/*
- * 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>
+ * 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/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 "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 */
-/*****************************************************************************/
+/*
+ * SECTION: 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.
+ * The internal buffer is meant to store obaque blobs of data, so it does
+ * not 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.
+ * closed again. The number of pages used for this buffer is determined by
+ * the module parmeter eer_pages.
*
* 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_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.
* 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
+ * For all mentioned functions you need to get the bufferlock first and keep
+ * it until a complete record is written or read.
+ *
+ * All 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
+ * If the user does not 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.
* to protect the bufferlist.
*/
+static int eer_pages = 5;
+module_param(eer_pages, int, S_IRUGO|S_IWUSR);
+
struct eerbuffer {
struct list_head list;
char **buffer;
int residual;
};
-LIST_HEAD(bufferlist);
-
-static spinlock_t bufferlock = SPIN_LOCK_UNLOCKED;
-
-DECLARE_WAIT_QUEUE_HEAD(dasd_eer_read_wait_queue);
+static LIST_HEAD(bufferlist);
+static DEFINE_SPINLOCK(bufferlock);
+static 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
+ * Needs to be called with bufferlock held.
*/
-static int
-dasd_eer_get_free_bytes(struct eerbuffer *eerb)
+static int dasd_eer_get_free_bytes(struct eerbuffer *eerb)
{
- if (eerb->head < eerb->tail) {
+ if (eerb->head < eerb->tail)
return eerb->tail - eerb->head - 1;
- } else
- return eerb->buffersize - eerb->head + eerb->tail -1;
+ return eerb->buffersize - eerb->head + eerb->tail -1;
}
/*
* How many bytes of buffer space are used.
- * needs to be called with bufferlock held
+ * Needs to be called with bufferlock held.
*/
-static int
-dasd_eer_get_filled_bytes(struct eerbuffer *eerb)
+static int dasd_eer_get_filled_bytes(struct eerbuffer *eerb)
{
- if (eerb->head >= eerb->tail) {
+ if (eerb->head >= eerb->tail)
return eerb->head - eerb->tail;
- } else
- return eerb->buffersize - eerb->tail + eerb->head;
+ 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
+ * Needs to be called with bufferlock held.
*/
-static void
-dasd_eer_write_buffer(struct eerbuffer *eerb, int count, char *data)
+static void dasd_eer_write_buffer(struct eerbuffer *eerb,
+ char *data, int count)
{
unsigned long headindex,localhead;
while (rest > 0) {
headindex = eerb->head / PAGE_SIZE;
localhead = eerb->head % PAGE_SIZE;
- len = min(rest, (PAGE_SIZE - localhead));
+ 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 )
+ if (eerb->head == eerb->buffersize)
eerb->head = 0; /* wrap around */
- if (eerb->head > eerb->buffersize) {
- MESSAGE(KERN_ERR, "%s", "runaway buffer head.");
- BUG();
- }
+ BUG_ON(eerb->head > eerb->buffersize);
}
}
/*
- * needs to be called with bufferlock held
+ * Needs to be called with bufferlock held.
*/
-static int
-dasd_eer_read_buffer(struct eerbuffer *eerb, int count, char *data)
+static int dasd_eer_read_buffer(struct eerbuffer *eerb, char *data, int count)
{
unsigned long tailindex,localtail;
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);
+ 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 )
+ if (eerb->tail == eerb->buffersize)
eerb->tail = 0; /* wrap around */
- if (eerb->tail > eerb->buffersize) {
- MESSAGE(KERN_ERR, "%s", "runaway buffer tail.");
- BUG();
- }
+ BUG_ON(eerb->tail > eerb->buffersize);
}
return finalcount;
}
* 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
+ * Needs to be called with bufferlock held.
*/
-static int
-dasd_eer_start_record(struct eerbuffer *eerb, int count)
+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)) {
eerb->tail -= eerb->buffersize;
eerb->residual = -1;
}
- dasd_eer_read_buffer(eerb, sizeof(tailcount),
- (char*)(&tailcount));
+ dasd_eer_read_buffer(eerb, (char *) &tailcount,
+ sizeof(tailcount));
eerb->tail += tailcount;
if (eerb->tail >= eerb->buffersize)
eerb->tail -= eerb->buffersize;
}
- dasd_eer_write_buffer(eerb, sizeof(count), (char*)(&count));
+ dasd_eer_write_buffer(eerb, (char*) &count, sizeof(count));
return 0;
};
/*
- * release pages that are not used anymore
+ * Release pages that are not used anymore.
