s390/cio: add function chsc_sgib()

This patch implements the Set Guest Information Block operation
to request association or disassociation of a Guest Information
Block (GIB) with the Adapter Interruption Facility. The operation
is required to receive GIB alert interrupts for guest adapters
in conjunction with AIV and GISA.

Signed-off-by: Michael Mueller <mimu@linux.ibm.com>
Reviewed-by: Sebastian Ott <sebott@linux.ibm.com>
Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Halil Pasic <pasic@linux.ibm.com>
Acked-by: Janosch Frank <frankja@linux.ibm.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20190131085247.13826-9-mimu@linux.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>

drivers/s390/cio/chsc.c

@@ -1382,3 +1382,40 @@ int chsc_pnso_brinfo(struct subchannel_id schid,
 	return chsc_error_from_response(brinfo_area->response.code);
 }
 EXPORT_SYMBOL_GPL(chsc_pnso_brinfo);
+
+int chsc_sgib(u32 origin)
+{
+	struct {
+		struct chsc_header request;
+		u16 op;
+		u8  reserved01[2];
+		u8  reserved02:4;
+		u8  fmt:4;
+		u8  reserved03[7];
+		/* operation data area begin */
+		u8  reserved04[4];
+		u32 gib_origin;
+		u8  reserved05[10];
+		u8  aix;
+		u8  reserved06[4029];
+		struct chsc_header response;
+		u8  reserved07[4];
+	} *sgib_area;
+	int ret;
+
+	spin_lock_irq(&chsc_page_lock);
+	memset(chsc_page, 0, PAGE_SIZE);
+	sgib_area = chsc_page;
+	sgib_area->request.length = 0x0fe0;
+	sgib_area->request.code = 0x0021;
+	sgib_area->op = 0x1;
+	sgib_area->gib_origin = origin;
+
+	ret = chsc(sgib_area);
+	if (ret == 0)
+		ret = chsc_error_from_response(sgib_area->response.code);
+	spin_unlock_irq(&chsc_page_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(chsc_sgib);