diff options
| -rw-r--r-- | drivers/s390/char/sclp.c | 69 | ||||
| -rw-r--r-- | drivers/s390/char/sclp.h | 6 | ||||
| -rw-r--r-- | drivers/s390/char/sclp_con.c | 31 | ||||
| -rw-r--r-- | drivers/s390/char/sclp_vt220.c | 39 |
4 files changed, 138 insertions, 7 deletions
diff --git a/drivers/s390/char/sclp.c b/drivers/s390/char/sclp.c index bd6871bf545..a77febeead1 100644 --- a/drivers/s390/char/sclp.c +++ b/drivers/s390/char/sclp.c @@ -50,11 +50,42 @@ static char sclp_init_sccb[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE))); /* Suspend request */ static DECLARE_COMPLETION(sclp_request_queue_flushed); +/* Number of console pages to allocate, used by sclp_con.c and sclp_vt220.c */ +int sclp_console_pages = SCLP_CONSOLE_PAGES; +/* Flag to indicate if buffer pages are dropped on buffer full condition */ +int sclp_console_drop = 0; +/* Number of times the console dropped buffer pages */ +unsigned long sclp_console_full; + static void sclp_suspend_req_cb(struct sclp_req *req, void *data) { complete(&sclp_request_queue_flushed); } +static int __init sclp_setup_console_pages(char *str) +{ + int pages, rc; + + rc = kstrtoint(str, 0, &pages); + if (!rc && pages >= SCLP_CONSOLE_PAGES) + sclp_console_pages = pages; + return 1; +} + +__setup("sclp_con_pages=", sclp_setup_console_pages); + +static int __init sclp_setup_console_drop(char *str) +{ + int drop, rc; + + rc = kstrtoint(str, 0, &drop); + if (!rc && drop) + sclp_console_drop = 1; + return 1; +} + +__setup("sclp_con_drop=", sclp_setup_console_drop); + static struct sclp_req sclp_suspend_req; /* Timer for request retries. */ @@ -1013,11 +1044,47 @@ static const struct dev_pm_ops sclp_pm_ops = { .restore = sclp_restore, }; +static ssize_t sclp_show_console_pages(struct device_driver *dev, char *buf) +{ + return sprintf(buf, "%i\n", sclp_console_pages); +} + +static DRIVER_ATTR(con_pages, S_IRUSR, sclp_show_console_pages, NULL); + +static ssize_t sclp_show_con_drop(struct device_driver *dev, char *buf) +{ + return sprintf(buf, "%i\n", sclp_console_drop); +} + +static DRIVER_ATTR(con_drop, S_IRUSR, sclp_show_con_drop, NULL); + +static ssize_t sclp_show_console_full(struct device_driver *dev, char *buf) +{ + return sprintf(buf, "%lu\n", sclp_console_full); +} + +static DRIVER_ATTR(con_full, S_IRUSR, sclp_show_console_full, NULL); + +static struct attribute *sclp_drv_attrs[] = { + &driver_attr_con_pages.attr, + &driver_attr_con_drop.attr, + &driver_attr_con_full.attr, + NULL, +}; +static struct attribute_group sclp_drv_attr_group = { + .attrs = sclp_drv_attrs, +}; +static const struct attribute_group *sclp_drv_attr_groups[] = { + &sclp_drv_attr_group, + NULL, +}; + static struct platform_driver sclp_pdrv = { .driver = { .name = "sclp", .owner = THIS_MODULE, .pm = &sclp_pm_ops, + .groups = sclp_drv_attr_groups, }, }; @@ -1096,10 +1163,12 @@ static __init int sclp_initcall(void) rc = platform_driver_register(&sclp_pdrv); if (rc) return rc; + sclp_pdev = platform_device_register_simple("sclp", -1, NULL, 0); rc = IS_ERR(sclp_pdev) ? PTR_ERR(sclp_pdev) : 0; if (rc) goto fail_platform_driver_unregister; + rc = atomic_notifier_chain_register(&panic_notifier_list, &sclp_on_panic_nb); if (rc) diff --git a/drivers/s390/char/sclp.h b/drivers/s390/char/sclp.h index 25bcd4c0ed8..e11383f5d3d 100644 --- a/drivers/s390/char/sclp.h +++ b/drivers/s390/char/sclp.h @@ -15,7 +15,7 @@ /* maximum number of pages concerning our own memory management */ #define MAX_KMEM_PAGES (sizeof(unsigned long) << 3) -#define MAX_CONSOLE_PAGES 6 +#define SCLP_CONSOLE_PAGES 6 #define EVTYP_OPCMD 0x01 #define EVTYP_MSG 0x02 @@ -175,6 +175,10 @@ int sclp_service_call(sclp_cmdw_t command, void *sccb); int sclp_sdias_init(void); void sclp_sdias_exit(void); +extern int sclp_console_pages; +extern int sclp_console_drop; +extern unsigned long sclp_console_full; + /* useful