Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / s390 / char / tape_34xx.c
diff --git a/kernel/drivers/s390/char/tape_34xx.c b/kernel/drivers/s390/char/tape_34xx.c
new file mode 100644 (file)
index 0000000..de69f0d
--- /dev/null
@@ -0,0 +1,1232 @@
+/*
+ *    tape device discipline for 3480/3490 tapes.
+ *
+ *    Copyright IBM Corp. 2001, 2009
+ *    Author(s): Carsten Otte <cotte@de.ibm.com>
+ *              Tuan Ngo-Anh <ngoanh@de.ibm.com>
+ *              Martin Schwidefsky <schwidefsky@de.ibm.com>
+ */
+
+#define KMSG_COMPONENT "tape_34xx"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/bio.h>
+#include <linux/workqueue.h>
+#include <linux/slab.h>
+
+#define TAPE_DBF_AREA  tape_34xx_dbf
+
+#include "tape.h"
+#include "tape_std.h"
+
+/*
+ * Pointer to debug area.
+ */
+debug_info_t *TAPE_DBF_AREA = NULL;
+EXPORT_SYMBOL(TAPE_DBF_AREA);
+
+#define TAPE34XX_FMT_3480      0
+#define TAPE34XX_FMT_3480_2_XF 1
+#define TAPE34XX_FMT_3480_XF   2
+
+struct tape_34xx_block_id {
+       unsigned int    wrap            : 1;
+       unsigned int    segment         : 7;
+       unsigned int    format          : 2;
+       unsigned int    block           : 22;
+};
+
+/*
+ * A list of block ID's is used to faster seek blocks.
+ */
+struct tape_34xx_sbid {
+       struct list_head                list;
+       struct tape_34xx_block_id       bid;
+};
+
+static void tape_34xx_delete_sbid_from(struct tape_device *, int);
+
+/*
+ * Medium sense for 34xx tapes. There is no 'real' medium sense call.
+ * So we just do a normal sense.
+ */
+static void __tape_34xx_medium_sense(struct tape_request *request)
+{
+       struct tape_device *device = request->device;
+       unsigned char *sense;
+
+       if (request->rc == 0) {
+               sense = request->cpdata;
+
+               /*
+                * This isn't quite correct. But since INTERVENTION_REQUIRED
+                * means that the drive is 'neither ready nor on-line' it is
+                * only slightly inaccurate to say there is no tape loaded if
+                * the drive isn't online...
+                */
+               if (sense[0] & SENSE_INTERVENTION_REQUIRED)
+                       tape_med_state_set(device, MS_UNLOADED);
+               else
+                       tape_med_state_set(device, MS_LOADED);
+
+               if (sense[1] & SENSE_WRITE_PROTECT)
+                       device->tape_generic_status |= GMT_WR_PROT(~0);
+               else
+                       device->tape_generic_status &= ~GMT_WR_PROT(~0);
+       } else
+               DBF_EVENT(4, "tape_34xx: medium sense failed with rc=%d\n",
+                       request->rc);
+       tape_free_request(request);
+}
+
+static int tape_34xx_medium_sense(struct tape_device *device)
+{
+       struct tape_request *request;
+       int rc;
+
+       request = tape_alloc_request(1, 32);
+       if (IS_ERR(request)) {
+               DBF_EXCEPTION(6, "MSEN fail\n");
+               return PTR_ERR(request);
+       }
+
+       request->op = TO_MSEN;
+       tape_ccw_end(request->cpaddr, SENSE, 32, request->cpdata);
+       rc = tape_do_io_interruptible(device, request);
+       __tape_34xx_medium_sense(request);
+       return rc;
+}
+
+static void tape_34xx_medium_sense_async(struct tape_device *device)
+{
+       struct tape_request *request;
+
+       request = tape_alloc_request(1, 32);
+       if (IS_ERR(request)) {
+               DBF_EXCEPTION(6, "MSEN fail\n");
+               return;
+       }
+
+       request->op = TO_MSEN;
+       tape_ccw_end(request->cpaddr, SENSE, 32, request->cpdata);
+       request->callback = (void *) __tape_34xx_medium_sense;
+       request->callback_data = NULL;
+       tape_do_io_async(device, request);
+}
+
+struct tape_34xx_work {
+       struct tape_device      *device;
+       enum tape_op             op;
+       struct work_struct       work;
+};
+
+/*
+ * These functions are currently used only to schedule a medium_sense for
+ * later execution. This is because we get an interrupt whenever a medium
+ * is inserted but cannot call tape_do_io* from an interrupt context.
+ * Maybe that's useful for other actions we want to start from the
+ * interrupt handler.
+ * Note: the work handler is called by the system work queue. The tape
+ * commands started by the handler need to be asynchrounous, otherwise
+ * a deadlock can occur e.g. in case of a deferred cc=1 (see __tape_do_irq).
