[PATCH v2] powerpc/xive: Fix bogus error code returned by OPAL

[Michael Ellerman]

On Wed, 2019-09-11 at 15:52:18 UTC, Greg Kurz wrote:
> There's a bug in skiboot that causes the OPAL_XIVE_ALLOCATE_IRQ call
> to return the 32-bit value 0xffffffff when OPAL has run out of IRQs.
> Unfortunatelty, OPAL return values are signed 64-bit entities and
> errors are supposed to be negative. If that happens, the linux code
> confusingly treats 0xffffffff as a valid IRQ number and panics at some
> point.
> 
> A fix was recently merged in skiboot:
> 
> e97391ae2bb5 ("xive: fix return value of opal_xive_allocate_irq()")
> 
> but we need a workaround anyway to support older skiboots already
> in the field.
> 
> Internally convert 0xffffffff to OPAL_RESOURCE which is the usual error
> returned upon resource exhaustion.
> 
> Cc: stable at vger.kernel.org # v4.12+
> Signed-off-by: Greg Kurz <groug at kaod.org>

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/6ccb4ac2bf8a35c694ead92f8ac5530a16e8f2c8

cheers