The implementation of the XICS interrupt controller contains several
(difficult to trigger) bugs due to the fact that we were not 100%
consistent with which irq numbering we used. In most places, global
numbers were used as handled by the presentation layer, however a few
functions took "local" numberings, that is the source number within
the interrupt source controller which is offset from the global
number. In most cases the function and its caller agreed on this, but
in a few cases it didn't.
This patch cleans this up by always using global numbering.
Translation to the local number is now always and only done when we
look up the individual interrupt source state structure. This should
remove the existing bugs and with luck reduce the chances of
re-introducing such bugs.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
Currently the pseries machine init code builds up an array, envs, of
CPUState pointers for all the cpus in the system. This is kind of
pointless, given the generic code already has a perfectly good linked list
of the cpus.
In addition, there are a number of places which assume that the cpu's
cpu_index field is equal to its index in this array. This is true in
practice, because cpu_index values are just assigned sequentially, but
it's conceptually incorrect and may not always be true.
Therefore, this patch abolishes the envs array, and explicitly uses the
generic cpu linked list and cpu_index values throughout.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
PAPR defines an interrupt control architecture which is logically divided
into ICS (Interrupt Control Presentation, each unit is responsible for
presenting interrupts to a particular "interrupt server", i.e. CPU) and
ICS (Interrupt Control Source, each unit responsible for one or more
hardware interrupts as numbered globally across the system). All PAPR
virtual IO devices expect to deliver interrupts via this mechanism. In
Linux, this interrupt controller system is handled by the "xics" driver.
On pSeries systems, access to the interrupt controller is virtualized via
hypercalls and RTAS methods. However, the virtualized interface is very
similar to the underlying interrupt controller hardware, and similar PICs
exist un-virtualized in some other systems.
This patch implements both the ICP and ICS sides of the PAPR interrupt
controller. For now, only the hypercall virtualized interface is provided,
however it would be relatively straightforward to graft an emulated
register interface onto the underlying interrupt logic if we want to add
a machine with a hardware ICS/ICP system in the future.
There are some limitations in this implementation: it is assumed for now
that only one instance of the ICS exists, although a full xics system can
have several, each responsible for a different group of hardware irqs.
ICP/ICS can handle both level-sensitve (LSI) and message signalled (MSI)
interrupt inputs. For now, this implementation supports only MSI
interrupts, since that is used by PAPR virtual IO devices.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