+ */
+static void
+tape_34xx_work_handler(struct work_struct *work)
+{
+       struct tape_34xx_work *p =
+               container_of(work, struct tape_34xx_work, work);
+       struct tape_device *device = p->device;
+
+       switch(p->op) {
+               case TO_MSEN:
+                       tape_34xx_medium_sense_async(device);
+                       break;
+               default:
+                       DBF_EVENT(3, "T34XX: internal error: unknown work\n");
+       }
+       tape_put_device(device);
+       kfree(p);
+}
+
+static int
+tape_34xx_schedule_work(struct tape_device *device, enum tape_op op)
+{
+       struct tape_34xx_work *p;
+
+       if ((p = kzalloc(sizeof(*p), GFP_ATOMIC)) == NULL)
+               return -ENOMEM;
+
+       INIT_WORK(&p->work, tape_34xx_work_handler);
+
+       p->device = tape_get_device(device);
+       p->op     = op;
+
+       schedule_work(&p->work);
+       return 0;
+}
+
+/*
+ * Done Handler is called when dev stat = DEVICE-END (successful operation)
+ */
+static inline int
+tape_34xx_done(struct tape_request *request)
+{
+       DBF_EVENT(6, "%s done\n", tape_op_verbose[request->op]);
+
+       switch (request->op) {
+               case TO_DSE:
+               case TO_RUN:
+               case TO_WRI:
+               case TO_WTM:
+               case TO_ASSIGN:
+               case TO_UNASSIGN:
+                       tape_34xx_delete_sbid_from(request->device, 0);
+                       break;
+               default:
+                       ;
+       }
+       return TAPE_IO_SUCCESS;
+}
+
+static inline int
+tape_34xx_erp_failed(struct tape_request *request, int rc)
+{
+       DBF_EVENT(3, "Error recovery failed for %s (RC=%d)\n",
+                 tape_op_verbose[request->op], rc);
+       return rc;
+}
+
+static inline int
+tape_34xx_erp_succeeded(struct tape_request *request)
+{
+       DBF_EVENT(3, "Error Recovery successful for %s\n",
+                 tape_op_verbose[request->op]);
+       return tape_34xx_done(request);
+}
+
+static inline int
+tape_34xx_erp_retry(struct tape_request *request)
+{
+       DBF_EVENT(3, "xerp retr %s\n", tape_op_verbose[request->op]);
+       return TAPE_IO_RETRY;
+}
+
+/*
+ * This function is called, when no request is outstanding and we get an
+ * interrupt
+ */
+static int
+tape_34xx_unsolicited_irq(struct tape_device *device, struct irb *irb)
+{
+       if (irb->scsw.cmd.dstat == 0x85) { /* READY */
+               /* A medium was inserted in the drive. */
+               DBF_EVENT(6, "xuud med\n");
+               tape_34xx_delete_sbid_from(device, 0);
+               tape_34xx_schedule_work(device, TO_MSEN);
+       } else {
+               DBF_EVENT(3, "unsol.irq! dev end: %08x\n", device->cdev_id);
+               tape_dump_sense_dbf(device, NULL, irb);
+       }
+       return TAPE_IO_SUCCESS;
+}
+
+/*
+ * Read Opposite Error Recovery Function:
+ * Used, when Read Forward does not work
+ */
+static int
+tape_34xx_erp_read_opposite(struct tape_device *device,
+                           struct tape_request *request)
+{
+       if (request->op == TO_RFO) {
+               /*
+                * We did read forward, but the data could not be read
+                * *correctly*. We transform the request to a read backward
+                * and try again.
+                */
+               tape_std_read_backward(device, request);
+               return tape_34xx_erp_retry(request);
+       }
+
+       /*
+        * We tried to read forward and backward, but hat no
+        * success -> failed.
+        */
+       return tape_34xx_erp_failed(request, -EIO);
+}
+
+static int
+tape_34xx_erp_bug(struct tape_device *device, struct tape_request *request,
+                 struct irb *irb, int no)
+{
+       if (request->op != TO_ASSIGN) {
+               dev_err(&device->cdev->dev, "An unexpected condition %d "
+                       "occurred in tape error recovery\n", no);
+               tape_dump_sense_dbf(device, request, irb);
+       }
+       return tape_34xx_erp_failed(request, -EIO);
+}
+
+/*
+ * Handle data overrun between cu and drive. The channel speed might
+ * be too slow.
+ */
+static int
+tape_34xx_erp_overrun(struct tape_device *device, struct tape_request *request,
+                     struct irb *irb)
+{
+       if (irb->ecw[3] == 0x40) {
+               dev_warn (&device->cdev->dev, "A data overrun occurred between"
+                       " the control unit and tape unit\n");
+               return tape_34xx_erp_failed(request, -EIO);
+       }
+       return tape_34xx_erp_bug(device, request, irb, -1);
+}
+
+/*
+ * Handle record sequence error.
+ */
+static int
+tape_34xx_erp_sequence(struct tape_device *device,
+                      struct tape_request *request, struct irb *irb)
+{
+       if (irb->ecw[3] == 0x41) {
+               /*
+                * cu detected incorrect block-id sequence on tape.
+                */
+               dev_warn (&device->cdev->dev, "The block ID sequence on the "
+                       "tape is incorrect\n");
+               return tape_34xx_erp_failed(request, -EIO);
+       }
+       /*
+        * Record sequence error bit is set, but erpa does not
+        * show record sequence error.
+        */
+       return tape_34xx_erp_bug(device, request, irb, -2);
+}
+
+/*
+ * This function analyses the tape's sense-data in case of a unit-check.
+ * If possible, it tries to recover from the error. Else the user is
+ * informed about the problem.
+ */
+static int
+tape_34xx_unit_check(struct tape_device *device, struct tape_request *request,
+                    struct irb *irb)
+{
+       int inhibit_cu_recovery;
+       __u8* sense;
+
+       inhibit_cu_recovery = (*device->modeset_byte & 0x80) ? 1 : 0;
+       sense = irb->ecw;
+
+       if (
+               sense[0] & SENSE_COMMAND_REJECT &&
+               sense[1] & SENSE_WRITE_PROTECT
+       ) {
+               if (
+                       request->op == TO_DSE ||
+                       request->op == TO_WRI ||
+                       request->op == TO_WTM
+               ) {
+                       /* medium is write protected */
+                       return tape_34xx_erp_failed(request, -EACCES);
+               } else {
+                       return tape_34xx_erp_bug(device, request, irb, -3);
+               }
+       }
+
+       /*
+        * Special cases for various tape-states when reaching
+        * end of recorded area
+        *
+        * FIXME: Maybe a special case of the special case:
+        *        sense[0] == SENSE_EQUIPMENT_CHECK &&
+        *        sense[1] == SENSE_DRIVE_ONLINE    &&
+        *        sense[3] == 0x47 (Volume Fenced)
+        *
+        *        This was caused by continued FSF or FSR after an
+        *        'End Of Data'.
