pci.c - emulators/tinyemu - Rivoreo Source Code Repositories

 /*
  * Simple PCI bus driver
  *
  * Copyright (c) 2017 Fabrice Bellard
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
 #include <inttypes.h>
 #include <assert.h>
 #include <stdarg.h>

 #include "cutils.h"
 #include "pci.h"

 //#define DEBUG_CONFIG

 typedef struct {
     uint32_t size; /* 0 means no mapping defined */
     uint8_t type;
     uint8_t enabled; /* true if mapping is enabled */
     void *opaque;
     PCIBarSetFunc *bar_set;
 } PCIIORegion;

 struct PCIDevice {
     PCIBus *bus;
     uint8_t devfn;
     IRQSignal irq[4];
     uint8_t config[256];
     uint8_t next_cap_offset; /* offset of the next capability */
     char *name; /* for debug only */
     PCIIORegion io_regions[PCI_NUM_REGIONS];
 };

 struct PCIBus {
     int bus_num;
     PCIDevice *device[256];
     PhysMemoryMap *mem_map;
     PhysMemoryMap *port_map;
     uint32_t irq_state[4][8]; /* one bit per device */
     IRQSignal irq[4];
 };

 static int bus_map_irq(PCIDevice *d, int irq_num)
 {
     int slot_addend;
     slot_addend = (d->devfn >> 3) - 1;
     return (irq_num + slot_addend) & 3;
 }

 static void pci_device_set_irq(void *opaque, int irq_num, int level)
 {
     PCIDevice *d = opaque;
     PCIBus *b = d->bus;
     uint32_t mask;
     int i, irq_level;

     //    printf("%s: pci_device_seq_irq: %d %d\n", d->name, irq_num, level);
     irq_num = bus_map_irq(d, irq_num);
     mask = 1 << (d->devfn & 0x1f);
     if (level)
         b->irq_state[irq_num][d->devfn >> 5] |= mask;
     else
         b->irq_state[irq_num][d->devfn >> 5] &= ~mask;

     /* compute the IRQ state */
     mask = 0;
     for(i = 0; i < 8; i++)
         mask |= b->irq_state[irq_num][i];
     irq_level = (mask != 0);
     set_irq(&b->irq[irq_num], irq_level);
 }

 static int devfn_alloc(PCIBus *b)
 {
     int devfn;
     for(devfn = 0; devfn < 256; devfn += 8) {
         if (!b->device[devfn])
             return devfn;
     }
     return -1;
 }

 /* devfn < 0 means to allocate it */
 PCIDevice *pci_register_device(PCIBus *b, const char *name, int devfn,
                                uint16_t vendor_id, uint16_t device_id,
                                uint8_t revision, uint16_t class_id)
 {
     PCIDevice *d;
     int i;

     if (devfn < 0) {
         devfn = devfn_alloc(b);
         if (devfn < 0)
             return NULL;
     }
     if (b->device[devfn])
         return NULL;

     d = mallocz(sizeof(PCIDevice));
     d->bus = b;
     d->name = strdup(name);
     d->devfn = devfn;

     put_le16(d->config + 0x00, vendor_id);
     put_le16(d->config + 0x02, device_id);
     d->config[0x08] = revision;
     put_le16(d->config + 0x0a, class_id);
     d->config[0x0e] = 0x00; /* header type */
     d->next_cap_offset = 0x40;

     for(i = 0; i < 4; i++)
         irq_init(&d->irq[i], pci_device_set_irq, d, i);
     b->device[devfn] = d;

     return d;
 }

 IRQSignal *pci_device_get_irq(PCIDevice *d, unsigned int irq_num)
 {
     assert(irq_num < 4);
     return &d->irq[irq_num];
 }

 static uint32_t pci_device_config_read(PCIDevice *d, uint32_t addr,
                                        int size_log2)
 {
     uint32_t val;
     switch(size_log2) {
     case 0:
         val = *(uint8_t *)(d->config + addr);
         break;
     case 1:
         /* Note: may be unaligned */
         if (addr <= 0xfe)
             val = get_le16(d->config + addr);
         else
             val = *(uint8_t *)(d->config + addr);
         break;
     case 2:
         /* always aligned */
         val = get_le32(d->config + addr);
         break;
     default:
         abort();
     }
 #ifdef DEBUG_CONFIG
     printf("pci_config_read: dev=%s addr=0x%02x val=0x%x s=%d\n",
            d->name, addr, val, 1 << size_log2);
 #endif
     return val;
 }