*/
-static void
-dasd_eer_free_buffer_pages(char **buf, int no_pages)
+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]);
- }
+ for (i = 0; i < no_pages; i++)
+ free_page((unsigned long) buf[i]);
}
/*
- * allocate a new set of memory pages
+ * Allocate a new set of memory pages.
*/
-static int
-dasd_eer_allocate_buffer_pages(char **buf, int no_pages)
+static int dasd_eer_allocate_buffer_pages(char **buf, int no_pages)
{
int i;
- for (i = 0; i < no_pages; ++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);
}
/*
- * 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
+ * SECTION: The extended error reporting functionality
*/
-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:
+ * function dasd_eer_write 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
* 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.
+ * The DASD_EER_STATECHANGE trigger is special since a sense subsystem
+ * status ccw need to be executed to gather the necessary sense data first.
+ * The dasd_eer_snss function will queue the SNSS request and the request
+ * callback will then call dasd_eer_write with the DASD_EER_STATCHANGE
+ * trigger.
*
* 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.
+ * dasd_eer_probe). There is one sense subsystem status request for each
+ * eer enabled DASD device. The presence of the cqr in device->eer_cqr
+ * indicates that eer is enable for the device. The use of the snss request
+ * is protected by the DASD_FLAG_EER_IN_USE bit. When this flag indicates
+ * that the cqr is currently in use, dasd_eer_snss cannot start a second
+ * request but sets the DASD_FLAG_EER_SNSS flag instead. The callback of
+ * the SNSS request will check the bit and call dasd_eer_snss again.
*/
-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 {
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.
* 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)
+static void dasd_eer_write_standard_trigger(struct dasd_device *device,
+ struct dasd_ccw_req *cqr,
+ int trigger)
{
struct dasd_ccw_req *temp_cqr;
int data_size;
struct eerbuffer *eerb;
/* go through cqr chain and count the valid sense data sets */
- temp_cqr = cqr;
data_size = 0;
- while (temp_cqr) {
+ for (temp_cqr = cqr; temp_cqr; temp_cqr = temp_cqr->refers)
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;
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) {
+ dasd_eer_write_buffer(eerb, (char *) &header, sizeof(header));
+ for (temp_cqr = cqr; temp_cqr; temp_cqr = temp_cqr->refers)
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");
+ dasd_eer_write_buffer(eerb, cqr->irb.ecw, 32);
+ dasd_eer_write_buffer(eerb, "EOR", 4);
}
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)
+static void dasd_eer_write_snss_trigger(struct dasd_device *device,
+ struct dasd_ccw_req *cqr,
+ int trigger)
{
int data_size;
int snss_rc;
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));
+ dasd_eer_write_buffer(eerb, (char *) &header , sizeof(header));
if (!snss_rc)
- dasd_eer_write_buffer(eerb, SNSS_DATA_SIZE, cqr->data);
- dasd_eer_write_buffer(eerb, 4,"EOR");
+ dasd_eer_write_buffer(eerb, cqr->data, SNSS_DATA_SIZE);
+ dasd_eer_write_buffer(eerb, "EOR", 4);
}
spin_unlock_irqrestore(&bufferlock, flags);
-
wake_up_interruptible(&dasd_eer_read_wait_queue);
}
/*
- * callback function for use with SNSS request
+ * This function is called for all triggers. It calls the appropriate
+ * function that writes the actual trigger records.
+ */
+void dasd_eer_write(struct dasd_device *device, struct dasd_ccw_req *cqr,
+ unsigned int id)
+{
+ if (!device->eer_cqr)
+ return;
+ switch (id) {
+ case DASD_EER_FATALERROR:
+ case DASD_EER_PPRCSUSPEND:
+ dasd_eer_write_standard_trigger(device, cqr, id);
+ break;
+ case DASD_EER_NOPATH:
+ dasd_eer_write_standard_trigger(device, NULL, id);
+ break;
+ case DASD_EER_STATECHANGE:
+ dasd_eer_write_snss_trigger(device, cqr, id);
+ break;
+ default: /* unknown trigger, so we write it without any sense data */
+ dasd_eer_write_standard_trigger(device, NULL, id);
+ break;
+ }
+}
+EXPORT_SYMBOL(dasd_eer_write);
+
+/*
+ * Start a sense subsystem status request.