+        */
+       if ((
+               sense[0] == SENSE_DATA_CHECK      ||
+               sense[0] == SENSE_EQUIPMENT_CHECK ||
+               sense[0] == SENSE_EQUIPMENT_CHECK + SENSE_DEFERRED_UNIT_CHECK
+       ) && (
+               sense[1] == SENSE_DRIVE_ONLINE ||
+               sense[1] == SENSE_BEGINNING_OF_TAPE + SENSE_WRITE_MODE
+       )) {
+               switch (request->op) {
+               /*
+                * sense[0] == SENSE_DATA_CHECK   &&
+                * sense[1] == SENSE_DRIVE_ONLINE
+                * sense[3] == 0x36 (End Of Data)
+                *
+                * Further seeks might return a 'Volume Fenced'.
+                */
+               case TO_FSF:
+               case TO_FSB:
+                       /* Trying to seek beyond end of recorded area */
+                       return tape_34xx_erp_failed(request, -ENOSPC);
+               case TO_BSB:
+                       return tape_34xx_erp_retry(request);
+
+               /*
+                * sense[0] == SENSE_DATA_CHECK   &&
+                * sense[1] == SENSE_DRIVE_ONLINE &&
+                * sense[3] == 0x36 (End Of Data)
+                */
+               case TO_LBL:
+                       /* Block could not be located. */
+                       tape_34xx_delete_sbid_from(device, 0);
+                       return tape_34xx_erp_failed(request, -EIO);
+
+               case TO_RFO:
+                       /* Read beyond end of recorded area -> 0 bytes read */
+                       return tape_34xx_erp_failed(request, 0);
+
+               /*
+                * sense[0] == SENSE_EQUIPMENT_CHECK &&
+                * sense[1] == SENSE_DRIVE_ONLINE    &&
+                * sense[3] == 0x38 (Physical End Of Volume)
+                */
+               case TO_WRI:
+                       /* Writing at physical end of volume */
+                       return tape_34xx_erp_failed(request, -ENOSPC);
+               default:
+                       return tape_34xx_erp_failed(request, 0);
+               }
+       }
+
+       /* Sensing special bits */
+       if (sense[0] & SENSE_BUS_OUT_CHECK)
+               return tape_34xx_erp_retry(request);
+
+       if (sense[0] & SENSE_DATA_CHECK) {
+               /*
+                * hardware failure, damaged tape or improper
+                * operating conditions
+                */
+               switch (sense[3]) {
+               case 0x23:
+                       /* a read data check occurred */
+                       if ((sense[2] & SENSE_TAPE_SYNC_MODE) ||
+                           inhibit_cu_recovery)
+                               // data check is not permanent, may be
+                               // recovered. We always use async-mode with
+                               // cu-recovery, so this should *never* happen.
+                               return tape_34xx_erp_bug(device, request,
+                                                        irb, -4);
+
+                       /* data check is permanent, CU recovery has failed */
+                       dev_warn (&device->cdev->dev, "A read error occurred "
+                               "that cannot be recovered\n");
+                       return tape_34xx_erp_failed(request, -EIO);
+               case 0x25:
+                       // a write data check occurred
+                       if ((sense[2] & SENSE_TAPE_SYNC_MODE) ||
+                           inhibit_cu_recovery)
+                               // data check is not permanent, may be
+                               // recovered. We always use async-mode with
+                               // cu-recovery, so this should *never* happen.
+                               return tape_34xx_erp_bug(device, request,
+                                                        irb, -5);
+
+                       // data check is permanent, cu-recovery has failed
+                       dev_warn (&device->cdev->dev, "A write error on the "
+                               "tape cannot be recovered\n");
+                       return tape_34xx_erp_failed(request, -EIO);
+               case 0x26:
+                       /* Data Check (read opposite) occurred. */
+                       return tape_34xx_erp_read_opposite(device, request);
+               case 0x28:
+                       /* ID-Mark at tape start couldn't be written */
+                       dev_warn (&device->cdev->dev, "Writing the ID-mark "
+                               "failed\n");
+                       return tape_34xx_erp_failed(request, -EIO);
+               case 0x31:
+                       /* Tape void. Tried to read beyond end of device. */
+                       dev_warn (&device->cdev->dev, "Reading the tape beyond"
+                               " the end of the recorded area failed\n");
+                       return tape_34xx_erp_failed(request, -ENOSPC);
+               case 0x41:
+                       /* Record sequence error. */
+                       dev_warn (&device->cdev->dev, "The tape contains an "
+                               "incorrect block ID sequence\n");
+                       return tape_34xx_erp_failed(request, -EIO);
+               default:
+                       /* all data checks for 3480 should result in one of
+                        * the above erpa-codes. For 3490, other data-check
+                        * conditions do exist. */
+                       if (device->cdev->id.driver_info == tape_3480)
+                               return tape_34xx_erp_bug(device, request,
+                                                        irb, -6);
+               }
+       }
+
+       if (sense[0] & SENSE_OVERRUN)
+               return tape_34xx_erp_overrun(device, request, irb);
+
+       if (sense[1] & SENSE_RECORD_SEQUENCE_ERR)
+               return tape_34xx_erp_sequence(device, request, irb);
+
+       /* Sensing erpa codes */
+       switch (sense[3]) {
+       case 0x00:
+               /* Unit check with erpa code 0. Report and ignore. */
+               return TAPE_IO_SUCCESS;
+       case 0x21:
+               /*
+                * Data streaming not operational. CU will switch to
+                * interlock mode. Reissue the command.
