dasd_fba.c

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/*
 * Author(s)......: Holger Smolinski <[email protected]>
 * Bugreports.to..: <[email protected]>
 * Copyright IBM Corp. 1999, 2009
 */

#define KMSG_COMPONENT "dasd-fba"

#include <linux/stddef.h>
#include <linux/kernel.h>
#include <asm/debug.h>

#include <linux/slab.h>
#include <linux/hdreg.h>    /* HDIO_GETGEO              */
#include <linux/bio.h>
#include <linux/module.h>
#include <linux/init.h>

#include <asm/idals.h>
#include <asm/ebcdic.h>
#include <asm/io.h>
#include <asm/ccwdev.h>

#include "dasd_int.h"
#include "dasd_fba.h"

#ifdef PRINTK_HEADER
#undef PRINTK_HEADER
#endif              /* PRINTK_HEADER */
#define PRINTK_HEADER "dasd(fba):"

#define DASD_FBA_CCW_WRITE 0x41
#define DASD_FBA_CCW_READ 0x42
#define DASD_FBA_CCW_LOCATE 0x43
#define DASD_FBA_CCW_DEFINE_EXTENT 0x63

MODULE_LICENSE("GPL");

static struct dasd_discipline dasd_fba_discipline;

struct dasd_fba_private {
    struct dasd_fba_characteristics rdc_data;
};

static struct ccw_device_id dasd_fba_ids[] = {
    { CCW_DEVICE_DEVTYPE (0x6310, 0, 0x9336, 0), .driver_info = 0x1},
    { CCW_DEVICE_DEVTYPE (0x3880, 0, 0x3370, 0), .driver_info = 0x2},
    { /* end of list */ },
};

MODULE_DEVICE_TABLE(ccw, dasd_fba_ids);

static struct ccw_driver dasd_fba_driver; /* see below */
static int
dasd_fba_probe(struct ccw_device *cdev)
{
    return dasd_generic_probe(cdev, &dasd_fba_discipline);
}

static int
dasd_fba_set_online(struct ccw_device *cdev)
{
    return dasd_generic_set_online(cdev, &dasd_fba_discipline);
}

static struct ccw_driver dasd_fba_driver = {
    .driver = {
        .name   = "dasd-fba",
        .owner  = THIS_MODULE,
    },
    .ids         = dasd_fba_ids,
    .probe       = dasd_fba_probe,
    .remove      = dasd_generic_remove,
    .set_offline = dasd_generic_set_offline,
    .set_online  = dasd_fba_set_online,
    .notify      = dasd_generic_notify,
    .path_event  = dasd_generic_path_event,
    .freeze      = dasd_generic_pm_freeze,
    .thaw        = dasd_generic_restore_device,
    .restore     = dasd_generic_restore_device,
    .int_class   = IOINT_DAS,
};

static void
define_extent(struct ccw1 * ccw, struct DE_fba_data *data, int rw,
          int blksize, int beg, int nr)
{
    ccw->cmd_code = DASD_FBA_CCW_DEFINE_EXTENT;
    ccw->flags = 0;
    ccw->count = 16;
    ccw->cda = (__u32) __pa(data);
    memset(data, 0, sizeof (struct DE_fba_data));
    if (rw == WRITE)
        (data->mask).perm = 0x0;
    else if (rw == READ)
        (data->mask).perm = 0x1;
    else
        data->mask.perm = 0x2;
    data->blk_size = blksize;
    data->ext_loc = beg;
    data->ext_end = nr - 1;
}

static void
locate_record(struct ccw1 * ccw, struct LO_fba_data *data, int rw,
          int block_nr, int block_ct)
{
    ccw->cmd_code = DASD_FBA_CCW_LOCATE;
    ccw->flags = 0;
    ccw->count = 8;
    ccw->cda = (__u32) __pa(data);
    memset(data, 0, sizeof (struct LO_fba_data));
    if (rw == WRITE)
        data->operation.cmd = 0x5;
    else if (rw == READ)
        data->operation.cmd = 0x6;
    else
        data->operation.cmd = 0x8;
    data->blk_nr = block_nr;
    data->blk_ct = block_ct;
}

