On 11/27/18 9:20 PM, Laura Abbott wrote:
> On 11/26/18 10:43 AM, Alexey Skidanov wrote:
>>
>>
>> On 11/26/18 6:39 PM, Laura Abbott wrote:
>>> On 11/25/18 2:02 PM, Alexey Skidanov wrote:
>>>>
>>>>
>>>> On 11/25/18 11:40 PM, Laura Abbott wrote:
>>>>> On 11/25/18 1:22 PM, Alexey Skidanov wrote:
>>>>>>
>>>>>>
>>>>>> On 11/25/18 10:51 PM, Laura Abbott wrote:
>>>>>>> On 11/11/18 11:29 AM, Alexey Skidanov wrote:
>>>>>>>> Create chunk heap of specified size and base address by adding
>>>>>>>> "ion_chunk_heap=size@start" kernel boot parameter.
>>>>>>>>
>>>>>>>> Signed-off-by: Alexey Skidanov <alexey.skidanov@xxxxxxxxx>
>>>>>>>> ---
>>>>>>>> drivers/staging/android/ion/ion_chunk_heap.c | 40
>>>>>>>> ++++++++++++++++++++++++++++
>>>>>>>> 1 file changed, 40 insertions(+)
>>>>>>>>
>>>>>>>> diff --git a/drivers/staging/android/ion/ion_chunk_heap.c
>>>>>>>> b/drivers/staging/android/ion/ion_chunk_heap.c
>>>>>>>> index 159d72f..67573aa4 100644
>>>>>>>> --- a/drivers/staging/android/ion/ion_chunk_heap.c
>>>>>>>> +++ b/drivers/staging/android/ion/ion_chunk_heap.c
>>>>>>>> @@ -135,6 +135,7 @@ struct ion_heap *ion_chunk_heap_create(struct
>>>>>>>> ion_platform_heap *heap_data)
>>>>>>>> }
>>>>>>>> chunk_heap->base = heap_data->base;
>>>>>>>> chunk_heap->size = heap_data->size;
>>>>>>>> + chunk_heap->heap.name = heap_data->name;
>>>>>>>> chunk_heap->allocated = 0;
>>>>>>>> gen_pool_add(chunk_heap->pool, chunk_heap->base,
>>>>>>>> heap_data->size, -1);
>>>>>>>> @@ -151,3 +152,42 @@ struct ion_heap *ion_chunk_heap_create(struct
>>>>>>>> ion_platform_heap *heap_data)
>>>>>>>> return ERR_PTR(ret);
>>>>>>>> }
>>>>>>>> +static u64 base;
>>>>>>>> +static u64 size;
>>>>>>>> +
>>>>>>>> +static int __init setup_heap(char *param)
>>>>>>>> +{
>>>>>>>> + char *p, *pp;
>>>>>>>> +
>>>>>>>> + size = memparse(param, &p);
>>>>>>>> + if (param == p)
>>>>>>>> + return -EINVAL;
>>>>>>>> +
>>>>>>>> + if (*p == '@')
>>>>>>>> + base = memparse(p + 1, &pp);
>>>>>>>> + else
>>>>>>>> + return -EINVAL;
>>>>>>>> +
>>>>>>>> + if (p == pp)
>>>>>>>> + return -EINVAL;
>>>>>>>> +
>>>>>>>> + return 0;
>>>>>>>> +}
>>>>>>>> +
>>>>>>>> +__setup("ion_chunk_heap=", setup_heap);
>>>>>>>> +
>>>>>>>> +static int ion_add_chunk_heap(void)
>>>>>>>> +{
>>>>>>>> + struct ion_heap *heap;
>>>>>>>> + struct ion_platform_heap plat_heap = {.base = base,
>>>>>>>> + .size = size,
>>>>>>>> + .name = "chunk_heap",
>>>>>>>> + .priv = (void *)PAGE_SIZE};
>>>>>>>> + heap = ion_chunk_heap_create(&plat_heap);
>>>>>>>> + if (heap)
>>>>>>>> + ion_device_add_heap(heap);
>>>>>>>> +
>>>>>>>> + return 0;
>>>>>>>> +}
>>>>>>>> +device_initcall(ion_add_chunk_heap);
>>>>>>>> +
>>>>>>>>
>>>>>>>
>>>>>>> This solves a problem but not enough of the problem.
>>>>>>>
>>>>>>> We need to be able to support more than one chunk/carveout
>>>>>>> heap.
>>>>>> This is easy to support.
>>>>>> This also assumes that the memory has already been
>>>>>>> reserved/placed and that you know the base and size to
>>>>>>> pass on the command line. Part of the issue with the carveout
>>>>>>> heaps is that we need a way to tell the kernel to reserve
>>>>>>> the memory early enough and then get that information to
>>>>>>> Ion. Hard coding memory locations tends to be buggy from
>>>>>>> my past experience with Ion.
>>>>>> memmap= kernel option marks the memory region(s) as reserved (Zone
>>>>>> Allocator doesn't use this memory region(s)). So the heap(s) may
>>>>>> manage
>>>>>> this memory region(s).
>>>>>
>>>>> memmap= is x86 only. I really don't like using the command line for
>>>>> specifying the base/size as it seems likely to conflict with platforms
>>>>> that rely on devicetree for reserving memory regions.
>>>>>
>>>>> Thanks,
>>>>> Laura
>>>>>
>>>> I see ... So probably the better way is the one similar to this
>>>> https://elixir.bootlin.com/linux/latest/source/kernel/dma/contiguous.c#L245
>>>>
>>>>
>>>> ?
>>>>
>>>
>>> Correct. For platforms that need devicetree, we need a way to specify
>>> that a region should become an Ion heap. I went through a similar
>>> exercise with CMA heaps before I kind of gave up on figuring out a
>>> binding and just had Ion enumerate all CMA heaps. We do still need
>>> a solution to work with non-DT platforms as well so whatever we
>>> come up with needs to plausibly work for both cases. Your solution
>>> would cover the non-DT case but I'd really like to make sure we
>>> at least have a path forward for the devicetree case as well.
>>
>> I would say that we have the following steps to consider:
>>
>> 1. Memory reservation. The suggested solution doesn't care how it's done.
>>
>> 2. Per-heap information passing to the Kernel. It's different for DT and
>> non-DT cases.
>>
>> 3. Heap objects instantiation. The DT and non-DT cases have different
>> ways/formats to pass this per-heap information. But once the parsing is
>> done, the rest of the code is common.
>>
>> I think it clearly defines the steps covering both cases. What do you
>> think?
>>
>
> Yes, that sounds about right.
>
So, in this patch step #2 - is setup_heap() and step #3 - is
ion_add_chunk_heap(). The only missing part is to support several heap
instances creation, correct?
Thanks,
Alexey
>> Thanks,
>> Alexey
>>>
>>> Thanks,
>>> Laura
>>>
>>>> Thanks,
>>>> Alexey
>>>>
>>>>>>>
>>>>>>> If you'd like to see about coming up with a complete solution,
>>>>>>> feel free to resubmit but I'm still strongly considering
>>>>>>> removing these heaps.
>>>>>>>
>>>>>> I will add the multiple heaps support and resubmit the patch
>>>>>>> Thanks,
>>>>>>> Laura
>>>>>> Thanks,
>>>>>> Alexey
>>>>>>
>>>>>
>>>
>
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