 PhysMemoryMap *pci_device_get_mem_map(PCIDevice *d)
 {
     return d->bus->mem_map;
 }

 PhysMemoryMap *pci_device_get_port_map(PCIDevice *d)
 {
     return d->bus->port_map;
 }

 void pci_register_bar(PCIDevice *d, unsigned int bar_num,
                       uint32_t size, int type,
                       void *opaque, PCIBarSetFunc *bar_set)
 {
     PCIIORegion *r;
     uint32_t val, config_addr;

     assert(bar_num < PCI_NUM_REGIONS);
     assert((size & (size - 1)) == 0); /* power of two */
     assert(size >= 4);
     r = &d->io_regions[bar_num];
     assert(r->size == 0);
     r->size = size;
     r->type = type;
     r->enabled = FALSE;
     r->opaque = opaque;
     r->bar_set = bar_set;
     /* set the config value */
     val = 0;
     if (bar_num == PCI_ROM_SLOT) {
         config_addr = 0x30;
     } else {
         val |= r->type;
         config_addr = 0x10 + 4 * bar_num;
     }
     put_le32(&d->config[config_addr], val);
 }

 static void pci_update_mappings(PCIDevice *d)
 {
     int cmd, i, offset;
     uint32_t new_addr;
     BOOL new_enabled;
     PCIIORegion *r;

     cmd = get_le16(&d->config[PCI_COMMAND]);

     for(i = 0; i < PCI_NUM_REGIONS; i++) {
         r = &d->io_regions[i];
         if (i == PCI_ROM_SLOT) {
             offset = 0x30;
         } else {
             offset = 0x10 + i * 4;
         }
         new_addr = get_le32(&d->config[offset]);
         new_enabled = FALSE;
         if (r->size != 0) {
             if ((r->type & PCI_ADDRESS_SPACE_IO) &&
                 (cmd & PCI_COMMAND_IO)) {
                 new_enabled = TRUE;
             } else {
                 if (cmd & PCI_COMMAND_MEMORY) {
                     if (i == PCI_ROM_SLOT) {
                         new_enabled = (new_addr & 1);
                     } else {
                         new_enabled = TRUE;
                     }
                 }
             }
         }
         if (new_enabled) {
             /* new address */
             new_addr = get_le32(&d->config[offset]) & ~(r->size - 1);
             r->bar_set(r->opaque, i, new_addr, TRUE);
             r->enabled = TRUE;
         } else if (r->enabled) {
             r->bar_set(r->opaque, i, 0, FALSE);
             r->enabled = FALSE;
         }
     }
 }

 /* return != 0 if write is not handled */
 static int pci_write_bar(PCIDevice *d, uint32_t addr,
                           uint32_t val)
 {
     PCIIORegion *r;
     int reg;

     if (addr == 0x30)
         reg = PCI_ROM_SLOT;
     else
         reg = (addr - 0x10) >> 2;
     //    printf("%s: write bar addr=%x data=%x\n", d->name, addr, val);
     r = &d->io_regions[reg];
     if (r->size == 0)
         return -1;
     if (reg == PCI_ROM_SLOT) {
         val = val & ((~(r->size - 1)) | 1);
     } else {
         val = (val & ~(r->size - 1)) | r->type;
     }
     put_le32(d->config + addr, val);
     pci_update_mappings(d);
     return 0;
 }

 static void pci_device_config_write8(PCIDevice *d, uint32_t addr,
                                      uint32_t data)
 {
     int can_write;

     if (addr == PCI_STATUS || addr == (PCI_STATUS + 1)) {
         /* write 1 reset bits */
         d->config[addr] &= ~data;
         return;
     }

     switch(d->config[0x0e]) {
     case 0x00:
     case 0x80:
         switch(addr) {
         case 0x00:
         case 0x01:
         case 0x02:
         case 0x03:
         case 0x08:
         case 0x09:
         case 0x0a:
         case 0x0b:
         case 0x0e:
         case 0x10 ... 0x27: /* base */
         case 0x30 ... 0x33: /* rom */
         case 0x3d:
             can_write = 0;
             break;
         default:
             can_write = 1;
             break;
         }
         break;
     default:
     case 0x01:
         switch(addr) {
         case 0x00:
         case 0x01:
         case 0x02:
         case 0x03:
         case 0x08:
         case 0x09:
         case 0x0a:
         case 0x0b:
         case 0x0e:
         case 0x38 ... 0x3b: /* rom */
         case 0x3d:
             can_write = 0;
             break;
         default:
             can_write = 1;
             break;
         }
         break;
     }
     if (can_write)
         d->config[addr] = data;
 }


 static void pci_device_config_write(PCIDevice *d, uint32_t addr,
                                     uint32_t data, int size_log2)
 {
     int size, i;
     uint32_t addr1;

