[Qemu-devel] [PATCH] Fix serial interface vmstate

["Pavel Dovgaluk" <Pavel.Dovgaluk@ispras.ru>]

  This patch fixes save/restore of serial interface's state.
  It includes changing of fcr setter function (it now does not invoke
an interrupt while loading vmstate), and saving/restoring all
fields that describe the state of serial interface (including timers).

Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@gmail.com>
---
 hw/serial.c |  133 ++++++++++++++++++++++++++++++++++++++--------------------
 1 files changed, 87 insertions(+), 46 deletions(-)

diff --git a/hw/serial.c b/hw/serial.c
index 0ee61dd..936e048 100644
--- a/hw/serial.c
+++ b/hw/serial.c
@@ -362,6 +362,62 @@ static void serial_xmit(void *opaque)
 }
 
 
+/* Setter for FCR.
+   is_load flag means, that value is set while loading VM state
+   and interrupt should not be invoked */
+static void serial_write_fcr(void *opaque, uint32_t val, int is_load)
+{
+    SerialState *s = opaque;
+
+    val = val & 0xFF;
+
+    if (s->fcr == val)
+        return;
+
+    /* Did the enable/disable flag change? If so, make sure FIFOs get flushed */
+    if ((val ^ s->fcr) & UART_FCR_FE)
+        val |= UART_FCR_XFR | UART_FCR_RFR;
+
+    /* FIFO clear */
+
+    if (val & UART_FCR_RFR) {
+        qemu_del_timer(s->fifo_timeout_timer);
+        s->timeout_ipending=0;
+        fifo_clear(s,RECV_FIFO);
+    }
+
+    if (val & UART_FCR_XFR) {
+        fifo_clear(s,XMIT_FIFO);
+    }
+
+    if (val & UART_FCR_FE) {
+        s->iir |= UART_IIR_FE;
+        /* Set RECV_FIFO trigger Level */
+        switch (val & 0xC0) {
+        case UART_FCR_ITL_1:
+            s->recv_fifo.itl = 1;
+            break;
+        case UART_FCR_ITL_2:
+            s->recv_fifo.itl = 4;
+            break;
+        case UART_FCR_ITL_3:
+            s->recv_fifo.itl = 8;
+            break;
+        case UART_FCR_ITL_4:
+            s->recv_fifo.itl = 14;
+            break;
+        }
+    } else
+        s->iir &= ~UART_IIR_FE;
+
+    /* Set fcr - or at least the bits in it that are supposed to "stick" */
+    s->fcr = val & 0xC9;
+    if (!is_load) {
+        serial_update_irq(s);
+    }
+}
+
+
 static void serial_ioport_write(void *opaque, uint32_t addr, uint32_t val)
 {
     SerialState *s = opaque;
@@ -414,50 +470,7 @@ static void serial_ioport_write(void *opaque, uint32_t addr, uint32_t val)
         }
         break;
     case 2:
-        val = val & 0xFF;
-
-        if (s->fcr == val)
-            break;
-
-        /* Did the enable/disable flag change? If so, make sure FIFOs get flushed */
-        if ((val ^ s->fcr) & UART_FCR_FE)
-            val |= UART_FCR_XFR | UART_FCR_RFR;
-
-        /* FIFO clear */
-
-        if (val & UART_FCR_RFR) {
-            qemu_del_timer(s->fifo_timeout_timer);
-            s->timeout_ipending=0;
-            fifo_clear(s,RECV_FIFO);
-        }
-
-        if (val & UART_FCR_XFR) {
-            fifo_clear(s,XMIT_FIFO);
-        }
-
-        if (val & UART_FCR_FE) {
-            s->iir |= UART_IIR_FE;
-            /* Set RECV_FIFO trigger Level */
-            switch (val & 0xC0) {
-            case UART_FCR_ITL_1:
-                s->recv_fifo.itl = 1;
-                break;
-            case UART_FCR_ITL_2:
-                s->recv_fifo.itl = 4;
-                break;
-            case UART_FCR_ITL_3:
-                s->recv_fifo.itl = 8;
-                break;
-            case UART_FCR_ITL_4:
-                s->recv_fifo.itl = 14;
-                break;
-            }
-        } else
-            s->iir &= ~UART_IIR_FE;
-
-        /* Set fcr - or at least the bits in it that are supposed to "stick" */
-        s->fcr = val & 0xC9;
-        serial_update_irq(s);
+        serial_write_fcr(s, val, 0);
         break;
     case 3:
         {
@@ -673,20 +686,38 @@ static int serial_post_load(void *opaque, int version_id)
         s->fcr_vmstate = 0;
     }
     /* Initialize fcr via setter to perform essential side-effects */
-    serial_ioport_write(s, 0x02, s->fcr_vmstate);
+    serial_write_fcr(s, s->fcr_vmstate, 1);
     serial_update_parameters(s);
     return 0;
 }
 
+
+static const VMStateDescription vmstate_fifo = {
+    .name = "serial FIFO",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields      = (VMStateField []) {
+        VMSTATE_BUFFER(data, SerialFIFO),
+        VMSTATE_UINT8(count, SerialFIFO),
+        VMSTATE_UINT8(itl, SerialFIFO),
+        VMSTATE_UINT8(tail, SerialFIFO),
+        VMSTATE_UINT8(head, SerialFIFO),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+
 static const VMStateDescription vmstate_serial = {
     .name = "serial",
-    .version_id = 3,
+    .version_id = 4,
     .minimum_version_id = 2,
     .pre_save = serial_pre_save,
     .post_load = serial_post_load,
     .fields      = (VMStateField []) {
         VMSTATE_UINT16_V(divider, SerialState, 2),
         VMSTATE_UINT8(rbr, SerialState),
+        VMSTATE_UINT8_V(thr, SerialState, 4),
+        VMSTATE_UINT8_V(tsr, SerialState, 4),
         VMSTATE_UINT8(ier, SerialState),
         VMSTATE_UINT8(iir, SerialState),
         VMSTATE_UINT8(lcr, SerialState),
@@ -695,6 +726,16 @@ static const VMStateDescription vmstate_serial = {
         VMSTATE_UINT8(msr, SerialState),
         VMSTATE_UINT8(scr, SerialState),
         VMSTATE_UINT8_V(fcr_vmstate, SerialState, 3),
+        VMSTATE_INT32_V(thr_ipending, SerialState, 4),
+        VMSTATE_INT32_V(last_break_enable, SerialState, 4),
+        VMSTATE_INT32_V(tsr_retry, SerialState, 4),
+        VMSTATE_STRUCT(recv_fifo, SerialState, 4, vmstate_fifo, SerialFIFO),
+        VMSTATE_STRUCT(xmit_fifo, SerialState, 4, vmstate_fifo, SerialFIFO),
+        VMSTATE_TIMER_V(fifo_timeout_timer, SerialState, 4),
+        VMSTATE_INT32_V(timeout_ipending, SerialState, 4),
+        VMSTATE_TIMER_V(transmit_timer, SerialState, 4),
+        VMSTATE_INT32_V(poll_msl, SerialState, 4),
+        VMSTATE_TIMER_V(modem_status_poll, SerialState, 4),
         VMSTATE_END_OF_LIST()
     }
 };