PCI interrupt support - PCI BIOS interrupt remapping - more accurate memory mapping - 'info pci' monitor command

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@823 c046a42c-6fe2-441c-8c8c-71466251a162

1 files changed, 469 insertions, 74 deletions

diff --git a/hw/pci.c b/hw/pci.c
index 2c5f30b..ff5a44e 100644
--- a/hw/pci.c
+++ b/hw/pci.c
@@ -25,6 +25,21 @@
 
 //#define DEBUG_PCI
 
+#define PCI_VENDOR_ID		0x00	/* 16 bits */
+#define PCI_DEVICE_ID		0x02	/* 16 bits */
+#define PCI_COMMAND		0x04	/* 16 bits */
+#define  PCI_COMMAND_IO		0x1	/* Enable response in I/O space */
+#define  PCI_COMMAND_MEMORY	0x2	/* Enable response in Memory space */
+#define PCI_CLASS_DEVICE        0x0a    /* Device class */
+#define PCI_INTERRUPT_LINE	0x3c	/* 8 bits */
+#define PCI_INTERRUPT_PIN	0x3d	/* 8 bits */
+#define PCI_MIN_GNT		0x3e	/* 8 bits */
+#define PCI_MAX_LAT		0x3f	/* 8 bits */
+
+/* just used for simpler irq handling. */
+#define PCI_DEVICES_MAX 64
+#define PCI_IRQ_WORDS   ((PCI_DEVICES_MAX + 31) / 32)
+
 typedef struct PCIBridge {
     uint32_t config_reg;
     PCIDevice **pci_bus[256];
@@ -32,6 +47,8 @@ typedef struct PCIBridge {
 
 static PCIBridge pci_bridge;
 target_phys_addr_t pci_mem_base;
+static int pci_irq_index;
+static uint32_t pci_irq_levels[4][PCI_IRQ_WORDS];
 
 /* -1 for devfn means auto assign */
 PCIDevice *pci_register_device(const char *name, int instance_size,
@@ -42,6 +59,9 @@ PCIDevice *pci_register_device(const char *name, int instance_size,
     PCIBridge *s = &pci_bridge;
     PCIDevice *pci_dev, **bus;
 
+    if (pci_irq_index >= PCI_DEVICES_MAX)
+        return NULL;
+    
     if (!s->pci_bus[bus_num]) {
         s->pci_bus[bus_num] = qemu_mallocz(256 * sizeof(PCIDevice *));
         if (!s->pci_bus[bus_num])
@@ -62,8 +82,14 @@ PCIDevice *pci_register_device(const char *name, int instance_size,
     pci_dev->bus_num = bus_num;
     pci_dev->devfn = devfn;
     pstrcpy(pci_dev->name, sizeof(pci_dev->name), name);
+
+    if (!config_read)
+        config_read = pci_default_read_config;
+    if (!config_write)
+        config_write = pci_default_write_config;
     pci_dev->config_read = config_read;
     pci_dev->config_write = config_write;
+    pci_dev->irq_index = pci_irq_index++;
     bus[devfn] = pci_dev;
     return pci_dev;
 }
@@ -83,30 +109,160 @@ void pci_register_io_region(PCIDevice *pci_dev, int region_num,
     r->map_func = map_func;
 }
 
-static void pci_config_writel(void* opaque, uint32_t addr, uint32_t val)
+static void pci_addr_writel(void* opaque, uint32_t addr, uint32_t val)
 {
     PCIBridge *s = opaque;
     s->config_reg = val;
 }
 
-static uint32_t pci_config_readl(void* opaque, uint32_t addr)
+static uint32_t pci_addr_readl(void* opaque, uint32_t addr)
 {
     PCIBridge *s = opaque;
     return s->config_reg;
 }
 