static int
dasd_fba_check_characteristics(struct dasd_device *device)
{
    struct dasd_block *block;
    struct dasd_fba_private *private;
    struct ccw_device *cdev = device->cdev;
    int rc;
    int readonly;

    private = (struct dasd_fba_private *) device->private;
    if (!private) {
        private = kzalloc(sizeof(*private), GFP_KERNEL | GFP_DMA);
        if (!private) {
            dev_warn(&device->cdev->dev,
                 "Allocating memory for private DASD "
                 "data failed\n");
            return -ENOMEM;
        }
        device->private = (void *) private;
    } else {
        memset(private, 0, sizeof(*private));
    }
    block = dasd_alloc_block();
    if (IS_ERR(block)) {
        DBF_EVENT_DEVID(DBF_WARNING, cdev, "%s", "could not allocate "
                "dasd block structure");
        device->private = NULL;
        kfree(private);
        return PTR_ERR(block);
    }
    device->block = block;
    block->base = device;

    /* Read Device Characteristics */
    rc = dasd_generic_read_dev_chars(device, DASD_FBA_MAGIC,
                     &private->rdc_data, 32);
    if (rc) {
        DBF_EVENT_DEVID(DBF_WARNING, cdev, "Read device "
                "characteristics returned error %d", rc);
        device->block = NULL;
        dasd_free_block(block);
        device->private = NULL;
        kfree(private);
        return rc;
    }

    device->default_expires = DASD_EXPIRES;
    device->path_data.opm = LPM_ANYPATH;

    readonly = dasd_device_is_ro(device);
    if (readonly)
        set_bit(DASD_FLAG_DEVICE_RO, &device->flags);

    dev_info(&device->cdev->dev,
         "New FBA DASD %04X/%02X (CU %04X/%02X) with %d MB "
         "and %d B/blk%s\n",
         cdev->id.dev_type,
         cdev->id.dev_model,
         cdev->id.cu_type,
         cdev->id.cu_model,
         ((private->rdc_data.blk_bdsa *
           (private->rdc_data.blk_size >> 9)) >> 11),
         private->rdc_data.blk_size,
         readonly ? ", read-only device" : "");
    return 0;
}

static int dasd_fba_do_analysis(struct dasd_block *block)
{
    struct dasd_fba_private *private;
    int sb, rc;

    private = (struct dasd_fba_private *) block->base->private;
    rc = dasd_check_blocksize(private->rdc_data.blk_size);
    if (rc) {
        DBF_DEV_EVENT(DBF_WARNING, block->base, "unknown blocksize %d",
                private->rdc_data.blk_size);
        return rc;
    }
    block->blocks = private->rdc_data.blk_bdsa;
    block->bp_block = private->rdc_data.blk_size;
    block->s2b_shift = 0;   /* bits to shift 512 to get a block */
    for (sb = 512; sb < private->rdc_data.blk_size; sb = sb << 1)
        block->s2b_shift++;
    return 0;
}

static int dasd_fba_fill_geometry(struct dasd_block *block,
                  struct hd_geometry *geo)
{
    if (dasd_check_blocksize(block->bp_block) != 0)
        return -EINVAL;
    geo->cylinders = (block->blocks << block->s2b_shift) >> 10;
    geo->heads = 16;
    geo->sectors = 128 >> block->s2b_shift;
    return 0;
}

static dasd_erp_fn_t
dasd_fba_erp_action(struct dasd_ccw_req * cqr)
{
    return dasd_default_erp_action;
}

static dasd_erp_fn_t
dasd_fba_erp_postaction(struct dasd_ccw_req * cqr)
{
    if (cqr->function == dasd_default_erp_action)
        return dasd_default_erp_postaction;

