hw/ide/pci.c - qemu - Git at Google

 /*
  * QEMU IDE Emulation: PCI Bus support.
  *
  * Copyright (c) 2003 Fabrice Bellard
  * Copyright (c) 2006 Openedhand Ltd.
  *
  * 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 "qemu/osdep.h"
 #include "hw/hw.h"
 #include "hw/pci/pci.h"
 #include "hw/isa/isa.h"
 #include "sysemu/dma.h"
 #include "qemu/error-report.h"
 #include "hw/ide/pci.h"
 #include "trace.h"

 #define BMDMA_PAGE_SIZE 4096

 #define BM_MIGRATION_COMPAT_STATUS_BITS \
         (IDE_RETRY_DMA | IDE_RETRY_PIO | \
         IDE_RETRY_READ | IDE_RETRY_FLUSH)

 static void bmdma_start_dma(IDEDMA *dma, IDEState *s,
                             BlockCompletionFunc *dma_cb)
 {
     BMDMAState *bm = DO_UPCAST(BMDMAState, dma, dma);

     bm->dma_cb = dma_cb;
     bm->cur_prd_last = 0;
     bm->cur_prd_addr = 0;
     bm->cur_prd_len = 0;

     if (bm->status & BM_STATUS_DMAING) {
         bm->dma_cb(bmdma_active_if(bm), 0);
     }
 }

 /**
  * Prepare an sglist based on available PRDs.
  * @limit: How many bytes to prepare total.
  *
  * Returns the number of bytes prepared, -1 on error.
  * IDEState.io_buffer_size will contain the number of bytes described
  * by the PRDs, whether or not we added them to the sglist.
  */
 static int32_t bmdma_prepare_buf(IDEDMA *dma, int32_t limit)
 {
     BMDMAState *bm = DO_UPCAST(BMDMAState, dma, dma);
     IDEState *s = bmdma_active_if(bm);
     PCIDevice *pci_dev = PCI_DEVICE(bm->pci_dev);
     struct {
         uint32_t addr;
         uint32_t size;
     } prd;
     int l, len;

     pci_dma_sglist_init(&s->sg, pci_dev,
                         s->nsector / (BMDMA_PAGE_SIZE / 512) + 1);
     s->io_buffer_size = 0;
     for(;;) {
         if (bm->cur_prd_len == 0) {
             /* end of table (with a fail safe of one page) */
             if (bm->cur_prd_last ||
                 (bm->cur_addr - bm->addr) >= BMDMA_PAGE_SIZE) {
                 return s->sg.size;
             }
             pci_dma_read(pci_dev, bm->cur_addr, &prd, 8);
             bm->cur_addr += 8;
             prd.addr = le32_to_cpu(prd.addr);
             prd.size = le32_to_cpu(prd.size);
             len = prd.size & 0xfffe;
             if (len == 0)
                 len = 0x10000;
             bm->cur_prd_len = len;
             bm->cur_prd_addr = prd.addr;
             bm->cur_prd_last = (prd.size & 0x80000000);
         }
         l = bm->cur_prd_len;
         if (l > 0) {
             uint64_t sg_len;

             /* Don't add extra bytes to the SGList; consume any remaining
              * PRDs from the guest, but ignore them. */
             sg_len = MIN(limit - s->sg.size, bm->cur_prd_len);
             if (sg_len) {
                 qemu_sglist_add(&s->sg, bm->cur_prd_addr, sg_len);
             }

             bm->cur_prd_addr += l;
             bm->cur_prd_len -= l;
             s->io_buffer_size += l;
         }
     }

     qemu_sglist_destroy(&s->sg);
     s->io_buffer_size = 0;
     return -1;
 }

 /* return 0 if buffer completed */
 static int bmdma_rw_buf(IDEDMA *dma, int is_write)
 {
     BMDMAState *bm = DO_UPCAST(BMDMAState, dma, dma);
     IDEState *s = bmdma_active_if(bm);
     PCIDevice *pci_dev = PCI_DEVICE(bm->pci_dev);
     struct {
         uint32_t addr;
         uint32_t size;
     } prd;
     int l, len;