-static void unmap_region(PCIIORegion *r)
+static void pci_update_mappings(PCIDevice *d)
+{
+    PCIIORegion *r;
+    int cmd, i;
+    uint32_t last_addr, new_addr;
+    
+    cmd = le16_to_cpu(*(uint16_t *)(d->config + PCI_COMMAND));
+    for(i = 0; i < 6; i++) {
+        r = &d->io_regions[i];
+        if (r->size != 0) {
+            if (r->type & PCI_ADDRESS_SPACE_IO) {
+                if (cmd & PCI_COMMAND_IO) {
+                    new_addr = le32_to_cpu(*(uint32_t *)(d->config + 
+                                                         0x10 + i * 4));
+                    new_addr = new_addr & ~(r->size - 1);
+                    last_addr = new_addr + r->size - 1;
+                    /* NOTE: we have only 64K ioports on PC */
+                    if (last_addr <= new_addr || new_addr == 0 ||
+                        last_addr >= 0x10000) {
+                        new_addr = -1;
+                    }
+                } else {
+                    new_addr = -1;
+                }
+            } else {
+                if (cmd & PCI_COMMAND_MEMORY) {
+                    new_addr = le32_to_cpu(*(uint32_t *)(d->config + 
+                                                         0x10 + i * 4));
+                    new_addr = new_addr & ~(r->size - 1);
+                    last_addr = new_addr + r->size - 1;
+                    /* NOTE: we do not support wrapping */
+                    /* XXX: as we cannot support really dynamic
+                       mappings, we handle specific values as invalid
+                       mappings. */
+                    if (last_addr <= new_addr || new_addr == 0 ||
+                        last_addr == -1) {
+                        new_addr = -1;
+                    }
+                } else {
+                    new_addr = -1;
+                }
+            }
+            /* now do the real mapping */
+            if (new_addr != r->addr) {
+                if (r->addr != -1) {
+                    if (r->type & PCI_ADDRESS_SPACE_IO) {
+                        int class;
+                        /* NOTE: specific hack for IDE in PC case:
+                           only one byte must be mapped. */
+                        class = d->config[0x0a] | (d->config[0x0b] << 8);
+                        if (class == 0x0101 && r->size == 4) {
+                            isa_unassign_ioport(r->addr + 2, 1);
+                        } else {
+                            isa_unassign_ioport(r->addr, r->size);
+                        }
+                    } else {
+                        cpu_register_physical_memory(r->addr + pci_mem_base, 
+                                                     r->size, 
+                                                     IO_MEM_UNASSIGNED);
+                    }
+                }
+                r->addr = new_addr;
+                if (r->addr != -1) {
+                    r->map_func(d, i, r->addr, r->size, r->type);
+                }
+            }
+        }
+    }
+}
+
+uint32_t pci_default_read_config(PCIDevice *d, 
+                                 uint32_t address, int len)
 {
-    if (r->addr == -1)
+    uint32_t val;
+    switch(len) {
+    case 1:
+        val = d->config[address];
+        break;
+    case 2:
+        val = le16_to_cpu(*(uint16_t *)(d->config + address));
+        break;
+    default:
+    case 4:
+        val = le32_to_cpu(*(uint32_t *)(d->config + address));
+        break;
+    }
+    return val;
+}
+
+void pci_default_write_config(PCIDevice *d, 
+                              uint32_t address, uint32_t val, int len)
+{
+    int can_write, i;
+    uint32_t end;
+
+    if (len == 4 && (address >= 0x10 && address < 0x10 + 4 * 6)) {
+        PCIIORegion *r;
+        int reg;
+
+        reg = (address - 0x10) >> 2;
+        r = &d->io_regions[reg];
+        if (r->size == 0)
+            goto default_config;
+        /* compute the stored value */
+        val &= ~(r->size - 1);
+        val |= r->type;
+        *(uint32_t *)(d->config + 0x10 + reg * 4) = cpu_to_le32(val);
+        pci_update_mappings(d);
         return;
-#ifdef DEBUG_PCI
-    printf("unmap addr=%08x size=%08x\n", r->addr, r->size);
-#endif
-    if (r->type & PCI_ADDRESS_SPACE_IO) {
-        isa_unassign_ioport(r->addr, r->size);
-    } else {
-        cpu_register_physical_memory(r->addr + pci_mem_base, r->size, 
-                                     IO_MEM_UNASSIGNED);
+    }
+ default_config:
+    /* not efficient, but simple */
+    for(i = 0; i < len; i++) {
+        /* default read/write accesses */
+        switch(address) {
+        case 0x00:
+        case 0x01:
+        case 0x02:
+        case 0x03:
+        case 0x08:
+        case 0x09:
+        case 0x0a:
+        case 0x0b:
+        case 0x0e:
+        case 0x3d:
+            can_write = 0;
+            break;
+        default:
+            can_write = 1;
+            break;
+        }
+        if (can_write) {
+            d->config[address] = val;
+        }
+        address++;
+        val >>= 8;
+    }
+
+    end = address + len;
+    if (end > PCI_COMMAND && address < (PCI_COMMAND + 2)) {
+        /* if the command register is modified, we must modify the mappings */
+        pci_update_mappings(d);
     }
 }
 