+ * Needs to be called with the device held.
*/
-static void
-dasd_eer_SNSS_cb(struct dasd_ccw_req *cqr, void *data)
+void dasd_eer_snss(struct dasd_device *device)
{
- 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);
+ struct dasd_ccw_req *cqr;
+
+ cqr = device->eer_cqr;
+ if (!cqr) /* Device not eer enabled. */
return;
- };
- clear_bit(CQR_IN_USE, &private->flags);
- spin_unlock_irqrestore(&snsslock, irqflags);
- dasd_eer_sense_subsystem_status(device);
- return;
+ if (test_and_set_bit(DASD_FLAG_EER_IN_USE, &device->flags)) {
+ /* Sense subsystem status request in use. */
+ set_bit(DASD_FLAG_EER_SNSS, &device->flags);
+ return;
+ }
+ clear_bit(DASD_FLAG_EER_SNSS, &device->flags);
+ cqr->status = DASD_CQR_QUEUED;
+ list_add(&cqr->list, &device->ccw_queue);
+ dasd_schedule_bh(device);
}
/*
- * clean a used cqr before using it again
+ * Callback function for use with sense subsystem status request.
*/
-static void
-dasd_eer_clean_SNSS_request(struct dasd_ccw_req *cqr)
+static void dasd_eer_snss_cb(struct dasd_ccw_req *cqr, void *data)
{
- 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);
+ struct dasd_device *device = cqr->device;
+ unsigned long flags;
+
+ dasd_eer_write(device, cqr, DASD_EER_STATECHANGE);
+ spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+ if (device->eer_cqr == cqr) {
+ clear_bit(DASD_FLAG_EER_IN_USE, &device->flags);
+ if (test_bit(DASD_FLAG_EER_SNSS, &device->flags))
+ /* Another SNSS has been requested in the meantime. */
+ dasd_eer_snss(device);
+ cqr = NULL;
+ }
+ spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
+ if (cqr)
+ /*
+ * Extended error recovery has been switched off while
+ * the SNSS request was running. It could even have
+ * been switched off and on again in which case there
+ * is a new ccw in device->eer_cqr. Free the "old"
+ * snss request now.
+ */
+ dasd_kfree_request(cqr, device);
}
/*
- * 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.
+ * Enable error reporting on a given device.
*/
-static void
-dasd_eer_sense_subsystem_status(void *data)
+int dasd_eer_enable(struct dasd_device *device)
{
- struct dasd_device *device;
- struct dasd_eer_private *private;
struct dasd_ccw_req *cqr;
- struct ccw1 *ccw;
- unsigned long irqflags;
+ unsigned long flags;
+
+ if (device->eer_cqr)
+ return 0;
+
+ if (!device->discipline || strcmp(device->discipline->name, "ECKD"))
+ return -EPERM; /* FIXME: -EMEDIUMTYPE ? */
+
+ cqr = dasd_kmalloc_request("ECKD", 1 /* SNSS */,
+ SNSS_DATA_SIZE, device);
+ if (!cqr)
+ return -ENOMEM;
- 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->cpaddr->cmd_code = DASD_ECKD_CCW_SNSS;
+ cqr->cpaddr->count = SNSS_DATA_SIZE;
+ cqr->cpaddr->flags = 0;
+ cqr->cpaddr->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);
+ cqr->callback = dasd_eer_snss_cb;
- return;
+ spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+ if (!device->eer_cqr) {
+ device->eer_cqr = cqr;
+ cqr = NULL;
+ }
+ spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
+ if (cqr)
+ dasd_kfree_request(cqr, device);
+ return 0;
}
/*
- * This function is called for all triggers. It calls the appropriate
- * function that writes the actual trigger records.
+ * Disable error reporting on a given device.