     for(;;) {
         l = s->io_buffer_size - s->io_buffer_index;
         if (l <= 0)
             break;
         if (bm->cur_prd_len == 0) {
             /* end of table (with a fail safe of one page) */
             if (bm->cur_prd_last ||
                 (bm->cur_addr - bm->addr) >= BMDMA_PAGE_SIZE)
                 return 0;
             pci_dma_read(pci_dev, bm->cur_addr, &prd, 8);
             bm->cur_addr += 8;
             prd.addr = le32_to_cpu(prd.addr);
             prd.size = le32_to_cpu(prd.size);
             len = prd.size & 0xfffe;
             if (len == 0)
                 len = 0x10000;
             bm->cur_prd_len = len;
             bm->cur_prd_addr = prd.addr;
             bm->cur_prd_last = (prd.size & 0x80000000);
         }
         if (l > bm->cur_prd_len)
             l = bm->cur_prd_len;
         if (l > 0) {
             if (is_write) {
                 pci_dma_write(pci_dev, bm->cur_prd_addr,
                               s->io_buffer + s->io_buffer_index, l);
             } else {
                 pci_dma_read(pci_dev, bm->cur_prd_addr,
                              s->io_buffer + s->io_buffer_index, l);
             }
             bm->cur_prd_addr += l;
             bm->cur_prd_len -= l;
             s->io_buffer_index += l;
         }
     }
     return 1;
 }

 static void bmdma_set_inactive(IDEDMA *dma, bool more)
 {
     BMDMAState *bm = DO_UPCAST(BMDMAState, dma, dma);

     bm->dma_cb = NULL;
     if (more) {
         bm->status |= BM_STATUS_DMAING;
     } else {
         bm->status &= ~BM_STATUS_DMAING;
     }
 }

 static void bmdma_restart_dma(IDEDMA *dma)
 {
     BMDMAState *bm = DO_UPCAST(BMDMAState, dma, dma);

     bm->cur_addr = bm->addr;
 }

 static void bmdma_cancel(BMDMAState *bm)
 {
     if (bm->status & BM_STATUS_DMAING) {
         /* cancel DMA request */
         bmdma_set_inactive(&bm->dma, false);
     }
 }

 static void bmdma_reset(IDEDMA *dma)
 {
     BMDMAState *bm = DO_UPCAST(BMDMAState, dma, dma);

     trace_bmdma_reset();
     bmdma_cancel(bm);
     bm->cmd = 0;
     bm->status = 0;
     bm->addr = 0;
     bm->cur_addr = 0;
     bm->cur_prd_last = 0;
     bm->cur_prd_addr = 0;
     bm->cur_prd_len = 0;
 }

 static void bmdma_irq(void *opaque, int n, int level)
 {
     BMDMAState *bm = opaque;

     if (!level) {
         /* pass through lower */
         qemu_set_irq(bm->irq, level);
         return;
     }

     bm->status |= BM_STATUS_INT;

     /* trigger the real irq */
     qemu_set_irq(bm->irq, level);
 }

 void bmdma_cmd_writeb(BMDMAState *bm, uint32_t val)
 {
     trace_bmdma_cmd_writeb(val);

     /* Ignore writes to SSBM if it keeps the old value */
     if ((val & BM_CMD_START) != (bm->cmd & BM_CMD_START)) {
         if (!(val & BM_CMD_START)) {
             ide_cancel_dma_sync(idebus_active_if(bm->bus));
             bm->status &= ~BM_STATUS_DMAING;
         } else {
             bm->cur_addr = bm->addr;
             if (!(bm->status & BM_STATUS_DMAING)) {
                 bm->status |= BM_STATUS_DMAING;
                 /* start dma transfer if possible */
                 if (bm->dma_cb)
                     bm->dma_cb(bmdma_active_if(bm), 0);
             }
         }
     }