@@ -115,7 +271,7 @@ static void pci_data_write(void *opaque, uint32_t addr,
 {
     PCIBridge *s = opaque;
     PCIDevice **bus, *pci_dev;
-    int config_addr, reg;
+    int config_addr;
     
 #if defined(DEBUG_PCI) && 0
     printf("pci_data_write: addr=%08x val=%08x len=%d\n",
@@ -134,41 +290,11 @@ static void pci_data_write(void *opaque, uint32_t addr,
     if (!pci_dev)
         return;
     config_addr = (s->config_reg & 0xfc) | (addr & 3);
-
 #if defined(DEBUG_PCI)
     printf("pci_config_write: %s: addr=%02x val=%08x len=%d\n",
            pci_dev->name, config_addr, val, len);
 #endif
-    if (len == 4 && (config_addr >= 0x10 && config_addr < 0x10 + 4 * 6)) {
-        PCIIORegion *r;
-        reg = (config_addr - 0x10) >> 2;
-        r = &pci_dev->io_regions[reg];
-        if (r->size == 0)
-            goto default_config;
-        if (val != 0xffffffff && val != 0) {
-            /* XXX: the memory assignment should be global to handle
-               overlaps, but it is not needed at this stage */
-            /* first unmap the old region */
-            unmap_region(r);
-            /* change the address */
-            if (r->type & PCI_ADDRESS_SPACE_IO) 
-                r->addr = val & ~0x3;
-            else
-                r->addr = val & ~0xf;
-#ifdef DEBUG_PCI
-            printf("map addr=%08x size=%08x type=%d\n", 
-                   r->addr, r->size, r->type);
-#endif
-            r->map_func(pci_dev, reg, r->addr, r->size, r->type);
-        }
-        /* now compute the stored value */
-        val &= ~(r->size - 1);
-        val |= r->type;
-        *(uint32_t *)(pci_dev->config + 0x10 + reg * 4) = cpu_to_le32(val);
-    } else {
-    default_config:
-        pci_dev->config_write(pci_dev, config_addr, val, len);
-    }
+    pci_dev->config_write(pci_dev, config_addr, val, len);
 }
 
 static uint32_t pci_data_read(void *opaque, uint32_t addr, 
@@ -238,28 +364,13 @@ static uint32_t pci_data_readl(void* opaque, uint32_t addr)
 
 /* i440FX PCI bridge */
 
-static uint32_t i440_read_config(PCIDevice *d, 
-                                 uint32_t address, int len)
-{
-    uint32_t val;
-    val = 0;
-    memcpy(&val, d->config + address, len);
-    return val;
-}
-
-static void i440_write_config(PCIDevice *d, 
-                              uint32_t address, uint32_t val, int len)
-{
-    memcpy(d->config + address, &val, len);
-}
-
 void i440fx_init(void)
 {
     PCIBridge *s = &pci_bridge;
     PCIDevice *d;
 
-    register_ioport_write(0xcf8, 4, 4, pci_config_writel, s);
-    register_ioport_read(0xcf8, 4, 4, pci_config_readl, s);
+    register_ioport_write(0xcf8, 4, 4, pci_addr_writel, s);
+    register_ioport_read(0xcf8, 4, 4, pci_addr_readl, s);
 
     register_ioport_write(0xcfc, 4, 1, pci_data_writeb, s);
     register_ioport_write(0xcfc, 4, 2, pci_data_writew, s);
@@ -269,7 +380,7 @@ void i440fx_init(void)
     register_ioport_read(0xcfc, 4, 4, pci_data_readl, s);
 
     d = pci_register_device("i440FX", sizeof(PCIDevice), 0, 0, 
-                            i440_read_config, i440_write_config);
+                            NULL, NULL);
 
     d->config[0x00] = 0x86; // vendor_id
     d->config[0x01] = 0x80;
@@ -282,35 +393,295 @@ void i440fx_init(void)
     d->config[0x0e] = 0x01; // header_type
 }
 
