rust: pl011: extend registers to 32 bits

The PL011 Technical Reference Manual lists the "real" size of the
registers in table 3-1, and only rounds up to the next byte when
describing the registers; for example, UARTDR is listed as having
width 12/8 (12 bits read, 8 written) and only bits 15:0 are listed
in "Table 3-2 UARTDR Register".

However, in practice these are 32-bit registers, accessible only
through 32-bit MMIO accesses; preserving the fiction that they're
smaller introduces multiple casts (to go from the bilge bitfield
type to e.g u16 to u64) and more importantly it breaks the
migration stream because the Rust vmstate macros are not yet
type safe.

So, just make everything 32-bits wide.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 16 insertions, 20 deletions

diff --git a/rust/hw/char/pl011/src/device.rs b/rust/hw/char/pl011/src/device.rs
index 5e3a9c6f58..090e5d6450 100644
--- a/rust/hw/char/pl011/src/device.rs
+++ b/rust/hw/char/pl011/src/device.rs
@@ -186,9 +186,9 @@ impl PL011State {
     pub fn read(&mut self, offset: hwaddr, _size: c_uint) -> std::ops::ControlFlow<u64, u64> {
         use RegisterOffset::*;
 
-        std::ops::ControlFlow::Break(match RegisterOffset::try_from(offset) {
+        let value = match RegisterOffset::try_from(offset) {
             Err(v) if (0x3f8..0x400).contains(&(v >> 2)) => {
-                u64::from(self.device_id[(offset - 0xfe0) >> 2])
+                u32::from(self.device_id[(offset - 0xfe0) >> 2])
             }
             Err(_) => {
                 // qemu_log_mask(LOG_GUEST_ERROR, "pl011_read: Bad offset 0x%x\n", (int)offset);
@@ -214,27 +214,25 @@ impl PL011State {
                 let c = u32::from(c);
                 return std::ops::ControlFlow::Continue(u64::from(c));
             }
-            Ok(RSR) => u8::from(self.receive_status_error_clear).into(),
-            Ok(FR) => u16::from(self.flags).into(),
-            Ok(FBRD) => self.fbrd.into(),
-            Ok(ILPR) => self.ilpr.into(),
-            Ok(IBRD) => self.ibrd.into(),
-            Ok(LCR_H) => u16::from(self.line_control).into(),
-            Ok(CR) => {
-                // We exercise our self-control.
-                u16::from(self.control).into()
-            }
-            Ok(FLS) => self.ifl.into(),
-            Ok(IMSC) => self.int_enabled.into(),
-            Ok(RIS) => self.int_level.into(),
-            Ok(MIS) => u64::from(self.int_level & self.int_enabled),
+            Ok(RSR) => u32::from(self.receive_status_error_clear),
+            Ok(FR) => u32::from(self.flags),
+            Ok(FBRD) => self.fbrd,
+            Ok(ILPR) => self.ilpr,
+            Ok(IBRD) => self.ibrd,
+            Ok(LCR_H) => u32::from(self.line_control),
+            Ok(CR) => u32::from(self.control),
+            Ok(FLS) => self.ifl,
+            Ok(IMSC) => self.int_enabled,
+            Ok(RIS) => self.int_level,
+            Ok(MIS) => self.int_level & self.int_enabled,
             Ok(ICR) => {
                 // "The UARTICR Register is the interrupt clear register and is write-only"
                 // Source: ARM DDI 0183G 3.3.13 Interrupt Clear Register, UARTICR
                 0
             }
-            Ok(DMACR) => self.dmacr.into(),
-        })
+            Ok(DMACR) => self.dmacr,
+        };
+        std::ops::ControlFlow::Break(value.into())
     }
 
     pub fn write(&mut self, offset: hwaddr, value: u64) {
@@ -276,7 +274,6 @@ impl PL011State {
                 self.fbrd = value;
             }
             Ok(LCR_H) => {
-                let value = value as u16;
                 let new_val: registers::LineControl = value.into();
                 // Reset the FIFO state on FIFO enable or disable
                 if bool::from(self.line_control.fifos_enabled())
@@ -303,7 +300,6 @@ impl PL011State {
             }
             Ok(CR) => {
                 // ??? Need to implement the enable bit.
-                let value = value as u16;
                 self.control = value.into();
                 self.loopback_mdmctrl();
             }