2014-07-07 10:36:44

by Marek Szyprowski

[permalink] [raw]
Subject: Re: [PATCH 4/4] drivers: dma-contiguous: add initialization from device tree

Hello,

On 2014-07-04 07:52, Joonsoo Kim wrote:
>> -----Original Message-----
>> From: Marek Szyprowski [mailto:[email protected]]
>> Sent: Wednesday, July 02, 2014 7:49 PM
>>
>> Subject: [PATCH 4/4] drivers: dma-contiguous: add initialization from
>> device tree
>>
>> Add a code to create CMA region from reserved memory and add support for
>> handling 'shared-dma-pool' reserved-memory device tree nodes.
>>
>> Signed-off-by: Marek Szyprowski <[email protected]>
>> ---
>> drivers/base/dma-contiguous.c | 67
>> +++++++++++++++++++++++++++++++++++++++++
>> include/linux/cma.h | 3 ++
>> mm/cma.c | 69
> ++++++++++++++++++++++++++++++++-----------
>> 3 files changed, 122 insertions(+), 17 deletions(-)
>>

...

>> +/**
>> * cma_declare_contiguous() - reserve custom contiguous area
>> * @base: Base address of the reserved area optional, use 0 for any
>> * @size: Size of the reserved area (in bytes),
>> @@ -162,18 +210,12 @@ int __init cma_declare_contiguous(phys_addr_t base,
>> phys_addr_t alignment, unsigned int order_per_bit,
>> bool fixed, struct cma **res_cma)
>> {
>> - struct cma *cma;
>> - int ret = 0;
>> + int ret;
>>
>> pr_debug("%s(size %lx, base %08lx, limit %08lx alignment %08lx)\n",
>> __func__, (unsigned long)size, (unsigned long)base,
>> (unsigned long)limit, (unsigned long)alignment);
>>
>> - if (cma_area_count == ARRAY_SIZE(cma_areas)) {
>> - pr_err("Not enough slots for CMA reserved regions!\n");
>> - return -ENOSPC;
>> - }
>> -
> Hello, Marek.
>
> After this change, if we have not enough cma_areas, memory will leak.
> I think that we need separate function to check constraint and this
> function should be called before reserving memory in
> cma_declare_contiguous().

Well, I will leave this check to avoid memory leak then.

> BTW, this mail doesn't appear in LKML. What happens? :)

I have no idea, I will send second version then.

Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland