ide.c

xen虚拟机源代码安装包

        n = IDE_DMA_BUF_SECTORS;
    s->io_buffer_index = 0;
    s->io_buffer_size = n * 512;

    if (dma_buf_rw(bm, 0) == 0)
        goto eot;
#ifdef DEBUG_AIO
    printf("aio_write: sector_num=%lld n=%d\n", sector_num, n);
#endif
    bm->aiocb = bdrv_aio_write(s->bs, sector_num, s->io_buffer, n,
                               ide_write_dma_cb, bm);
    ide_dma_submit_check(s, ide_write_dma_cb, bm);
}

static void ide_sector_write_dma(IDEState *s)
{
    s->status = READY_STAT | SEEK_STAT | DRQ_STAT | BUSY_STAT;
    s->io_buffer_index = 0;
    s->io_buffer_size = 0;
    ide_dma_start(s, ide_write_dma_cb);
}

static void ide_device_utterly_broken(IDEState *s) {
    s->status |= BUSY_STAT;
    s->bs = NULL;
    /* This prevents all future commands from working.  All of the
     * asynchronous callbacks (and ide_set_irq, as a safety measure)
     * check to see whether this has happened and bail if so.
     */
}

static void ide_flush_cb(void *opaque, int ret)
{
    IDEState *s = opaque;

    if (!s->bs) return; /* yikes */

    if (ret) {
        /* We are completely doomed.  The IDE spec does not permit us
	 * to return an error from a flush except via a protocol which
	 * requires us to say where the error is and which
	 * contemplates the guest repeating the flush attempt to
	 * attempt flush the remaining data.  We can't support that
	 * because f(data)sync (which is what the block drivers use
	 * eventually) doesn't report the necessary information or
	 * give us the necessary control.  So we make the disk vanish.
	 */
	ide_device_utterly_broken(s);
	return;
    }
    else
        s->status = READY_STAT;
    ide_set_irq(s);
}

static void ide_atapi_cmd_ok(IDEState *s)
{
    s->error = 0;
    s->status = READY_STAT;
    s->nsector = (s->nsector & ~7) | ATAPI_INT_REASON_IO | ATAPI_INT_REASON_CD;
    ide_set_irq(s);
}

static void ide_atapi_cmd_error(IDEState *s, int sense_key, int asc)
{
#ifdef DEBUG_IDE_ATAPI
    printf("atapi_cmd_error: sense=0x%x asc=0x%x\n", sense_key, asc);
#endif
    s->error = sense_key << 4;
    s->status = READY_STAT | ERR_STAT;
    s->nsector = (s->nsector & ~7) | ATAPI_INT_REASON_IO | ATAPI_INT_REASON_CD;
    s->sense_key = sense_key;
    s->asc = asc;
    ide_set_irq(s);
}

static inline void cpu_to_ube16(uint8_t *buf, int val)
{
    buf[0] = val >> 8;
    buf[1] = val;
}

static inline void cpu_to_ube32(uint8_t *buf, unsigned int val)
{
    buf[0] = val >> 24;
    buf[1] = val >> 16;
    buf[2] = val >> 8;
    buf[3] = val;
}

static inline int ube16_to_cpu(const uint8_t *buf)
{
    return (buf[0] << 8) | buf[1];
}

static inline int ube32_to_cpu(const uint8_t *buf)
{
    return (buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | buf[3];
}

static void lba_to_msf(uint8_t *buf, int lba)
{
    lba += 150;
    buf[0] = (lba / 75) / 60;
    buf[1] = (lba / 75) % 60;
    buf[2] = lba % 75;
}

static void cd_data_to_raw(uint8_t *buf, int lba)
{
    /* sync bytes */
    buf[0] = 0x00;
    memset(buf + 1, 0xff, 10);
    buf[11] = 0x00;
    buf += 12;
    /* MSF */
    lba_to_msf(buf, lba);
    buf[3] = 0x01; /* mode 1 data */
    buf += 4;
    /* data */
    buf += 2048;
    /* XXX: ECC not computed */
    memset(buf, 0, 288);
}

static int cd_read_sector(BlockDriverState *bs, int lba, uint8_t *buf,
                           int sector_size)
{
    int ret;

    switch(sector_size) {
    case 2048:
        ret = bdrv_read(bs, (int64_t)lba << 2, buf, 4);
        break;
    case 2352:
        ret = bdrv_read(bs, (int64_t)lba << 2, buf + 16, 4);
        if (ret < 0)
            return ret;
        cd_data_to_raw(buf, lba);
        break;
    default:
        ret = -EIO;
        break;
    }
    return ret;
}

static void ide_atapi_io_error(IDEState *s, int ret)
{
    /* XXX: handle more errors */
    if (ret == -ENOMEDIUM) {
        ide_atapi_cmd_error(s, SENSE_NOT_READY,
                            ASC_MEDIUM_NOT_PRESENT);
    } else {
        ide_atapi_cmd_error(s, SENSE_ILLEGAL_REQUEST,
                            ASC_LOGICAL_BLOCK_OOR);
    }
}