 #ifdef DEBUG_CONFIG
     printf("pci_config_write: dev=%s addr=0x%02x val=0x%x s=%d\n",
            d->name, addr, data, 1 << size_log2);
 #endif
     if (size_log2 == 2 &&
         ((addr >= 0x10 && addr < 0x10 + 4 * 6) ||
          addr == 0x30)) {
         if (pci_write_bar(d, addr, data) == 0)
             return;
     }
     size = 1 << size_log2;
     for(i = 0; i < size; i++) {
         addr1 = addr + i;
         if (addr1 <= 0xff) {
             pci_device_config_write8(d, addr1, (data >> (i * 8)) & 0xff);
         }
     }
     if (PCI_COMMAND >= addr && PCI_COMMAND < addr + size) {
         pci_update_mappings(d);
     }
 }


 static void pci_data_write(PCIBus *s, uint32_t addr,
                            uint32_t data, int size_log2)
 {
     PCIDevice *d;
     int bus_num, devfn, config_addr;

     bus_num = (addr >> 16) & 0xff;
     if (bus_num != s->bus_num)
         return;
     devfn = (addr >> 8) & 0xff;
     d = s->device[devfn];
     if (!d)
         return;
     config_addr = addr & 0xff;
     pci_device_config_write(d, config_addr, data, size_log2);
 }

 static const uint32_t val_ones[3] = { 0xff, 0xffff, 0xffffffff };

 static uint32_t pci_data_read(PCIBus *s, uint32_t addr, int size_log2)
 {
     PCIDevice *d;
     int bus_num, devfn, config_addr;

     bus_num = (addr >> 16) & 0xff;
     if (bus_num != s->bus_num)
         return val_ones[size_log2];
     devfn = (addr >> 8) & 0xff;
     d = s->device[devfn];
     if (!d)
         return val_ones[size_log2];
     config_addr = addr & 0xff;
     return pci_device_config_read(d, config_addr, size_log2);
 }

 /* warning: only valid for one DEVIO page. Return NULL if no memory at
    the given address */
 uint8_t *pci_device_get_dma_ptr(PCIDevice *d, uint64_t addr, BOOL is_rw)
 {
     return phys_mem_get_ram_ptr(d->bus->mem_map, addr, is_rw);
 }

 void pci_device_set_config8(PCIDevice *d, uint8_t addr, uint8_t val)
 {
     d->config[addr] = val;
 }

 void pci_device_set_config16(PCIDevice *d, uint8_t addr, uint16_t val)
 {
     put_le16(&d->config[addr], val);
 }

 int pci_device_get_devfn(PCIDevice *d)
 {
     return d->devfn;
 }

 /* return the offset of the capability or < 0 if error. */
 int pci_add_capability(PCIDevice *d, const uint8_t *buf, int size)
 {
     int offset;

     offset = d->next_cap_offset;
     if ((offset + size) > 256)
         return -1;
     d->next_cap_offset += size;
     d->config[PCI_STATUS] |= PCI_STATUS_CAP_LIST;
     memcpy(d->config + offset, buf, size);
     d->config[offset + 1] = d->config[PCI_CAPABILITY_LIST];
     d->config[PCI_CAPABILITY_LIST] = offset;
     return offset;
 }

 /* i440FX host bridge */

 struct I440FXState {
     PCIBus *pci_bus;
     PCIDevice *pci_dev;
     PCIDevice *piix3_dev;
     uint32_t config_reg;
     uint8_t pic_irq_state[16];
     IRQSignal *pic_irqs; /* 16 irqs */
 };

 static void i440fx_write_addr(void *opaque, uint32_t offset,
                               uint32_t data, int size_log2)
 {
     I440FXState *s = opaque;
     s->config_reg = data;
 }

 static uint32_t i440fx_read_addr(void *opaque, uint32_t offset, int size_log2)
 {
     I440FXState *s = opaque;
     return s->config_reg;
 }

 static void i440fx_write_data(void *opaque, uint32_t offset,
                               uint32_t data, int size_log2)
 {
     I440FXState *s = opaque;
     if (s->config_reg & 0x80000000) {
         if (size_log2 == 2) {
             /* it is simpler to assume 32 bit config accesses are
                always aligned */
             pci_data_write(s->pci_bus, s->config_reg & ~3, data, size_log2);
         } else {
             pci_data_write(s->pci_bus, s->config_reg | offset, data, size_log2);
         }
     }
 }