+                */
+               return tape_34xx_erp_retry(request);
+       case 0x22:
+               /*
+                * Path equipment check. Might be drive adapter error, buffer
+                * error on the lower interface, internal path not usable,
+                * or error during cartridge load.
+                */
+               dev_warn (&device->cdev->dev, "A path equipment check occurred"
+                       " for the tape device\n");
+               return tape_34xx_erp_failed(request, -EIO);
+       case 0x24:
+               /*
+                * Load display check. Load display was command was issued,
+                * but the drive is displaying a drive check message. Can
+                * be threated as "device end".
+                */
+               return tape_34xx_erp_succeeded(request);
+       case 0x27:
+               /*
+                * Command reject. May indicate illegal channel program or
+                * buffer over/underrun. Since all channel programs are
+                * issued by this driver and ought be correct, we assume a
+                * over/underrun situation and retry the channel program.
+                */
+               return tape_34xx_erp_retry(request);
+       case 0x29:
+               /*
+                * Function incompatible. Either the tape is idrc compressed
+                * but the hardware isn't capable to do idrc, or a perform
+                * subsystem func is issued and the CU is not on-line.
+                */
+               return tape_34xx_erp_failed(request, -EIO);
+       case 0x2a:
+               /*
+                * Unsolicited environmental data. An internal counter
+                * overflows, we can ignore this and reissue the cmd.
+                */
+               return tape_34xx_erp_retry(request);
+       case 0x2b:
+               /*
+                * Environmental data present. Indicates either unload
+                * completed ok or read buffered log command completed ok.
+                */
+               if (request->op == TO_RUN) {
+                       /* Rewind unload completed ok. */
+                       tape_med_state_set(device, MS_UNLOADED);
+                       return tape_34xx_erp_succeeded(request);
+               }
+               /* tape_34xx doesn't use read buffered log commands. */
+               return tape_34xx_erp_bug(device, request, irb, sense[3]);
+       case 0x2c:
+               /*
+                * Permanent equipment check. CU has tried recovery, but
+                * did not succeed.
+                */
+               return tape_34xx_erp_failed(request, -EIO);
+       case 0x2d:
+               /* Data security erase failure. */
+               if (request->op == TO_DSE)
+                       return tape_34xx_erp_failed(request, -EIO);
+               /* Data security erase failure, but no such command issued. */
+               return tape_34xx_erp_bug(device, request, irb, sense[3]);
+       case 0x2e:
+               /*
+                * Not capable. This indicates either that the drive fails
+                * reading the format id mark or that that format specified
+                * is not supported by the drive.
+                */
+               dev_warn (&device->cdev->dev, "The tape unit cannot process "
+                       "the tape format\n");
+               return tape_34xx_erp_failed(request, -EMEDIUMTYPE);
+       case 0x30:
+               /* The medium is write protected. */
+               dev_warn (&device->cdev->dev, "The tape medium is write-"
+                       "protected\n");
+               return tape_34xx_erp_failed(request, -EACCES);
+       case 0x32:
+               // Tension loss. We cannot recover this, it's an I/O error.
+               dev_warn (&device->cdev->dev, "The tape does not have the "
+                       "required tape tension\n");
+               return tape_34xx_erp_failed(request, -EIO);
+       case 0x33:
+               /*
+                * Load Failure. The cartridge was not inserted correctly or
+                * the tape is not threaded correctly.
+                */
+               dev_warn (&device->cdev->dev, "The tape unit failed to load"
+                       " the cartridge\n");
+               tape_34xx_delete_sbid_from(device, 0);
+               return tape_34xx_erp_failed(request, -EIO);
+       case 0x34:
+               /*
+                * Unload failure. The drive cannot maintain tape tension
+                * and control tape movement during an unload operation.
+                */
+               dev_warn (&device->cdev->dev, "Automatic unloading of the tape"
+                       " cartridge failed\n");
+               if (request->op == TO_RUN)
+                       return tape_34xx_erp_failed(request, -EIO);
+               return tape_34xx_erp_bug(device, request, irb, sense[3]);
+       case 0x35:
+               /*
+                * Drive equipment check. One of the following:
+                * - cu cannot recover from a drive detected error
+                * - a check code message is shown on drive display
+                * - the cartridge loader does not respond correctly
+                * - a failure occurs during an index, load, or unload cycle
+                */
+               dev_warn (&device->cdev->dev, "An equipment check has occurred"
+                       " on the tape unit\n");
+               return tape_34xx_erp_failed(request, -EIO);
+       case 0x36:
+               if (device->cdev->id.driver_info == tape_3490)
+                       /* End of data. */
+                       return tape_34xx_erp_failed(request, -EIO);
+               /* This erpa is reserved for 3480 */
+               return tape_34xx_erp_bug(device, request, irb, sense[3]);
+       case 0x37:
+               /*
+                * Tape length error. The tape is shorter than reported in
+                * the beginning-of-tape data.
+                */
+               dev_warn (&device->cdev->dev, "The tape information states an"
+                       " incorrect length\n");
+               return tape_34xx_erp_failed(request, -EIO);
+       case 0x38:
+               /*
+                * Physical end of tape. A read/write operation reached
+                * the physical end of tape.
