[PATCH] s390: revert dasd eer module

Revert dasd eer module until we have a common understanding of how the
interface should be.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 0 insertions, 1090 deletions

diff --git a/drivers/s390/block/dasd_eer.c b/drivers/s390/block/dasd_eer.c
deleted file mode 100644
index f70cd7716b24..000000000000
--- a/drivers/s390/block/dasd_eer.c
+++ /dev/null
@@ -1,1090 +0,0 @@
-/*
- *      character device driver for extended error reporting
- *
- *
- *      Copyright (C) 2005 IBM Corporation
- *      extended error reporting for DASD ECKD devices
- *      Author(s): Stefan Weinhuber <wein@de.ibm.com>
- *
- */
-
-#include <linux/init.h>
-#include <linux/fs.h>
-#include <linux/kernel.h>
-#include <linux/miscdevice.h>
-#include <linux/module.h>
-#include <linux/moduleparam.h>
-#include <linux/device.h>
-#include <linux/workqueue.h>
-#include <linux/poll.h>
-#include <linux/notifier.h>
-
-#include <asm/uaccess.h>
-#include <asm/semaphore.h>
-#include <asm/atomic.h>
-#include <asm/ebcdic.h>
-
-#include "dasd_int.h"
-#include "dasd_eckd.h"
-
-
-MODULE_LICENSE("GPL");
-
-MODULE_AUTHOR("Stefan Weinhuber <wein@de.ibm.com>");
-MODULE_DESCRIPTION("DASD extended error reporting module");
-
-
-#ifdef PRINTK_HEADER
-#undef PRINTK_HEADER
-#endif                          /* PRINTK_HEADER */
-#define PRINTK_HEADER "dasd(eer):"
-
-
-
-
-
-/*****************************************************************************/
-/*      the internal buffer                                                  */
-/*****************************************************************************/
-
-/*
- * The internal buffer is meant to store obaque blobs of data, so it doesn't
- * know of higher level concepts like triggers.
- * It consists of a number of pages that are used as a ringbuffer. Each data
- * blob is stored in a simple record that consists of an integer, which
- * contains the size of the following data, and the data bytes themselfes.
- *
- * To allow for multiple independent readers we create one internal buffer
- * each time the device is opened and destroy the buffer when the file is
- * closed again.
- *
- * One record can be written to a buffer by using the functions
- * - dasd_eer_start_record (one time per record to write the size to the buffer
- *                          and reserve the space for the data)
- * - dasd_eer_write_buffer (one or more times per record to write the data)
- * The data can be written in several steps but you will have to compute
- * the total size up front for the invocation of dasd_eer_start_record.
- * If the ringbuffer is full, dasd_eer_start_record will remove the required
- * number of old records.
- *
- * A record is typically read in two steps, first read the integer that
- * specifies the size of the following data, then read the data.
- * Both can be done by
- * - dasd_eer_read_buffer
- *
- * For all mentioned functions you need to get the bufferlock first and keep it
- * until a complete record is written or read.
- */
-
-
-/*
- * Alle information necessary to keep track of an internal buffer is kept in
- * a struct eerbuffer. The buffer specific to a file pointer is strored in
- * the private_data field of that file. To be able to write data to all
- * existing buffers, each buffer is also added to the bufferlist.
- * If the user doesn't want to read a complete record in one go, we have to
- * keep track of the rest of the record. residual stores the number of bytes
- * that are still to deliver. If the rest of the record is invalidated between
- * two reads then residual will be set to -1 so that the next read will fail.
- * All entries in the eerbuffer structure are protected with the bufferlock.
- * To avoid races between writing to a buffer on the one side and creating
- * and destroying buffers on the other side, the bufferlock must also be used
- * to protect the bufferlist.
- */
-
-struct eerbuffer {
-        struct list_head list;
-        char **buffer;
-        int buffersize;
-        int buffer_page_count;
-        int head;
-        int tail;
-        int residual;
-};
-
-LIST_HEAD(bufferlist);
-
-static spinlock_t bufferlock = SPIN_LOCK_UNLOCKED;
-
-DECLARE_WAIT_QUEUE_HEAD(dasd_eer_read_wait_queue);
-
-/*
- * How many free bytes are available on the buffer.
- * needs to be called with bufferlock held
- */
-static int
-dasd_eer_get_free_bytes(struct eerbuffer *eerb)
-{
-        if (eerb->head < eerb->tail) {
-                return eerb->tail - eerb->head - 1;
-        } else
-                return eerb->buffersize - eerb->head + eerb->tail -1;
-}
-
-/*
- * How many bytes of buffer space are used.
- * needs to be called with bufferlock held
- */
-static int
-dasd_eer_get_filled_bytes(struct eerbuffer *eerb)
-{
-
-        if (eerb->head >= eerb->tail) {
-                return eerb->head - eerb->tail;
-        } else
-                return eerb->buffersize - eerb->tail + eerb->head;
-}
-
-/*
- * The dasd_eer_write_buffer function just copies count bytes of data
- * to the buffer. Make sure to call dasd_eer_start_record first, to
- * make sure that enough free space is available.