 static uint32_t i440fx_read_data(void *opaque, uint32_t offset, int size_log2)
 {
     I440FXState *s = opaque;
     if (!(s->config_reg & 0x80000000))
         return val_ones[size_log2];
     if (size_log2 == 2) {
         /* it is simpler to assume 32 bit config accesses are
            always aligned */
         return pci_data_read(s->pci_bus, s->config_reg & ~3, size_log2);
     } else {
         return pci_data_read(s->pci_bus, s->config_reg | offset, size_log2);
     }
 }

 static void i440fx_set_irq(void *opaque, int irq_num, int irq_level)
 {
     I440FXState *s = opaque;
     PCIDevice *hd = s->piix3_dev;
     int pic_irq;

     /* map to the PIC irq (different IRQs can be mapped to the same
        PIC irq) */
     hd->config[0x60 + irq_num] &= ~0x80;
     pic_irq = hd->config[0x60 + irq_num];
     if (pic_irq < 16) {
         if (irq_level)
             s->pic_irq_state[pic_irq] |= 1 << irq_num;
         else
             s->pic_irq_state[pic_irq] &= ~(1 << irq_num);
         set_irq(&s->pic_irqs[pic_irq], (s->pic_irq_state[pic_irq] != 0));
     }
 }

 I440FXState *i440fx_init(PCIBus **pbus, int *ppiix3_devfn,
                          PhysMemoryMap *mem_map, PhysMemoryMap *port_map,
                          IRQSignal *pic_irqs)
 {
     I440FXState *s;
     PCIBus *b;
     PCIDevice *d;
     int i;

     s = mallocz(sizeof(*s));

     b = mallocz(sizeof(PCIBus));
     b->bus_num = 0;
     b->mem_map = mem_map;
     b->port_map = port_map;

     s->pic_irqs = pic_irqs;
     for(i = 0; i < 4; i++) {
         irq_init(&b->irq[i], i440fx_set_irq, s, i);
     }

     cpu_register_device(port_map, 0xcf8, 1, s, i440fx_read_addr, i440fx_write_addr,
                         DEVIO_SIZE32);
     cpu_register_device(port_map, 0xcfc, 4, s, i440fx_read_data, i440fx_write_data,
                         DEVIO_SIZE8 | DEVIO_SIZE16 | DEVIO_SIZE32);
     d = pci_register_device(b, "i440FX", 0, 0x8086, 0x1237, 0x02, 0x0600);
     put_le16(&d->config[PCI_SUBSYSTEM_VENDOR_ID], 0x1af4); /* Red Hat, Inc. */
     put_le16(&d->config[PCI_SUBSYSTEM_ID], 0x1100); /* QEMU virtual machine */

     s->pci_dev = d;
     s->pci_bus = b;

     s->piix3_dev = pci_register_device(b, "PIIX3", 8, 0x8086, 0x7000,
                                        0x00, 0x0601);
     pci_device_set_config8(s->piix3_dev, 0x0e, 0x80); /* header type */

     *pbus = b;
     *ppiix3_devfn = s->piix3_dev->devfn;
     return s;
 }

 /* in case no BIOS is used, map the interrupts. */
 void i440fx_map_interrupts(I440FXState *s, uint8_t *elcr,
                            const uint8_t *pci_irqs)
 {
     PCIBus *b = s->pci_bus;
     PCIDevice *d, *hd;
     int irq_num, pic_irq, devfn, i;

     /* set a default PCI IRQ mapping to PIC IRQs */
     hd = s->piix3_dev;

     elcr[0] = 0;
     elcr[1] = 0;
     for(i = 0; i < 4; i++) {
         irq_num = pci_irqs[i];
         hd->config[0x60 + i] = irq_num;
         elcr[irq_num >> 3] |= (1 << (irq_num & 7));
     }

     for(devfn = 0; devfn < 256; devfn++) {
         d = b->device[devfn];
         if (!d)
             continue;
         if (d->config[PCI_INTERRUPT_PIN]) {
             irq_num = 0;
             irq_num = bus_map_irq(d, irq_num);
             pic_irq = hd->config[0x60 + irq_num];
             if (pic_irq < 16) {
                 d->config[PCI_INTERRUPT_LINE] = pic_irq;
             }
         }
     }
 }
	/*
	* Simple PCI bus driver
	*
	* Copyright (c) 2017 Fabrice Bellard
	*
	* Permission is hereby granted, free of charge, to any person obtaining a copy
	* of this software and associated documentation files (the "Software"), to deal
	* in the Software without restriction, including without limitation the rights
	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	* copies of the Software, and to permit persons to whom the Software is
	* furnished to do so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice shall be included in
	* all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	* THE SOFTWARE.
	*/
	#include <stdlib.h>
	#include <stdio.h>
	#include <string.h>
	#include <inttypes.h>
	#include <assert.h>
	#include <stdarg.h>