     bm->cmd = val & 0x09;
 }

 static uint64_t bmdma_addr_read(void *opaque, hwaddr addr,
                                 unsigned width)
 {
     BMDMAState *bm = opaque;
     uint32_t mask = (1ULL << (width * 8)) - 1;
     uint64_t data;

     data = (bm->addr >> (addr * 8)) & mask;
     trace_bmdma_addr_read(data);
     return data;
 }

 static void bmdma_addr_write(void *opaque, hwaddr addr,
                              uint64_t data, unsigned width)
 {
     BMDMAState *bm = opaque;
     int shift = addr * 8;
     uint32_t mask = (1ULL << (width * 8)) - 1;

     trace_bmdma_addr_write(data);
     bm->addr &= ~(mask << shift);
     bm->addr |= ((data & mask) << shift) & ~3;
 }

 MemoryRegionOps bmdma_addr_ioport_ops = {
     .read = bmdma_addr_read,
     .write = bmdma_addr_write,
     .endianness = DEVICE_LITTLE_ENDIAN,
 };

 static bool ide_bmdma_current_needed(void *opaque)
 {
     BMDMAState *bm = opaque;

     return (bm->cur_prd_len != 0);
 }

 static bool ide_bmdma_status_needed(void *opaque)
 {
     BMDMAState *bm = opaque;

     /* Older versions abused some bits in the status register for internal
      * error state. If any of these bits are set, we must add a subsection to
      * transfer the real status register */
     uint8_t abused_bits = BM_MIGRATION_COMPAT_STATUS_BITS;

     return ((bm->status & abused_bits) != 0);
 }

 static int ide_bmdma_pre_save(void *opaque)
 {
     BMDMAState *bm = opaque;
     uint8_t abused_bits = BM_MIGRATION_COMPAT_STATUS_BITS;

     if (!(bm->status & BM_STATUS_DMAING) && bm->dma_cb) {
         bm->bus->error_status =
             ide_dma_cmd_to_retry(bmdma_active_if(bm)->dma_cmd);
     }
     bm->migration_retry_unit = bm->bus->retry_unit;
     bm->migration_retry_sector_num = bm->bus->retry_sector_num;
     bm->migration_retry_nsector = bm->bus->retry_nsector;
     bm->migration_compat_status =
         (bm->status & ~abused_bits) | (bm->bus->error_status & abused_bits);

     return 0;
 }

 /* This function accesses bm->bus->error_status which is loaded only after
  * BMDMA itself. This is why the function is called from ide_pci_post_load
  * instead of being registered with VMState where it would run too early. */
 static int ide_bmdma_post_load(void *opaque, int version_id)
 {
     BMDMAState *bm = opaque;
     uint8_t abused_bits = BM_MIGRATION_COMPAT_STATUS_BITS;

     if (bm->status == 0) {
         bm->status = bm->migration_compat_status & ~abused_bits;
         bm->bus->error_status |= bm->migration_compat_status & abused_bits;
     }
     if (bm->bus->error_status) {
         bm->bus->retry_sector_num = bm->migration_retry_sector_num;
         bm->bus->retry_nsector = bm->migration_retry_nsector;
         bm->bus->retry_unit = bm->migration_retry_unit;
     }

     return 0;
 }

 static const VMStateDescription vmstate_bmdma_current = {
     .name = "ide bmdma_current",
     .version_id = 1,
     .minimum_version_id = 1,
     .needed = ide_bmdma_current_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT32(cur_addr, BMDMAState),
         VMSTATE_UINT32(cur_prd_last, BMDMAState),
         VMSTATE_UINT32(cur_prd_addr, BMDMAState),
         VMSTATE_UINT32(cur_prd_len, BMDMAState),
         VMSTATE_END_OF_LIST()
     }
 };

 static const VMStateDescription vmstate_bmdma_status = {
     .name ="ide bmdma/status",
     .version_id = 1,
     .minimum_version_id = 1,
     .needed = ide_bmdma_status_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT8(status, BMDMAState),
         VMSTATE_END_OF_LIST()
     }
 };

