From d4f5d79e97ca6e903700d3d9455afb5694cc4833 Mon Sep 17 00:00:00 2001 From: Sebastian Ott Date: Tue, 26 Jun 2018 15:09:32 +0200 Subject: s390/css: reduce stsch calls Both css_evaluate_new_subchannel and cio_validate_subchannel used stsch and css_sch_is_valid to check for a valid device. Reduce stsch calls during subchannel evaluation by re-using schib data. Also the type/devno valid information is only checked once. Signed-off-by: Sebastian Ott Reviewed-by: Peter Oberparleiter Signed-off-by: Martin Schwidefsky --- drivers/s390/cio/cio.c | 65 +++++------------------------------------------- drivers/s390/cio/cio.h | 1 - drivers/s390/cio/css.c | 67 ++++++++++++++++++++++++++++++++++++-------------- drivers/s390/cio/css.h | 3 ++- 4 files changed, 57 insertions(+), 79 deletions(-) diff --git a/drivers/s390/cio/cio.c b/drivers/s390/cio/cio.c index 4b8f29f83421..de744ca158fd 100644 --- a/drivers/s390/cio/cio.c +++ b/drivers/s390/cio/cio.c @@ -526,64 +526,6 @@ int cio_disable_subchannel(struct subchannel *sch) } EXPORT_SYMBOL_GPL(cio_disable_subchannel); -/** - * cio_validate_subchannel - basic validation of subchannel - * @schid: subchannel id - * @schib: subchannel information block to be filled out - * - * Check if subchannel is valid and should be used. - * Return codes: - * 0 on success - * -ENXIO for non-defined subchannels - * -ENODEV for invalid subchannels or blacklisted devices - * -EIO for subchannels in an invalid subchannel set - */ -int cio_validate_subchannel(struct subchannel_id schid, struct schib *schib) -{ - char dbf_txt[15]; - int ccode; - int err; - - sprintf(dbf_txt, "valsch%x", schid.sch_no); - CIO_TRACE_EVENT(4, dbf_txt); - - /* - * The first subchannel that is not-operational (ccode==3) - * indicates that there aren't any more devices available. - * If stsch gets an exception, it means the current subchannel set - * is not valid. - */ - ccode = stsch(schid, schib); - if (ccode) { - err = (ccode == 3) ? -ENXIO : ccode; - goto out; - } - - switch (schib->pmcw.st) { - case SUBCHANNEL_TYPE_IO: - case SUBCHANNEL_TYPE_MSG: - if (!css_sch_is_valid(schib)) - err = -ENODEV; - else if (is_blacklisted(schid.ssid, schib->pmcw.dev)) { - CIO_MSG_EVENT(6, "Blacklisted device detected " - "at devno %04X, subchannel set %x\n", - schib->pmcw.dev, schid.ssid); - err = -ENODEV; - } else - err = 0; - break; - default: - err = 0; - } - if (err) - goto out; - - CIO_MSG_EVENT(4, "Subchannel 0.%x.%04x reports subchannel type %04X\n", - schid.ssid, schid.sch_no, schib->pmcw.st); -out: - return err; -} - /* * do_cio_interrupt() handles all normal I/O device IRQ's */ @@ -707,6 +649,7 @@ struct subchannel *cio_probe_console(void) { struct subchannel_id schid; struct subchannel *sch; + struct schib schib; int sch_no, ret; sch_no = cio_get_console_sch_no(); @@ -716,7 +659,11 @@ struct subchannel *cio_probe_console(void) } init_subchannel_id(&schid); schid.sch_no = sch_no; - sch = css_alloc_subchannel(schid); + ret = stsch(schid, &schib); + if (ret) + return ERR_PTR(-ENODEV); + + sch = css_alloc_subchannel(schid, &schib); if (IS_ERR(sch)) return sch; diff --git a/drivers/s390/cio/cio.h b/drivers/s390/cio/cio.h index 234aa068dd8f..9811fd8a0c73 100644 --- a/drivers/s390/cio/cio.h +++ b/drivers/s390/cio/cio.h @@ -119,7 +119,6 @@ DECLARE_PER_CPU(struct irb, cio_irb); #define to_subchannel(n) container_of(n, struct subchannel, dev) -extern int cio_validate_subchannel(struct subchannel_id, struct schib *); extern int cio_enable_subchannel(struct subchannel *, u32); extern int cio_disable_subchannel (struct subchannel *); extern int cio_cancel (struct subchannel *); diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c index e4d6537cdd87..aea502922646 100644 --- a/drivers/s390/cio/css.c +++ b/drivers/s390/cio/css.c @@ -25,6 +25,7 @@ #include "css.h" #include "cio.h" +#include "blacklist.h" #include "cio_debug.h" #include "ioasm.h" #include "chsc.h" @@ -168,13 +169,43 @@ static void css_subchannel_release(struct device *dev) kfree(sch); } -struct subchannel *css_alloc_subchannel(struct subchannel_id schid) +static int css_validate_subchannel(struct subchannel_id schid, + struct schib *schib) +{ + int err; + + switch (schib->pmcw.st) { + case SUBCHANNEL_TYPE_IO: + case SUBCHANNEL_TYPE_MSG: + if (!css_sch_is_valid(schib)) + err = -ENODEV; + else if (is_blacklisted(schid.ssid, schib->pmcw.dev)) { + CIO_MSG_EVENT(6, "Blacklisted device detected " + "at devno %04X, subchannel set %x\n", + schib->pmcw.dev, schid.ssid); + err = -ENODEV; + } else + err = 0; + break; + default: + err = 0; + } + if (err) + goto out; + + CIO_MSG_EVENT(4, "Subchannel 0.%x.%04x reports subchannel type %04X\n", + schid.ssid, schid.sch_no, schib->pmcw.st); +out: + return err; +} + +struct subchannel *css_alloc_subchannel(struct subchannel_id schid, + struct schib *schib) { struct subchannel *sch; - struct schib schib; int ret; - ret = cio_validate_subchannel(schid, &schib); + ret = css_validate_subchannel(schid, schib); if (ret < 0) return ERR_PTR(ret); @@ -183,8 +214,8 @@ struct subchannel *css_alloc_subchannel(struct subchannel_id schid) return ERR_PTR(-ENOMEM); sch->schid = schid; - sch->schib = schib; - sch->st = schib.pmcw.st; + sch->schib = *schib; + sch->st = schib->pmcw.st; ret = css_sch_create_locks(sch); if (ret) @@ -386,12 +417,12 @@ int css_register_subchannel(struct subchannel *sch) return ret; } -static int css_probe_device(struct subchannel_id schid) +static int css_probe_device(struct subchannel_id schid, struct schib *schib) { struct subchannel *sch; int ret; - sch = css_alloc_subchannel(schid); + sch = css_alloc_subchannel(schid, schib); if (IS_ERR(sch)) return PTR_ERR(sch); @@ -440,23 +471,23 @@ EXPORT_SYMBOL_GPL(css_sch_is_valid); static int css_evaluate_new_subchannel(struct subchannel_id schid, int slow) { struct schib schib; + int ccode; if (!slow) { /* Will be done on the slow path. */ return -EAGAIN; } - if (stsch(schid, &schib)) { - /* Subchannel is not provided. */ - return -ENXIO; - } - if (!css_sch_is_valid(&schib)) { - /* Unusable - ignore. */ - return 0; - } - CIO_MSG_EVENT(4, "event: sch 0.%x.%04x, new\n", schid.ssid, - schid.sch_no); + /* + * The first subchannel that is not-operational (ccode==3) + * indicates that there aren't any more devices available. + * If stsch gets an exception, it means the current subchannel set + * is not valid. + */ + ccode = stsch(schid, &schib); + if (ccode) + return (ccode == 3) ? -ENXIO : ccode; - return css_probe_device(schid); + return css_probe_device(schid, &schib); } static int css_evaluate_known_subchannel(struct subchannel *sch, int slow) diff --git a/drivers/s390/cio/css.h b/drivers/s390/cio/css.h index 30357cbf350a..8d832900a63d 100644 --- a/drivers/s390/cio/css.h +++ b/drivers/s390/cio/css.h @@ -103,7 +103,8 @@ extern void css_driver_unregister(struct css_driver *); extern void css_sch_device_unregister(struct subchannel *); extern int css_register_subchannel(struct subchannel *); -extern struct subchannel *css_alloc_subchannel(struct subchannel_id); +extern struct subchannel *css_alloc_subchannel(struct subchannel_id, + struct schib *schib); extern struct subchannel *get_subchannel_by_schid(struct subchannel_id); extern int css_init_done; extern int max_ssid; -- cgit v1.2.3