sparc64: vcc: Add write & write_room TTY operations

Add handlers to support TTY write & write_room operations

Signed-off-by: Jagannathan Raman <jag.raman@oracle.com>
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
Reviewed-by: Shannon Nelson <shannon.nelson@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/tty/vcc.c b/drivers/tty/vcc.c
index 67be5a5..0c0fe22 100644 (file)
--- a/drivers/tty/vcc.c
+++ b/drivers/tty/vcc.c
@@ -844,10 +844,105 @@ static void vcc_hangup(struct tty_struct *tty)
        tty_port_hangup(tty->port);
 }
 
+static int vcc_write(struct tty_struct *tty, const unsigned char *buf,
+                    int count)
+{
+       struct vcc_port *port;
+       struct vio_vcc *pkt;
+       unsigned long flags;
+       int total_sent = 0;
+       int tosend = 0;
+       int rv = -EINVAL;
+
+       if (unlikely(!tty)) {
+               pr_err("VCC: write: Invalid TTY handle\n");
+               return -ENXIO;
+       }
+
+       port = vcc_get_ne(tty->index);
+       if (unlikely(!port)) {
+               pr_err("VCC: write: Failed to find VCC port");
+               return -ENODEV;
+       }
+
+       spin_lock_irqsave(&port->lock, flags);
+
+       pkt = &port->buffer;
+       pkt->tag.type = VIO_TYPE_DATA;
+
+       while (count > 0) {
+               /* Minimum of data to write and space available */
+               tosend = min(count, (VCC_BUFF_LEN - port->chars_in_buffer));
+
+               if (!tosend)
+                       break;
+
+               memcpy(&pkt->data[port->chars_in_buffer], &buf[total_sent],
+                      tosend);
+               port->chars_in_buffer += tosend;
+               pkt->tag.stype = tosend;
+
+               vccdbg("TAG [%02x:%02x:%04x:%08x]\n", pkt->tag.type,
+                      pkt->tag.stype, pkt->tag.stype_env, pkt->tag.sid);
+               vccdbg("DATA [%s]\n", pkt->data);
+               vccdbgl(port->vio.lp);
+
+               /* Since we know we have enough room in VCC buffer for tosend
+                * we record that it was sent regardless of whether the
+                * hypervisor actually took it because we have it buffered.
+                */
+               rv = ldc_write(port->vio.lp, pkt, (VIO_TAG_SIZE + tosend));
+               vccdbg("VCC: write: ldc_write(%d)=%d\n",
+                      (VIO_TAG_SIZE + tosend), rv);
+
+               total_sent += tosend;
+               count -= tosend;
+               if (rv < 0) {
+                       vcc_kick_tx(port);
+                       break;
+               }
+
+               port->chars_in_buffer = 0;
+       }
+
+       spin_unlock_irqrestore(&port->lock, flags);
+
+       vcc_put(port, false);
+
+       vccdbg("VCC: write: total=%d rv=%d", total_sent, rv);
+
+       return total_sent ? total_sent : rv;
+}
+
+static int vcc_write_room(struct tty_struct *tty)
+{
+       struct vcc_port *port;
+       u64 num;
+
+       if (unlikely(!tty)) {
+               pr_err("VCC: write_room: Invalid TTY handle\n");
+               return -ENXIO;
+       }
+
+       port = vcc_get_ne(tty->index);
+       if (unlikely(!port)) {
+               pr_err("VCC: write_room: Failed to find VCC port\n");
+               return -ENODEV;
+       }
+
+       num = VCC_BUFF_LEN - port->chars_in_buffer;
+
+       vcc_put(port, false);
+
+       return num;
+}
+
 static const struct tty_operations vcc_ops = {
-       .open   = vcc_open,
-       .close  = vcc_close,
-       .hangup = vcc_hangup,
+       .open           = vcc_open,
+       .close          = vcc_close,
+       .hangup         = vcc_hangup,
+       .write          = vcc_write,
+       .write_room     = vcc_write_room,
 };
 
 #define VCC_TTY_FLAGS   (TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_REAL_RAW)