[Skiboot] [PATCH] phb4: Disable 32-bit MSI in capi mode

[christophe lombard]

Le 14/08/2018 à 14:10, Frederic Barrat a écrit :
> If a capi device does a DMA write targeting an address lower than 4GB,
> it does so through a 32-bit operation, per the PCI spec. In capi mode,
> the first TVE entry is configured in bypass mode, so the address is
> valid. But with any (bad) luck, the address could be 0xFFFFxxxx, thus
> looking like a 32-bit MSI.
> 
> We currently enable both 32-bit and 64-bit MSIs, so the PHB will
> interpret the DMA write as a MSI, which very likely results in an EEH
> (MSI with a bad payload size).
> 
> We can fix it by disabling 32-bit MSI when switching the PHB to capi
> mode. Capi devices are 64-bit.
> 
> Cc: stable
> Signed-off-by: Frederic Barrat <fbarrat at linux.ibm.com>
> ---
> Stewart: this is for CORAL and is undergoing a round of testing on a
> wider scale. It should only be merged once confirmed ok, hopefully
> later this week.
> 
> 

Thanks.

Reviewed-by: Christophe Lombard <clombard at linux.vnet.ibm.com>