- * needs to be called with bufferlock held
- */
-static void
-dasd_eer_write_buffer(struct eerbuffer *eerb, int count, char *data)
-{
-
-        unsigned long headindex,localhead;
-        unsigned long rest, len;
-        char *nextdata;
-
-        nextdata = data;
-        rest = count;
-        while (rest > 0) {
-                headindex = eerb->head / PAGE_SIZE;
-                localhead = eerb->head % PAGE_SIZE;
-                len = min(rest, (PAGE_SIZE - localhead));
-                memcpy(eerb->buffer[headindex]+localhead, nextdata, len);
-                nextdata += len;
-                rest -= len;
-                eerb->head += len;
-                if ( eerb->head == eerb->buffersize )
-                        eerb->head = 0; /* wrap around */
-                if (eerb->head > eerb->buffersize) {
-                        MESSAGE(KERN_ERR, "%s", "runaway buffer head.");
-                        BUG();
-                }
-        }
-}
-
-/*
- * needs to be called with bufferlock held
- */
-static int
-dasd_eer_read_buffer(struct eerbuffer *eerb, int count, char *data)
-{
-
-        unsigned long tailindex,localtail;
-        unsigned long rest, len, finalcount;
-        char *nextdata;
-
-        finalcount = min(count, dasd_eer_get_filled_bytes(eerb));
-        nextdata = data;
-        rest = finalcount;
-        while (rest > 0) {
-                tailindex = eerb->tail / PAGE_SIZE;
-                localtail = eerb->tail % PAGE_SIZE;
-                len = min(rest, (PAGE_SIZE - localtail));
-                memcpy(nextdata, eerb->buffer[tailindex]+localtail, len);
-                nextdata += len;
-                rest -= len;
-                eerb->tail += len;
-                if ( eerb->tail == eerb->buffersize )
-                        eerb->tail = 0; /* wrap around */
-                if (eerb->tail > eerb->buffersize) {
-                        MESSAGE(KERN_ERR, "%s", "runaway buffer tail.");
-                        BUG();
-                }
-        }
-        return finalcount;
-}
-
-/*
- * Whenever you want to write a blob of data to the internal buffer you
- * have to start by using this function first. It will write the number
- * of bytes that will be written to the buffer. If necessary it will remove
- * old records to make room for the new one.
- * needs to be called with bufferlock held
- */
-static int
-dasd_eer_start_record(struct eerbuffer *eerb, int count)
-{
-        int tailcount;
-        if (count + sizeof(count) > eerb->buffersize)
-                return -ENOMEM;
-        while (dasd_eer_get_free_bytes(eerb) < count + sizeof(count)) {
-                if (eerb->residual > 0) {
-                        eerb->tail += eerb->residual;
-                        if (eerb->tail >= eerb->buffersize)
-                                eerb->tail -= eerb->buffersize;
-                        eerb->residual = -1;
-                }
-                dasd_eer_read_buffer(eerb, sizeof(tailcount),
-                                     (char*)(&tailcount));
-                eerb->tail += tailcount;
-                if (eerb->tail >= eerb->buffersize)
-                        eerb->tail -= eerb->buffersize;
-        }
-        dasd_eer_write_buffer(eerb, sizeof(count), (char*)(&count));
-
-        return 0;
-};
-
-/*
- * release pages that are not used anymore
- */
-static void
-dasd_eer_free_buffer_pages(char **buf, int no_pages)
-{
-        int i;
-
-        for (i = 0; i < no_pages; ++i) {
-                free_page((unsigned long)buf[i]);
-        }
-}
-
-/*
- * allocate a new set of memory pages
- */
-static int
-dasd_eer_allocate_buffer_pages(char **buf, int no_pages)
-{
-        int i;
-
-        for (i = 0; i < no_pages; ++i) {
-                buf[i] = (char *) get_zeroed_page(GFP_KERNEL);
-                if (!buf[i]) {
-                        dasd_eer_free_buffer_pages(buf, i);
-                        return -ENOMEM;
-                }
-        }
-        return 0;
-}
-
-/*
- * empty the buffer by resetting head and tail
- * In case there is a half read data blob in the buffer, we set residual
- * to -1 to indicate that the remainder of the blob is lost.
