Re: Getting Physical address of a buffer
Re: Getting Physical address of a buffer
- Subject: Re: Getting Physical address of a buffer
- From: shailesh jain <email@hidden>
- Date: Fri, 6 Aug 2010 11:47:12 -0700
@Shantonu - I was under the impression that IO* KPIs should only be
used by IOKit driver ?
@Mike - Virtualization. If you care to involve hypervisor in your
memory tricks then virtual address of the guest buffer is useless. You
want physical address.
@Others - I will check KPIs that you guys mention.
Seems like most device drivers that care about DMA would probably be
an IOKit driver else what I am asking for seems like very basic
requirement.
Shailesh Jain
On Fri, Aug 6, 2010 at 9:18 AM, Michael Smith <email@hidden> wrote:
>
> Why would you like to get the physical address of this buffer? What do you
> think it will tell you?
> = Mike
> On Aug 5, 2010, at 11:10 AM, shailesh jain wrote:
>
> Hello again!
> I have a kernel extension (which is not an IOKit driver) that uses
> OSMalloc_ KPI to allocate buffer. I pass in OSMT_DEFAULT so that
> buffers that it returns are wired to memory. I have a use case where
> in I would like
> to get physical address of the first byte of the buffer. I understand
> that buffer will not be contiguous in Physical memory and I am fine
> with that. Do we have such an interface ---
>
> something like: physAddr = virt_to_phys(buffer); // Gives physical
> address of first byte of the buffer
>
>
> --
> Shailesh Jain
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--
Shailesh Jain
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