[PATCH 5/5] powerpc/fsl_msi: add 'msiregs' kernel parameter

Scott Wood scottwood at freescale.com
Sat Jun 15 08:13:54 EST 2013


On 06/14/2013 02:15:59 AM, Minghuan Lian wrote:
> 1. Only MSIIR1 can index 16 MSI registers, but when using MSIIR1
> the IRQs of a register are not continuous. for example, the first
> register irq values are 0x0, 0x10, 0x20, 0x30 ... 0x1f0. So it
> is hard to use 'msi-available-ranges' property to indicate the
> available ranges and 'msi-available-ranges' property has been
> removed from dts node, so this patch removes the related code.
> 
> 2. Add 'msiregs' kernel parameter instead of 'msi-available-ranges'
> functionality.

The reason we used a device tree property was because this is for  
virtualization and AMP scenarios where this instance of Linux does not  
own all of the MSI registers.

I don't see any reasonable way to partition an MPIC v4.3 MSI group --  
but there are more groups, so it's not that bad.  What's the use case  
for this patch?

-Scott


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