+                */
+               if (request->op==TO_WRI ||
+                   request->op==TO_DSE ||
+                   request->op==TO_WTM)
+                       return tape_34xx_erp_failed(request, -ENOSPC);
+               return tape_34xx_erp_failed(request, -EIO);
+       case 0x39:
+               /* Backward at Beginning of tape. */
+               return tape_34xx_erp_failed(request, -EIO);
+       case 0x3a:
+               /* Drive switched to not ready. */
+               dev_warn (&device->cdev->dev, "The tape unit is not ready\n");
+               return tape_34xx_erp_failed(request, -EIO);
+       case 0x3b:
+               /* Manual rewind or unload. This causes an I/O error. */
+               dev_warn (&device->cdev->dev, "The tape medium has been "
+                       "rewound or unloaded manually\n");
+               tape_34xx_delete_sbid_from(device, 0);
+               return tape_34xx_erp_failed(request, -EIO);
+       case 0x42:
+               /*
+                * Degraded mode. A condition that can cause degraded
+                * performance is detected.
+                */
+               dev_warn (&device->cdev->dev, "The tape subsystem is running "
+                       "in degraded mode\n");
+               return tape_34xx_erp_retry(request);
+       case 0x43:
+               /* Drive not ready. */
+               tape_34xx_delete_sbid_from(device, 0);
+               tape_med_state_set(device, MS_UNLOADED);
+               /* Some commands commands are successful even in this case */
+               if (sense[1] & SENSE_DRIVE_ONLINE) {
+                       switch(request->op) {
+                               case TO_ASSIGN:
+                               case TO_UNASSIGN:
+                               case TO_DIS:
+                               case TO_NOP:
+                                       return tape_34xx_done(request);
+                                       break;
+                               default:
+                                       break;
+                       }
+               }
+               return tape_34xx_erp_failed(request, -ENOMEDIUM);
+       case 0x44:
+               /* Locate Block unsuccessful. */
+               if (request->op != TO_BLOCK && request->op != TO_LBL)
+                       /* No locate block was issued. */
+                       return tape_34xx_erp_bug(device, request,
+                                                irb, sense[3]);
+               return tape_34xx_erp_failed(request, -EIO);
+       case 0x45:
+               /* The drive is assigned to a different channel path. */
+               dev_warn (&device->cdev->dev, "The tape unit is already "
+                       "assigned\n");
+               return tape_34xx_erp_failed(request, -EIO);
+       case 0x46:
+               /*
+                * Drive not on-line. Drive may be switched offline,
+                * the power supply may be switched off or
+                * the drive address may not be set correctly.
+                */
+               dev_warn (&device->cdev->dev, "The tape unit is not online\n");
+               return tape_34xx_erp_failed(request, -EIO);
+       case 0x47:
+               /* Volume fenced. CU reports volume integrity is lost. */
+               dev_warn (&device->cdev->dev, "The control unit has fenced "
+                       "access to the tape volume\n");
+               tape_34xx_delete_sbid_from(device, 0);
+               return tape_34xx_erp_failed(request, -EIO);
+       case 0x48:
+               /* Log sense data and retry request. */
+               return tape_34xx_erp_retry(request);
+       case 0x49:
+               /* Bus out check. A parity check error on the bus was found. */
+               dev_warn (&device->cdev->dev, "A parity error occurred on the "
+                       "tape bus\n");
+               return tape_34xx_erp_failed(request, -EIO);
+       case 0x4a:
+               /* Control unit erp failed. */
+               dev_warn (&device->cdev->dev, "I/O error recovery failed on "
+                       "the tape control unit\n");
+               return tape_34xx_erp_failed(request, -EIO);
+       case 0x4b:
+               /*
+                * CU and drive incompatible. The drive requests micro-program
+                * patches, which are not available on the CU.
+                */
+               dev_warn (&device->cdev->dev, "The tape unit requires a "
+                       "firmware update\n");
+               return tape_34xx_erp_failed(request, -EIO);
+       case 0x4c:
+               /*
+                * Recovered Check-One failure. Cu develops a hardware error,
+                * but is able to recover.
+                */
+               return tape_34xx_erp_retry(request);
+       case 0x4d:
+               if (device->cdev->id.driver_info == tape_3490)
+                       /*
+                        * Resetting event received. Since the driver does
+                        * not support resetting event recovery (which has to
+                        * be handled by the I/O Layer), retry our command.
+                        */
+                       return tape_34xx_erp_retry(request);
+               /* This erpa is reserved for 3480. */
+               return tape_34xx_erp_bug(device, request, irb, sense[3]);
+       case 0x4e:
+               if (device->cdev->id.driver_info == tape_3490) {
+                       /*
+                        * Maximum block size exceeded. This indicates, that
+                        * the block to be written is larger than allowed for
+                        * buffered mode.
+                        */
+                       dev_warn (&device->cdev->dev, "The maximum block size"
+                               " for buffered mode is exceeded\n");
+                       return tape_34xx_erp_failed(request, -ENOBUFS);
+               }
+               /* This erpa is reserved for 3480. */
+               return tape_34xx_erp_bug(device, request, irb, sense[3]);
+       case 0x50:
+               /*
+                * Read buffered log (Overflow). CU is running in extended
+                * buffered log mode, and a counter overflows. This should
+                * never happen, since we're never running in extended
+                * buffered log mode.
+                */
+               return tape_34xx_erp_retry(request);
+       case 0x51:
+               /*
+                * Read buffered log (EOV). EOF processing occurs while the
+                * CU is in extended buffered log mode. This should never
+                * happen, since we're never running in extended buffered
+                * log mode.
