Re: [Qemu-devel] [STABLE][PATCH 2/4] Move block dma helpers aiocb to store dma state

[Mark McLoughlin <markmc@redhat.com>]

On Thu, 2009-05-14 at 11:56 +0100, Mark McLoughlin wrote:
> From: Avi Kivity <avi@redhat.com>
> 
> Use the dedicated dma aiocb to store intermediate state for dma block
> transactions.
> 
> Signed-off-by: Avi Kivity <avi@redhat.com>

Signed-off-by: Mark McLoughlin <markmc@redhat.com>

> ---
>  dma-helpers.c |   37 ++++++++++++++++++++-----------------
>  1 files changed, 20 insertions(+), 17 deletions(-)
> 
> diff --git a/dma-helpers.c b/dma-helpers.c
> index 19fa4f0..96a120c 100644
> --- a/dma-helpers.c
> +++ b/dma-helpers.c
> @@ -39,6 +39,7 @@ void qemu_sglist_destroy(QEMUSGList *qsg)
>  }
>  
>  typedef struct {
> +    BlockDriverAIOCB common;
>      BlockDriverState *bs;
>      BlockDriverAIOCB *acb;
>      QEMUSGList *sg;
> @@ -48,13 +49,13 @@ typedef struct {
>      target_phys_addr_t sg_cur_byte;
>      QEMUIOVector iov;
>      QEMUBH *bh;
> -} DMABlockState;
> +} DMAAIOCB;
>  
>  static void dma_bdrv_cb(void *opaque, int ret);
>  
>  static void reschedule_dma(void *opaque)
>  {
> -    DMABlockState *dbs = (DMABlockState *)opaque;
> +    DMAAIOCB *dbs = (DMAAIOCB *)opaque;
>  
>      qemu_bh_delete(dbs->bh);
>      dbs->bh = NULL;
> @@ -63,7 +64,7 @@ static void reschedule_dma(void *opaque)
>  
>  static void continue_after_map_failure(void *opaque)
>  {
> -    DMABlockState *dbs = (DMABlockState *)opaque;
> +    DMAAIOCB *dbs = (DMAAIOCB *)opaque;
>  
>      dbs->bh = qemu_bh_new(reschedule_dma, dbs);
>      qemu_bh_schedule(dbs->bh);
> @@ -71,11 +72,12 @@ static void continue_after_map_failure(void *opaque)
>  
>  static void dma_bdrv_cb(void *opaque, int ret)
>  {
> -    DMABlockState *dbs = (DMABlockState *)opaque;
> +    DMAAIOCB *dbs = (DMAAIOCB *)opaque;
>      target_phys_addr_t cur_addr, cur_len;
>      void *mem;
>      int i;
>  
> +    dbs->acb = NULL;
>      dbs->sector_num += dbs->iov.size / 512;
>      for (i = 0; i < dbs->iov.niov; ++i) {
>          cpu_physical_memory_unmap(dbs->iov.iov[i].iov_base,
> @@ -85,10 +87,9 @@ static void dma_bdrv_cb(void *opaque, int ret)
>      qemu_iovec_reset(&dbs->iov);
>  
>      if (dbs->sg_cur_index == dbs->sg->nsg || ret < 0) {
> -        dbs->acb->cb(dbs->acb->opaque, ret);
> +        dbs->common.cb(dbs->common.opaque, ret);
>          qemu_iovec_destroy(&dbs->iov);
> -        qemu_aio_release(dbs->acb);
> -        qemu_free(dbs);
> +        qemu_aio_release(dbs);
>          return;
>      }
>  
> @@ -112,11 +113,11 @@ static void dma_bdrv_cb(void *opaque, int ret)
>      }
>  
>      if (dbs->is_write) {
> -        bdrv_aio_writev(dbs->bs, dbs->sector_num, &dbs->iov,
> -                        dbs->iov.size / 512, dma_bdrv_cb, dbs);
> +        dbs->acb = bdrv_aio_writev(dbs->bs, dbs->sector_num, &dbs->iov,
> +                                   dbs->iov.size / 512, dma_bdrv_cb, dbs);
>      } else {
> -        bdrv_aio_readv(dbs->bs, dbs->sector_num, &dbs->iov,
> -                       dbs->iov.size / 512, dma_bdrv_cb, dbs);
> +        dbs->acb = bdrv_aio_readv(dbs->bs, dbs->sector_num, &dbs->iov,
> +                                  dbs->iov.size / 512, dma_bdrv_cb, dbs);
>      }
>  }
>  
> @@ -125,10 +126,10 @@ static BlockDriverAIOCB *dma_bdrv_io(
>      BlockDriverCompletionFunc *cb, void *opaque,
>      int is_write)
>  {
> -    DMABlockState *dbs = qemu_malloc(sizeof(*dbs));
> +    DMAAIOCB *dbs =  qemu_aio_get_pool(&dma_aio_pool, bs, cb, opaque);
>  
> +    dbs->acb = NULL;
>      dbs->bs = bs;
> -    dbs->acb = qemu_aio_get_pool(&dma_aio_pool, bs, cb, opaque);
>      dbs->sg = sg;
>      dbs->sector_num = sector_num;
>      dbs->sg_cur_index = 0;
> @@ -137,7 +138,7 @@ static BlockDriverAIOCB *dma_bdrv_io(
>      dbs->bh = NULL;
>      qemu_iovec_init(&dbs->iov, sg->nsg);
>      dma_bdrv_cb(dbs, 0);
> -    return dbs->acb;
> +    return &dbs->common;
>  }
>  
> 
> @@ -157,12 +158,14 @@ BlockDriverAIOCB *dma_bdrv_write(BlockDriverState *bs,
>  
>  static void dma_aio_cancel(BlockDriverAIOCB *acb)
>  {
> -    DMABlockState *dbs = (DMABlockState *)acb->opaque;
> +    DMAAIOCB *dbs = container_of(acb, DMAAIOCB, common);
>  
> -    bdrv_aio_cancel(dbs->acb);
> +    if (dbs->acb) {
> +        bdrv_aio_cancel(dbs->acb);
> +    }
>  }
>  
>  void dma_helper_init(void)
>  {
> -    aio_pool_init(&dma_aio_pool, sizeof(BlockDriverAIOCB), dma_aio_cancel);
> +    aio_pool_init(&dma_aio_pool, sizeof(DMAAIOCB), dma_aio_cancel);
>  }