    DBF_DEV_EVENT(DBF_WARNING, cqr->startdev, "unknown ERP action %p",
            cqr->function);
    return NULL;
}

static void dasd_fba_check_for_device_change(struct dasd_device *device,
                         struct dasd_ccw_req *cqr,
                         struct irb *irb)
{
    char mask;

    /* first of all check for state change pending interrupt */
    mask = DEV_STAT_ATTENTION | DEV_STAT_DEV_END | DEV_STAT_UNIT_EXCEP;
    if ((irb->scsw.cmd.dstat & mask) == mask)
        dasd_generic_handle_state_change(device);
};

static struct dasd_ccw_req *dasd_fba_build_cp(struct dasd_device * memdev,
                          struct dasd_block *block,
                          struct request *req)
{
    struct dasd_fba_private *private;
    unsigned long *idaws;
    struct LO_fba_data *LO_data;
    struct dasd_ccw_req *cqr;
    struct ccw1 *ccw;
    struct req_iterator iter;
    struct bio_vec *bv;
    char *dst;
    int count, cidaw, cplength, datasize;
    sector_t recid, first_rec, last_rec;
    unsigned int blksize, off;
    unsigned char cmd;

    private = (struct dasd_fba_private *) block->base->private;
    if (rq_data_dir(req) == READ) {
        cmd = DASD_FBA_CCW_READ;
    } else if (rq_data_dir(req) == WRITE) {
        cmd = DASD_FBA_CCW_WRITE;
    } else
        return ERR_PTR(-EINVAL);
    blksize = block->bp_block;
    /* Calculate record id of first and last block. */
    first_rec = blk_rq_pos(req) >> block->s2b_shift;
    last_rec =
        (blk_rq_pos(req) + blk_rq_sectors(req) - 1) >> block->s2b_shift;
    /* Check struct bio and count the number of blocks for the request. */
    count = 0;
    cidaw = 0;
    rq_for_each_segment(bv, req, iter) {
        if (bv->bv_len & (blksize - 1))
            /* Fba can only do full blocks. */
            return ERR_PTR(-EINVAL);
        count += bv->bv_len >> (block->s2b_shift + 9);
#if defined(CONFIG_64BIT)
        if (idal_is_needed (page_address(bv->bv_page), bv->bv_len))
            cidaw += bv->bv_len / blksize;
#endif
    }
    /* Paranoia. */
    if (count != last_rec - first_rec + 1)
        return ERR_PTR(-EINVAL);
    /* 1x define extent + 1x locate record + number of blocks */
    cplength = 2 + count;
    /* 1x define extent + 1x locate record */
    datasize = sizeof(struct DE_fba_data) + sizeof(struct LO_fba_data) +
        cidaw * sizeof(unsigned long);
    /*
     * Find out number of additional locate record ccws if the device
     * can't do data chaining.
     */
    if (private->rdc_data.mode.bits.data_chain == 0) {
        cplength += count - 1;
        datasize += (count - 1)*sizeof(struct LO_fba_data);
    }
    /* Allocate the ccw request. */
    cqr = dasd_smalloc_request(DASD_FBA_MAGIC, cplength, datasize, memdev);
    if (IS_ERR(cqr))
        return cqr;
    ccw = cqr->cpaddr;
    /* First ccw is define extent. */
    define_extent(ccw++, cqr->data, rq_data_dir(req),
              block->bp_block, blk_rq_pos(req), blk_rq_sectors(req));
    /* Build locate_record + read/write ccws. */
    idaws = (unsigned long *) (cqr->data + sizeof(struct DE_fba_data));
    LO_data = (struct LO_fba_data *) (idaws + cidaw);
    /* Locate record for all blocks for smart devices. */
    if (private->rdc_data.mode.bits.data_chain != 0) {
        ccw[-1].flags |= CCW_FLAG_CC;
        locate_record(ccw++, LO_data++, rq_data_dir(req), 0, count);
    }
    recid = first_rec;
    rq_for_each_segment(bv, req, iter) {
        dst = page_address(bv->bv_page) + bv->bv_offset;
        if (dasd_page_cache) {
            char *copy = kmem_cache_alloc(dasd_page_cache,
                              GFP_DMA | __GFP_NOWARN);
            if (copy && rq_data_dir(req) == WRITE)
                memcpy(copy + bv->bv_offset, dst, bv->bv_len);
            if (copy)
                dst = copy + bv->bv_offset;
        }
        for (off = 0; off < bv->bv_len; off += blksize) {
            /* Locate record for stupid devices. */
            if (private->rdc_data.mode.bits.data_chain == 0) {
                ccw[-1].flags |= CCW_FLAG_CC;
                locate_record(ccw, LO_data++,
                          rq_data_dir(req),
                          recid - first_rec, 1);
                ccw->flags = CCW_FLAG_CC;
                ccw++;
            } else {
                if (recid > first_rec)
                    ccw[-1].flags |= CCW_FLAG_DC;
                else
                    ccw[-1].flags |= CCW_FLAG_CC;
            }
            ccw->cmd_code = cmd;
            ccw->count = block->bp_block;
            if (idal_is_needed(dst, blksize)) {
                ccw->cda = (__u32)(addr_t) idaws;
                ccw->flags = CCW_FLAG_IDA;
                idaws = idal_create_words(idaws, dst, blksize);
            } else {
                ccw->cda = (__u32)(addr_t) dst;
                ccw->flags = 0;
            }
            ccw++;
            dst += blksize;
            recid++;
        }
    }
    if (blk_noretry_request(req) ||
        block->base->features & DASD_FEATURE_FAILFAST)
        set_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags);
    cqr->startdev = memdev;
    cqr->memdev = memdev;
    cqr->block = block;
    cqr->expires = memdev->default_expires * HZ;    /* default 5 minutes */
    cqr->retries = 32;
    cqr->buildclk = get_clock();
    cqr->status = DASD_CQR_FILLED;
    return cqr;
}