 static const VMStateDescription vmstate_bmdma = {
     .name = "ide bmdma",
     .version_id = 3,
     .minimum_version_id = 0,
     .pre_save  = ide_bmdma_pre_save,
     .fields = (VMStateField[]) {
         VMSTATE_UINT8(cmd, BMDMAState),
         VMSTATE_UINT8(migration_compat_status, BMDMAState),
         VMSTATE_UINT32(addr, BMDMAState),
         VMSTATE_INT64(migration_retry_sector_num, BMDMAState),
         VMSTATE_UINT32(migration_retry_nsector, BMDMAState),
         VMSTATE_UINT8(migration_retry_unit, BMDMAState),
         VMSTATE_END_OF_LIST()
     },
     .subsections = (const VMStateDescription*[]) {
         &vmstate_bmdma_current,
         &vmstate_bmdma_status,
         NULL
     }
 };

 static int ide_pci_post_load(void *opaque, int version_id)
 {
     PCIIDEState *d = opaque;
     int i;

     for(i = 0; i < 2; i++) {
         /* current versions always store 0/1, but older version
            stored bigger values. We only need last bit */
         d->bmdma[i].migration_retry_unit &= 1;
         ide_bmdma_post_load(&d->bmdma[i], -1);
     }

     return 0;
 }

 const VMStateDescription vmstate_ide_pci = {
     .name = "ide",
     .version_id = 3,
     .minimum_version_id = 0,
     .post_load = ide_pci_post_load,
     .fields = (VMStateField[]) {
         VMSTATE_PCI_DEVICE(parent_obj, PCIIDEState),
         VMSTATE_STRUCT_ARRAY(bmdma, PCIIDEState, 2, 0,
                              vmstate_bmdma, BMDMAState),
         VMSTATE_IDE_BUS_ARRAY(bus, PCIIDEState, 2),
         VMSTATE_IDE_DRIVES(bus[0].ifs, PCIIDEState),
         VMSTATE_IDE_DRIVES(bus[1].ifs, PCIIDEState),
         VMSTATE_END_OF_LIST()
     }
 };

 void pci_ide_create_devs(PCIDevice *dev, DriveInfo **hd_table)
 {
     PCIIDEState *d = PCI_IDE(dev);
     static const int bus[4]  = { 0, 0, 1, 1 };
     static const int unit[4] = { 0, 1, 0, 1 };
     int i;

     for (i = 0; i < 4; i++) {
         if (hd_table[i] == NULL)
             continue;
         ide_create_drive(d->bus+bus[i], unit[i], hd_table[i]);
     }
 }

 static const struct IDEDMAOps bmdma_ops = {
     .start_dma = bmdma_start_dma,
     .prepare_buf = bmdma_prepare_buf,
     .rw_buf = bmdma_rw_buf,
     .restart_dma = bmdma_restart_dma,
     .set_inactive = bmdma_set_inactive,
     .reset = bmdma_reset,
 };

 void bmdma_init(IDEBus *bus, BMDMAState *bm, PCIIDEState *d)
 {
     if (bus->dma == &bm->dma) {
         return;
     }

     bm->dma.ops = &bmdma_ops;
     bus->dma = &bm->dma;
     bm->irq = bus->irq;
     bus->irq = qemu_allocate_irq(bmdma_irq, bm, 0);
     bm->pci_dev = d;
 }

 static const TypeInfo pci_ide_type_info = {
     .name = TYPE_PCI_IDE,
     .parent = TYPE_PCI_DEVICE,
     .instance_size = sizeof(PCIIDEState),
     .abstract = true,
     .interfaces = (InterfaceInfo[]) {
         { INTERFACE_CONVENTIONAL_PCI_DEVICE },
         { },
     },
 };

 static void pci_ide_register_types(void)
 {
     type_register_static(&pci_ide_type_info);
 }

 type_init(pci_ide_register_types)
	/*
	* QEMU IDE Emulation: PCI Bus support.
	*
	* Copyright (c) 2003 Fabrice Bellard
	* Copyright (c) 2006 Openedhand Ltd.
	*
	* 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 "qemu/osdep.h"
	#include "hw/hw.h"
	#include "hw/pci/pci.h"
	#include "hw/isa/isa.h"
	#include "sysemu/dma.h"
	#include "qemu/error-report.h"
	#include "hw/ide/pci.h"
	#include "trace.h"

