How to alloc_pages from a given physical memory?

[Kamil Konieczny]

On 06.07.2017 11:43, kipade wrote:
> In fact, I want to allocate a continous of pages from a given physical 
> address for a shm object in
> 
> shmem_file_setup, might i should write a customized shmem_file_setup2 
> for this?

> I use arm 32bit cpu, with kernel 3.14

why do want this specific address 0x90000000 ?

can it be 0x40000000 ? or 0x50000000 ? or 0x68880000 ?

is this 0x90000000 located in hardware registers ?

some memory regions are not accessible directly for allocation,
because they are used for communication with hardware SoC,
and so they are used by kernel drivers or directly by kernel

kernel driver may or may not expose that memory region for user space,
but this is driver work

maybe you should ask on platform forum,
you did not answer my question on what platform you are working

>>>> On 06.07.2017 05:08, kipade wrote:
>>>>> Here I want to allocate a block of shared memory from a given physical
>>>>> address, such as 0x90000000, 6M. However, alloc_pages can't fit this
>>>>> point. I had reserved enugh pages via cmem, there also have enough
>>>>> continous pages for such allocation anywhere else. What should I do?

-- 
Best regards,
Kamil Konieczny
Samsung R&D Institute Poland