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authorSebastian Ott <sebott@linux.vnet.ibm.com>2016-06-21 16:26:25 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2016-07-15 14:32:01 +0200
commit687cb7f21695469626f683d709d931ad41b2ca68 (patch)
treeb312b6bbec4cdfafd8561e3b74b86827c21c16ca /drivers/s390/cio
parentf9773768f10c6af77778df67d6050778de42f120 (diff)
downloadop-kernel-dev-687cb7f21695469626f683d709d931ad41b2ca68.zip
op-kernel-dev-687cb7f21695469626f683d709d931ad41b2ca68.tar.gz
s390/chsc: improve channel path descriptor determination
When we fetch channel path descriptors via chsc we use a suboptimal struct chsc_scpd and adjust that by casting the response to a generic chsc_response_struct. Simplify the code by improving struct chsc_scpd. Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'drivers/s390/cio')
-rw-r--r--drivers/s390/cio/chsc.c10
-rw-r--r--drivers/s390/cio/chsc.h5
2 files changed, 7 insertions, 8 deletions
diff --git a/drivers/s390/cio/chsc.c b/drivers/s390/cio/chsc.c
index 4fe9531..940e725 100644
--- a/drivers/s390/cio/chsc.c
+++ b/drivers/s390/cio/chsc.c
@@ -940,7 +940,6 @@ EXPORT_SYMBOL_GPL(chsc_determine_channel_path_desc);
int chsc_determine_base_channel_path_desc(struct chp_id chpid,
struct channel_path_desc *desc)
{
- struct chsc_response_struct *chsc_resp;
struct chsc_scpd *scpd_area;
unsigned long flags;
int ret;
@@ -950,8 +949,8 @@ int chsc_determine_base_channel_path_desc(struct chp_id chpid,
ret = chsc_determine_channel_path_desc(chpid, 0, 0, 0, 0, scpd_area);
if (ret)
goto out;
- chsc_resp = (void *)&scpd_area->response;
- memcpy(desc, &chsc_resp->data, sizeof(*desc));
+
+ memcpy(desc, scpd_area->data, sizeof(*desc));
out:
spin_unlock_irqrestore(&chsc_page_lock, flags);
return ret;
@@ -960,7 +959,6 @@ out:
int chsc_determine_fmt1_channel_path_desc(struct chp_id chpid,
struct channel_path_desc_fmt1 *desc)
{
- struct chsc_response_struct *chsc_resp;
struct chsc_scpd *scpd_area;
unsigned long flags;
int ret;
@@ -970,8 +968,8 @@ int chsc_determine_fmt1_channel_path_desc(struct chp_id chpid,
ret = chsc_determine_channel_path_desc(chpid, 0, 1, 1, 0, scpd_area);
if (ret)
goto out;
- chsc_resp = (void *)&scpd_area->response;
- memcpy(desc, &chsc_resp->data, sizeof(*desc));
+
+ memcpy(desc, scpd_area->data, sizeof(*desc));
out:
spin_unlock_irqrestore(&chsc_page_lock, flags);
return ret;
diff --git a/drivers/s390/cio/chsc.h b/drivers/s390/cio/chsc.h
index 0de134c..67c87b6 100644
--- a/drivers/s390/cio/chsc.h
+++ b/drivers/s390/cio/chsc.h
@@ -112,8 +112,9 @@ struct chsc_scpd {
u32 last_chpid:8;
u32 zeroes1;
struct chsc_header response;
- u8 data[PAGE_SIZE - 20];
-} __attribute__ ((packed));
+ u32:32;
+ u8 data[0];
+} __packed;
struct chsc_sda_area {
struct chsc_header request;
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