s390x/3270: IDA support for 3270 via CcwDataStream

Let us convert the 3270 code so it uses the recently introduced
CcwDataStream abstraction instead of blindly assuming direct data access.

This patch does not change behavior beyond introducing IDA support: for
direct data access CCWs everything stays as-is. (If there are bugs, they
are also preserved).

Signed-off-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
Message-Id: <20170920172314.102710-2-pasic@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>

hw/char/terminal3270.c

@@ -182,14 +182,18 @@ static void terminal_init(EmulatedCcw3270Device *dev, Error **errp)
                              terminal_read, chr_event, NULL, t, NULL, true);
 }
 
-static int read_payload_3270(EmulatedCcw3270Device *dev, uint32_t cda,
-                             uint16_t count)
+static inline CcwDataStream *get_cds(Terminal3270 *t)
+{
+    return &(CCW_DEVICE(&t->cdev)->sch->cds);
+}
+
+static int read_payload_3270(EmulatedCcw3270Device *dev)
 {
     Terminal3270 *t = TERMINAL_3270(dev);
     int len;
 
-    len = MIN(count, t->in_len);
-    cpu_physical_memory_write(cda, t->inv, len);
+    len = MIN(ccw_dstream_avail(get_cds(t)), t->in_len);
+    ccw_dstream_write_buf(get_cds(t), t->inv, len);
     t->in_len -= len;
 
     return len;
@@ -222,11 +226,11 @@ static int insert_IAC_escape_char(uint8_t *outv, int out_len)
  * Write 3270 outbound to socket.
  * Return the count of 3270 data field if succeeded, zero if failed.
  */
-static int write_payload_3270(EmulatedCcw3270Device *dev, uint8_t cmd,
-                              uint32_t cda, uint16_t count)
+static int write_payload_3270(EmulatedCcw3270Device *dev, uint8_t cmd)
 {
     Terminal3270 *t = TERMINAL_3270(dev);
     int retval = 0;
+    int count = ccw_dstream_avail(get_cds(t));
 
     assert(count <= (OUTPUT_BUFFER_SIZE - 3) / 2);
 
@@ -244,7 +248,7 @@ static int write_payload_3270(EmulatedCcw3270Device *dev, uint8_t cmd,
         return count;
     }
     t->outv[0] = cmd;
-    cpu_physical_memory_read(cda, &t->outv[1], count);
+    ccw_dstream_read_buf(get_cds(t), &t->outv[1], count);
     t->out_len = count + 1;
 
     t->out_len = insert_IAC_escape_char(t->outv, t->out_len);

hw/s390x/3270-ccw.c

@@ -28,7 +28,7 @@ static int handle_payload_3270_read(EmulatedCcw3270Device *dev, CCW1 *ccw)
         return -EFAULT;
     }
 
-    len = ck->read_payload_3270(dev, ccw->cda, ccw->count);
+    len = ck->read_payload_3270(dev);
     ccw_dev->sch->curr_status.scsw.count = ccw->count - len;
 
     return 0;
@@ -45,7 +45,7 @@ static int handle_payload_3270_write(EmulatedCcw3270Device *dev, CCW1 *ccw)
         return -EFAULT;
     }
 
-    len = ck->write_payload_3270(dev, ccw->cmd_code, ccw->cda, ccw->count);
+    len = ck->write_payload_3270(dev, ccw->cmd_code);
 
     if (len <= 0) {
         return -EIO;

include/hw/s390x/3270-ccw.h

@@ -45,9 +45,8 @@ typedef struct EmulatedCcw3270Class {
     CCWDeviceClass parent_class;
 
     void (*init)(EmulatedCcw3270Device *, Error **);
-    int (*read_payload_3270)(EmulatedCcw3270Device *, uint32_t, uint16_t);
-    int (*write_payload_3270)(EmulatedCcw3270Device *, uint8_t, uint32_t,
-                              uint16_t);
+    int (*read_payload_3270)(EmulatedCcw3270Device *);
+    int (*write_payload_3270)(EmulatedCcw3270Device *, uint8_t);
 } EmulatedCcw3270Class;
 
 #endif