Re: [PATCH 1/2] drivers: dma-contiguous: clean source code and prepare for device tree

[Laura Abbott <lauraa@codeaurora.org>]

Hi,

On 2/14/2013 4:45 AM, Marek Szyprowski wrote:
> This patch cleans the initialization of dma contiguous framework. The
> all-in-one dma_declare_contiguous() function is now separated into
> dma_contiguous_reserve_area() which only steals the the memory from
> memblock allocator and dma_contiguous_add_device() function, which
> assigns given device to the specified reserved memory area. This improves
> the flexibility in defining contiguous memory areas and assigning device
> to them, because now it is possible to assign more than one device to
> the given contiguous memory area. This split in initialization is also
> required for upcoming device tree support.
>
> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
> Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
> ---
>   drivers/base/dma-contiguous.c        |  210 +++++++++++++++++++++-------------
>   include/asm-generic/dma-contiguous.h |    4 +-
>   include/linux/dma-contiguous.h       |   32 +++++-
>   3 files changed, 161 insertions(+), 85 deletions(-)
>
> diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c
> index 0ca5442..085389c 100644
> --- a/drivers/base/dma-contiguous.c
> +++ b/drivers/base/dma-contiguous.c
> @@ -39,7 +39,33 @@ struct cma {
>   	unsigned long	*bitmap;
>   };
>
> -struct cma *dma_contiguous_default_area;
> +static DEFINE_MUTEX(cma_mutex);
> +
> +struct cma *dma_contiguous_def_area;
> +phys_addr_t dma_contiguous_def_base;
> +
> +static struct cma_area {
> +	phys_addr_t base;
> +	unsigned long size;
> +	struct cma *cma;
> +} cma_areas[MAX_CMA_AREAS] __initdata;
> +static unsigned cma_area_count __initdata;
> +

cma_areas and cma_area_count are accessed from cma_get_area which gets 
called from cma_assign_device_from_dt. You need to drop the __initdata 
since the notifier can be called at anytime.

Thanks,
Laura

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