	#include "cutils.h"
	#include "pci.h"

	//#define DEBUG_CONFIG

	typedef struct {
	uint32_t size; /* 0 means no mapping defined */
	uint8_t type;
	uint8_t enabled; /* true if mapping is enabled */
	void *opaque;
	PCIBarSetFunc *bar_set;
	} PCIIORegion;

	struct PCIDevice {
	PCIBus *bus;
	uint8_t devfn;
	IRQSignal irq[4];
	uint8_t config[256];
	uint8_t next_cap_offset; /* offset of the next capability */
	char name; / for debug only */
	PCIIORegion io_regions[PCI_NUM_REGIONS];
	};

	struct PCIBus {
	int bus_num;
	PCIDevice *device[256];
	PhysMemoryMap *mem_map;
	PhysMemoryMap *port_map;
	uint32_t irq_state[4][8]; /* one bit per device */
	IRQSignal irq[4];
	};

	static int bus_map_irq(PCIDevice *d, int irq_num)
	{
	int slot_addend;
	slot_addend = (d->devfn >> 3) - 1;
	return (irq_num + slot_addend) & 3;
	}

	static void pci_device_set_irq(void *opaque, int irq_num, int level)
	{
	PCIDevice *d = opaque;
	PCIBus *b = d->bus;
	uint32_t mask;
	int i, irq_level;

	// printf("%s: pci_device_seq_irq: %d %d\n", d->name, irq_num, level);
	irq_num = bus_map_irq(d, irq_num);
	mask = 1 << (d->devfn & 0x1f);
	if (level)
	b->irq_state[irq_num][d->devfn >> 5] \|= mask;
	else
	b->irq_state[irq_num][d->devfn >> 5] &= ~mask;

	/* compute the IRQ state */
	mask = 0;
	for(i = 0; i < 8; i++)
	mask \|= b->irq_state[irq_num][i];
	irq_level = (mask != 0);
	set_irq(&b->irq[irq_num], irq_level);
	}

	static int devfn_alloc(PCIBus *b)
	{
	int devfn;
	for(devfn = 0; devfn < 256; devfn += 8) {
	if (!b->device[devfn])
	return devfn;
	}
	return -1;
	}

	/* devfn < 0 means to allocate it */
	PCIDevice pci_register_device(PCIBus b, const char *name, int devfn,
	uint16_t vendor_id, uint16_t device_id,
	uint8_t revision, uint16_t class_id)
	{
	PCIDevice *d;
	int i;

	if (devfn < 0) {
	devfn = devfn_alloc(b);
	if (devfn < 0)
	return NULL;
	}
	if (b->device[devfn])
	return NULL;

	d = mallocz(sizeof(PCIDevice));
	d->bus = b;
	d->name = strdup(name);
	d->devfn = devfn;

	put_le16(d->config + 0x00, vendor_id);
	put_le16(d->config + 0x02, device_id);
	d->config[0x08] = revision;
	put_le16(d->config + 0x0a, class_id);
	d->config[0x0e] = 0x00; /* header type */
	d->next_cap_offset = 0x40;

	for(i = 0; i < 4; i++)
	irq_init(&d->irq[i], pci_device_set_irq, d, i);
	b->device[devfn] = d;

	return d;
	}

	IRQSignal pci_device_get_irq(PCIDevice d, unsigned int irq_num)
	{
	assert(irq_num < 4);
	return &d->irq[irq_num];
	}

	static uint32_t pci_device_config_read(PCIDevice *d, uint32_t addr,
	int size_log2)
	{
	uint32_t val;
	switch(size_log2) {
	case 0:
	val = (uint8_t )(d->config + addr);
	break;
	case 1:
	/* Note: may be unaligned */
	if (addr <= 0xfe)
	val = get_le16(d->config + addr);
	else
	val = (uint8_t )(d->config + addr);
	break;
	case 2:
	/* always aligned */
	val = get_le32(d->config + addr);
	break;
	default:
	abort();
	}
	#ifdef DEBUG_CONFIG
	printf("pci_config_read: dev=%s addr=0x%02x val=0x%x s=%d\n",
	d->name, addr, val, 1 << size_log2);
	#endif
	return val;
	}

