MMU in vxWroks 6.2 issues

Hello all

I wrote a driver in kernel space in vxWorks 6.2. The driver is a DMA
driver that receives a src and a dst address, and copies from src to
dst.

The src and dst are allocated in RTP space (user space) (pointers
having addresses of 0xA0034000 e.g.).

The DMA fails on transfer error when trying to perform the transaction.

AFAIK, in vxWorks 6.2 the address space is flat, so there should be a
one-to-one correspondence between virtual-physical addresses.
[color=blue]
>From what I see, the pointer values i get from memalign are too large[/color]
to be physical (see above), I tried converting from virtual to
physical, but there seems to be no such function implemented in
vxWorks.

Any help would be appreciated..
Sinan.

"sinan" <awad.sinan@gmail.com> wrote:
[color=blue]
>Hello all
>
>I wrote a driver in kernel space in vxWorks 6.2. The driver is a DMA
>driver that receives a src and a dst address, and copies from src to
>dst.
>
>The src and dst are allocated in RTP space (user space) (pointers
>having addresses of 0xA0034000 e.g.).
>
>The DMA fails on transfer error when trying to perform the transaction.
>
>AFAIK, in vxWorks 6.2 the address space is flat, so there should be a
>one-to-one correspondence between virtual-physical addresses.
>[/color]

Kernel address space is flat, RTP address space is not flat. Your driver
needs to call cacheDrvVirtToPhys, or similar depending on the platform,
for a physical address.

[color=blue][color=green]
>>From what I see, the pointer values i get from memalign are too large[/color]
>to be physical (see above), I tried converting from virtual to
>physical, but there seems to be no such function implemented in
>vxWorks.
>
>Any help would be appreciated..
>Sinan.[/color]

1. The function needs a parameter of type CACHE_FUNCS, have no idea
what to give it (found dmaCacheFuncs structure, but the virtToPhys func
there is NULL)
What should I give it as CACHE_FUNCS ?!

2. I tried vmTranslate also, by calling it from the kernel with the
kernels context, it returns NULL.

3. Tried also somehow to extract the rtpId from a TCB, and try to
access the poolMgr object inside, no use and it's too hard.

Thanks in advance.

"sinan" <awad.sinan@gmail.com> wrote:

Which platform?
[color=blue]
>1. The function needs a parameter of type CACHE_FUNCS, have no idea
>what to give it (found dmaCacheFuncs structure, but the virtToPhys func
>there is NULL)
>What should I give it as CACHE_FUNCS ?!
>
>2. I tried vmTranslate also, by calling it from the kernel with the
>kernels context, it returns NULL.
>
>3. Tried also somehow to extract the rtpId from a TCB, and try to
>access the poolMgr object inside, no use and it's too hard.
>
>Thanks in advance.[/color]

"sinan" <awad.sinan@gmail.com> wrote:
[color=blue]
>1. The function needs a parameter of type CACHE_FUNCS, have no idea
>what to give it (found dmaCacheFuncs structure, but the virtToPhys func
>there is NULL)
>What should I give it as CACHE_FUNCS ?!
>
>2. I tried vmTranslate also, by calling it from the kernel with the
>kernels context, it returns NULL.
>
>3. Tried also somehow to extract the rtpId from a TCB, and try to
>access the poolMgr object inside, no use and it's too hard.
>
>Thanks in advance.[/color]

Sorry, try vmTranslate.

Tried it.
I'm running vxWorks 6.2, on MPC8349.
WindRiver seems to forgot to supply a translation function for this
platform, since the cahceLib struct holds NULL instead of the
translation function.

Any other ideas?
Thanks

"sinan" <awad.sinan@gmail.com> wrote:
[color=blue]
>Tried it.
>I'm running vxWorks 6.2, on MPC8349.
>WindRiver seems to forgot to supply a translation function for this
>platform, since the cahceLib struct holds NULL instead of the
>translation function.
>
>Any other ideas?
>Thanks[/color]

It doesn't need a cacheLib because cache snooping is enabled.
vmTranslate is not associated with cache, it's an MMU function,
so it should be working.

Well, right and wrong..

when I said "cacheLib" I didn't mean the cacheLib library, but instead
the cacheDmaFuncs mapping, MMU translation functions are also
referenced in this "cacheLib" struct. Anyway, cache snooping is NOT on
by default.

The MMU functions need a context as the first argument to translate
addresses, since the address I'm trying to translate is inside an RTP,
I need the RTP vm context, which I have no way to extract.

When using vmTranslate in the target shell, I get a NULL in the address
that it translated to, which is wierd.

I've used vmTranslate also inside the kernel, the return value of the
function is OK, but the physical address returned is NULL. Looked into
mmuPpcLib.c, it appears to be implemented. (mmuPpcTranslate).

I've opened a TSR at windriver, the person there is SOO off that he is
saying that RTPs do not use virtual addressing..

Any other ideas are most welcome.
Sinan.