	#define BMDMA_PAGE_SIZE 4096

	#define BM_MIGRATION_COMPAT_STATUS_BITS \
	(IDE_RETRY_DMA \| IDE_RETRY_PIO \| \
	IDE_RETRY_READ \| IDE_RETRY_FLUSH)

	static void bmdma_start_dma(IDEDMA dma, IDEState s,
	BlockCompletionFunc *dma_cb)
	{
	BMDMAState *bm = DO_UPCAST(BMDMAState, dma, dma);

	bm->dma_cb = dma_cb;
	bm->cur_prd_last = 0;
	bm->cur_prd_addr = 0;
	bm->cur_prd_len = 0;

	if (bm->status & BM_STATUS_DMAING) {
	bm->dma_cb(bmdma_active_if(bm), 0);
	}
	}

	/**
	* Prepare an sglist based on available PRDs.
	* @limit: How many bytes to prepare total.
	*
	* Returns the number of bytes prepared, -1 on error.
	* IDEState.io_buffer_size will contain the number of bytes described
	* by the PRDs, whether or not we added them to the sglist.
	*/
	static int32_t bmdma_prepare_buf(IDEDMA *dma, int32_t limit)
	{
	BMDMAState *bm = DO_UPCAST(BMDMAState, dma, dma);
	IDEState *s = bmdma_active_if(bm);
	PCIDevice *pci_dev = PCI_DEVICE(bm->pci_dev);
	struct {
	uint32_t addr;
	uint32_t size;
	} prd;
	int l, len;

	pci_dma_sglist_init(&s->sg, pci_dev,
	s->nsector / (BMDMA_PAGE_SIZE / 512) + 1);
	s->io_buffer_size = 0;
	for(;;) {
	if (bm->cur_prd_len == 0) {
	/* end of table (with a fail safe of one page) */
	if (bm->cur_prd_last \|\|
	(bm->cur_addr - bm->addr) >= BMDMA_PAGE_SIZE) {
	return s->sg.size;
	}
	pci_dma_read(pci_dev, bm->cur_addr, &prd, 8);
	bm->cur_addr += 8;
	prd.addr = le32_to_cpu(prd.addr);
	prd.size = le32_to_cpu(prd.size);
	len = prd.size & 0xfffe;
	if (len == 0)
	len = 0x10000;
	bm->cur_prd_len = len;
	bm->cur_prd_addr = prd.addr;
	bm->cur_prd_last = (prd.size & 0x80000000);
	}
	l = bm->cur_prd_len;
	if (l > 0) {
	uint64_t sg_len;

	/* Don't add extra bytes to the SGList; consume any remaining
	* PRDs from the guest, but ignore them. */
	sg_len = MIN(limit - s->sg.size, bm->cur_prd_len);
	if (sg_len) {
	qemu_sglist_add(&s->sg, bm->cur_prd_addr, sg_len);
	}

	bm->cur_prd_addr += l;
	bm->cur_prd_len -= l;
	s->io_buffer_size += l;
	}
	}

	qemu_sglist_destroy(&s->sg);
	s->io_buffer_size = 0;
	return -1;
	}

	/* return 0 if buffer completed */
	static int bmdma_rw_buf(IDEDMA *dma, int is_write)
	{
	BMDMAState *bm = DO_UPCAST(BMDMAState, dma, dma);
	IDEState *s = bmdma_active_if(bm);
	PCIDevice *pci_dev = PCI_DEVICE(bm->pci_dev);
	struct {
	uint32_t addr;
	uint32_t size;
	} prd;
	int l, len;