	PhysMemoryMap pci_device_get_mem_map(PCIDevice d)
	{
	return d->bus->mem_map;
	}

	PhysMemoryMap pci_device_get_port_map(PCIDevice d)
	{
	return d->bus->port_map;
	}

	void pci_register_bar(PCIDevice *d, unsigned int bar_num,
	uint32_t size, int type,
	void opaque, PCIBarSetFunc bar_set)
	{
	PCIIORegion *r;
	uint32_t val, config_addr;

	assert(bar_num < PCI_NUM_REGIONS);
	assert((size & (size - 1)) == 0); /* power of two */
	assert(size >= 4);
	r = &d->io_regions[bar_num];
	assert(r->size == 0);
	r->size = size;
	r->type = type;
	r->enabled = FALSE;
	r->opaque = opaque;
	r->bar_set = bar_set;
	/* set the config value */
	val = 0;
	if (bar_num == PCI_ROM_SLOT) {
	config_addr = 0x30;
	} else {
	val \|= r->type;
	config_addr = 0x10 + 4 * bar_num;
	}
	put_le32(&d->config[config_addr], val);
	}

	static void pci_update_mappings(PCIDevice *d)
	{
	int cmd, i, offset;
	uint32_t new_addr;
	BOOL new_enabled;
	PCIIORegion *r;

	cmd = get_le16(&d->config[PCI_COMMAND]);

	for(i = 0; i < PCI_NUM_REGIONS; i++) {
	r = &d->io_regions[i];
	if (i == PCI_ROM_SLOT) {
	offset = 0x30;
	} else {
	offset = 0x10 + i * 4;
	}
	new_addr = get_le32(&d->config[offset]);
	new_enabled = FALSE;
	if (r->size != 0) {
	if ((r->type & PCI_ADDRESS_SPACE_IO) &&
	(cmd & PCI_COMMAND_IO)) {
	new_enabled = TRUE;
	} else {
	if (cmd & PCI_COMMAND_MEMORY) {
	if (i == PCI_ROM_SLOT) {
	new_enabled = (new_addr & 1);
	} else {
	new_enabled = TRUE;
	}
	}
	}
	}
	if (new_enabled) {
	/* new address */
	new_addr = get_le32(&d->config[offset]) & ~(r->size - 1);
	r->bar_set(r->opaque, i, new_addr, TRUE);
	r->enabled = TRUE;
	} else if (r->enabled) {
	r->bar_set(r->opaque, i, 0, FALSE);
	r->enabled = FALSE;
	}
	}
	}

	/* return != 0 if write is not handled */
	static int pci_write_bar(PCIDevice *d, uint32_t addr,
	uint32_t val)
	{
	PCIIORegion *r;
	int reg;

	if (addr == 0x30)
	reg = PCI_ROM_SLOT;
	else
	reg = (addr - 0x10) >> 2;
	// printf("%s: write bar addr=%x data=%x\n", d->name, addr, val);
	r = &d->io_regions[reg];
	if (r->size == 0)
	return -1;
	if (reg == PCI_ROM_SLOT) {
	val = val & ((~(r->size - 1)) \| 1);
	} else {
	val = (val & ~(r->size - 1)) \| r->type;
	}
	put_le32(d->config + addr, val);
	pci_update_mappings(d);
	return 0;
	}

	static void pci_device_config_write8(PCIDevice *d, uint32_t addr,
	uint32_t data)
	{
	int can_write;

	if (addr == PCI_STATUS \|\| addr == (PCI_STATUS + 1)) {
	/* write 1 reset bits */
	d->config[addr] &= ~data;
	return;
	}

	switch(d->config[0x0e]) {
	case 0x00:
	case 0x80:
	switch(addr) {
	case 0x00:
	case 0x01:
	case 0x02:
	case 0x03:
	case 0x08:
	case 0x09:
	case 0x0a:
	case 0x0b:
	case 0x0e:
	case 0x10 ... 0x27: /* base */
	case 0x30 ... 0x33: /* rom */
	case 0x3d:
	can_write = 0;
	break;
	default:
	can_write = 1;
	break;
	}
	break;
	default:
	case 0x01:
	switch(addr) {
	case 0x00:
	case 0x01:
	case 0x02:
	case 0x03:
	case 0x08:
	case 0x09:
	case 0x0a:
	case 0x0b:
	case 0x0e:
	case 0x38 ... 0x3b: /* rom */
	case 0x3d:
	can_write = 0;
	break;
	default:
	can_write = 1;
	break;
	}
	break;
	}
	if (can_write)
	d->config[addr] = data;
	}


	static void pci_device_config_write(PCIDevice *d, uint32_t addr,
	uint32_t data, int size_log2)
	{
	int size, i;
	uint32_t addr1;