- */
-static void
-dasd_eer_purge_buffer(struct eerbuffer *eerb)
-{
-        unsigned long flags;
-
-        spin_lock_irqsave(&bufferlock, flags);
-        if (eerb->residual > 0)
-                eerb->residual = -1;
-        eerb->tail=0;
-        eerb->head=0;
-        spin_unlock_irqrestore(&bufferlock, flags);
-}
-
-/*
- * set the size of the buffer, newsize is the new number of pages to be used
- * we don't try to copy any data back an forth, so any resize will also purge
- * the buffer
- */
-static int
-dasd_eer_resize_buffer(struct eerbuffer *eerb, int newsize)
-{
-        int i, oldcount, reuse;
-        char **new;
-        char **old;
-        unsigned long flags;
-
-        if (newsize < 1)
-                return -EINVAL;
-        if (eerb->buffer_page_count == newsize) {
-                /* documented behaviour is that any successfull invocation
-                 * will purge all records */
-                dasd_eer_purge_buffer(eerb);
-                return 0;
-        }
-        new = kmalloc(newsize*sizeof(char*), GFP_KERNEL);
-        if (!new)
-                return -ENOMEM;
-
-        reuse=min(eerb->buffer_page_count, newsize);
-        for (i = 0; i < reuse; ++i) {
-                new[i] = eerb->buffer[i];
-        }
-        if (eerb->buffer_page_count < newsize) {
-                if (dasd_eer_allocate_buffer_pages(
-                            &new[eerb->buffer_page_count],
-                            newsize - eerb->buffer_page_count)) {
-                        kfree(new);
-                        return -ENOMEM;
-                }
-        }
-
-        spin_lock_irqsave(&bufferlock, flags);
-        old = eerb->buffer;
-        eerb->buffer = new;
-        if (eerb->residual > 0)
-                eerb->residual = -1;
-        eerb->tail = 0;
-        eerb->head = 0;
-        oldcount = eerb->buffer_page_count;
-        eerb->buffer_page_count = newsize;
-        spin_unlock_irqrestore(&bufferlock, flags);
-
-        if (oldcount > newsize) {
-                for (i = newsize; i < oldcount; ++i) {
-                        free_page((unsigned long)old[i]);
-                }
-        }
-        kfree(old);
-
-        return 0;
-}
-
-
-/*****************************************************************************/
-/*      The extended error reporting functionality                           */
-/*****************************************************************************/
-
-/*
- * When a DASD device driver wants to report an error, it calls the
- * function dasd_eer_write_trigger (via a notifier mechanism) and gives the
- * respective trigger ID as parameter.
- * Currently there are four kinds of triggers:
- *
- * DASD_EER_FATALERROR:  all kinds of unrecoverable I/O problems
- * DASD_EER_PPRCSUSPEND: PPRC was suspended
- * DASD_EER_NOPATH:      There is no path to the device left.
- * DASD_EER_STATECHANGE: The state of the device has changed.
- *
- * For the first three triggers all required information can be supplied by
- * the caller. For these triggers a record is written by the function
- * dasd_eer_write_standard_trigger.
- *
- * When dasd_eer_write_trigger is called to write a DASD_EER_STATECHANGE
- * trigger, we have to gather the necessary sense data first. We cannot queue
- * the necessary SNSS (sense subsystem status) request immediatly, since we
- * are likely to run in a deadlock situation. Instead, we schedule a
- * work_struct that calls the function dasd_eer_sense_subsystem_status to
- * create and start an SNSS  request asynchronously.
- *
- * To avoid memory allocations at runtime, the necessary memory is allocated
- * when the extended error reporting is enabled for a device (by
- * dasd_eer_probe). There is one private eer data structure for each eer
- * enabled DASD device. It contains memory for the work_struct, one SNSS cqr
- * and a flags field that is used to coordinate the use of the cqr. The call
- * to write a state change trigger can come in at any time, so we have one flag
- * CQR_IN_USE that protects the cqr itself. When this flag indicates that the
- * cqr is currently in use, dasd_eer_sense_subsystem_status cannot start a
- * second request but sets the SNSS_REQUESTED flag instead.
- *
- * When the request is finished, the callback function dasd_eer_SNSS_cb
- * is called. This function will invoke the function
- * dasd_eer_write_SNSS_trigger to finally write the trigger. It will also
- * check the SNSS_REQUESTED flag and if it is set it will call
- * dasd_eer_sense_subsystem_status again.
- *
- * To avoid race conditions during the handling of the lock, the flags must
- * be protected by the snsslock.
- */
-
-struct dasd_eer_private {
-        struct dasd_ccw_req *cqr;
-        unsigned long flags;
-        struct work_struct worker;
-};
-
-static void dasd_eer_destroy(struct dasd_device *device,
-                             struct dasd_eer_private *eer);
-static int
-dasd_eer_write_trigger(struct dasd_eer_trigger *trigger);
-static void dasd_eer_sense_subsystem_status(void *data);
-static int dasd_eer_notify(struct notifier_block *self,
-                           unsigned long action, void *data);
-
-struct workqueue_struct *dasd_eer_workqueue;
-
-#define SNSS_DATA_SIZE 44
-static spinlock_t snsslock = SPIN_LOCK_UNLOCKED;
-
-#define DASD_EER_BUSID_SIZE 10
-struct dasd_eer_header {
-        __u32 total_size;
-        __u32 trigger;
-        __u64 tv_sec;
-        __u64 tv_usec;
-        char busid[DASD_EER_BUSID_SIZE];
-} __attribute__ ((packed));
-
-static struct notifier_block dasd_eer_nb = {
-        .notifier_call = dasd_eer_notify,
-};
-
-/*
- * flags for use with dasd_eer_private
- */
-#define CQR_IN_USE     0
-#define SNSS_REQUESTED 1
-
-/*
- * This function checks if extended error reporting is available for a given
- * dasd_device. If yes, then it creates and returns a struct dasd_eer,
- * otherwise it returns an -EPERM error pointer.