static int
dasd_fba_free_cp(struct dasd_ccw_req *cqr, struct request *req)
{
    struct dasd_fba_private *private;
    struct ccw1 *ccw;
    struct req_iterator iter;
    struct bio_vec *bv;
    char *dst, *cda;
    unsigned int blksize, off;
    int status;

    if (!dasd_page_cache)
        goto out;
    private = (struct dasd_fba_private *) cqr->block->base->private;
    blksize = cqr->block->bp_block;
    ccw = cqr->cpaddr;
    /* Skip over define extent & locate record. */
    ccw++;
    if (private->rdc_data.mode.bits.data_chain != 0)
        ccw++;
    rq_for_each_segment(bv, req, iter) {
        dst = page_address(bv->bv_page) + bv->bv_offset;
        for (off = 0; off < bv->bv_len; off += blksize) {
            /* Skip locate record. */
            if (private->rdc_data.mode.bits.data_chain == 0)
                ccw++;
            if (dst) {
                if (ccw->flags & CCW_FLAG_IDA)
                    cda = *((char **)((addr_t) ccw->cda));
                else
                    cda = (char *)((addr_t) ccw->cda);
                if (dst != cda) {
                    if (rq_data_dir(req) == READ)
                        memcpy(dst, cda, bv->bv_len);
                    kmem_cache_free(dasd_page_cache,
                        (void *)((addr_t)cda & PAGE_MASK));
                }
                dst = NULL;
            }
            ccw++;
        }
    }
out:
    status = cqr->status == DASD_CQR_DONE;
    dasd_sfree_request(cqr, cqr->memdev);
    return status;
}

static void dasd_fba_handle_terminated_request(struct dasd_ccw_req *cqr)
{
    cqr->status = DASD_CQR_FILLED;
};

