[S390] chsc: use the global page to determine the chp desriptor
chsc_determine_channel_path_desc is called by a wrapper
who allocates a response struct. The response data
is then memcpy'ed to this response struct by
chsc_determine_channel_path_desc.
Change chsc_determine_base_channel_path_desc to use the
global chsc_page and deliver it to the function doing
the actual chsc call. The channel path desriptor is
then directly read from the response data.
As a result we get rid of the additional allocation
for the response struct.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/cio/chsc_sch.c b/drivers/s390/cio/chsc_sch.c
index f2b77e7..3c3f3ff 100644
--- a/drivers/s390/cio/chsc_sch.c
+++ b/drivers/s390/cio/chsc_sch.c
@@ -688,25 +688,31 @@
static int chsc_ioctl_chpd(void __user *user_chpd)
{
+ struct chsc_scpd *scpd_area;
struct chsc_cpd_info *chpd;
int ret;
chpd = kzalloc(sizeof(*chpd), GFP_KERNEL);
- if (!chpd)
- return -ENOMEM;
+ scpd_area = (void *)get_zeroed_page(GFP_KERNEL | GFP_DMA);
+ if (!scpd_area || !chpd) {
+ ret = -ENOMEM;
+ goto out_free;
+ }
if (copy_from_user(chpd, user_chpd, sizeof(*chpd))) {
ret = -EFAULT;
goto out_free;
}
ret = chsc_determine_channel_path_desc(chpd->chpid, chpd->fmt,
chpd->rfmt, chpd->c, chpd->m,
- &chpd->chpdb);
+ scpd_area);
if (ret)
goto out_free;
+ memcpy(&chpd->chpdb, &scpd_area->response, scpd_area->response.length);
if (copy_to_user(user_chpd, chpd, sizeof(*chpd)))
ret = -EFAULT;
out_free:
kfree(chpd);
+ free_page((unsigned long)scpd_area);
return ret;
}