cxl: Do adapter fence check before handling afu interrupt

[Michael Ellerman]

On Wed, 2016-11-16 at 14:09:33 UTC, Vaibhav Jain wrote:
> If an afu interrupt is in flight when an eeh error is triggered the
> control still reaches the function native_irq_multiplexed and the
> PE-Handle read from the CXL_PSL_PEHandle_An register is 0xffff. The
> function then erroneously assumes that the interrupt belonged to a
> detached context and generates a warning with full stack dump in the
> kernel log complaining:
> 
> "Unable to demultiplex CXL PSL IRQ for PE 65535 DSISR ffffffff DAR
> ffffffff. (Possible AFU HW issue - was a term/remove acked with
> outstanding transactions"
> 
> To fix this the patch adds new code to the function
> native_irq_multiplexed function to compares the read value of register
> CXL_PSL_PEHandle_An to ~0ULL. If true then logs a warning message
> saying that the interrupt is being ignored and returns IRQ_HANDLED from
> the irq handler.
> 
> Reviewed-by: Andrew Donnellan <andrew.donnellan at au1.ibm.com>
> Acked-by: Frederic Barrat <fbarrat at linux.vnet.ibm.com>
> Acked-by: Ian Munsie <imunsie at au1.ibm.com>
> Signed-off-by: Vaibhav Jain <vaibhav at linux.vnet.ibm.com>

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/abf051be684be768c1ee079514f4d0

cheers