static int
dasd_fba_fill_info(struct dasd_device * device,
           struct dasd_information2_t * info)
{
    info->label_block = 1;
    info->FBA_layout = 1;
    info->format = DASD_FORMAT_LDL;
    info->characteristics_size = sizeof(struct dasd_fba_characteristics);
    memcpy(info->characteristics,
           &((struct dasd_fba_private *) device->private)->rdc_data,
           sizeof (struct dasd_fba_characteristics));
    info->confdata_size = 0;
    return 0;
}

static void
dasd_fba_dump_sense_dbf(struct dasd_device *device, struct irb *irb,
            char *reason)
{
    u64 *sense;

    sense = (u64 *) dasd_get_sense(irb);
    if (sense) {
        DBF_DEV_EVENT(DBF_EMERG, device,
                  "%s: %s %02x%02x%02x %016llx %016llx %016llx "
                  "%016llx", reason,
                  scsw_is_tm(&irb->scsw) ? "t" : "c",
                  scsw_cc(&irb->scsw), scsw_cstat(&irb->scsw),
                  scsw_dstat(&irb->scsw), sense[0], sense[1],
                  sense[2], sense[3]);
    } else {
        DBF_DEV_EVENT(DBF_EMERG, device, "%s",
                  "SORRY - NO VALID SENSE AVAILABLE\n");
    }
}


static void
dasd_fba_dump_sense(struct dasd_device *device, struct dasd_ccw_req * req,
            struct irb *irb)
{
    char *page;
    struct ccw1 *act, *end, *last;
    int len, sl, sct, count;

    page = (char *) get_zeroed_page(GFP_ATOMIC);
    if (page == NULL) {
        DBF_DEV_EVENT(DBF_WARNING, device, "%s",
                "No memory to dump sense data");
        return;
    }
    len = sprintf(page, KERN_ERR PRINTK_HEADER
              " I/O status report for device %s:\n",
              dev_name(&device->cdev->dev));
    len += sprintf(page + len, KERN_ERR PRINTK_HEADER
               " in req: %p CS: 0x%02X DS: 0x%02X\n", req,
               irb->scsw.cmd.cstat, irb->scsw.cmd.dstat);
    len += sprintf(page + len, KERN_ERR PRINTK_HEADER
               " device %s: Failing CCW: %p\n",
               dev_name(&device->cdev->dev),
               (void *) (addr_t) irb->scsw.cmd.cpa);
    if (irb->esw.esw0.erw.cons) {
        for (sl = 0; sl < 4; sl++) {
            len += sprintf(page + len, KERN_ERR PRINTK_HEADER
                       " Sense(hex) %2d-%2d:",
                       (8 * sl), ((8 * sl) + 7));

            for (sct = 0; sct < 8; sct++) {
                len += sprintf(page + len, " %02x",
                           irb->ecw[8 * sl + sct]);
            }
            len += sprintf(page + len, "\n");
        }
    } else {
            len += sprintf(page + len, KERN_ERR PRINTK_HEADER
                   " SORRY - NO VALID SENSE AVAILABLE\n");
    }
    printk(KERN_ERR "%s", page);

    /* dump the Channel Program */
    /* print first CCWs (maximum 8) */
    act = req->cpaddr;
        for (last = act; last->flags & (CCW_FLAG_CC | CCW_FLAG_DC); last++);
    end = min(act + 8, last);
    len = sprintf(page, KERN_ERR PRINTK_HEADER
              " Related CP in req: %p\n", req);
    while (act <= end) {
        len += sprintf(page + len, KERN_ERR PRINTK_HEADER
                   " CCW %p: %08X %08X DAT:",
                   act, ((int *) act)[0], ((int *) act)[1]);
        for (count = 0; count < 32 && count < act->count;
             count += sizeof(int))
            len += sprintf(page + len, " %08X",
                       ((int *) (addr_t) act->cda)
                       [(count>>2)]);
        len += sprintf(page + len, "\n");
        act++;
    }
    printk(KERN_ERR "%s", page);


