Re: [Qemu-devel] [PATCH 01/13] Better support for dma_addr_t variables

[Anthony Liguori <anthony@codemonkey.ws>]

On 06/19/2012 01:39 AM, Benjamin Herrenschmidt wrote:
> From: David Gibson<david@gibson.dropbear.id.au>
>
> A while back, we introduced the dma_addr_t type, which is supposed to
> be used for bus visible memory addresses.  At present, this is an
> alias for target_phys_addr_t, but this will change when we eventually
> add support for guest visible IOMMUs.
>
> There are some instances of target_phys_addr_t in the code now which
> should really be dma_addr_t, but can't be trivially converted due to
> missing features which this patch corrects.
>
>   * We add DMA_ADDR_BITS analagous to TARGET_PHYS_ADDR_BITS.  This is
>     important where we need to make a compile-time (#if) based on the
>     size of dma_addr_t.
>
>   * We add a new helper macro to create device properties which take a
>     dma_addr_t, currently an alias to DEFINE_PROP_TADDR().
>
> Signed-off-by: David Gibson<david@gibson.dropbear.id.au>
> Signed-off-by: Benjamin Herrenschmidt<benh@kernel.crashing.org>
> ---
>   dma.h         |    1 +
>   hw/qdev-dma.h |   12 ++++++++++++
>   2 files changed, 13 insertions(+)
>   create mode 100644 hw/qdev-dma.h
>
> diff --git a/dma.h b/dma.h
> index 8c1ec8f..fe08b72 100644
> --- a/dma.h
> +++ b/dma.h
> @@ -31,6 +31,7 @@ struct QEMUSGList {
>   #if defined(TARGET_PHYS_ADDR_BITS)
>   typedef target_phys_addr_t dma_addr_t;
>
> +#define DMA_ADDR_BITS TARGET_PHYS_ADDR_BITS
>   #define DMA_ADDR_FMT TARGET_FMT_plx
>
>   struct ScatterGatherEntry {
> diff --git a/hw/qdev-dma.h b/hw/qdev-dma.h
> new file mode 100644
> index 0000000..f0ff558
> --- /dev/null
> +++ b/hw/qdev-dma.h
> @@ -0,0 +1,12 @@
> +/*
> + * Support for dma_addr_t typed properties
> + *
> + * Copyright (C) 2012 David Gibson, IBM Corporation.
> + *
> + * This work is licensed under the terms of the GNU GPL, version 2 or later.
> + * See the COPYING file in the top-level directory.
> + */
> +#include "qdev-addr.h"
> +
> +#define DEFINE_PROP_DMAADDR(_n, _s, _f, _d)                               \
> +    DEFINE_PROP_TADDR(_n, _s, _f, _d)

Why not make life easy and fix dma_addr_t to 64-bit?

Regards,

Anthony Liguori