	#ifdef DEBUG_CONFIG
	printf("pci_config_write: dev=%s addr=0x%02x val=0x%x s=%d\n",
	d->name, addr, data, 1 << size_log2);
	#endif
	if (size_log2 == 2 &&
	((addr >= 0x10 && addr < 0x10 + 4 * 6) \|\|
	addr == 0x30)) {
	if (pci_write_bar(d, addr, data) == 0)
	return;
	}
	size = 1 << size_log2;
	for(i = 0; i < size; i++) {
	addr1 = addr + i;
	if (addr1 <= 0xff) {
	pci_device_config_write8(d, addr1, (data >> (i * 8)) & 0xff);
	}
	}
	if (PCI_COMMAND >= addr && PCI_COMMAND < addr + size) {
	pci_update_mappings(d);
	}
	}


	static void pci_data_write(PCIBus *s, uint32_t addr,
	uint32_t data, int size_log2)
	{
	PCIDevice *d;
	int bus_num, devfn, config_addr;

	bus_num = (addr >> 16) & 0xff;
	if (bus_num != s->bus_num)
	return;
	devfn = (addr >> 8) & 0xff;
	d = s->device[devfn];
	if (!d)
	return;
	config_addr = addr & 0xff;
	pci_device_config_write(d, config_addr, data, size_log2);
	}

	static const uint32_t val_ones[3] = { 0xff, 0xffff, 0xffffffff };

	static uint32_t pci_data_read(PCIBus *s, uint32_t addr, int size_log2)
	{
	PCIDevice *d;
	int bus_num, devfn, config_addr;

	bus_num = (addr >> 16) & 0xff;
	if (bus_num != s->bus_num)
	return val_ones[size_log2];
	devfn = (addr >> 8) & 0xff;
	d = s->device[devfn];
	if (!d)
	return val_ones[size_log2];
	config_addr = addr & 0xff;
	return pci_device_config_read(d, config_addr, size_log2);
	}

	/* warning: only valid for one DEVIO page. Return NULL if no memory at
	the given address */
	uint8_t pci_device_get_dma_ptr(PCIDevice d, uint64_t addr, BOOL is_rw)
	{
	return phys_mem_get_ram_ptr(d->bus->mem_map, addr, is_rw);
	}

	void pci_device_set_config8(PCIDevice *d, uint8_t addr, uint8_t val)
	{
	d->config[addr] = val;
	}

	void pci_device_set_config16(PCIDevice *d, uint8_t addr, uint16_t val)
	{
	put_le16(&d->config[addr], val);
	}

	int pci_device_get_devfn(PCIDevice *d)
	{
	return d->devfn;
	}

	/* return the offset of the capability or < 0 if error. */
	int pci_add_capability(PCIDevice d, const uint8_t buf, int size)
	{
	int offset;

	offset = d->next_cap_offset;
	if ((offset + size) > 256)
	return -1;
	d->next_cap_offset += size;
	d->config[PCI_STATUS] \|= PCI_STATUS_CAP_LIST;
	memcpy(d->config + offset, buf, size);
	d->config[offset + 1] = d->config[PCI_CAPABILITY_LIST];
	d->config[PCI_CAPABILITY_LIST] = offset;
	return offset;
	}

	/* i440FX host bridge */

	struct I440FXState {
	PCIBus *pci_bus;
	PCIDevice *pci_dev;
	PCIDevice *piix3_dev;
	uint32_t config_reg;
	uint8_t pic_irq_state[16];
	IRQSignal pic_irqs; / 16 irqs */
	};

	static void i440fx_write_addr(void *opaque, uint32_t offset,
	uint32_t data, int size_log2)
	{
	I440FXState *s = opaque;
	s->config_reg = data;
	}

	static uint32_t i440fx_read_addr(void *opaque, uint32_t offset, int size_log2)
	{
	I440FXState *s = opaque;
	return s->config_reg;
	}