    /* print failing CCW area */
    len = 0;
    if (act <  ((struct ccw1 *)(addr_t) irb->scsw.cmd.cpa) - 2) {
        act = ((struct ccw1 *)(addr_t) irb->scsw.cmd.cpa) - 2;
        len += sprintf(page + len, KERN_ERR PRINTK_HEADER "......\n");
    }
    end = min((struct ccw1 *)(addr_t) irb->scsw.cmd.cpa + 2, last);
    while (act <= end) {
        len += sprintf(page + len, KERN_ERR PRINTK_HEADER
                   " CCW %p: %08X %08X DAT:",
                   act, ((int *) act)[0], ((int *) act)[1]);
        for (count = 0; count < 32 && count < act->count;
             count += sizeof(int))
            len += sprintf(page + len, " %08X",
                       ((int *) (addr_t) act->cda)
                       [(count>>2)]);
        len += sprintf(page + len, "\n");
        act++;
    }

    /* print last CCWs */
    if (act <  last - 2) {
        act = last - 2;
        len += sprintf(page + len, KERN_ERR PRINTK_HEADER "......\n");
    }
    while (act <= last) {
        len += sprintf(page + len, KERN_ERR PRINTK_HEADER
                   " CCW %p: %08X %08X DAT:",
                   act, ((int *) act)[0], ((int *) act)[1]);
        for (count = 0; count < 32 && count < act->count;
             count += sizeof(int))
            len += sprintf(page + len, " %08X",
                       ((int *) (addr_t) act->cda)
                       [(count>>2)]);
        len += sprintf(page + len, "\n");
        act++;
    }
    if (len > 0)
        printk(KERN_ERR "%s", page);
    free_page((unsigned long) page);
}

/*
 * max_blocks is dependent on the amount of storage that is available
 * in the static io buffer for each device. Currently each device has
 * 8192 bytes (=2 pages). For 64 bit one dasd_mchunkt_t structure has
 * 24 bytes, the struct dasd_ccw_req has 136 bytes and each block can use
 * up to 16 bytes (8 for the ccw and 8 for the idal pointer). In
 * addition we have one define extent ccw + 16 bytes of data and a
 * locate record ccw for each block (stupid devices!) + 16 bytes of data.
 * That makes:
 * (8192 - 24 - 136 - 8 - 16) / 40 = 200.2 blocks at maximum.
 * We want to fit two into the available memory so that we can immediately
 * start the next request if one finishes off. That makes 100.1 blocks
 * for one request. Give a little safety and the result is 96.
 */
static struct dasd_discipline dasd_fba_discipline = {
    .owner = THIS_MODULE,
    .name = "FBA ",
    .ebcname = "FBA ",
    .max_blocks = 96,
    .check_device = dasd_fba_check_characteristics,
    .do_analysis = dasd_fba_do_analysis,
    .verify_path = dasd_generic_verify_path,
    .fill_geometry = dasd_fba_fill_geometry,
    .start_IO = dasd_start_IO,
    .term_IO = dasd_term_IO,
    .handle_terminated_request = dasd_fba_handle_terminated_request,
    .erp_action = dasd_fba_erp_action,
    .erp_postaction = dasd_fba_erp_postaction,
    .check_for_device_change = dasd_fba_check_for_device_change,
    .build_cp = dasd_fba_build_cp,
    .free_cp = dasd_fba_free_cp,
    .dump_sense = dasd_fba_dump_sense,
    .dump_sense_dbf = dasd_fba_dump_sense_dbf,
    .fill_info = dasd_fba_fill_info,
};

static int __init
dasd_fba_init(void)
{
    int ret;

    ASCEBC(dasd_fba_discipline.ebcname, 4);
    ret = ccw_driver_register(&dasd_fba_driver);
    if (!ret)
        wait_for_device_probe();

    return ret;
}

static void __exit
dasd_fba_cleanup(void)
{
    ccw_driver_unregister(&dasd_fba_driver);
}

module_init(dasd_fba_init);
module_exit(dasd_fba_cleanup);