- */
-struct dasd_eer_private *
-dasd_eer_probe(struct dasd_device *device)
-{
-        struct dasd_eer_private *private;
-
-        if (!(device && device->discipline
-              && !strcmp(device->discipline->name, "ECKD"))) {
-                return ERR_PTR(-EPERM);
-        }
-        /* allocate the private data structure */
-        private = (struct dasd_eer_private *)kmalloc(
-                sizeof(struct dasd_eer_private), GFP_KERNEL);
-        if (!private) {
-                return ERR_PTR(-ENOMEM);
-        }
-        INIT_WORK(&private->worker, dasd_eer_sense_subsystem_status,
-                  (void *)device);
-        private->cqr = dasd_kmalloc_request("ECKD",
-                                            1 /* SNSS */ ,
-                                            SNSS_DATA_SIZE ,
-                                            device);
-        if (!private->cqr) {
-                kfree(private);
-                return ERR_PTR(-ENOMEM);
-        }
-        private->flags = 0;
-        return private;
-};
-
-/*
- * If our private SNSS request is queued, remove it from the
- * dasd ccw queue so we can free the requests memory.
- */
-static void
-dasd_eer_dequeue_SNSS_request(struct dasd_device *device,
-                              struct dasd_eer_private *eer)
-{
-        struct list_head *lst, *nxt;
-        struct dasd_ccw_req *cqr, *erpcqr;
-        dasd_erp_fn_t erp_fn;
-
-        spin_lock_irq(get_ccwdev_lock(device->cdev));
-        list_for_each_safe(lst, nxt, &device->ccw_queue) {
-                cqr = list_entry(lst, struct dasd_ccw_req, list);
-                /* we are looking for two kinds or requests */
-                /* first kind: our SNSS request: */
-                if (cqr == eer->cqr) {
-                        if (cqr->status == DASD_CQR_IN_IO)
-                                device->discipline->term_IO(cqr);
-                        list_del(&cqr->list);
-                        break;
-                }
-                /* second kind: ERP requests for our SNSS request */
-                if (cqr->refers) {
-                        /* If this erp request chain ends in our cqr, then */
-                        /* cal the erp_postaction to clean it up  */
-                        erpcqr = cqr;
-                        while (erpcqr->refers) {
-                                erpcqr = erpcqr->refers;
-                        }
-                        if (erpcqr == eer->cqr) {
-                                erp_fn = device->discipline->erp_postaction(
-                                         cqr);
-                                erp_fn(cqr);
-                        }
-                        continue;
-                }
-        }
-        spin_unlock_irq(get_ccwdev_lock(device->cdev));
-}
-
-/*
- * This function dismantles a struct dasd_eer that was created by
- * dasd_eer_probe. Since we want to free our private data structure,
- * we must make sure that the memory is not in use anymore.
- * We have to flush the work queue and remove a possible SNSS request
- * from the dasd queue.
- */
-static void
-dasd_eer_destroy(struct dasd_device *device, struct dasd_eer_private *eer)
-{
-        flush_workqueue(dasd_eer_workqueue);
-        dasd_eer_dequeue_SNSS_request(device, eer);
-        dasd_kfree_request(eer->cqr, device);
-        kfree(eer);
-};
-
-/*
- * enable the extended error reporting for a particular device
- */
-static int
-dasd_eer_enable_on_device(struct dasd_device *device)
-{
-        void *eer;
-        if (!device)
-                return -ENODEV;
-        if (device->eer)
-                return 0;
-        if (!try_module_get(THIS_MODULE)) {
-                return -EINVAL;
-        }
-        eer = (void *)dasd_eer_probe(device);
-        if (IS_ERR(eer)) {
-                module_put(THIS_MODULE);
-                return PTR_ERR(eer);
-        }
-        device->eer = eer;
-        return 0;
-}
-
-/*
- * enable the extended error reporting for a particular device
- */
-static int
-dasd_eer_disable_on_device(struct dasd_device *device)
-{
-        struct dasd_eer_private *eer = device->eer;
-
-        if (!device)
-                return -ENODEV;
-        if (!device->eer)
-                return 0;
-        device->eer = NULL;
-        dasd_eer_destroy(device,eer);
-        module_put(THIS_MODULE);
-
-        return 0;
-}
-
-/*
- * Set extended error reporting (eer)
- * Note: This will be registered as a DASD ioctl, to be called on DASD devices.