	static void i440fx_write_data(void *opaque, uint32_t offset,
	uint32_t data, int size_log2)
	{
	I440FXState *s = opaque;
	if (s->config_reg & 0x80000000) {
	if (size_log2 == 2) {
	/* it is simpler to assume 32 bit config accesses are
	always aligned */
	pci_data_write(s->pci_bus, s->config_reg & ~3, data, size_log2);
	} else {
	pci_data_write(s->pci_bus, s->config_reg \| offset, data, size_log2);
	}
	}
	}

	static uint32_t i440fx_read_data(void *opaque, uint32_t offset, int size_log2)
	{
	I440FXState *s = opaque;
	if (!(s->config_reg & 0x80000000))
	return val_ones[size_log2];
	if (size_log2 == 2) {
	/* it is simpler to assume 32 bit config accesses are
	always aligned */
	return pci_data_read(s->pci_bus, s->config_reg & ~3, size_log2);
	} else {
	return pci_data_read(s->pci_bus, s->config_reg \| offset, size_log2);
	}
	}

	static void i440fx_set_irq(void *opaque, int irq_num, int irq_level)
	{
	I440FXState *s = opaque;
	PCIDevice *hd = s->piix3_dev;
	int pic_irq;

	/* map to the PIC irq (different IRQs can be mapped to the same
	PIC irq) */
	hd->config[0x60 + irq_num] &= ~0x80;
	pic_irq = hd->config[0x60 + irq_num];
	if (pic_irq < 16) {
	if (irq_level)
	s->pic_irq_state[pic_irq] \|= 1 << irq_num;
	else
	s->pic_irq_state[pic_irq] &= ~(1 << irq_num);
	set_irq(&s->pic_irqs[pic_irq], (s->pic_irq_state[pic_irq] != 0));
	}
	}

	I440FXState i440fx_init(PCIBus pbus, int ppiix3_devfn,
	PhysMemoryMap mem_map, PhysMemoryMap port_map,
	IRQSignal *pic_irqs)
	{
	I440FXState *s;
	PCIBus *b;
	PCIDevice *d;
	int i;

	s = mallocz(sizeof(*s));

	b = mallocz(sizeof(PCIBus));
	b->bus_num = 0;
	b->mem_map = mem_map;
	b->port_map = port_map;

	s->pic_irqs = pic_irqs;
	for(i = 0; i < 4; i++) {
	irq_init(&b->irq[i], i440fx_set_irq, s, i);
	}

	cpu_register_device(port_map, 0xcf8, 1, s, i440fx_read_addr, i440fx_write_addr,
	DEVIO_SIZE32);
	cpu_register_device(port_map, 0xcfc, 4, s, i440fx_read_data, i440fx_write_data,
	DEVIO_SIZE8 \| DEVIO_SIZE16 \| DEVIO_SIZE32);
	d = pci_register_device(b, "i440FX", 0, 0x8086, 0x1237, 0x02, 0x0600);
	put_le16(&d->config[PCI_SUBSYSTEM_VENDOR_ID], 0x1af4); /* Red Hat, Inc. */
	put_le16(&d->config[PCI_SUBSYSTEM_ID], 0x1100); /* QEMU virtual machine */

	s->pci_dev = d;
	s->pci_bus = b;

	s->piix3_dev = pci_register_device(b, "PIIX3", 8, 0x8086, 0x7000,
	0x00, 0x0601);
	pci_device_set_config8(s->piix3_dev, 0x0e, 0x80); /* header type */

	*pbus = b;
	*ppiix3_devfn = s->piix3_dev->devfn;
	return s;
	}

	/* in case no BIOS is used, map the interrupts. */
	void i440fx_map_interrupts(I440FXState s, uint8_t elcr,
	const uint8_t *pci_irqs)
	{
	PCIBus *b = s->pci_bus;
	PCIDevice d, hd;
	int irq_num, pic_irq, devfn, i;

	/* set a default PCI IRQ mapping to PIC IRQs */
	hd = s->piix3_dev;

	elcr[0] = 0;
	elcr[1] = 0;
	for(i = 0; i < 4; i++) {
	irq_num = pci_irqs[i];
	hd->config[0x60 + i] = irq_num;
	elcr[irq_num >> 3] \|= (1 << (irq_num & 7));
	}

	for(devfn = 0; devfn < 256; devfn++) {
	d = b->device[devfn];
	if (!d)
	continue;
	if (d->config[PCI_INTERRUPT_PIN]) {
	irq_num = 0;
	irq_num = bus_map_irq(d, irq_num);
	pic_irq = hd->config[0x60 + irq_num];
	if (pic_irq < 16) {
	d->config[PCI_INTERRUPT_LINE] = pic_irq;
	}
	}
	}
	}