+                */
+               return tape_34xx_erp_retry(request);
+       case 0x52:
+               /* End of Volume complete. Rewind unload completed ok. */
+               if (request->op == TO_RUN) {
+                       tape_med_state_set(device, MS_UNLOADED);
+                       tape_34xx_delete_sbid_from(device, 0);
+                       return tape_34xx_erp_succeeded(request);
+               }
+               return tape_34xx_erp_bug(device, request, irb, sense[3]);
+       case 0x53:
+               /* Global command intercept. */
+               return tape_34xx_erp_retry(request);
+       case 0x54:
+               /* Channel interface recovery (temporary). */
+               return tape_34xx_erp_retry(request);
+       case 0x55:
+               /* Channel interface recovery (permanent). */
+               dev_warn (&device->cdev->dev, "A channel interface error cannot be"
+                       " recovered\n");
+               return tape_34xx_erp_failed(request, -EIO);
+       case 0x56:
+               /* Channel protocol error. */
+               dev_warn (&device->cdev->dev, "A channel protocol error "
+                       "occurred\n");
+               return tape_34xx_erp_failed(request, -EIO);
+       case 0x57:
+               /*
+                * 3480: Attention intercept.
+                * 3490: Global status intercept.
+                */
+               return tape_34xx_erp_retry(request);
+       case 0x5a:
+               /*
+                * Tape length incompatible. The tape inserted is too long,
+                * which could cause damage to the tape or the drive.
+                */
+               dev_warn (&device->cdev->dev, "The tape unit does not support "
+                       "the tape length\n");
+               return tape_34xx_erp_failed(request, -EIO);
+       case 0x5b:
+               /* Format 3480 XF incompatible */
+               if (sense[1] & SENSE_BEGINNING_OF_TAPE)
+                       /* The tape will get overwritten. */
+                       return tape_34xx_erp_retry(request);
+               dev_warn (&device->cdev->dev, "The tape unit does not support"
+                       " format 3480 XF\n");
+               return tape_34xx_erp_failed(request, -EIO);
+       case 0x5c:
+               /* Format 3480-2 XF incompatible */
+               dev_warn (&device->cdev->dev, "The tape unit does not support tape "
+                       "format 3480-2 XF\n");
+               return tape_34xx_erp_failed(request, -EIO);
+       case 0x5d:
+               /* Tape length violation. */
+               dev_warn (&device->cdev->dev, "The tape unit does not support"
+                       " the current tape length\n");
+               return tape_34xx_erp_failed(request, -EMEDIUMTYPE);
+       case 0x5e:
+               /* Compaction algorithm incompatible. */
+               dev_warn (&device->cdev->dev, "The tape unit does not support"
+                       " the compaction algorithm\n");
+               return tape_34xx_erp_failed(request, -EMEDIUMTYPE);
+
+               /* The following erpas should have been covered earlier. */
+       case 0x23: /* Read data check. */
+       case 0x25: /* Write data check. */
+       case 0x26: /* Data check (read opposite). */
+       case 0x28: /* Write id mark check. */
+       case 0x31: /* Tape void. */
+       case 0x40: /* Overrun error. */
+       case 0x41: /* Record sequence error. */
+               /* All other erpas are reserved for future use. */
+       default:
+               return tape_34xx_erp_bug(device, request, irb, sense[3]);
+       }
+}
+
+/*
+ * 3480/3490 interrupt handler
+ */
+static int
+tape_34xx_irq(struct tape_device *device, struct tape_request *request,
+             struct irb *irb)
+{
+       if (request == NULL)
+               return tape_34xx_unsolicited_irq(device, irb);
+
+       if ((irb->scsw.cmd.dstat & DEV_STAT_UNIT_EXCEP) &&
+           (irb->scsw.cmd.dstat & DEV_STAT_DEV_END) &&
+           (request->op == TO_WRI)) {
+               /* Write at end of volume */
+               return tape_34xx_erp_failed(request, -ENOSPC);
+       }
+
+       if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_CHECK)
+               return tape_34xx_unit_check(device, request, irb);
+
+       if (irb->scsw.cmd.dstat & DEV_STAT_DEV_END) {
+               /*
+                * A unit exception occurs on skipping over a tapemark block.
+                */
+               if (irb->scsw.cmd.dstat & DEV_STAT_UNIT_EXCEP) {
+                       if (request->op == TO_BSB || request->op == TO_FSB)
+                               request->rescnt++;
+                       else
+                               DBF_EVENT(5, "Unit Exception!\n");
+               }
+               return tape_34xx_done(request);
+       }
+
+       DBF_EVENT(6, "xunknownirq\n");
+       tape_dump_sense_dbf(device, request, irb);
+       return TAPE_IO_STOP;
+}
+
+/*
+ * ioctl_overload
+ */
+static int
+tape_34xx_ioctl(struct tape_device *device, unsigned int cmd, unsigned long arg)
+{
+       if (cmd == TAPE390_DISPLAY) {
+               struct display_struct disp;
+
+               if (copy_from_user(&disp, (char __user *) arg, sizeof(disp)) != 0)
+                       return -EFAULT;
+
+               return tape_std_display(device, &disp);
+       } else
+               return -EINVAL;
+}
+
+static inline void
+tape_34xx_append_new_sbid(struct tape_34xx_block_id bid, struct list_head *l)
+{
+       struct tape_34xx_sbid * new_sbid;
+
+       new_sbid = kmalloc(sizeof(*new_sbid), GFP_ATOMIC);
+       if (!new_sbid)
+               return;
+
+       new_sbid->bid = bid;
+       list_add(&new_sbid->list, l);
+}
+
+/*
+ * Build up the search block ID list. The block ID consists of a logical
+ * block number and a hardware specific part. The hardware specific part
+ * helps the tape drive to speed up searching for a specific block.
+ */
+static void
+tape_34xx_add_sbid(struct tape_device *device, struct tape_34xx_block_id bid)
+{
+       struct list_head *      sbid_list;
+       struct tape_34xx_sbid * sbid;
+       struct list_head *      l;
+
+       /*
+        * immediately return if there is no list at all or the block to add
+        * is located in segment 1 of wrap 0 because this position is used
+        * if no hardware position data is supplied.