/* The whole ATAPI transfer logic is handled in this function */
static void ide_atapi_cmd_reply_end(IDEState *s)
{
    int byte_count_limit, size, ret;
#ifdef DEBUG_IDE_ATAPI
    printf("reply: tx_size=%d elem_tx_size=%d index=%d\n",
           s->packet_transfer_size,
           s->elementary_transfer_size,
           s->io_buffer_index);
#endif
    if (s->packet_transfer_size <= 0) {
        /* end of transfer */
        ide_transfer_stop(s);
        s->status = READY_STAT;
        s->nsector = (s->nsector & ~7) | ATAPI_INT_REASON_IO | ATAPI_INT_REASON_CD;
        ide_set_irq(s);
#ifdef DEBUG_IDE_ATAPI
        printf("status=0x%x\n", s->status);
#endif
    } else {
        /* see if a new sector must be read */
        if (s->lba != -1 && s->io_buffer_index >= s->cd_sector_size) {
            ret = cd_read_sector(s->bs, s->lba, s->io_buffer, s->cd_sector_size);
            if (ret < 0) {
                ide_transfer_stop(s);
                ide_atapi_io_error(s, ret);
                return;
            }
            s->lba++;
            s->io_buffer_index = 0;
        }
        if (s->elementary_transfer_size > 0) {
            /* there are some data left to transmit in this elementary
               transfer */
            size = s->cd_sector_size - s->io_buffer_index;
            if (size > s->elementary_transfer_size)
                size = s->elementary_transfer_size;
            ide_transfer_start(s, s->io_buffer + s->io_buffer_index,
                               size, ide_atapi_cmd_reply_end);
            s->packet_transfer_size -= size;
            s->elementary_transfer_size -= size;
            s->io_buffer_index += size;
        } else {
            /* a new transfer is needed */
            s->nsector = (s->nsector & ~7) | ATAPI_INT_REASON_IO;
            byte_count_limit = s->lcyl | (s->hcyl << 8);
#ifdef DEBUG_IDE_ATAPI
            printf("byte_count_limit=%d\n", byte_count_limit);
#endif
            if (byte_count_limit == 0xffff)
                byte_count_limit--;
            size = s->packet_transfer_size;
            if (size > byte_count_limit) {
                /* byte count limit must be even if this case */
                if (byte_count_limit & 1)
                    byte_count_limit--;
                size = byte_count_limit;
            }
            s->lcyl = size;
            s->hcyl = size >> 8;
            s->elementary_transfer_size = size;
            /* we cannot transmit more than one sector at a time */
            if (s->lba != -1) {
                if (size > (s->cd_sector_size - s->io_buffer_index))
                    size = (s->cd_sector_size - s->io_buffer_index);
            }
            ide_transfer_start(s, s->io_buffer + s->io_buffer_index,
                               size, ide_atapi_cmd_reply_end);
            s->packet_transfer_size -= size;
            s->elementary_transfer_size -= size;
            s->io_buffer_index += size;
            ide_set_irq(s);
#ifdef DEBUG_IDE_ATAPI
            printf("status=0x%x\n", s->status);
#endif
        }
    }
}

/* send a reply of 'size' bytes in s->io_buffer to an ATAPI command */
static void ide_atapi_cmd_reply(IDEState *s, int size, int max_size)
{
    if (size > max_size)
        size = max_size;
    s->lba = -1; /* no sector read */
    s->packet_transfer_size = size;
    s->io_buffer_size = size;    /* dma: send the reply data as one chunk */
    s->elementary_transfer_size = 0;
    s->io_buffer_index = 0;

    if (s->atapi_dma) {
    	s->status = READY_STAT | DRQ_STAT;
	ide_dma_start(s, ide_atapi_cmd_read_dma_cb);
    } else {
    	s->status = READY_STAT;
    	ide_atapi_cmd_reply_end(s);
    }
}

/* start a CD-CDROM read command */
static void ide_atapi_cmd_read_pio(IDEState *s, int lba, int nb_sectors,
                                   int sector_size)
{
    s->lba = lba;
    s->packet_transfer_size = nb_sectors * sector_size;
    s->elementary_transfer_size = 0;
    s->io_buffer_index = sector_size;
    s->cd_sector_size = sector_size;

    s->status = READY_STAT;
    ide_atapi_cmd_reply_end(s);
}

/* ATAPI DMA support */

/* XXX: handle read errors */
static void ide_atapi_cmd_read_dma_cb(void *opaque, int ret)
{
    BMDMAState *bm = opaque;
    IDEState *s = bm->ide_if;
    int data_offset, n;