	for(;;) {
	l = s->io_buffer_size - s->io_buffer_index;
	if (l <= 0)
	break;
	if (bm->cur_prd_len == 0) {
	/* end of table (with a fail safe of one page) */
	if (bm->cur_prd_last \|\|
	(bm->cur_addr - bm->addr) >= BMDMA_PAGE_SIZE)
	return 0;
	pci_dma_read(pci_dev, bm->cur_addr, &prd, 8);
	bm->cur_addr += 8;
	prd.addr = le32_to_cpu(prd.addr);
	prd.size = le32_to_cpu(prd.size);
	len = prd.size & 0xfffe;
	if (len == 0)
	len = 0x10000;
	bm->cur_prd_len = len;
	bm->cur_prd_addr = prd.addr;
	bm->cur_prd_last = (prd.size & 0x80000000);
	}
	if (l > bm->cur_prd_len)
	l = bm->cur_prd_len;
	if (l > 0) {
	if (is_write) {
	pci_dma_write(pci_dev, bm->cur_prd_addr,
	s->io_buffer + s->io_buffer_index, l);
	} else {
	pci_dma_read(pci_dev, bm->cur_prd_addr,
	s->io_buffer + s->io_buffer_index, l);
	}
	bm->cur_prd_addr += l;
	bm->cur_prd_len -= l;
	s->io_buffer_index += l;
	}
	}
	return 1;
	}

	static void bmdma_set_inactive(IDEDMA *dma, bool more)
	{
	BMDMAState *bm = DO_UPCAST(BMDMAState, dma, dma);

	bm->dma_cb = NULL;
	if (more) {
	bm->status \|= BM_STATUS_DMAING;
	} else {
	bm->status &= ~BM_STATUS_DMAING;
	}
	}

	static void bmdma_restart_dma(IDEDMA *dma)
	{
	BMDMAState *bm = DO_UPCAST(BMDMAState, dma, dma);

	bm->cur_addr = bm->addr;
	}

	static void bmdma_cancel(BMDMAState *bm)
	{
	if (bm->status & BM_STATUS_DMAING) {
	/* cancel DMA request */
	bmdma_set_inactive(&bm->dma, false);
	}
	}

	static void bmdma_reset(IDEDMA *dma)
	{
	BMDMAState *bm = DO_UPCAST(BMDMAState, dma, dma);

	trace_bmdma_reset();
	bmdma_cancel(bm);
	bm->cmd = 0;
	bm->status = 0;
	bm->addr = 0;
	bm->cur_addr = 0;
	bm->cur_prd_last = 0;
	bm->cur_prd_addr = 0;
	bm->cur_prd_len = 0;
	}

	static void bmdma_irq(void *opaque, int n, int level)
	{
	BMDMAState *bm = opaque;

	if (!level) {
	/* pass through lower */
	qemu_set_irq(bm->irq, level);
	return;
	}

	bm->status \|= BM_STATUS_INT;

	/* trigger the real irq */
	qemu_set_irq(bm->irq, level);
	}

	void bmdma_cmd_writeb(BMDMAState *bm, uint32_t val)
	{
	trace_bmdma_cmd_writeb(val);

	/* Ignore writes to SSBM if it keeps the old value */
	if ((val & BM_CMD_START) != (bm->cmd & BM_CMD_START)) {
	if (!(val & BM_CMD_START)) {
	ide_cancel_dma_sync(idebus_active_if(bm->bus));
	bm->status &= ~BM_STATUS_DMAING;
	} else {
	bm->cur_addr = bm->addr;
	if (!(bm->status & BM_STATUS_DMAING)) {
	bm->status \|= BM_STATUS_DMAING;
	/* start dma transfer if possible */
	if (bm->dma_cb)
	bm->dma_cb(bmdma_active_if(bm), 0);
	}
	}
	}

