[Qemu-devel] [PATCH 1/2] Route PC irqs to ISA bus instead of i8259 directly

[Avi Kivity <avi@redhat.com>]

A PC has its motherboard IRQ lines connected to both the PIC and IOAPIC.
Currently, qemu routes IRQs to the PIC which then calls the IOAPIC, an
incestuous arrangement.  In order to clean this up, create a new ISA IRQ
abstraction, and have devices raise ISA IRQs (which in turn raise the i8259
IRQs as usual).

Signed-off-by: Avi Kivity <avi@redhat.com>
---
 hw/pc.c |   44 ++++++++++++++++++++++++++++++--------------
 1 files changed, 30 insertions(+), 14 deletions(-)

diff --git a/hw/pc.c b/hw/pc.c
index bc9e646..a6be4a8 100644
--- a/hw/pc.c
+++ b/hw/pc.c
@@ -87,6 +87,17 @@ static void option_rom_setup_reset(target_phys_addr_t addr, unsigned size)
     qemu_register_reset(option_rom_reset, rrd);
 }
 
+typedef struct isa_irq_state {
+    qemu_irq *i8259;
+} IsaIrqState;
+
+static void isa_irq_handler(void *opaque, int n, int level)
+{
+    IsaIrqState *isa = (IsaIrqState *)opaque;
+
+    qemu_set_irq(isa->i8259[n], level);
+}
+
 static void ioport80_write(void *opaque, uint32_t addr, uint32_t data)
 {
 }
@@ -1119,7 +1130,9 @@ static void pc_init1(ram_addr_t ram_size,
     int piix3_devfn = -1;
     CPUState *env;
     qemu_irq *cpu_irq;
+    qemu_irq *isa_irq;
     qemu_irq *i8259;
+    IsaIrqState *isa_irq_state;
     DriveInfo *dinfo;
     BlockDriverState *hd[MAX_IDE_BUS * MAX_IDE_DEVS];
     BlockDriverState *fd[MAX_FD];
@@ -1264,10 +1277,13 @@ static void pc_init1(ram_addr_t ram_size,
 
     cpu_irq = qemu_allocate_irqs(pic_irq_request, NULL, 1);
     i8259 = i8259_init(cpu_irq[0]);
-    ferr_irq = i8259[13];
+    isa_irq_state = qemu_mallocz(sizeof(*isa_irq_state));
+    isa_irq_state->i8259 = i8259;
+    isa_irq = qemu_allocate_irqs(isa_irq_handler, isa_irq_state, 16);
+    ferr_irq = isa_irq[13];
 
     if (pci_enabled) {
-        pci_bus = i440fx_init(&i440fx_state, i8259);
+        pci_bus = i440fx_init(&i440fx_state, isa_irq);
         piix3_devfn = piix3_init(pci_bus, -1);
     } else {
         pci_bus = NULL;
@@ -1297,7 +1313,7 @@ static void pc_init1(ram_addr_t ram_size,
         }
     }
 
-    rtc_state = rtc_init(0x70, i8259[8], 2000);
+    rtc_state = rtc_init(0x70, isa_irq[8], 2000);
 
     qemu_register_boot_set(pc_boot_set, rtc_state);
 
@@ -1307,10 +1323,10 @@ static void pc_init1(ram_addr_t ram_size,
     if (pci_enabled) {
         ioapic = ioapic_init();
     }
-    pit = pit_init(0x40, i8259[0]);
+    pit = pit_init(0x40, isa_irq[0]);
     pcspk_init(pit);
     if (!no_hpet) {
-        hpet_init(i8259);
+        hpet_init(isa_irq);
     }
     if (pci_enabled) {
         pic_set_alt_irq_func(isa_pic, ioapic_set_irq, ioapic);
@@ -1318,14 +1334,14 @@ static void pc_init1(ram_addr_t ram_size,
 
     for(i = 0; i < MAX_SERIAL_PORTS; i++) {
         if (serial_hds[i]) {
-            serial_init(serial_io[i], i8259[serial_irq[i]], 115200,
+            serial_init(serial_io[i], isa_irq[serial_irq[i]], 115200,
                         serial_hds[i]);
         }
     }
 
     for(i = 0; i < MAX_PARALLEL_PORTS; i++) {
         if (parallel_hds[i]) {
-            parallel_init(parallel_io[i], i8259[parallel_irq[i]],
+            parallel_init(parallel_io[i], isa_irq[parallel_irq[i]],
                           parallel_hds[i]);
         }
     }
@@ -1336,7 +1352,7 @@ static void pc_init1(ram_addr_t ram_size,
         NICInfo *nd = &nd_table[i];
 
         if (!pci_enabled || (nd->model && strcmp(nd->model, "ne2k_isa") == 0))
-            pc_init_ne2k_isa(nd, i8259);
+            pc_init_ne2k_isa(nd, isa_irq);
         else
             pci_nic_init(nd, "ne2k_pci", NULL);
     }
@@ -1354,25 +1370,25 @@ static void pc_init1(ram_addr_t ram_size,
     }
 
     if (pci_enabled) {
-        pci_piix3_ide_init(pci_bus, hd, piix3_devfn + 1, i8259);
+        pci_piix3_ide_init(pci_bus, hd, piix3_devfn + 1, isa_irq);
     } else {
         for(i = 0; i < MAX_IDE_BUS; i++) {
-            isa_ide_init(ide_iobase[i], ide_iobase2[i], i8259[ide_irq[i]],
+            isa_ide_init(ide_iobase[i], ide_iobase2[i], isa_irq[ide_irq[i]],
 	                 hd[MAX_IDE_DEVS * i], hd[MAX_IDE_DEVS * i + 1]);
         }
     }
 
-    i8042_init(i8259[1], i8259[12], 0x60);
+    i8042_init(isa_irq[1], isa_irq[12], 0x60);
     DMA_init(0);
 #ifdef HAS_AUDIO
-    audio_init(pci_enabled ? pci_bus : NULL, i8259);
+    audio_init(pci_enabled ? pci_bus : NULL, isa_irq);
 #endif
 
     for(i = 0; i < MAX_FD; i++) {
         dinfo = drive_get(IF_FLOPPY, 0, i);
         fd[i] = dinfo ? dinfo->bdrv : NULL;
     }
-    floppy_controller = fdctrl_init(i8259[6], 2, 0, 0x3f0, fd);
+    floppy_controller = fdctrl_init(isa_irq[6], 2, 0, 0x3f0, fd);
 
     cmos_init(below_4g_mem_size, above_4g_mem_size, boot_device, hd);
 
@@ -1385,7 +1401,7 @@ static void pc_init1(ram_addr_t ram_size,
         i2c_bus *smbus;
 
         /* TODO: Populate SPD eeprom data.  */
-        smbus = piix4_pm_init(pci_bus, piix3_devfn + 3, 0xb100, i8259[9]);
+        smbus = piix4_pm_init(pci_bus, piix3_devfn + 3, 0xb100, isa_irq[9]);
         for (i = 0; i < 8; i++) {
             DeviceState *eeprom;
             eeprom = qdev_create((BusState *)smbus, "smbus-eeprom");
-- 
1.6.2.5