i8259: Replace PicState::pics_state with master flag

This reflects how real PICs indentify their role (in non-buffered mode):
Pass the state of the /SP input on pic_init and use it instead of
pics_state to differentiate between master and slave mode.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>

hw/i8259.c

@@ -59,7 +59,7 @@ typedef struct PicState {
     uint8_t elcr; /* PIIX edge/trigger selection*/
     uint8_t elcr_mask;
     qemu_irq int_out;
-    PicState2 *pics_state;
+    bool master; /* reflects /SP input pin */
     MemoryRegion base_io;
     MemoryRegion elcr_io;
 } PicState;
@@ -107,8 +107,9 @@ static int pic_get_irq(PicState *s)
     mask = s->isr;
     if (s->special_mask)
         mask &= ~s->imr;
-    if (s->special_fully_nested_mode && s == &s->pics_state->pics[0])
+    if (s->special_fully_nested_mode && s->master) {
         mask &= ~(1 << 2);
+    }
     cur_priority = get_priority(s, mask);
     if (priority < cur_priority) {
         /* higher priority found: an irq should be generated */
@@ -126,8 +127,7 @@ static void pic_update_irq(PicState *s)
     irq = pic_get_irq(s);
     if (irq >= 0) {
         DPRINTF("pic%d: imr=%x irr=%x padd=%d\n",
-                s == &s->pics_state->pics[0] ? 0 : 1, s->imr, s->irr,
-                s->priority_add);
+                s->master ? 0 : 1, s->imr, s->irr, s->priority_add);
         qemu_irq_raise(s->int_out);
     } else {
         qemu_irq_lower(s->int_out);
@@ -454,9 +454,11 @@ static const MemoryRegionOps pic_elcr_ioport_ops = {
 };
 
 /* XXX: add generic master/slave system */
-static void pic_init(int io_addr, int elcr_addr, PicState *s, qemu_irq int_out)
+static void pic_init(int io_addr, int elcr_addr, PicState *s, qemu_irq int_out,
+                     bool master)
 {
     s->int_out = int_out;
+    s->master = master;
 
     memory_region_init_io(&s->base_io, &pic_base_ioport_ops, s, "pic", 2);
     memory_region_init_io(&s->elcr_io, &pic_elcr_ioport_ops, s, "elcr", 1);
@@ -512,12 +514,10 @@ qemu_irq *i8259_init(qemu_irq parent_irq)
 
     s = g_malloc0(sizeof(PicState2));
     irqs = qemu_allocate_irqs(i8259_set_irq, s, 16);
-    pic_init(0x20, 0x4d0, &s->pics[0], parent_irq);
-    pic_init(0xa0, 0x4d1, &s->pics[1], irqs[2]);
+    pic_init(0x20, 0x4d0, &s->pics[0], parent_irq, true);
+    pic_init(0xa0, 0x4d1, &s->pics[1], irqs[2], false);
     s->pics[0].elcr_mask = 0xf8;
     s->pics[1].elcr_mask = 0xde;
-    s->pics[0].pics_state = s;
-    s->pics[1].pics_state = s;
     isa_pic = s;
     return irqs;
 }