[7/7] powerpc/85xx: Fix the RapidIO maintenance access functions

From: Thomas Moll <thomas.moll@sysgo.com>

Fix the maintenance access functions to farend RapidIO devices.
1. Fixed shift of the given offset, to open the maintenance window
2. Mask offset to limit access to the opened maintenance window
3. Added extended destid part to rowtear register, required for 16bit mode

For easier handling of the access routines, the access was limited to aligned
memory regions. This should be no problem because all registers are 32bit
wide.

Signed-off-by: Thomas Moll <thomas.moll@sysgo.com>
---

 fsl_rio.c |   34 ++++++++++++++++++++++++++++------
 1 file changed, 28 insertions(+), 6 deletions(-)


---

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Bounine, Alexandre wrote:
> Hi Micha,
> 
> I tested it on my setup - it works.
> Maybe Thomas may give more details on this change.

Did you (for fun) try once to decrease the maintenance window to say, 4 
kB? Then you really need these "high" bits to work properly.

Or did you try with some register at offset > 4MB? The Tundra's have 
registers going up to 0x14000 or so? So don't need 16MB addressing for that.

Thanks, Micha


>> -----Original Message-----
>> From: Micha Nelissen [mailto:micha@neli.hopto.org]
>> Sent: Wednesday, February 24, 2010 3:21 PM
>> To: Alexandre Bounine
>> Subject: Re: [PATCH 7/7] powerpc/85xx: Fix the RapidIO maintenance
> access functions
>> Alexandre Bounine wrote:
>>>  	out_be32(&priv->maint_atmu_regs->rowtar,
>>> -		 (destid << 22) | (hopcount << 12) | ((offset & ~0x3) >>
> 9));
>>> +		 (destid << 22) | (hopcount << 12) | (offset >> 12));
>>> +	out_be32(&priv->maint_atmu_regs->rowtear,  (destid >> 10));
>> Did this actually work for you? The (offset >> 12) is due to the 4MB
>> window size right?
>>
>> Micha
>

Quoting "Micha Nelissen" <micha@neli.hopto.org>:

> Bounine, Alexandre wrote:
>> Hi Micha,
>>
>> I tested it on my setup - it works.
>> Maybe Thomas may give more details on this change.
>
> Did you (for fun) try once to decrease the maintenance window to  
> say, 4 kB? Then you really need these "high" bits to work properly.

We have never changed the configuration of the window size in Linux,  
but we have an test application that uses these 4kb window setting.
With the current window configuration in Linux, I expect problems when  
someone tries to read a register that is located at offset > 512KB. I  
have currently no equipment to verify this behaviour.

>
> Or did you try with some register at offset > 4MB? The Tundra's have  
> registers going up to 0x14000 or so? So don't need 16MB addressing  
> for that.
We have devices that requires access to registers that are located at  
offset > 15MB.

>
> Thanks, Micha
>
>
>>> -----Original Message-----
>>> From: Micha Nelissen [mailto:micha@neli.hopto.org]
>>> Sent: Wednesday, February 24, 2010 3:21 PM
>>> To: Alexandre Bounine
>>> Subject: Re: [PATCH 7/7] powerpc/85xx: Fix the RapidIO maintenance
>> access functions
>>> Alexandre Bounine wrote:
>>>> 	out_be32(&priv->maint_atmu_regs->rowtar,
>>>> -		 (destid << 22) | (hopcount << 12) | ((offset & ~0x3) >>
>> 9));
>>>> +		 (destid << 22) | (hopcount << 12) | (offset >> 12));
>>>> +	out_be32(&priv->maint_atmu_regs->rowtear,  (destid >> 10));
>>> Did this actually work for you? The (offset >> 12) is due to the 4MB
>>> window size right?
>>>
>>> Micha
>>
>
>