-/* NOTE: the following should be done by the BIOS */
+/* PIIX3 PCI to ISA bridge */
+
+typedef struct PIIX3State {
+    PCIDevice dev;
+} PIIX3State;
+
+PIIX3State *piix3_state;
+
+static void piix3_reset(PIIX3State *d)
+{
+    uint8_t *pci_conf = d->dev.config;
+
+    pci_conf[0x04] = 0x07; // master, memory and I/O
+    pci_conf[0x05] = 0x00;
+    pci_conf[0x06] = 0x00;
+    pci_conf[0x07] = 0x02; // PCI_status_devsel_medium
+    pci_conf[0x4c] = 0x4d;
+    pci_conf[0x4e] = 0x03;
+    pci_conf[0x4f] = 0x00;
+    pci_conf[0x60] = 0x80;
+    pci_conf[0x69] = 0x02;
+    pci_conf[0x70] = 0x80;
+    pci_conf[0x76] = 0x0c;
+    pci_conf[0x77] = 0x0c;
+    pci_conf[0x78] = 0x02;
+    pci_conf[0x79] = 0x00;
+    pci_conf[0x80] = 0x00;
+    pci_conf[0x82] = 0x00;
+    pci_conf[0xa0] = 0x08;
+    pci_conf[0xa0] = 0x08;
+    pci_conf[0xa2] = 0x00;
+    pci_conf[0xa3] = 0x00;
+    pci_conf[0xa4] = 0x00;
+    pci_conf[0xa5] = 0x00;
+    pci_conf[0xa6] = 0x00;
+    pci_conf[0xa7] = 0x00;
+    pci_conf[0xa8] = 0x0f;
+    pci_conf[0xaa] = 0x00;
+    pci_conf[0xab] = 0x00;
+    pci_conf[0xac] = 0x00;
+    pci_conf[0xae] = 0x00;
+}
+
+void piix3_init(void)
+{
+    PIIX3State *d;
+    uint8_t *pci_conf;
+
+    d = (PIIX3State *)pci_register_device("PIIX3", sizeof(PIIX3State),
+                                          0, -1, 
+                                          NULL, NULL);
+    piix3_state = d;
+    pci_conf = d->dev.config;
+
+    pci_conf[0x00] = 0x86; // Intel
+    pci_conf[0x01] = 0x80;
+    pci_conf[0x02] = 0x00; // 82371SB PIIX3 PCI-to-ISA bridge (Step A1)
+    pci_conf[0x03] = 0x70;
+    pci_conf[0x0a] = 0x01; // class_sub = PCI_ISA
+    pci_conf[0x0b] = 0x06; // class_base = PCI_bridge
+    pci_conf[0x0e] = 0x80; // header_type = PCI_multifunction, generic
+
+    piix3_reset(d);
+}
+
+/***********************************************************/
+/* generic PCI irq support */
+
+/* return the global irq number corresponding to a given device irq
+   pin. We could also use the bus number to have a more precise
+   mapping. */
+static inline int pci_slot_get_pirq(PCIDevice *pci_dev, int irq_num)
+{
+    int slot_addend;
+    slot_addend = (pci_dev->devfn >> 3);
+    return (irq_num + slot_addend) & 3;
+}
+
+/* 0 <= irq_num <= 3. level must be 0 or 1 */
+void pci_set_irq(PCIDevice *pci_dev, int irq_num, int level)
+{
+    int irq_index, shift, pic_irq, pic_level;
+    uint32_t *p;
+
+    irq_num = pci_slot_get_pirq(pci_dev, irq_num);
+    irq_index = pci_dev->irq_index;
+    p = &pci_irq_levels[irq_num][irq_index >> 5];
+    shift = (irq_index & 0x1f);
+    *p = (*p & ~(1 << shift)) | (level << shift);
+
+    /* now we change the pic irq level according to the piix irq mappings */
+    pic_irq = piix3_state->dev.config[0x60 + irq_num];
+    if (pic_irq < 16) {
+        /* the pic level is the logical OR of all the PCI irqs mapped
+           to it */
+        pic_level = 0;
+#if (PCI_IRQ_WORDS == 2)
+        pic_level = ((pci_irq_levels[irq_num][0] | 
+                      pci_irq_levels[irq_num][1]) != 0);
+#else
+        {
+            int i;
+            pic_level = 0;
+            for(i = 0; i < PCI_IRQ_WORDS; i++) {
+                if (pci_irq_levels[irq_num][i]) {
+                    pic_level = 1;
+                    break;
+                }
+            }
+        }
+#endif
+        pic_set_irq(pic_irq, pic_level);
+    }
+}
+
+/***********************************************************/
+/* monitor info on PCI */
+
+static void pci_info_device(PCIDevice *d)
+{
+    int i, class;
+    PCIIORegion *r;
+
+    printf("  Bus %2d, device %3d, function %d:\n",
+           d->bus_num, d->devfn >> 3, d->devfn & 7);