- */
-static int
-dasd_ioctl_set_eer(struct block_device *bdev, int no, long args)
-{
-        struct dasd_device *device;
-        int intval;
-
-        if (!capable(CAP_SYS_ADMIN))
-                return -EACCES;
-        if (bdev != bdev->bd_contains)
-                /* Error-reporting is not allowed for partitions */
-                return -EINVAL;
-        if (get_user(intval, (int __user *) args))
-                return -EFAULT;
-        device =  bdev->bd_disk->private_data;
-        if (device == NULL)
-                return -ENODEV;
-
-        intval = (intval != 0);
-        DEV_MESSAGE (KERN_DEBUG, device,
-                     "set eer on device to %d", intval);
-        if (intval)
-                return dasd_eer_enable_on_device(device);
-        else
-                return dasd_eer_disable_on_device(device);
-}
-
-/*
- * Get value of extended error reporting.
- * Note: This will be registered as a DASD ioctl, to be called on DASD devices.
- */
-static int
-dasd_ioctl_get_eer(struct block_device *bdev, int no, long args)
-{
-        struct dasd_device *device;
-
-        device =  bdev->bd_disk->private_data;
-        if (device == NULL)
-                return -ENODEV;
-        return put_user((device->eer != NULL), (int __user *) args);
-}
-
-/*
- * The following function can be used for those triggers that have
- * all necessary data available when the function is called.
- * If the parameter cqr is not NULL, the chain of requests will be searched
- * for valid sense data, and all valid sense data sets will be added to
- * the triggers data.
- */
-static int
-dasd_eer_write_standard_trigger(int trigger, struct dasd_device *device,
-                                struct dasd_ccw_req *cqr)
-{
-        struct dasd_ccw_req *temp_cqr;
-        int data_size;
-        struct timeval tv;
-        struct dasd_eer_header header;
-        unsigned long flags;
-        struct eerbuffer *eerb;
-
-        /* go through cqr chain and count the valid sense data sets */
-        temp_cqr = cqr;
-        data_size = 0;
-        while (temp_cqr) {
-                if (temp_cqr->irb.esw.esw0.erw.cons)
-                        data_size += 32;
-                temp_cqr = temp_cqr->refers;
-        }
-
-        header.total_size = sizeof(header) + data_size + 4; /* "EOR" */
-        header.trigger = trigger;
-        do_gettimeofday(&tv);
-        header.tv_sec = tv.tv_sec;
-        header.tv_usec = tv.tv_usec;
-        strncpy(header.busid, device->cdev->dev.bus_id, DASD_EER_BUSID_SIZE);
-
-        spin_lock_irqsave(&bufferlock, flags);
-        list_for_each_entry(eerb, &bufferlist, list) {
-                dasd_eer_start_record(eerb, header.total_size);
-                dasd_eer_write_buffer(eerb, sizeof(header), (char*)(&header));
-                temp_cqr = cqr;
-                while (temp_cqr) {
-                        if (temp_cqr->irb.esw.esw0.erw.cons)
-                                dasd_eer_write_buffer(eerb, 32, cqr->irb.ecw);
-                        temp_cqr = temp_cqr->refers;
-                }
-                dasd_eer_write_buffer(eerb, 4,"EOR");
-        }
-        spin_unlock_irqrestore(&bufferlock, flags);
-
-        wake_up_interruptible(&dasd_eer_read_wait_queue);
-
-        return 0;
-}
-
-/*
- * This function writes a DASD_EER_STATECHANGE trigger.
