[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.c b/drivers/s390/cio/chsc.c
index d12c152..27aca39 100644
--- a/drivers/s390/cio/chsc.c
+++ b/drivers/s390/cio/chsc.c
@@ -639,36 +639,18 @@
}
int chsc_determine_channel_path_desc(struct chp_id chpid, int fmt, int rfmt,
- int c, int m,
- struct chsc_response_struct *resp)
+ int c, int m, void *page)
{
+ struct chsc_scpd *scpd_area;
int ccode, ret;
- struct {
- struct chsc_header request;
- u32 : 2;
- u32 m : 1;
- u32 c : 1;
- u32 fmt : 4;
- u32 cssid : 8;
- u32 : 4;
- u32 rfmt : 4;
- u32 first_chpid : 8;
- u32 : 24;
- u32 last_chpid : 8;
- u32 zeroes1;
- struct chsc_header response;
- u8 data[PAGE_SIZE - 20];
- } __attribute__ ((packed)) *scpd_area;
-
if ((rfmt == 1) && !css_general_characteristics.fcs)
return -EINVAL;
if ((rfmt == 2) && !css_general_characteristics.cib)
return -EINVAL;
- spin_lock_irq(&chsc_page_lock);
- memset(chsc_page, 0, PAGE_SIZE);
- scpd_area = chsc_page;
+ memset(page, 0, PAGE_SIZE);
+ scpd_area = page;
scpd_area->request.length = 0x0010;
scpd_area->request.code = 0x0002;
scpd_area->cssid = chpid.cssid;
@@ -680,20 +662,13 @@
scpd_area->rfmt = rfmt;
ccode = chsc(scpd_area);
- if (ccode > 0) {
- ret = (ccode == 3) ? -ENODEV : -EBUSY;
- goto out;
- }
+ if (ccode > 0)
+ return (ccode == 3) ? -ENODEV : -EBUSY;
ret = chsc_error_from_response(scpd_area->response.code);
- if (ret == 0)
- /* Success. */
- memcpy(resp, &scpd_area->response, scpd_area->response.length);
- else
+ if (ret)
CIO_CRW_EVENT(2, "chsc: scpd failed (rc=%04x)\n",
scpd_area->response.code);
-out:
- spin_unlock_irq(&chsc_page_lock);
return ret;
}
EXPORT_SYMBOL_GPL(chsc_determine_channel_path_desc);
@@ -702,17 +677,18 @@
struct channel_path_desc *desc)
{
struct chsc_response_struct *chsc_resp;
+ struct chsc_scpd *scpd_area;
int ret;
- chsc_resp = kzalloc(sizeof(*chsc_resp), GFP_KERNEL);
- if (!chsc_resp)
- return -ENOMEM;
- ret = chsc_determine_channel_path_desc(chpid, 0, 0, 0, 0, chsc_resp);
+ spin_lock_irq(&chsc_page_lock);
+ scpd_area = chsc_page;
+ ret = chsc_determine_channel_path_desc(chpid, 0, 0, 0, 0, scpd_area);
if (ret)
- goto out_free;
+ goto out;
+ chsc_resp = (void *)&scpd_area->response;
memcpy(desc, &chsc_resp->data, sizeof(*desc));
-out_free:
- kfree(chsc_resp);
+out:
+ spin_unlock_irq(&chsc_page_lock);
return ret;
}