*/
-static int
-dasd_eer_write_trigger(struct dasd_eer_trigger *trigger)
+void dasd_eer_disable(struct dasd_device *device)
{
- int rc;
- struct dasd_eer_private *private = trigger->device->eer;
+ struct dasd_ccw_req *cqr;
+ unsigned long flags;
+ int in_use;
- 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;
+ if (!device->eer_cqr)
+ return;
+ spin_lock_irqsave(get_ccwdev_lock(device->cdev), flags);
+ cqr = device->eer_cqr;
+ device->eer_cqr = NULL;
+ clear_bit(DASD_FLAG_EER_SNSS, &device->flags);
+ in_use = test_and_clear_bit(DASD_FLAG_EER_IN_USE, &device->flags);
+ spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
+ if (cqr && !in_use)
+ dasd_kfree_request(cqr, device);
}
/*
- * This function is registered with the dasd device driver and gets called
- * for all dasd eer notifications.
+ * SECTION: the device operations
*/
-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
* to transfer in a readbuffer, which is protected by the readbuffer_mutex.
*/
static char readbuffer[PAGE_SIZE];
-DECLARE_MUTEX(readbuffer_mutex);
+static DECLARE_MUTEX(readbuffer_mutex);
-
-static int
-dasd_eer_open(struct inode *inp, struct file *filp)
+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 = kzalloc(sizeof(struct eerbuffer), GFP_KERNEL);
+ if (!eerb)
+ return -ENOMEM;
+ eerb->buffer_page_count = eer_pages;
+ if (eerb->buffer_page_count < 1 ||
+ eerb->buffer_page_count > INT_MAX / PAGE_SIZE) {
+ kfree(eerb);
+ MESSAGE(KERN_WARNING, "can't open device since module "
+ "parameter eer_pages is smaller then 1 or"
+ " bigger then %d", (int)(INT_MAX / PAGE_SIZE));
+ return -EINVAL;
+ }
eerb->buffersize = eerb->buffer_page_count * PAGE_SIZE;
- eerb->buffer = kmalloc(eerb->buffer_page_count*sizeof(char*),
+ eerb->buffer = kmalloc(eerb->buffer_page_count * sizeof(char *),
GFP_KERNEL);
- if (!eerb->buffer)
+ if (!eerb->buffer) {
+ kfree(eerb);
return -ENOMEM;
+ }
if (dasd_eer_allocate_buffer_pages(eerb->buffer,
eerb->buffer_page_count)) {
kfree(eerb->buffer);
+ kfree(eerb);
return -ENOMEM;
}
filp->private_data = eerb;
return nonseekable_open(inp,filp);
}
-static int
-dasd_eer_close(struct inode *inp, struct file *filp)
+static int dasd_eer_close(struct inode *inp, struct file *filp)
{
struct eerbuffer *eerb;
unsigned long flags;
- eerb = (struct eerbuffer *)filp->private_data;
+ eerb = (struct eerbuffer *) filp->private_data;
spin_lock_irqsave(&bufferlock, flags);
list_del(&eerb->list);
spin_unlock_irqrestore(&bufferlock, flags);
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)
+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))
+ eerb = (struct eerbuffer *) filp->private_data;
+ if (down_interruptible(&readbuffer_mutex))
return -ERESTARTSYS;
spin_lock_irqsave(&bufferlock, flags);
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);
+ 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));
+ tc = dasd_eer_read_buffer(eerb, (char *) &tailcount,
+ sizeof(tailcount));
if (!tc) {
/* no data available */
spin_unlock_irqrestore(&bufferlock, flags);
rc = wait_event_interruptible(
dasd_eer_read_wait_queue,
eerb->head != eerb->tail);
- if (rc) {
+ if (rc)
return rc;
- }
- if(down_interruptible(&readbuffer_mutex))
+ if (down_interruptible(&readbuffer_mutex))
return -ERESTARTSYS;
spin_lock_irqsave(&bufferlock, flags);
}
eerb->residual = tailcount - effective_count;
}
- tc = dasd_eer_read_buffer(eerb, effective_count, readbuffer);
+ tc = dasd_eer_read_buffer(eerb, readbuffer, effective_count);
WARN_ON(tc != effective_count);
spin_unlock_irqrestore(&bufferlock, flags);
return effective_count;
}
-static unsigned int
-dasd_eer_poll (struct file *filp, poll_table *ptable)
+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;
+ 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)
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,
.fops = &dasd_eer_fops,
};
-
-/*****************************************************************************/
-/* Init and exit */
-/*****************************************************************************/
-
-static int
-__init dasd_eer_init(void)
+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 rc;
}
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)
+void 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);
git.openpandora.org / pandora-kernel.git / blobdiff