- */
-static void
-dasd_eer_write_SNSS_trigger(struct dasd_device *device,
-                            struct dasd_ccw_req *cqr)
-{
-        int data_size;
-        int snss_rc;
-        struct timeval tv;
-        struct dasd_eer_header header;
-        unsigned long flags;
-        struct eerbuffer *eerb;
-
-        snss_rc = (cqr->status == DASD_CQR_FAILED) ? -EIO : 0;
-        if (snss_rc)
-                data_size = 0;
-        else
-                data_size = SNSS_DATA_SIZE;
-
-        header.total_size = sizeof(header) + data_size + 4; /* "EOR" */
-        header.trigger = DASD_EER_STATECHANGE;
-        do_gettimeofday(&tv);
-        header.tv_sec = tv.tv_sec;
-        header.tv_usec = tv.tv_usec;
-        strncpy(header.busid, device->cdev->dev.bus_id, DASD_EER_BUSID_SIZE);
-
-        spin_lock_irqsave(&bufferlock, flags);
-        list_for_each_entry(eerb, &bufferlist, list) {
-                dasd_eer_start_record(eerb, header.total_size);
-                dasd_eer_write_buffer(eerb, sizeof(header),(char*)(&header));
-                if (!snss_rc)
-                        dasd_eer_write_buffer(eerb, SNSS_DATA_SIZE, cqr->data);
-                dasd_eer_write_buffer(eerb, 4,"EOR");
-        }
-        spin_unlock_irqrestore(&bufferlock, flags);
-
-        wake_up_interruptible(&dasd_eer_read_wait_queue);
-}
-
-/*
- * callback function for use with SNSS request
- */
-static void
-dasd_eer_SNSS_cb(struct dasd_ccw_req *cqr, void *data)
-{
-        struct dasd_device *device;
-        struct dasd_eer_private *private;
-        unsigned long irqflags;
-
-        device = (struct dasd_device *)data;
-        private = (struct dasd_eer_private *)device->eer;
-        dasd_eer_write_SNSS_trigger(device, cqr);
-        spin_lock_irqsave(&snsslock, irqflags);
-        if(!test_and_clear_bit(SNSS_REQUESTED, &private->flags)) {
-                clear_bit(CQR_IN_USE, &private->flags);
-                spin_unlock_irqrestore(&snsslock, irqflags);
-                return;
-        };
-        clear_bit(CQR_IN_USE, &private->flags);
-        spin_unlock_irqrestore(&snsslock, irqflags);
-        dasd_eer_sense_subsystem_status(device);
-        return;
-}
-
-/*
- * clean a used cqr before using it again
- */
-static void
-dasd_eer_clean_SNSS_request(struct dasd_ccw_req *cqr)
-{
-        struct ccw1 *cpaddr = cqr->cpaddr;
-        void *data = cqr->data;
-
-        memset(cqr, 0, sizeof(struct dasd_ccw_req));
-        memset(cpaddr, 0, sizeof(struct ccw1));
-        memset(data, 0, SNSS_DATA_SIZE);
-        cqr->cpaddr = cpaddr;
-        cqr->data = data;
-        strncpy((char *) &cqr->magic, "ECKD", 4);
-        ASCEBC((char *) &cqr->magic, 4);
-        set_bit(DASD_CQR_FLAGS_USE_ERP, &cqr->flags);
-}
-
-/*
- * build and start an SNSS request
- * This function is called from a work queue so we have to
- * pass the dasd_device pointer as a void pointer.
- */
-static void
-dasd_eer_sense_subsystem_status(void *data)
-{
-        struct dasd_device *device;
-        struct dasd_eer_private *private;
-        struct dasd_ccw_req *cqr;
-        struct ccw1 *ccw;
-        unsigned long irqflags;
-
-        device = (struct dasd_device *)data;
-        private = (struct dasd_eer_private *)device->eer;
-        if (!private) /* device not eer enabled any more */
-                return;
-        cqr = private->cqr;
-        spin_lock_irqsave(&snsslock, irqflags);
-        if(test_and_set_bit(CQR_IN_USE, &private->flags)) {
-                set_bit(SNSS_REQUESTED, &private->flags);
-                spin_unlock_irqrestore(&snsslock, irqflags);
-                return;
-        };
-        spin_unlock_irqrestore(&snsslock, irqflags);
-        dasd_eer_clean_SNSS_request(cqr);
-        cqr->device = device;
-        cqr->retries = 255;
-        cqr->expires = 10 * HZ;
-
-        ccw = cqr->cpaddr;
-        ccw->cmd_code = DASD_ECKD_CCW_SNSS;
-        ccw->count = SNSS_DATA_SIZE;
-        ccw->flags = 0;
-        ccw->cda = (__u32)(addr_t)cqr->data;
-
-        cqr->buildclk = get_clock();
-        cqr->status = DASD_CQR_FILLED;
-        cqr->callback = dasd_eer_SNSS_cb;
-        cqr->callback_data = (void *)device;
-        dasd_add_request_head(cqr);
-
-        return;
-}
-
-/*
- * This function is called for all triggers. It calls the appropriate
- * function that writes the actual trigger records.
- */
-static int
-dasd_eer_write_trigger(struct dasd_eer_trigger *trigger)
-{
-        int rc;
-        struct dasd_eer_private *private = trigger->device->eer;
-
-        switch (trigger->id) {
-        case DASD_EER_FATALERROR:
-        case DASD_EER_PPRCSUSPEND:
-                rc = dasd_eer_write_standard_trigger(
-                        trigger->id, trigger->device, trigger->cqr);
-                break;
-        case DASD_EER_NOPATH:
-                rc = dasd_eer_write_standard_trigger(
-                        trigger->id, trigger->device, NULL);
-                break;
-        case DASD_EER_STATECHANGE:
-                if (queue_work(dasd_eer_workqueue, &private->worker)) {
-                        rc=0;
-                } else {
-                        /* If the work_struct was already queued, it can't
-                         * be queued again. But this is OK since we don't
-                         * need to have it queued twice.
