[PULL 39/48] rust: pl011: extract CharBackend receive logic into a separate function

[Paolo Bonzini]

Prepare for moving all references to the registers and the FIFO into a
separate struct.

Reviewed-by: Zhao Liu <zhao1....@intel.com>
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
 rust/hw/char/pl011/src/device.rs | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/rust/hw/char/pl011/src/device.rs b/rust/hw/char/pl011/src/device.rs
index 58b54547336..de5110038a5 100644
--- a/rust/hw/char/pl011/src/device.rs
+++ b/rust/hw/char/pl011/src/device.rs
@@ -6,7 +6,7 @@
 use std::{
     ffi::CStr,
     ops::ControlFlow,
-    os::raw::{c_int, c_uint, c_void},
+    os::raw::{c_int, c_void},
 };
 
 use qemu_api::{
@@ -488,6 +488,12 @@ pub fn can_receive(&self) -> bool {
         self.read_count < self.fifo_depth()
     }
 
+    pub fn receive(&mut self, ch: u32) {
+        if !self.loopback_enabled() {
+            self.put_fifo(ch)
+        }
+    }
+
     pub fn event(&mut self, event: QEMUChrEvent) {
         if event == QEMUChrEvent::CHR_EVENT_BREAK && !self.loopback_enabled() {
             self.put_fifo(registers::Data::BREAK.into());
@@ -513,7 +519,7 @@ pub fn fifo_depth(&self) -> u32 {
         1
     }
 
-    pub fn put_fifo(&mut self, value: c_uint) {
+    pub fn put_fifo(&mut self, value: u32) {
         let depth = self.fifo_depth();
         assert!(depth > 0);
         let slot = (self.read_pos + self.read_count) & (depth - 1);
@@ -622,12 +628,9 @@ pub fn write(&mut self, offset: hwaddr, value: u64) {
 pub unsafe extern "C" fn pl011_receive(opaque: *mut c_void, buf: *const u8, 
size: c_int) {
     let mut state = NonNull::new(opaque).unwrap().cast::<PL011State>();
     unsafe {
-        if state.as_ref().loopback_enabled() {
-            return;
-        }
         if size > 0 {
             debug_assert!(!buf.is_null());
-            state.as_mut().put_fifo(c_uint::from(buf.read_volatile()))
+            state.as_mut().receive(u32::from(buf.read_volatile()));
         }
     }
 }
-- 
2.48.1