	bm->cmd = val & 0x09;
	}

	static uint64_t bmdma_addr_read(void *opaque, hwaddr addr,
	unsigned width)
	{
	BMDMAState *bm = opaque;
	uint32_t mask = (1ULL << (width * 8)) - 1;
	uint64_t data;

	data = (bm->addr >> (addr * 8)) & mask;
	trace_bmdma_addr_read(data);
	return data;
	}

	static void bmdma_addr_write(void *opaque, hwaddr addr,
	uint64_t data, unsigned width)
	{
	BMDMAState *bm = opaque;
	int shift = addr * 8;
	uint32_t mask = (1ULL << (width * 8)) - 1;

	trace_bmdma_addr_write(data);
	bm->addr &= ~(mask << shift);
	bm->addr \|= ((data & mask) << shift) & ~3;
	}

	MemoryRegionOps bmdma_addr_ioport_ops = {
	.read = bmdma_addr_read,
	.write = bmdma_addr_write,
	.endianness = DEVICE_LITTLE_ENDIAN,
	};

	static bool ide_bmdma_current_needed(void *opaque)
	{
	BMDMAState *bm = opaque;

	return (bm->cur_prd_len != 0);
	}

	static bool ide_bmdma_status_needed(void *opaque)
	{
	BMDMAState *bm = opaque;

	/* Older versions abused some bits in the status register for internal
	* error state. If any of these bits are set, we must add a subsection to
	* transfer the real status register */
	uint8_t abused_bits = BM_MIGRATION_COMPAT_STATUS_BITS;

	return ((bm->status & abused_bits) != 0);
	}

	static int ide_bmdma_pre_save(void *opaque)
	{
	BMDMAState *bm = opaque;
	uint8_t abused_bits = BM_MIGRATION_COMPAT_STATUS_BITS;

	if (!(bm->status & BM_STATUS_DMAING) && bm->dma_cb) {
	bm->bus->error_status =
	ide_dma_cmd_to_retry(bmdma_active_if(bm)->dma_cmd);
	}
	bm->migration_retry_unit = bm->bus->retry_unit;
	bm->migration_retry_sector_num = bm->bus->retry_sector_num;
	bm->migration_retry_nsector = bm->bus->retry_nsector;
	bm->migration_compat_status =
	(bm->status & ~abused_bits) \| (bm->bus->error_status & abused_bits);

	return 0;
	}

	/* This function accesses bm->bus->error_status which is loaded only after
	* BMDMA itself. This is why the function is called from ide_pci_post_load
	* instead of being registered with VMState where it would run too early. */
	static int ide_bmdma_post_load(void *opaque, int version_id)
	{
	BMDMAState *bm = opaque;
	uint8_t abused_bits = BM_MIGRATION_COMPAT_STATUS_BITS;

	if (bm->status == 0) {
	bm->status = bm->migration_compat_status & ~abused_bits;
	bm->bus->error_status \|= bm->migration_compat_status & abused_bits;
	}
	if (bm->bus->error_status) {
	bm->bus->retry_sector_num = bm->migration_retry_sector_num;
	bm->bus->retry_nsector = bm->migration_retry_nsector;
	bm->bus->retry_unit = bm->migration_retry_unit;
	}

	return 0;
	}

	static const VMStateDescription vmstate_bmdma_current = {
	.name = "ide bmdma_current",
	.version_id = 1,
	.minimum_version_id = 1,
	.needed = ide_bmdma_current_needed,
	.fields = (VMStateField[]) {
	VMSTATE_UINT32(cur_addr, BMDMAState),
	VMSTATE_UINT32(cur_prd_last, BMDMAState),
	VMSTATE_UINT32(cur_prd_addr, BMDMAState),
	VMSTATE_UINT32(cur_prd_len, BMDMAState),
	VMSTATE_END_OF_LIST()
	}
	};

	static const VMStateDescription vmstate_bmdma_status = {
	.name ="ide bmdma/status",
	.version_id = 1,
	.minimum_version_id = 1,
	.needed = ide_bmdma_status_needed,
	.fields = (VMStateField[]) {
	VMSTATE_UINT8(status, BMDMAState),
	VMSTATE_END_OF_LIST()
	}
	};

