Re: [PATCH] of: alloc anywhere from memblock if range not specified

Leonard Crestez
2017-01-10T16:16:46Z

Hello,

I have some trouble with this patch.

It seems the intention is to allow CMA to be placed in highmem. If the
CMA area is larger than highmem and no alloc-ranges is specified (just a
size) it is possible to end up allocating a area that spans from
multiple zones. This later breaks checks in cma_activate_area and makes
most dma allocations fail.

Am I missing something or this a bug?

On Mon, Feb 22, 2016 at 3:45 PM, Vinayak Menon <vinmenon-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
wrote:
>
> early_init_dt_alloc_reserved_memory_arch passes end as 0 to
> __memblock_alloc_base, when limits are not specified. But
> __memblock_alloc_base takes end value of 0 as MEMBLOCK_ALLOC_ACCESSIBLE
> and limits the end to memblock.current_limit. This results in regions
> never being placed in HIGHMEM area, for e.g. CMA.
> Let __memblock_alloc_base allocate from anywhere in memory if limits are
> not specified.
>
> Acked-by: Marek Szyprowski <m.szyprowski-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
> Signed-off-by: Vinayak Menon <vinmenon-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
> ---
> drivers/of/of_reserved_mem.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
> index 1a3556a..ed01c01 100644
> --- a/drivers/of/of_reserved_mem.c
> +++ b/drivers/of/of_reserved_mem.c
> @@ -32,11 +32,13 @@ int __init __weak early_init_dt_alloc_reserved_memory_arch(phys_addr_t size,
> phys_addr_t align, phys_addr_t start, phys_addr_t end, bool nomap,
> phys_addr_t *res_base)
> {
> + phys_addr_t base;
> /*
> * We use __memblock_alloc_base() because memblock_alloc_base()
> * panic()s on allocation failure.
> */
> - phys_addr_t base = __memblock_alloc_base(size, align, end);
> + end = !end ? MEMBLOCK_ALLOC_ANYWHERE : end;
> + base = __memblock_alloc_base(size, align, end);
> if (!base)
> return -ENOMEM;
>
> --
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