+    class = le16_to_cpu(*((uint16_t *)(d->config + PCI_CLASS_DEVICE)));
+    printf("    ");
+    switch(class) {
+    case 0x0101:
+        printf("IDE controller");
+        break;
+    case 0x0200:
+        printf("Ethernet controller");
+        break;
+    case 0x0300:
+        printf("VGA controller");
+        break;
+    default:
+        printf("Class %04x", class);
+        break;
+    }
+    printf(": PCI device %04x:%04x\n",
+           le16_to_cpu(*((uint16_t *)(d->config + PCI_VENDOR_ID))),
+           le16_to_cpu(*((uint16_t *)(d->config + PCI_DEVICE_ID))));
+
+    if (d->config[PCI_INTERRUPT_PIN] != 0) {
+        printf("      IRQ %d.\n", d->config[PCI_INTERRUPT_LINE]);
+    }
+    for(i = 0;i < 6; i++) {
+        r = &d->io_regions[i];
+        if (r->size != 0) {
+            printf("      BAR%d: ", i);
+            if (r->type & PCI_ADDRESS_SPACE_IO) {
+                printf("I/O at 0x%04x [0x%04x].\n", 
+                       r->addr, r->addr + r->size - 1);
+            } else {
+                printf("32 bit memory at 0x%08x [0x%08x].\n", 
+                       r->addr, r->addr + r->size - 1);
+            }
+        }
+    }
+}
+
+void pci_info(void)
+{
+    PCIBridge *s = &pci_bridge;
+    PCIDevice **bus;
+    int bus_num, devfn;
+    
+    for(bus_num = 0; bus_num < 256; bus_num++) {
+        bus = s->pci_bus[bus_num];
+        if (bus) {
+            for(devfn = 0; devfn < 256; devfn++) {
+                if (bus[devfn])
+                    pci_info_device(bus[devfn]);
+            }
+        }
+    }
+}
+
+/***********************************************************/
+/* XXX: the following should be moved to the PC BIOS */
+
+static uint32_t isa_inb(uint32_t addr)
+{
+    return cpu_inb(cpu_single_env, addr);
+}
+
+static void isa_outb(uint32_t val, uint32_t addr)
+{
+    cpu_outb(cpu_single_env, addr, val);
+}
+
+static uint32_t isa_inw(uint32_t addr)
+{
+    return cpu_inw(cpu_single_env, addr);
+}
+
+static void isa_outw(uint32_t val, uint32_t addr)
+{
+    cpu_outw(cpu_single_env, addr, val);
+}
+
+static uint32_t isa_inl(uint32_t addr)
+{
+    return cpu_inl(cpu_single_env, addr);
+}
+
+static void isa_outl(uint32_t val, uint32_t addr)
+{
+    cpu_outl(cpu_single_env, addr, val);
+}
+
+static void pci_config_writel(PCIDevice *d, uint32_t addr, uint32_t val)
+{
+    PCIBridge *s = &pci_bridge;
+    s->config_reg = 0x80000000 | (d->bus_num << 16) | 
+        (d->devfn << 8) | addr;
+    pci_data_write(s, 0, val, 4);
+}
+
+static void pci_config_writew(PCIDevice *d, uint32_t addr, uint32_t val)
+{
+    PCIBridge *s = &pci_bridge;
+    s->config_reg = 0x80000000 | (d->bus_num << 16) | 
+        (d->devfn << 8) | (addr & ~3);
+    pci_data_write(s, addr & 3, val, 2);
+}
+
+static void pci_config_writeb(PCIDevice *d, uint32_t addr, uint32_t val)
+{
+    PCIBridge *s = &pci_bridge;
+    s->config_reg = 0x80000000 | (d->bus_num << 16) | 
+        (d->devfn << 8) | (addr & ~3);
+    pci_data_write(s, addr & 3, val, 1);
+}
+
+static uint32_t pci_config_readl(PCIDevice *d, uint32_t addr)
+{
+    PCIBridge *s = &pci_bridge;
+    s->config_reg = 0x80000000 | (d->bus_num << 16) | 
+        (d->devfn << 8) | addr;
+    return pci_data_read(s, 0, 4);
+}
+
+static uint32_t pci_config_readw(PCIDevice *d, uint32_t addr)
+{
+    PCIBridge *s = &pci_bridge;
+    s->config_reg = 0x80000000 | (d->bus_num << 16) | 
+        (d->devfn << 8) | (addr & ~3);
+    return pci_data_read(s, addr & 3, 2);
+}
+
+static uint32_t pci_config_readb(PCIDevice *d, uint32_t addr)
+{
+    PCIBridge *s = &pci_bridge;
+    s->config_reg = 0x80000000 | (d->bus_num << 16) | 
+        (d->devfn << 8) | (addr & ~3);
+    return pci_data_read(s, addr & 3, 1);
+}
 