    if (!s->bs) return; /* yikes */

    if (!s->bs) return; /* yikes */

    if (ret < 0) {
        ide_atapi_io_error(s, ret);
        goto eot;
    }

    if (s->io_buffer_size > 0) {
	/*
	 * For a cdrom read sector command (s->lba != -1),
	 * adjust the lba for the next s->io_buffer_size chunk
	 * and dma the current chunk.
	 * For a command != read (s->lba == -1), just transfer
	 * the reply data.
	 */
	if (s->lba != -1) {
	    if (s->cd_sector_size == 2352) {
		n = 1;
		cd_data_to_raw(s->io_buffer, s->lba);
	    } else {
		n = s->io_buffer_size >> 11;
	    }
	    s->lba += n;
	}
        s->packet_transfer_size -= s->io_buffer_size;
        if (dma_buf_rw(bm, 1) == 0)
            goto eot;
    }

    if (s->packet_transfer_size <= 0) {
        s->status = READY_STAT;
        s->nsector = (s->nsector & ~7) | ATAPI_INT_REASON_IO | ATAPI_INT_REASON_CD;
        ide_set_irq(s);
    eot:
	ide_dma_eot(bm);
        return;
    }

    s->io_buffer_index = 0;
    if (s->cd_sector_size == 2352) {
        n = 1;
        s->io_buffer_size = s->cd_sector_size;
        data_offset = 16;
    } else {
        n = s->packet_transfer_size >> 11;
        if (n > (IDE_DMA_BUF_SECTORS / 4))
            n = (IDE_DMA_BUF_SECTORS / 4);
        s->io_buffer_size = n * 2048;
        data_offset = 0;
    }
#ifdef DEBUG_AIO
    printf("aio_read_cd: lba=%u n=%d\n", s->lba, n);
#endif
    bm->aiocb = bdrv_aio_read(s->bs, (int64_t)s->lba << 2,
                              s->io_buffer + data_offset, n * 4,
                              ide_atapi_cmd_read_dma_cb, bm);
    if (!bm->aiocb) {
        /* Note: media not present is the most likely case */
        ide_atapi_cmd_error(s, SENSE_NOT_READY,
                            ASC_MEDIUM_NOT_PRESENT);
        goto eot;
    }
}

/* start a CD-CDROM read command with DMA */
/* XXX: test if DMA is available */
static void ide_atapi_cmd_read_dma(IDEState *s, int lba, int nb_sectors,
                                   int sector_size)
{
    s->lba = lba;
    s->packet_transfer_size = nb_sectors * sector_size;
    s->io_buffer_index = 0;
    s->io_buffer_size = 0;
    s->cd_sector_size = sector_size;

    /* XXX: check if BUSY_STAT should be set */
    s->status = READY_STAT | DRQ_STAT | BUSY_STAT;
    ide_dma_start(s, ide_atapi_cmd_read_dma_cb);
}

static void ide_atapi_cmd_read(IDEState *s, int lba, int nb_sectors,
                               int sector_size)
{
#ifdef DEBUG_IDE_ATAPI
    printf("read %s: LBA=%d nb_sectors=%d\n", s->atapi_dma ? "dma" : "pio",
	lba, nb_sectors);
#endif
    if (s->atapi_dma) {
        ide_atapi_cmd_read_dma(s, lba, nb_sectors, sector_size);
    } else {
        ide_atapi_cmd_read_pio(s, lba, nb_sectors, sector_size);
    }
}

static inline uint8_t ide_atapi_set_profile(uint8_t *buf, uint8_t *index,
                                            uint16_t profile)
{
    uint8_t *buf_profile = buf + 12; /* start of profiles */

    buf_profile += ((*index) * 4); /* start of indexed profile */
    cpu_to_ube16 (buf_profile, profile);
    buf_profile[2] = ((buf_profile[0] == buf[6]) && (buf_profile[1] == buf[7]));

    /* each profile adds 4 bytes to the response */
    (*index)++;
    buf[11] += 4; /* Additional Length */

    return 4;
}

static void ide_atapi_cmd(IDEState *s)
{
    const uint8_t *packet;
    uint8_t *buf;
    int max_len;

    packet = s->io_buffer;
    buf = s->io_buffer;
#ifdef DEBUG_IDE_ATAPI
    {
        int i;
        printf("ATAPI limit=0x%x packet:", s->lcyl | (s->hcyl << 8));
        for(i = 0; i < ATAPI_PACKET_SIZE; i++) {
            printf(" %02x", packet[i]);
        }
        printf("\n");
    }
#endif
    switch(s->io_buffer[0]) {
    case GPCMD_TEST_UNIT_READY:
        if (bdrv_is_inserted(s->bs)) {
            if (s->is_cdrom && s->sense_key == SENSE_NOT_READY) {
                ide_atapi_cmd_error(s, SENSE_UNIT_ATTENTION,
                                    ASC_MEDIUM_MAY_HAVE_CHANGED);
                break;
            }