From 20c644680af1ef9a6b36c0873f59498c98b07ab1 Mon Sep 17 00:00:00 2001 From: Stefan Weinhuber Date: Fri, 24 Mar 2006 03:15:25 -0800 Subject: [PATCH] s390: dasd extended error reporting The DASD extended error reporting is a facility that allows to get detailed information about certain problems in the DASD I/O. This information can be used to implement fail-over applications that can recover these problems. Signed-off-by: Stefan Weinhuber Signed-off-by: Martin Schwidefsky Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/s390/block/Kconfig | 8 + drivers/s390/block/Makefile | 3 + drivers/s390/block/dasd.c | 29 +- drivers/s390/block/dasd_3990_erp.c | 3 + drivers/s390/block/dasd_devmap.c | 41 +++ drivers/s390/block/dasd_eckd.h | 1 + drivers/s390/block/dasd_eer.c | 682 +++++++++++++++++++++++++++++++++++++ drivers/s390/block/dasd_int.h | 46 +++ 8 files changed, 812 insertions(+), 1 deletion(-) create mode 100644 drivers/s390/block/dasd_eer.c (limited to 'drivers/s390/block') diff --git a/drivers/s390/block/Kconfig b/drivers/s390/block/Kconfig index 08b3f24..929d6ff 100644 --- a/drivers/s390/block/Kconfig +++ b/drivers/s390/block/Kconfig @@ -55,4 +55,12 @@ config DASD_DIAG Disks under VM. If you are not running under VM or unsure what it is, say "N". +config DASD_EER + bool "Extended error reporting (EER)" + depends on DASD + help + This driver provides a character device interface to the + DASD extended error reporting. This is only needed if you want to + use applications written for the EER facility. + endif diff --git a/drivers/s390/block/Makefile b/drivers/s390/block/Makefile index 163e975..be9f22d 100644 --- a/drivers/s390/block/Makefile +++ b/drivers/s390/block/Makefile @@ -7,6 +7,9 @@ dasd_fba_mod-objs := dasd_fba.o dasd_3370_erp.o dasd_9336_erp.o dasd_diag_mod-objs := dasd_diag.o dasd_mod-objs := dasd.o dasd_ioctl.o dasd_proc.o dasd_devmap.o \ dasd_genhd.o dasd_erp.o +ifdef CONFIG_DASD_EER +dasd_mod-objs += dasd_eer.o +endif obj-$(CONFIG_DASD) += dasd_mod.o obj-$(CONFIG_DASD_DIAG) += dasd_diag_mod.o diff --git a/drivers/s390/block/dasd.c b/drivers/s390/block/dasd.c index 9e0b371..f32f744 100644 --- a/drivers/s390/block/dasd.c +++ b/drivers/s390/block/dasd.c @@ -151,6 +151,8 @@ dasd_state_new_to_known(struct dasd_device *device) static inline void dasd_state_known_to_new(struct dasd_device * device) { + /* Disable extended error reporting for this device. */ + dasd_eer_disable(device); /* Forget the discipline information. */ if (device->discipline) module_put(device->discipline->owner); @@ -892,6 +894,9 @@ dasd_handle_state_change_pending(struct dasd_device *device) struct dasd_ccw_req *cqr; struct list_head *l, *n; + /* First of all start sense subsystem status request. */ + dasd_eer_snss(device); + device->stopped &= ~DASD_STOPPED_PENDING; /* restart all 'running' IO on queue */ @@ -1111,6 +1116,19 @@ restart: } goto restart; } + + /* First of all call extended error reporting. */ + if (dasd_eer_enabled(device) && + cqr->status == DASD_CQR_FAILED) { + dasd_eer_write(device, cqr, DASD_EER_FATALERROR); + + /* restart request */ + cqr->status = DASD_CQR_QUEUED; + cqr->retries = 255; + device->stopped |= DASD_STOPPED_QUIESCE; + goto restart; + } + /* Process finished ERP request. */ if (cqr->refers) { __dasd_process_erp(device, cqr); @@ -1248,7 +1266,8 @@ __dasd_start_head(struct dasd_device * device) cqr = list_entry(device->ccw_queue.next, struct dasd_ccw_req, list); /* check FAILFAST */ if (device->stopped & ~DASD_STOPPED_PENDING && - test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags)) { + test_bit(DASD_CQR_FLAGS_FAILFAST, &cqr->flags) && + (!dasd_eer_enabled(device))) { cqr->status = DASD_CQR_FAILED; dasd_schedule_bh(device); } @@ -1807,6 +1826,7 @@ dasd_exit(void) #ifdef CONFIG_PROC_FS dasd_proc_exit(); #endif + dasd_eer_exit(); if (dasd_page_cache != NULL) { kmem_cache_destroy(dasd_page_cache); dasd_page_cache = NULL; @@ -2003,6 +2023,9 @@ dasd_generic_notify(struct ccw_device *cdev, int event) switch (event) { case CIO_GONE: case CIO_NO_PATH: + /* First of all call extended error reporting. */ + dasd_eer_write(device, NULL, DASD_EER_NOPATH); + if (device->state < DASD_STATE_BASIC) break; /* Device is active. We want to keep it. */ @@ -2060,6 +2083,7 @@ dasd_generic_auto_online (struct ccw_driver *dasd_discipline_driver) put_driver(drv); } + static int __init dasd_init(void) { @@ -2092,6 +2116,9 @@ dasd_init(void) rc = dasd_parse(); if (rc) goto failed; + rc = dasd_eer_init(); + if (rc) + goto failed; #ifdef CONFIG_PROC_FS rc = dasd_proc_init(); if (rc) diff --git a/drivers/s390/block/dasd_3990_erp.c b/drivers/s390/block/dasd_3990_erp.c index 4ee0f93..2ed5156 100644 --- a/drivers/s390/block/dasd_3990_erp.c +++ b/drivers/s390/block/dasd_3990_erp.c @@ -1108,6 +1108,9 @@ dasd_3990_handle_env_data(struct dasd_ccw_req * erp, char *sense) case 0x0B: DEV_MESSAGE(KERN_WARNING, device, "%s", "FORMAT F - Volume is suspended duplex"); + /* call extended error reporting (EER) */ + dasd_eer_write(device, erp->refers, + DASD_EER_PPRCSUSPEND); break; case 0x0C: DEV_MESSAGE(KERN_WARNING, device, "%s", diff --git a/drivers/s390/block/dasd_devmap.c b/drivers/s390/block/dasd_devmap.c index 1629b27..f576f24 100644 --- a/drivers/s390/block/dasd_devmap.c +++ b/drivers/s390/block/dasd_devmap.c @@ -715,10 +715,51 @@ dasd_discipline_show(struct device *dev, struct device_attribute *attr, char *bu static DEVICE_ATTR(discipline, 0444, dasd_discipline_show, NULL); +/* + * extended error-reporting + */ +static ssize_t +dasd_eer_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct dasd_devmap *devmap; + int eer_flag; + + devmap = dasd_find_busid(dev->bus_id); + if (!IS_ERR(devmap) && devmap->device) + eer_flag = dasd_eer_enabled(devmap->device); + else + eer_flag = 0; + return snprintf(buf, PAGE_SIZE, eer_flag ? "1\n" : "0\n"); +} + +static ssize_t +dasd_eer_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct dasd_devmap *devmap; + int rc; + + devmap = dasd_devmap_from_cdev(to_ccwdev(dev)); + if (IS_ERR(devmap)) + return PTR_ERR(devmap); + if (!devmap->device) + return count; + if (buf[0] == '1') { + rc = dasd_eer_enable(devmap->device); + if (rc) + return rc; + } else + dasd_eer_disable(devmap->device); + return count; +} + +static DEVICE_ATTR(eer_enabled, 0644, dasd_eer_show, dasd_eer_store); + static struct attribute * dasd_attrs[] = { &dev_attr_readonly.attr, &dev_attr_discipline.attr, &dev_attr_use_diag.attr, + &dev_attr_eer_enabled.attr, NULL, }; diff --git a/drivers/s390/block/dasd_eckd.h b/drivers/s390/block/dasd_eckd.h index bc3823d..ad8524b 100644 --- a/drivers/s390/block/dasd_eckd.h +++ b/drivers/s390/block/dasd_eckd.h @@ -29,6 +29,7 @@ #define DASD_ECKD_CCW_PSF 0x27 #define DASD_ECKD_CCW_RSSD 0x3e #define DASD_ECKD_CCW_LOCATE_RECORD 0x47 +#define DASD_ECKD_CCW_SNSS 0x54 #define DASD_ECKD_CCW_DEFINE_EXTENT 0x63 #define DASD_ECKD_CCW_WRITE_MT 0x85 #define DASD_ECKD_CCW_READ_MT 0x86 diff --git a/drivers/s390/block/dasd_eer.c b/drivers/s390/block/dasd_eer.c new file mode 100644 index 0000000..2d946b6 --- /dev/null +++ b/drivers/s390/block/dasd_eer.c @@ -0,0 +1,682 @@ +/* + * Character device driver for extended error reporting. + * + * Copyright (C) 2005 IBM Corporation + * extended error reporting for DASD ECKD devices + * Author(s): Stefan Weinhuber + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include + +#include "dasd_int.h" +#include "dasd_eckd.h" + +#ifdef PRINTK_HEADER +#undef PRINTK_HEADER +#endif /* PRINTK_HEADER */ +#define PRINTK_HEADER "dasd(eer):" + +/* + * SECTION: the internal buffer + */ + +/* + * 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. 