 static uint32_t pci_bios_io_addr;
 static uint32_t pci_bios_mem_addr;
+/* host irqs corresponding to PCI irqs A-D */
+static uint8_t pci_irqs[4] = { 11, 9, 11, 9 };
 
 static void pci_set_io_region_addr(PCIDevice *d, int region_num, uint32_t addr)
 {
-    PCIBridge *s = &pci_bridge;
     PCIIORegion *r;
+    uint16_t cmd;
 
-    s->config_reg = 0x80000000 | (d->bus_num << 16) | 
-        (d->devfn << 8) | (0x10 + region_num * 4);
-    pci_data_write(s, 0, addr, 4);
+    pci_config_writel(d, 0x10 + region_num * 4, addr);
     r = &d->io_regions[region_num];
 
     /* enable memory mappings */
+    cmd = pci_config_readw(d, PCI_COMMAND);
     if (r->type & PCI_ADDRESS_SPACE_IO)
-        d->config[0x04] |= 1;
+        cmd |= 1;
     else
-        d->config[0x04] |= 2;
+        cmd |= 2;
+    pci_config_writew(d, PCI_COMMAND, cmd);
 }
 
-
 static void pci_bios_init_device(PCIDevice *d)
 {
     int class;
     PCIIORegion *r;
     uint32_t *paddr;
-    int i;
+    int i, pin, pic_irq;
 
     class = d->config[0x0a] | (d->config[0x0b] << 8);
     switch(class) {
@@ -321,6 +692,10 @@ static void pci_bios_init_device(PCIDevice *d)
         pci_set_io_region_addr(d, 2, 0x170);
         pci_set_io_region_addr(d, 3, 0x374);
         break;
+    case 0x0300:
+        /* VGA: map frame buffer to default Bochs VBE address */
+        pci_set_io_region_addr(d, 0, 0xE0000000);
+        break;
     default:
         /* default memory mappings */
         for(i = 0; i < 6; i++) {
@@ -337,6 +712,14 @@ static void pci_bios_init_device(PCIDevice *d)
         }
         break;
     }
+
+    /* map the interrupt */
+    pin = pci_config_readb(d, PCI_INTERRUPT_PIN);
+    if (pin != 0) {
+        pin = pci_slot_get_pirq(d, pin - 1);
+        pic_irq = pci_irqs[pin];
+        pci_config_writeb(d, PCI_INTERRUPT_LINE, pic_irq);
+    }
 }
 
 /*
@@ -348,11 +731,25 @@ void pci_bios_init(void)
 {
     PCIBridge *s = &pci_bridge;
     PCIDevice **bus;
-    int bus_num, devfn;
+    int bus_num, devfn, i, irq;
+    uint8_t elcr[2];
 
     pci_bios_io_addr = 0xc000;
     pci_bios_mem_addr = 0xf0000000;
 
+    /* activate IRQ mappings */
+    elcr[0] = 0x00;
+    elcr[1] = 0x00;
+    for(i = 0; i < 4; i++) {
+        irq = pci_irqs[i];
+        /* set to trigger level */
+        elcr[irq >> 3] |= (1 << (irq & 7));
+        /* activate irq remapping in PIIX */
+        pci_config_writeb((PCIDevice *)piix3_state, 0x60 + i, irq);
+    }
+    isa_outb(elcr[0], 0x4d0);
+    isa_outb(elcr[1], 0x4d1);
+
     for(bus_num = 0; bus_num < 256; bus_num++) {
         bus = s->pci_bus[bus_num];
         if (bus) {
@@ -363,5 +760,3 @@ void pci_bios_init(void)
         }
     }
 }
-
-