pci_alloc_consistent doubt

[Dhananjay Maske]

On Sun, Mar 31, 2013 at 12:11 AM, Dhananjay Maske <
dhananjay.maske87 at gmail.com> wrote:

> Hi Everyone,
>   Can some one please help me with pci_alloc_consistent and how to use the
> buffer allocated by it ?.
>
>
> Thank you in Advance.
> Djay
>
>
> On Thu, Mar 28, 2013 at 10:08 AM, Dhananjay Maske <
> dhananjay.maske87 at gmail.com> wrote:
>
>>
>>
>>
>> On Thu, Mar 28, 2013 at 1:14 AM, Dhananjay Maske <
>> dhananjay.maske87 at gmail.com> wrote:
>>
>>> Hi All,
>>>      I am fairly New to Linux kernel Programming and i have few
>>> questions with respect to pci_alloc_consistent .
>>>
>>> 1) as we know pci_alloc_consistent allocates dma buffers which is
>>> visible to DMA controller as well as CPU.
>>>     virt_add = pci_alloc_consistent(pdev, size, dma_addr_t bus_adrr);
>>>
>>> here it will allocate a buffer and return its virtual address and
>>> corresponding bus address.
>>>
>>> My question is do these two address ultimately point to similar location
>>> but from different perspectives ?.
>>>
>>> 2) After allocating these address, how do we proceed given that i have a
>>> ASIC register which has the dma_rx_desc_start address ?
>>>
>>> 3) Also does all the HW's which support dma have the descriptor data
>>> structures by provided by Vender or is there any specific format that dev
>>> has to be aware of for designing such descriptor for that particular driver
>>> ?
>>>
>>
>>
>
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