+        */
+       sbid_list = (struct list_head *) device->discdata;
+       if (!sbid_list || (bid.segment < 2 && bid.wrap == 0))
+               return;
+
+       /*
+        * Search the position where to insert the new entry. Hardware
+        * acceleration uses only the segment and wrap number. So we
+        * need only one entry for a specific wrap/segment combination.
+        * If there is a block with a lower number but the same hard-
+        * ware position data we just update the block number in the
+        * existing entry.
+        */
+       list_for_each(l, sbid_list) {
+               sbid = list_entry(l, struct tape_34xx_sbid, list);
+
+               if (
+                       (sbid->bid.segment == bid.segment) &&
+                       (sbid->bid.wrap    == bid.wrap)
+               ) {
+                       if (bid.block < sbid->bid.block)
+                               sbid->bid = bid;
+                       else return;
+                       break;
+               }
+
+               /* Sort in according to logical block number. */
+               if (bid.block < sbid->bid.block) {
+                       tape_34xx_append_new_sbid(bid, l->prev);
+                       break;
+               }
+       }
+       /* List empty or new block bigger than last entry. */
+       if (l == sbid_list)
+               tape_34xx_append_new_sbid(bid, l->prev);
+
+       DBF_LH(4, "Current list is:\n");
+       list_for_each(l, sbid_list) {
+               sbid = list_entry(l, struct tape_34xx_sbid, list);
+               DBF_LH(4, "%d:%03d@%05d\n",
+                       sbid->bid.wrap,
+                       sbid->bid.segment,
+                       sbid->bid.block
+               );
+       }
+}
+
+/*
+ * Delete all entries from the search block ID list that belong to tape blocks
+ * equal or higher than the given number.
+ */
+static void
+tape_34xx_delete_sbid_from(struct tape_device *device, int from)
+{
+       struct list_head *      sbid_list;
+       struct tape_34xx_sbid * sbid;
+       struct list_head *      l;
+       struct list_head *      n;
+
+       sbid_list = (struct list_head *) device->discdata;
+       if (!sbid_list)
+               return;
+
+       list_for_each_safe(l, n, sbid_list) {
+               sbid = list_entry(l, struct tape_34xx_sbid, list);
+               if (sbid->bid.block >= from) {
+                       DBF_LH(4, "Delete sbid %d:%03d@%05d\n",
+                               sbid->bid.wrap,
+                               sbid->bid.segment,
+                               sbid->bid.block
+                       );
+                       list_del(l);
+                       kfree(sbid);
+               }
+       }
+}
+
+/*
+ * Merge hardware position data into a block id.
+ */
+static void
+tape_34xx_merge_sbid(
+       struct tape_device *            device,
+       struct tape_34xx_block_id *     bid
+) {
+       struct tape_34xx_sbid * sbid;
+       struct tape_34xx_sbid * sbid_to_use;
+       struct list_head *      sbid_list;
+       struct list_head *      l;
+
+       sbid_list = (struct list_head *) device->discdata;
+       bid->wrap    = 0;
+       bid->segment = 1;
+
+       if (!sbid_list || list_empty(sbid_list))
+               return;
+
+       sbid_to_use = NULL;
+       list_for_each(l, sbid_list) {
+               sbid = list_entry(l, struct tape_34xx_sbid, list);
+
+               if (sbid->bid.block >= bid->block)
+                       break;
+               sbid_to_use = sbid;
+       }
+       if (sbid_to_use) {
+               bid->wrap    = sbid_to_use->bid.wrap;
+               bid->segment = sbid_to_use->bid.segment;
+               DBF_LH(4, "Use %d:%03d@%05d for %05d\n",
+                       sbid_to_use->bid.wrap,
+                       sbid_to_use->bid.segment,
+                       sbid_to_use->bid.block,
+                       bid->block
+               );
+       }
+}
+
+static int
+tape_34xx_setup_device(struct tape_device * device)
+{
+       int                     rc;
+       struct list_head *      discdata;
+
+       DBF_EVENT(6, "34xx device setup\n");
+       if ((rc = tape_std_assign(device)) == 0) {
+               if ((rc = tape_34xx_medium_sense(device)) != 0) {
+                       DBF_LH(3, "34xx medium sense returned %d\n", rc);
+               }
+       }
+       discdata = kmalloc(sizeof(struct list_head), GFP_KERNEL);
+       if (discdata) {
+                       INIT_LIST_HEAD(discdata);
+                       device->discdata = discdata;
+       }
+
+       return rc;
+}
+
+static void
+tape_34xx_cleanup_device(struct tape_device *device)
+{
+       tape_std_unassign(device);
+       
+       if (device->discdata) {
+               tape_34xx_delete_sbid_from(device, 0);
+               kfree(device->discdata);
+               device->discdata = NULL;
+       }
+}
+
+
+/*
+ * MTTELL: Tell block. Return the number of block relative to current file.
+ */
+static int
+tape_34xx_mttell(struct tape_device *device, int mt_count)
+{
+       struct {
+               struct tape_34xx_block_id       cbid;
+               struct tape_34xx_block_id       dbid;
+       } __attribute__ ((packed)) block_id;
+       int rc;
+
+       rc = tape_std_read_block_id(device, (__u64 *) &block_id);
+       if (rc)
+               return rc;
+
+       tape_34xx_add_sbid(device, block_id.cbid);
+       return block_id.cbid.block;
+}
+
+/*
+ * MTSEEK: seek to the specified block.
+ */
+static int
+tape_34xx_mtseek(struct tape_device *device, int mt_count)
+{
+       struct tape_request *request;
+       struct tape_34xx_block_id *     bid;
+
+       if (mt_count > 0x3fffff) {
+               DBF_EXCEPTION(6, "xsee parm\n");
+               return -EINVAL;
+       }
+       request = tape_alloc_request(3, 4);
+       if (IS_ERR(request))
+               return PTR_ERR(request);
+
+       /* setup ccws */
+       request->op = TO_LBL;
+       bid         = (struct tape_34xx_block_id *) request->cpdata;
+       bid->format = (*device->modeset_byte & 0x08) ?
