macfb: don't use special irq_state and irq_mask variables in MacfbState

The current IRQ state and IRQ mask are handled exactly the same as standard
register accesses, so store these values directly in the regs array rather
than having separate variables for them.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20220305155530.9265-3-mark.cave-ayland@ilande.co.uk>
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>

hw/display/macfb.c

@@ -476,7 +476,8 @@ static void macfb_update_display(void *opaque)
 
 static void macfb_update_irq(MacfbState *s)
 {
-    uint32_t irq_state = s->irq_state & s->irq_mask;
+    uint32_t irq_state = s->regs[DAFB_INTR_STAT >> 2] &
+                         s->regs[DAFB_INTR_MASK >> 2];
 
     if (irq_state) {
         qemu_irq_raise(s->irq);
@@ -496,7 +497,7 @@ static void macfb_vbl_timer(void *opaque)
     MacfbState *s = opaque;
     int64_t next_vbl;
 
-    s->irq_state |= DAFB_INTR_VBL;
+    s->regs[DAFB_INTR_STAT >> 2] |= DAFB_INTR_VBL;
     macfb_update_irq(s);
 
     /* 60 Hz irq */
@@ -530,10 +531,8 @@ static uint64_t macfb_ctrl_read(void *opaque,
     case DAFB_MODE_VADDR2:
     case DAFB_MODE_CTRL1:
     case DAFB_MODE_CTRL2:
-        val = s->regs[addr >> 2];
-        break;
     case DAFB_INTR_STAT:
-        val = s->irq_state;
+        val = s->regs[addr >> 2];
         break;
     case DAFB_MODE_SENSE:
         val = macfb_sense_read(s);
@@ -568,7 +567,7 @@ static void macfb_ctrl_write(void *opaque,
         macfb_sense_write(s, val);
         break;
     case DAFB_INTR_MASK:
-        s->irq_mask = val;
+        s->regs[addr >> 2] = val;
         if (val & DAFB_INTR_VBL) {
             next_vbl = macfb_next_vbl();
             timer_mod(s->vbl_timer, next_vbl);
@@ -577,12 +576,12 @@ static void macfb_ctrl_write(void *opaque,
         }
         break;
     case DAFB_INTR_CLEAR:
-        s->irq_state &= ~DAFB_INTR_VBL;
+        s->regs[DAFB_INTR_STAT >> 2] &= ~DAFB_INTR_VBL;
         macfb_update_irq(s);
         break;
     case DAFB_RESET:
         s->palette_current = 0;
-        s->irq_state &= ~DAFB_INTR_VBL;
+        s->regs[DAFB_INTR_STAT >> 2] &= ~DAFB_INTR_VBL;
         macfb_update_irq(s);
         break;
     case DAFB_LUT:

include/hw/display/macfb.h

@@ -66,8 +66,6 @@ typedef struct MacfbState {
     uint32_t regs[MACFB_NUM_REGS];
     MacFbMode *mode;
 
-    uint32_t irq_state;
-    uint32_t irq_mask;
     QEMUTimer *vbl_timer;
     qemu_irq irq;
 } MacfbState;