From 687cb7f21695469626f683d709d931ad41b2ca68 Mon Sep 17 00:00:00 2001 From: Sebastian Ott Date: Tue, 21 Jun 2016 16:26:25 +0200 Subject: [PATCH] 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 Reviewed-by: Cornelia Huck Reviewed-by: Peter Oberparleiter Signed-off-by: Martin Schwidefsky --- drivers/s390/cio/chsc.c | 10 ++++------ drivers/s390/cio/chsc.h | 5 +++-- 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; -- 2.7.4