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

["Michael S. Tsirkin" <mst@redhat.com>]

On Tue, Mar 27, 2012 at 01:43:21PM +1100, David Gibson wrote:
> 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>

I don't have any issues with this but let's apply together
with the patch converting the devices that you mention.

> ---
>  dma.h         |    1 +
>  hw/qdev-dma.h |    4 ++++
>  2 files changed, 5 insertions(+), 0 deletions(-)
>  create mode 100644 hw/qdev-dma.h
> 
> diff --git a/dma.h b/dma.h
> index 05ac325..463095c 100644
> --- a/dma.h
> +++ b/dma.h
> @@ -32,6 +32,7 @@ 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..e407771
> --- /dev/null
> +++ b/hw/qdev-dma.h
> @@ -0,0 +1,4 @@
> +#include "qdev-addr.h"
> +
> +#define DEFINE_PROP_DMAADDR(_n, _s, _f, _d)                               \
> +    DEFINE_PROP_TADDR(_n, _s, _f, _d)

Headers need preprocessor guards so that multiple
inclusions don't trigger errors.
It does not matter much but did you consider sticking this
in dma.h instead of adding a new header?

> -- 
> 1.7.9.1