data {
    struct completion done;
    int rc;
};

void ccw_device_stlck_done(struct ccw_device *cdev, void *data, int rc)
{
    struct stlck_data *sdata = data;

    sdata->rc = rc;
    complete(&sdata->done);
}

/*
 * Perform unconditional reserve + release.
 */
int ccw_device_stlck(struct ccw_device *cdev)
{
    struct subchannel *sch = to_subchannel(cdev->dev.parent);
    struct stlck_data data;
    u8 *buffer;
    int rc;

    /* Check if steal lock operation is valid for this device. */
    if (cdev->drv) {
        if (!cdev->private->options.force)
            return -EINVAL;
    }
    buffer = kzalloc(64, GFP_DMA | GFP_KERNEL);
    if (!buffer)
        return -ENOMEM;
    init_completion(&data.done);
    data.rc = -EIO;
    spin_lock_irq(sch->lock);
    rc = cio_enable_subchannel(sch, (u32) (addr_t) sch);
    if (rc)
        goto out_unlock;
    /* Perform operation. */
    cdev->private->state = DEV_STATE_STEAL_LOCK,
    ccw_device_stlck_start(cdev, &data, &buffer[0], &buffer[32]);
    spin_unlock_irq(sch->lock);
    /* Wait for operation to finish. */
    if (wait_for_completion_interruptible(&data.done)) {
        /* Got a signal. */
        spin_lock_irq(sch->lock);
        ccw_request_cancel(cdev);
        spin_unlock_irq(sch->lock);
        wait_for_completion(&data.done);
    }
    rc = data.rc;
    /* Check results. */
    spin_lock_irq(sch->lock);
    cio_disable_subchannel(sch);
    cdev->private->state = DEV_STATE_BOXED;
out_unlock:
    spin_unlock_irq(sch->lock);
    kfree(buffer);

    return rc;
}

void *ccw_device_get_chp_desc(struct ccw_device *cdev, int chp_no)
{
    struct subchannel *sch;
    struct chp_id chpid;

    sch = to_subchannel(cdev->dev.parent);
    chp_id_init(&chpid);
    chpid.id = sch->schib.pmcw.chpid[chp_no];
    return chp_get_chp_desc(chpid);
}

void ccw_device_get_id(struct ccw_device *cdev, struct ccw_dev_id *dev_id)
{
    *dev_id = cdev->private->dev_id;
}
EXPORT_SYMBOL(ccw_device_get_id);

int ccw_device_tm_start_key(struct ccw_device *cdev, struct tcw *tcw,
                unsigned long intparm, u8 lpm, u8 key)
{
    struct subchannel *sch;
    int rc;

    sch = to_subchannel(cdev->dev.parent);
    if (!sch->schib.pmcw.ena)
        return -EINVAL;
    if (cdev->private->state == DEV_STATE_VERIFY) {
        /* Remember to fake irb when finished. */
        if (!cdev->private->flags.fake_irb) {
            cdev->private->flags.fake_irb = FAKE_TM_IRB;
            cdev->private->intparm = intparm;
            return 0;
        } else
            /* There's already a fake I/O around. */
            return -EBUSY;
    }
    if (cdev->private->state != DEV_STATE_ONLINE)
        return -EIO;
    /* Adjust requested path mask to exclude unusable paths. */
    if (lpm) {
        lpm &= sch->lpm;
        if (lpm == 0)
            return -EACCES;
    }
    rc = cio_tm_start_key(sch, tcw, lpm, key);
    if (rc == 0)
        cdev->private->intparm = intparm;
    return rc;
}
EXPORT_SYMBOL(ccw_device_tm_start_key);

int ccw_device_tm_start_timeout_key(struct ccw_device *cdev, struct tcw *tcw,
                    unsigned long intparm, u8 lpm, u8 key,
                    int expires)
{
    int ret;

    ccw_device_set_timeout(cdev, expires);
    ret = ccw_device_tm_start_key(cdev, tcw, intparm, lpm, key);
    if (ret != 0)
        ccw_device_set_timeout(cdev, 0);
    return ret;
}
EXPORT_SYMBOL(ccw_device_tm_start_timeout_key);

int ccw_device_tm_start(struct ccw_device *cdev, struct tcw *tcw,
            unsigned long intparm, u8 lpm)
{
    return ccw_device_tm_start_key(cdev, tcw, intparm, lpm,
                       PAGE_DEFAULT_KEY);
}
EXPORT_SYMBOL(ccw_device_tm_start);

int ccw_device_tm_start_timeout(struct ccw_device *cdev, struct tcw *tcw,
                   unsigned long intparm, u8 lpm, int expires)
{
    return ccw_device_tm_start_timeout_key(cdev, tcw, intparm, lpm,
                           PAGE_DEFAULT_KEY, expires);
}
EXPORT_SYMBOL(ccw_device_tm_start_timeout);

int ccw_device_get_mdc(struct ccw_device *cdev, u8 mask)
{
    struct subchannel *sch = to_subchannel(cdev->dev.parent);
    struct channel_path_desc_fmt1 desc;
    struct chp_id chpid;
    int mdc = 0, ret, i;

    /* Adjust requested path mask to excluded varied off paths. */
    if (mask)
        mask &= sch->lpm;
    else
        mask = sch->lpm;

    chp_id_init(&chpid);
    for (i = 0; i < 8; i++) {
        if (!(mask & (0x80 >> i)))
            continue;
        chpid.id = sch->schib.pmcw.chpid[i];
        ret = chsc_determine_fmt1_channel_path_desc(chpid, &desc);
        if (ret)
            return ret;
        if (!desc.f)
            return 0;
        if (!desc.r)
            mdc = 1;
        mdc = mdc ? min(mdc, (int)desc.mdc) : desc.mdc;
    }

    return mdc;
}
EXPORT_SYMBOL(ccw_device_get_mdc);

int ccw_device_tm_intrg(struct ccw_device *cdev)
{
    struct subchannel *sch = to_subchannel(cdev->dev.parent);

    if (!sch->schib.pmcw.ena)
        return -EINVAL;
    if (cdev->private->state != DEV_STATE_ONLINE)
        return -EIO;
    if (!scsw_is_tm(&sch->schib.scsw) ||
        !(scsw_actl(&sch->schib.scsw) & SCSW_ACTL_START_PEND))
        return -EINVAL;
    return cio_tm_intrg(sch);
}
EXPORT_SYMBOL(ccw_device_tm_intrg);

// FIXME: these have to go:

int
_ccw_device_get_subchannel_number(struct ccw_device *cdev)
{
    return cdev->private->schid.sch_no;
}


MODULE_LICENSE("GPL");
EXPORT_SYMBOL(ccw_device_set_options_mask);
EXPORT_SYMBOL(ccw_device_set_options);
EXPORT_SYMBOL(ccw_device_clear_options);
EXPORT_SYMBOL(ccw_device_clear);
EXPORT_SYMBOL(ccw_device_halt);
EXPORT_SYMBOL(ccw_device_resume);
EXPORT_SYMBOL(ccw_device_start_timeout);
EXPORT_SYMBOL(ccw_device_start);
EXPORT_SYMBOL(ccw_device_start_timeout_key);
EXPORT_SYMBOL(ccw_device_start_key);
EXPORT_SYMBOL(ccw_device_get_ciw);
EXPORT_SYMBOL(ccw_device_get_path_mask);
EXPORT_SYMBOL(_ccw_device_get_subchannel_number);
EXPORT_SYMBOL_GPL(ccw_device_get_chp_desc);