xen/arm: refactor vpl011_data_avail

Move the code to calculate in_fifo_level and out_fifo_level out of
vpl011_data_avail, to the caller.
This change will make it possible to reuse vpl011_data_avail with
different ring structures in a later patch.

Signed-off-by: Stefano Stabellini <stefanos@xilinx.com>
Acked-by: Julien Grall <julien.grall@arm.com>

diff --git a/xen/arch/arm/vpl011.c b/xen/arch/arm/vpl011.c
index cc9ef20e5efef694ac34df2b536402cefcd15ade..e29515a3b630f4c01db2a6a7016ab337057287fd 100644 (file)
--- a/xen/arch/arm/vpl011.c
+++ b/xen/arch/arm/vpl011.c
@@ -379,30 +379,13 @@ static const struct mmio_handler_ops vpl011_mmio_handler = {
     .write = vpl011_mmio_write,
 };
 
-static void vpl011_data_avail(struct domain *d)
+static void vpl011_data_avail(struct domain *d,
+                              XENCONS_RING_IDX in_fifo_level,
+                              XENCONS_RING_IDX in_size,
+                              XENCONS_RING_IDX out_fifo_level,
+                              XENCONS_RING_IDX out_size)
 {
-    unsigned long flags;
     struct vpl011 *vpl011 = &d->arch.vpl011;
-    struct xencons_interface *intf = vpl011->backend.dom.ring_buf;
-    XENCONS_RING_IDX in_cons, in_prod, out_cons, out_prod;
-    XENCONS_RING_IDX in_fifo_level, out_fifo_level;
-
-    VPL011_LOCK(d, flags);
-
-    in_cons = intf->in_cons;
-    in_prod = intf->in_prod;
-    out_cons = intf->out_cons;
-    out_prod = intf->out_prod;
-
-    smp_rmb();
-
-    in_fifo_level = xencons_queued(in_prod,
-                                   in_cons,
-                                   sizeof(intf->in));
-
-    out_fifo_level = xencons_queued(out_prod,
-                                    out_cons,
-                                    sizeof(intf->out));
 
     /**** Update the UART RX state ****/
 
@@ -411,11 +394,11 @@ static void vpl011_data_avail(struct domain *d)
         vpl011->uartfr &= ~RXFE;
 
     /* Set the FIFO_FULL bit if the Xen buffer is full. */
-    if ( in_fifo_level == sizeof(intf->in) )
+    if ( in_fifo_level == in_size )
         vpl011->uartfr |= RXFF;
 
     /* Assert the RX interrupt if the FIFO is more than half way filled. */
-    if ( in_fifo_level >= sizeof(intf->in) - SBSA_UART_FIFO_LEVEL )
+    if ( in_fifo_level >= in_size - SBSA_UART_FIFO_LEVEL )
         vpl011->uartris |= RXI;
 
     /*
@@ -428,7 +411,7 @@ static void vpl011_data_avail(struct domain *d)
 
     /**** Update the UART TX state ****/
 
-    if ( out_fifo_level != sizeof(intf->out) )
+    if ( out_fifo_level != out_size )
     {
         vpl011->uartfr &= ~TXFF;
 
@@ -446,13 +429,38 @@ static void vpl011_data_avail(struct domain *d)
 
     if ( out_fifo_level == 0 )
         vpl011->uartfr |= TXFE;
-
-    VPL011_UNLOCK(d, flags);
 }
 
 static void vpl011_notification(struct vcpu *v, unsigned int port)
 {
-    vpl011_data_avail(v->domain);
+    unsigned long flags;
+    struct domain *d = v->domain;
+    struct vpl011 *vpl011 = &d->arch.vpl011;
+    struct xencons_interface *intf = vpl011->backend.dom.ring_buf;
+    XENCONS_RING_IDX in_cons, in_prod, out_cons, out_prod;
+    XENCONS_RING_IDX in_fifo_level, out_fifo_level;
+
+    VPL011_LOCK(d, flags);
+
+    in_cons = intf->in_cons;
+    in_prod = intf->in_prod;
+    out_cons = intf->out_cons;
+    out_prod = intf->out_prod;
+
+    smp_rmb();
+
+    in_fifo_level = xencons_queued(in_prod,
+                                   in_cons,
+                                   sizeof(intf->in));
+
+    out_fifo_level = xencons_queued(out_prod,
+                                    out_cons,
+                                    sizeof(intf->out));
+
+    vpl011_data_avail(v->domain, in_fifo_level, sizeof(intf->in),
+                      out_fifo_level, sizeof(intf->out));
+
+    VPL011_UNLOCK(d, flags);
 }
 
 int domain_vpl011_init(struct domain *d, struct vpl011_init_info *info)