	static const VMStateDescription vmstate_bmdma = {
	.name = "ide bmdma",
	.version_id = 3,
	.minimum_version_id = 0,
	.pre_save = ide_bmdma_pre_save,
	.fields = (VMStateField[]) {
	VMSTATE_UINT8(cmd, BMDMAState),
	VMSTATE_UINT8(migration_compat_status, BMDMAState),
	VMSTATE_UINT32(addr, BMDMAState),
	VMSTATE_INT64(migration_retry_sector_num, BMDMAState),
	VMSTATE_UINT32(migration_retry_nsector, BMDMAState),
	VMSTATE_UINT8(migration_retry_unit, BMDMAState),
	VMSTATE_END_OF_LIST()
	},
	.subsections = (const VMStateDescription*[]) {
	&vmstate_bmdma_current,
	&vmstate_bmdma_status,
	NULL
	}
	};

	static int ide_pci_post_load(void *opaque, int version_id)
	{
	PCIIDEState *d = opaque;
	int i;

	for(i = 0; i < 2; i++) {
	/* current versions always store 0/1, but older version
	stored bigger values. We only need last bit */
	d->bmdma[i].migration_retry_unit &= 1;
	ide_bmdma_post_load(&d->bmdma[i], -1);
	}

	return 0;
	}

	const VMStateDescription vmstate_ide_pci = {
	.name = "ide",
	.version_id = 3,
	.minimum_version_id = 0,
	.post_load = ide_pci_post_load,
	.fields = (VMStateField[]) {
	VMSTATE_PCI_DEVICE(parent_obj, PCIIDEState),
	VMSTATE_STRUCT_ARRAY(bmdma, PCIIDEState, 2, 0,
	vmstate_bmdma, BMDMAState),
	VMSTATE_IDE_BUS_ARRAY(bus, PCIIDEState, 2),
	VMSTATE_IDE_DRIVES(bus[0].ifs, PCIIDEState),
	VMSTATE_IDE_DRIVES(bus[1].ifs, PCIIDEState),
	VMSTATE_END_OF_LIST()
	}
	};

	void pci_ide_create_devs(PCIDevice dev, DriveInfo *hd_table)
	{
	PCIIDEState *d = PCI_IDE(dev);
	static const int bus[4] = { 0, 0, 1, 1 };
	static const int unit[4] = { 0, 1, 0, 1 };
	int i;

	for (i = 0; i < 4; i++) {
	if (hd_table[i] == NULL)
	continue;
	ide_create_drive(d->bus+bus[i], unit[i], hd_table[i]);
	}
	}

	static const struct IDEDMAOps bmdma_ops = {
	.start_dma = bmdma_start_dma,
	.prepare_buf = bmdma_prepare_buf,
	.rw_buf = bmdma_rw_buf,
	.restart_dma = bmdma_restart_dma,
	.set_inactive = bmdma_set_inactive,
	.reset = bmdma_reset,
	};

	void bmdma_init(IDEBus bus, BMDMAState bm, PCIIDEState *d)
	{
	if (bus->dma == &bm->dma) {
	return;
	}

	bm->dma.ops = &bmdma_ops;
	bus->dma = &bm->dma;
	bm->irq = bus->irq;
	bus->irq = qemu_allocate_irq(bmdma_irq, bm, 0);
	bm->pci_dev = d;
	}

	static const TypeInfo pci_ide_type_info = {
	.name = TYPE_PCI_IDE,
	.parent = TYPE_PCI_DEVICE,
	.instance_size = sizeof(PCIIDEState),
	.abstract = true,
	.interfaces = (InterfaceInfo[]) {
	{ INTERFACE_CONVENTIONAL_PCI_DEVICE },
	{ },
	},
	};

	static void pci_ide_register_types(void)
	{
	type_register_static(&pci_ide_type_info);
	}

	type_init(pci_ide_register_types)