+                       TAPE34XX_FMT_3480_XF : TAPE34XX_FMT_3480;
+       bid->block  = mt_count;
+       tape_34xx_merge_sbid(device, bid);
+
+       tape_ccw_cc(request->cpaddr, MODE_SET_DB, 1, device->modeset_byte);
+       tape_ccw_cc(request->cpaddr + 1, LOCATE, 4, request->cpdata);
+       tape_ccw_end(request->cpaddr + 2, NOP, 0, NULL);
+
+       /* execute it */
+       return tape_do_io_free(device, request);
+}
+
+/*
+ * List of 3480/3490 magnetic tape commands.
+ */
+static tape_mtop_fn tape_34xx_mtop[TAPE_NR_MTOPS] = {
+       [MTRESET]        = tape_std_mtreset,
+       [MTFSF]          = tape_std_mtfsf,
+       [MTBSF]          = tape_std_mtbsf,
+       [MTFSR]          = tape_std_mtfsr,
+       [MTBSR]          = tape_std_mtbsr,
+       [MTWEOF]         = tape_std_mtweof,
+       [MTREW]          = tape_std_mtrew,
+       [MTOFFL]         = tape_std_mtoffl,
+       [MTNOP]          = tape_std_mtnop,
+       [MTRETEN]        = tape_std_mtreten,
+       [MTBSFM]         = tape_std_mtbsfm,
+       [MTFSFM]         = tape_std_mtfsfm,
+       [MTEOM]          = tape_std_mteom,
+       [MTERASE]        = tape_std_mterase,
+       [MTRAS1]         = NULL,
+       [MTRAS2]         = NULL,
+       [MTRAS3]         = NULL,
+       [MTSETBLK]       = tape_std_mtsetblk,
+       [MTSETDENSITY]   = NULL,
+       [MTSEEK]         = tape_34xx_mtseek,
+       [MTTELL]         = tape_34xx_mttell,
+       [MTSETDRVBUFFER] = NULL,
+       [MTFSS]          = NULL,
+       [MTBSS]          = NULL,
+       [MTWSM]          = NULL,
+       [MTLOCK]         = NULL,
+       [MTUNLOCK]       = NULL,
+       [MTLOAD]         = tape_std_mtload,
+       [MTUNLOAD]       = tape_std_mtunload,
+       [MTCOMPRESSION]  = tape_std_mtcompression,
+       [MTSETPART]      = NULL,
+       [MTMKPART]       = NULL
+};
+
+/*
+ * Tape discipline structure for 3480 and 3490.
+ */
+static struct tape_discipline tape_discipline_34xx = {
+       .owner = THIS_MODULE,
+       .setup_device = tape_34xx_setup_device,
+       .cleanup_device = tape_34xx_cleanup_device,
+       .process_eov = tape_std_process_eov,
+       .irq = tape_34xx_irq,
+       .read_block = tape_std_read_block,
+       .write_block = tape_std_write_block,
+       .ioctl_fn = tape_34xx_ioctl,
+       .mtop_array = tape_34xx_mtop
+};
+
+static struct ccw_device_id tape_34xx_ids[] = {
+       { CCW_DEVICE_DEVTYPE(0x3480, 0, 0x3480, 0), .driver_info = tape_3480},
+       { CCW_DEVICE_DEVTYPE(0x3490, 0, 0x3490, 0), .driver_info = tape_3490},
+       { /* end of list */ },
+};
+
+static int
+tape_34xx_online(struct ccw_device *cdev)
+{
+       return tape_generic_online(
+               dev_get_drvdata(&cdev->dev),
+               &tape_discipline_34xx
+       );
+}
+
+static struct ccw_driver tape_34xx_driver = {
+       .driver = {
+               .name = "tape_34xx",
+               .owner = THIS_MODULE,
+       },
+       .ids = tape_34xx_ids,
+       .probe = tape_generic_probe,
+       .remove = tape_generic_remove,
+       .set_online = tape_34xx_online,
+       .set_offline = tape_generic_offline,
+       .freeze = tape_generic_pm_suspend,
+       .int_class = IRQIO_TAP,
+};
+
+static int
+tape_34xx_init (void)
+{
+       int rc;
+
+       TAPE_DBF_AREA = debug_register ( "tape_34xx", 2, 2, 4*sizeof(long));
+       debug_register_view(TAPE_DBF_AREA, &debug_sprintf_view);
+#ifdef DBF_LIKE_HELL
+       debug_set_level(TAPE_DBF_AREA, 6);
+#endif
+
+       DBF_EVENT(3, "34xx init\n");
+       /* Register driver for 3480/3490 tapes. */
+       rc = ccw_driver_register(&tape_34xx_driver);
+       if (rc)
+               DBF_EVENT(3, "34xx init failed\n");
+       else
+               DBF_EVENT(3, "34xx registered\n");
+       return rc;
+}
+
+static void
+tape_34xx_exit(void)
+{
+       ccw_driver_unregister(&tape_34xx_driver);
+
+       debug_unregister(TAPE_DBF_AREA);
+}
+
+MODULE_DEVICE_TABLE(ccw, tape_34xx_ids);
+MODULE_AUTHOR("(C) 2001-2002 IBM Deutschland Entwicklung GmbH");
+MODULE_DESCRIPTION("Linux on zSeries channel attached 3480 tape device driver");
+MODULE_LICENSE("GPL");
+
+module_init(tape_34xx_init);
+module_exit(tape_34xx_exit);