-                         */
-                        rc = -EBUSY;
-                }
-                break;
-        default: /* unknown trigger, so we write it without any sense data */
-                rc = dasd_eer_write_standard_trigger(
-                        trigger->id, trigger->device, NULL);
-                break;
-        }
-        return rc;
-}
-
-/*
- * This function is registered with the dasd device driver and gets called
- * for all dasd eer notifications.
- */
-static int dasd_eer_notify(struct notifier_block *self,
-                            unsigned long action, void *data)
-{
-        switch (action) {
-        case DASD_EER_DISABLE:
-                dasd_eer_disable_on_device((struct dasd_device *)data);
-                break;
-        case DASD_EER_TRIGGER:
-                dasd_eer_write_trigger((struct dasd_eer_trigger *)data);
-                break;
-        }
-        return NOTIFY_OK;
-}
-
-
-/*****************************************************************************/
-/*      the device operations                                                */
-/*****************************************************************************/
-
-/*
- * On the one side we need a lock to access our internal buffer, on the
- * other side a copy_to_user can sleep. So we need to copy the data we have
- * to transfer in a readbuffer, which is protected by the readbuffer_mutex.
- */
-static char readbuffer[PAGE_SIZE];
-DECLARE_MUTEX(readbuffer_mutex);
-
-
-static int
-dasd_eer_open(struct inode *inp, struct file *filp)
-{
-        struct eerbuffer *eerb;
-        unsigned long flags;
-
-        eerb = kmalloc(sizeof(struct eerbuffer), GFP_KERNEL);
-        eerb->head = 0;
-        eerb->tail = 0;
-        eerb->residual = 0;
-        eerb->buffer_page_count = 1;
-        eerb->buffersize = eerb->buffer_page_count * PAGE_SIZE;
-        eerb->buffer = kmalloc(eerb->buffer_page_count*sizeof(char*),
-                               GFP_KERNEL);
-        if (!eerb->buffer)
-                return -ENOMEM;
-        if (dasd_eer_allocate_buffer_pages(eerb->buffer,
-                                           eerb->buffer_page_count)) {
-                kfree(eerb->buffer);
-                return -ENOMEM;
-        }
-        filp->private_data = eerb;
-        spin_lock_irqsave(&bufferlock, flags);
-        list_add(&eerb->list, &bufferlist);
-        spin_unlock_irqrestore(&bufferlock, flags);
-
-        return nonseekable_open(inp,filp);
-}
-
-static int
-dasd_eer_close(struct inode *inp, struct file *filp)
-{
-        struct eerbuffer *eerb;
-        unsigned long flags;
-
-        eerb = (struct eerbuffer *)filp->private_data;
-        spin_lock_irqsave(&bufferlock, flags);
-        list_del(&eerb->list);
-        spin_unlock_irqrestore(&bufferlock, flags);
-        dasd_eer_free_buffer_pages(eerb->buffer, eerb->buffer_page_count);
-        kfree(eerb->buffer);
-        kfree(eerb);
-
-        return 0;
-}
-
-static long
-dasd_eer_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
-{
-        int intval;
-        struct eerbuffer *eerb;
-
-        eerb = (struct eerbuffer *)filp->private_data;
-        switch (cmd) {
-        case DASD_EER_PURGE:
-                dasd_eer_purge_buffer(eerb);
-                return 0;
-        case DASD_EER_SETBUFSIZE:
-                if (get_user(intval, (int __user *)arg))
-                        return -EFAULT;
-                return dasd_eer_resize_buffer(eerb, intval);
-        default:
-                return -ENOIOCTLCMD;
-        }
-}
-
-static ssize_t
-dasd_eer_read(struct file *filp, char __user *buf, size_t count, loff_t *ppos)
-{
-        int tc,rc;
-        int tailcount,effective_count;
-        unsigned long flags;
-        struct eerbuffer *eerb;
-
-        eerb = (struct eerbuffer *)filp->private_data;
-        if(down_interruptible(&readbuffer_mutex))
-                return -ERESTARTSYS;
-
-        spin_lock_irqsave(&bufferlock, flags);
-
-        if (eerb->residual < 0) { /* the remainder of this record */
-                                  /* has been deleted             */
-                eerb->residual = 0;
-                spin_unlock_irqrestore(&bufferlock, flags);
-                up(&readbuffer_mutex);
-                return -EIO;
-        } else if (eerb->residual > 0) {
-                /* OK we still have a second half of a record to deliver */
-                effective_count = min(eerb->residual, (int)count);
-                eerb->residual -= effective_count;
-        } else {
-                tc = 0;
-                while (!tc) {
-                        tc = dasd_eer_read_buffer(eerb,
-                                sizeof(tailcount), (char*)(&tailcount));
-                        if (!tc) {
