On 25/2/23 19:11, BALATON Zoltan wrote:
From: Bernhard Beschow <shen...@gmail.com>

The real VIA south bridges implement a PCI IRQ router which is configured
by the BIOS or the OS. In order to respect these configurations, QEMU
needs to implement it as well.

Note: The implementation was taken from piix4_set_irq() in hw/isa/piix4.

Signed-off-by: Bernhard Beschow <shen...@gmail.com>
[balaton: declare gpio inputs instead of changing pci bus irqs so it can
  be connected in board code; remove some empty lines]
Signed-off-by: BALATON Zoltan <bala...@eik.bme.hu>
Tested-by: Rene Engel <reneenge...@emailn.de>
---
  hw/isa/vt82c686.c | 39 +++++++++++++++++++++++++++++++++++++++
  1 file changed, 39 insertions(+)

+static int via_isa_get_pci_irq(const ViaISAState *s, int irq_num)
+{
+    switch (irq_num) {
+    case 0:
+        return s->dev.config[0x55] >> 4;
+    case 1:
+        return s->dev.config[0x56] & 0xf;
+    case 2:
+        return s->dev.config[0x56] >> 4;
+    case 3:
+        return s->dev.config[0x57] >> 4;
+    }
+    return 0;
+}
+
+static void via_isa_set_pci_irq(void *opaque, int irq_num, int level)
+{
+    ViaISAState *s = opaque;
+    PCIBus *bus = pci_get_bus(&s->dev);
+    int pic_irq;
+
+    /* now we change the pic irq level according to the via irq mappings */
+    /* XXX: optimize */
+    pic_irq = via_isa_get_pci_irq(s, irq_num);
+    if (pic_irq < ISA_NUM_IRQS) {

the ISA IRQ is stored in 4-bit so will always be in range.

+        int i, pic_level;
+
+        /* The pic level is the logical OR of all the PCI irqs mapped to it. */
+        pic_level = 0;
+        for (i = 0; i < PCI_NUM_PINS; i++) {
+            if (pic_irq == via_isa_get_pci_irq(s, i)) {
+                pic_level |= pci_bus_get_irq_level(bus, i);
+            }
+        }
+        qemu_set_irq(s->isa_irqs[pic_irq], pic_level);
+    }
+}



Reply via email to