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_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. + * + * 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 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. + * 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. + */ + +static int eer_pages = 5; +module_param(eer_pages, int, S_IRUGO|S_IWUSR); + +struct eerbuffer { + struct list_head list; + char **buffer; + int buffersize; + int buffer_page_count; + int head; + int tail; + int residual; +}; + +static LIST_HEAD(bufferlist); +static spinlock_t bufferlock = SPIN_LOCK_UNLOCKED; +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. + */ +static int dasd_eer_get_free_bytes(struct eerbuffer *eerb) +{ + if (eerb->head < eerb->tail) + return eerb->tail - eerb->head - 1; + 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; + 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, + char *data, int count) +{ + + 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 */ + BUG_ON(eerb->head > eerb->buffersize); + } +} + +/* + * Needs to be called with bufferlock held. + */ +static int dasd_eer_read_buffer(struct eerbuffer *eerb, char *data, int count) +{ + + 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 */ + BUG_ON(eerb->tail > eerb->buffersize); + } + 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, (char *) &tailcount, + sizeof(tailcount)); + eerb->tail += tailcount; + if (eerb->tail >= eerb->buffersize) + eerb->tail -= eerb->buffersize; + } + dasd_eer_write_buffer(eerb, (char*) &count, sizeof(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; +} + +/* + * SECTION: The extended error reporting functionality + */ + +/* + * When a DASD device driver wants to report an error, it calls the + * 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 + * 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. + * + * 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 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. + */ + +#define SNSS_DATA_SIZE 44 + +#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]; +}; + +/* + * 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 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 timeval tv; + struct dasd_eer_header header; + unsigned long flags; + struct eerbuffer *eerb; + + /* go through cqr chain and count the valid sense data sets */ + data_size = 0; + for (temp_cqr = cqr; temp_cqr; temp_cqr = temp_cqr->refers) + if (temp_cqr->irb.esw.esw0.erw.cons) + data_size += 32; + + 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, (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, cqr->irb.ecw, 32); + dasd_eer_write_buffer(eerb, "EOR", 4); + } + spin_unlock_irqrestore(&bufferlock, flags); + wake_up_interruptible(&dasd_eer_read_wait_queue); +} + +/* + * 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 trigger) +{ + 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, (char *) &header , sizeof(header)); + if (!snss_rc) + 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); +} + +/* + * 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. + */ +void dasd_eer_snss(struct dasd_device *device) +{ + struct dasd_ccw_req *cqr; + + cqr = device->eer_cqr; + if (!cqr) /* Device not eer enabled. */ + 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); +} + +/* + * Callback function for use with sense subsystem status request. + */ +static void dasd_eer_snss_cb(struct dasd_ccw_req *cqr, void *data) +{ + 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); +} + +/* + * Enable error reporting on a given device. + */ +int dasd_eer_enable(struct dasd_device *device) +{ + struct dasd_ccw_req *cqr; + 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; + + cqr->device = device; + cqr->retries = 255; + cqr->expires = 10 * HZ; + + 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; + + 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; +} + +/* + * Disable error reporting on a given device. + */ +void dasd_eer_disable(struct dasd_device *device) +{ + struct dasd_ccw_req *cqr; + unsigned long flags; + int in_use; + + 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); +} + +/* + * SECTION: 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]; +static DECLARE_MUTEX(readbuffer_mutex); + +static int dasd_eer_open(struct inode *inp, struct file *filp) +{ + struct eerbuffer *eerb; + unsigned long flags; + + eerb = kzalloc(sizeof(struct eerbuffer), GFP_KERNEL); + 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 *), + GFP_KERNEL); + 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; + 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 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, (char *) &tailcount, + sizeof(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, readbuffer, effective_count); + 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, + .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, +}; + +int __init dasd_eer_init(void) +{ + int rc; + + rc = misc_register(&dasd_eer_dev); + if (rc) { + MESSAGE(KERN_ERR, "%s", "dasd_eer_init could not " + "register misc device"); + return rc; + } + + return 0; +} + +void __exit dasd_eer_exit(void) +{ + WARN_ON(misc_deregister(&dasd_eer_dev) != 0); +} diff --git a/drivers/s390/block/dasd_int.h b/drivers/s390/block/dasd_int.h index 6d7fa30..4293ba8 100644 --- a/drivers/s390/block/dasd_int.h +++ b/drivers/s390/block/dasd_int.h @@ -268,6 +268,23 @@ struct dasd_discipline { extern struct dasd_discipline *dasd_diag_discipline_pointer; + +/* + * Notification numbers for extended error reporting notifications: + * The DASD_EER_DISABLE notification is sent before a dasd_device (and it's + * eer pointer) is freed. The error reporting module needs to do all necessary + * cleanup steps. + * The DASD_EER_TRIGGER notification sends the actual error reports (triggers). + */ +#define DASD_EER_DISABLE 0 +#define DASD_EER_TRIGGER 1 + +/* Trigger IDs for extended error reporting DASD_EER_TRIGGER notification */ +#define DASD_EER_FATALERROR 1 +#define DASD_EER_NOPATH 2 +#define DASD_EER_STATECHANGE 3 +#define DASD_EER_PPRCSUSPEND 4 + struct dasd_device { /* Block device stuff. */ struct gendisk *gdp; @@ -281,6 +298,9 @@ struct dasd_device { unsigned long flags; /* per device flags */ unsigned short features; /* copy of devmap-features (read-only!) */ + /* extended error reporting stuff (eer) */ + struct dasd_ccw_req *eer_cqr; + /* Device discipline stuff. */ struct dasd_discipline *discipline; struct dasd_discipline *base_discipline; @@ -326,6 +346,8 @@ struct dasd_device { /* per device flags */ #define DASD_FLAG_DSC_ERROR 2 /* return -EIO when disconnected */ #define DASD_FLAG_OFFLINE 3 /* device is in offline processing */ +#define DASD_FLAG_EER_SNSS 4 /* A SNSS is required */ +#define DASD_FLAG_EER_IN_USE 5 /* A SNSS request is running */ void dasd_put_device_wake(struct dasd_device *); @@ -545,6 +567,30 @@ dasd_era_t dasd_9336_erp_examine(struct dasd_ccw_req *, struct irb *); dasd_era_t dasd_9343_erp_examine(struct dasd_ccw_req *, struct irb *); struct dasd_ccw_req *dasd_9343_erp_action(struct dasd_ccw_req *); +/* externals in dasd_eer.c */ +#ifdef CONFIG_DASD_EER +int dasd_eer_init(void); +void dasd_eer_exit(void); +int dasd_eer_enable(struct dasd_device *); +void dasd_eer_disable(struct dasd_device *); +void dasd_eer_write(struct dasd_device *, struct dasd_ccw_req *cqr, + unsigned int id); +void dasd_eer_snss(struct dasd_device *); + +static inline int dasd_eer_enabled(struct dasd_device *device) +{ + return device->eer_cqr != NULL; +} +#else +#define dasd_eer_init() (0) +#define dasd_eer_exit() do { } while (0) +#define dasd_eer_enable(d) (0) +#define dasd_eer_disable(d) do { } while (0) +#define dasd_eer_write(d,c,i) do { } while (0) +#define dasd_eer_snss(d) do { } while (0) +#define dasd_eer_enabled(d) (0) +#endif /* CONFIG_DASD_ERR */ + #endif /* __KERNEL__ */ #endif /* DASD_H */ -- cgit v1.1