-                                /* no data available */
-                                spin_unlock_irqrestore(&bufferlock, flags);
-                                up(&readbuffer_mutex);
-                                if (filp->f_flags & O_NONBLOCK)
-                                        return -EAGAIN;
-                                rc = wait_event_interruptible(
-                                        dasd_eer_read_wait_queue,
-                                        eerb->head != eerb->tail);
-                                if (rc) {
-                                        return rc;
-                                }
-                                if(down_interruptible(&readbuffer_mutex))
-                                        return -ERESTARTSYS;
-                                spin_lock_irqsave(&bufferlock, flags);
-                        }
-                }
-                WARN_ON(tc != sizeof(tailcount));
-                effective_count = min(tailcount,(int)count);
-                eerb->residual = tailcount - effective_count;
-        }
-
-        tc = dasd_eer_read_buffer(eerb, effective_count, readbuffer);
-        WARN_ON(tc != effective_count);
-
-        spin_unlock_irqrestore(&bufferlock, flags);
-
-        if (copy_to_user(buf, readbuffer, effective_count)) {
-                up(&readbuffer_mutex);
-                return -EFAULT;
-        }
-
-        up(&readbuffer_mutex);
-        return effective_count;
-}
-
-static unsigned int
-dasd_eer_poll (struct file *filp, poll_table *ptable)
-{
-        unsigned int mask;
-        unsigned long flags;
-        struct eerbuffer *eerb;
-
-        eerb = (struct eerbuffer *)filp->private_data;
-        poll_wait(filp, &dasd_eer_read_wait_queue, ptable);
-        spin_lock_irqsave(&bufferlock, flags);
-        if (eerb->head != eerb->tail)
-                mask = POLLIN | POLLRDNORM ;
-        else
-                mask = 0;
-        spin_unlock_irqrestore(&bufferlock, flags);
-        return mask;
-}
-
-static struct file_operations dasd_eer_fops = {
-        .open           = &dasd_eer_open,
-        .release        = &dasd_eer_close,
-        .unlocked_ioctl = &dasd_eer_ioctl,
-        .compat_ioctl   = &dasd_eer_ioctl,
-        .read           = &dasd_eer_read,
-        .poll           = &dasd_eer_poll,
-        .owner          = THIS_MODULE,
-};
-
-static struct miscdevice dasd_eer_dev = {
-        .minor      = MISC_DYNAMIC_MINOR,
-        .name       = "dasd_eer",
-        .fops       = &dasd_eer_fops,
-};
-
-
-/*****************************************************************************/
-/*      Init and exit                                                        */
-/*****************************************************************************/
-
-static int
-__init dasd_eer_init(void)
-{
-        int rc;
-
-        dasd_eer_workqueue = create_singlethread_workqueue("dasd_eer");
-        if (!dasd_eer_workqueue) {
-                MESSAGE(KERN_ERR , "%s", "dasd_eer_init could not "
-                       "create workqueue \n");
-                rc = -ENOMEM;
-                goto out;
-        }
-
-        rc = dasd_register_eer_notifier(&dasd_eer_nb);
-        if (rc) {
-                MESSAGE(KERN_ERR, "%s", "dasd_eer_init could not "
-                       "register error reporting");
-                goto queue;
-        }
-
-        dasd_ioctl_no_register(THIS_MODULE, BIODASDEERSET, dasd_ioctl_set_eer);
-        dasd_ioctl_no_register(THIS_MODULE, BIODASDEERGET, dasd_ioctl_get_eer);
-
-        /* we don't need our own character device,
-         * so we just register as misc device */
-        rc = misc_register(&dasd_eer_dev);
-        if (rc) {
-                MESSAGE(KERN_ERR, "%s", "dasd_eer_init could not "
-                       "register misc device");
-                goto unregister;
-        }
-
-        return 0;
-
-unregister:
-        dasd_unregister_eer_notifier(&dasd_eer_nb);
-        dasd_ioctl_no_unregister(THIS_MODULE, BIODASDEERSET,
-                                 dasd_ioctl_set_eer);
-        dasd_ioctl_no_unregister(THIS_MODULE, BIODASDEERGET,
-                                 dasd_ioctl_get_eer);
-queue:
-        destroy_workqueue(dasd_eer_workqueue);
-out:
-        return rc;
-
-}
-module_init(dasd_eer_init);
-
-static void
-__exit dasd_eer_exit(void)
-{
-        dasd_unregister_eer_notifier(&dasd_eer_nb);
-        dasd_ioctl_no_unregister(THIS_MODULE, BIODASDEERSET,
-                                 dasd_ioctl_set_eer);
-        dasd_ioctl_no_unregister(THIS_MODULE, BIODASDEERGET,
-                                 dasd_ioctl_get_eer);
-        destroy_workqueue(dasd_eer_workqueue);
-
-        WARN_ON(misc_deregister(&dasd_eer_dev) != 0);
-}
-module_exit(dasd_eer_exit);