[S390] cio: Rework css driver.

Rework the css driver methods to provide sane callbacks for
subchannels of all types.

As a bonus, this cleans up and simplyfies the machine check
handling for I/O subchannels a lot.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

1 files changed, 20 insertions, 0 deletions

diff --git a/drivers/s390/cio/chp.c b/drivers/s390/cio/chp.c
index 297cdceb0ca4..297f1653b52b 100644
--- a/drivers/s390/cio/chp.c
+++ b/drivers/s390/cio/chp.c
@@ -496,6 +496,26 @@ void chp_process_crw(int id, int status)
                 chsc_chp_offline(chpid);
 }
 
+int chp_ssd_get_mask(struct chsc_ssd_info *ssd, struct res_acc_data *data)
+{
+        int i;
+        int mask;
+
+        for (i = 0; i < 8; i++) {
+                mask = 0x80 >> i;
+                if (!(ssd->path_mask & mask))
+                        continue;
+                if (!chp_id_is_equal(&ssd->chpid[i], &data->chpid))
+                        continue;
+                if ((ssd->fla_valid_mask & mask) &&
+                    ((ssd->fla[i] & data->fla_mask) != data->fla))
+                        continue;
+                return mask;
+        }
+        return 0;
+}
+EXPORT_SYMBOL_GPL(chp_ssd_get_mask);
+
 static inline int info_bit_num(struct chp_id id)
 {
         return id.id + id.cssid * (__MAX_CHPID + 1);