inlines */ /* VM uses EBCDIC 037, LPAR+native(SE+HMC) use EBCDIC 500 */ diff --git a/drivers/s390/char/sclp_con.c b/drivers/s390/char/sclp_con.c index ecf45c54f8c..5880def98fc 100644 --- a/drivers/s390/char/sclp_con.c +++ b/drivers/s390/char/sclp_con.c @@ -130,6 +130,31 @@ sclp_console_timeout(unsigned long data) } /* + * Drop oldest console buffer if sclp_con_drop is set + */ +static int +sclp_console_drop_buffer(void) +{ + struct list_head *list; + struct sclp_buffer *buffer; + void *page; + + if (!sclp_console_drop) + return 0; + list = sclp_con_outqueue.next; + if (sclp_con_queue_running) + /* The first element is in I/O */ + list = list->next; + if (list == &sclp_con_outqueue) + return 0; + list_del(list); + buffer = list_entry(list, struct sclp_buffer, list); + page = sclp_unmake_buffer(buffer); + list_add_tail((struct list_head *) page, &sclp_con_pages); + return 1; +} + +/* * Writes the given message to S390 system console */ static void @@ -150,9 +175,13 @@ sclp_console_write(struct console *console, const char *message, do { /* make sure we have a console output buffer */ if (sclp_conbuf == NULL) { + if (list_empty(&sclp_con_pages)) + sclp_console_full++; while (list_empty(&sclp_con_pages)) { if (sclp_con_suspended) goto out; + if (sclp_console_drop_buffer()) + break; spin_unlock_irqrestore(&sclp_con_lock, flags); sclp_sync_wait(); spin_lock_irqsave(&sclp_con_lock, flags); @@ -297,7 +326,7 @@ sclp_console_init(void) return rc; /* Allocate pages for output buffering */ INIT_LIST_HEAD(&sclp_con_pages); - for (i = 0; i < MAX_CONSOLE_PAGES; i++) { + for (i = 0; i < sclp_console_pages; i++) { page = (void *) get_zeroed_page(GFP_KERNEL | GFP_DMA); list_add_tail(page, &sclp_con_pages); } diff --git a/drivers/s390/char/sclp_vt220.c b/drivers/s390/char/sclp_vt220.c index 5aaaa2ec8df..4eed38cd0af 100644 --- a/drivers/s390/char/sclp_vt220.c +++ b/drivers/s390/char/sclp_vt220.c @@ -362,6 +362,31 @@ sclp_vt220_timeout(unsigned long data) #define BUFFER_MAX_DELAY HZ/20 +/* + * Drop oldest console buffer if sclp_con_drop is set + */ +static int +sclp_vt220_drop_buffer(void) +{ + struct list_head *list; + struct sclp_vt220_request *request; + void *page; + + if (!sclp_console_drop) + return 0; + list = sclp_vt220_outqueue.next; + if (sclp_vt220_queue_running) + /* The first element is in I/O */ + list = list->next; + if (list == &sclp_vt220_outqueue) + return 0; + list_del(list); + request = list_entry(list, struct sclp_vt220_request, list); + page = request->sclp_req.sccb; + list_add_tail((struct list_head *) page, &sclp_vt220_empty); + return 1; +} + /* * Internal implementation of the write function. Write COUNT bytes of data * from memory at BUF @@ -390,12 +415,16 @@ __sclp_vt220_write(const unsigned char *buf, int count, int do_schedule, do { /* Create an sclp output buffer if none exists yet */ if (sclp_vt220_current_request == NULL) { + if (list_empty(&sclp_vt220_empty)) + sclp_console_full++; while (list_empty(&sclp_vt220_empty)) { - spin_unlock_irqrestore(&sclp_vt220_lock, flags); if (may_fail || sclp_vt220_suspended) goto out; - else - sclp_sync_wait(); + if (sclp_vt220_drop_buffer()) + break; + spin_unlock_irqrestore(&sclp_vt220_lock, flags); + + sclp_sync_wait(); spin_lock_irqsave(&sclp_vt220_lock, flags); } page = (void *) sclp_vt220_empty.next; @@ -428,8 +457,8 @@ __sclp_vt220_write(const unsigned char *buf, int count, int do_schedule, sclp_vt220_timer.expires = jiffies + BUFFER_MAX_DELAY; add_timer(&sclp_vt220_timer); } - spin_unlock_irqrestore(&sclp_vt220_lock, flags); out: + spin_unlock_irqrestore(&sclp_vt220_lock, flags); return overall_written; } @@ -803,7 +832,7 @@ sclp_vt220_con_init(void) if (!CONSOLE_IS_SCLP) return 0; - rc = __sclp_vt220_init(MAX_CONSOLE_PAGES); + rc = __sclp_vt220_init(sclp_console_pages); if (rc) return rc; /* Attach linux console */ |