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authorSebastian Ott <sebott@linux.ibm.com>2018-06-26 15:09:32 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2018-07-17 07:27:55 +0200
commitd4f5d79e97ca6e903700d3d9455afb5694cc4833 (patch)
tree13104c4b30fa7e9360f366c4e526640627705652 /drivers/s390/cio
parents390/css: validate subchannel prior to allocation (diff)
downloadlinux-d4f5d79e97ca6e903700d3d9455afb5694cc4833.tar.xz
linux-d4f5d79e97ca6e903700d3d9455afb5694cc4833.zip
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 <sebott@linux.ibm.com> Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'drivers/s390/cio')
-rw-r--r--drivers/s390/cio/cio.c65
-rw-r--r--drivers/s390/cio/cio.h1
-rw-r--r--drivers/s390/cio/css.c67
-rw-r--r--drivers/s390/cio/css.h3
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;