Implement MSI support for PA Semi PWRficient platforms. MSI is done
through a special range of sources on the openpic controller, and they're
unfortunately breaking the usual concepts of how sources are programmed:
* The source is calculated as 512 + the value written into the MSI
register
* The vector for this source is added to the source and reported
through IACK
This means that for simplicity, it makes much more sense to just set the
vector to 0 for the source, since that's really the vector we expect to
see from IACK.
Also, the affinity/priority registers will affect 16 sources at a
time. To avoid most (simple) users from being limited by this, allocate
16 sources per device but use only one. This means that there's a total
of 32 sources.
If we get usage scenarions that need more sources, the allocator should
probably be revised to take an alignment argument and size, not just do
natural alignment.
Finally, since I'm already touching the MPIC names on pasemi, rename
the base one from the somewhat odd " PAS-OPIC " to "PASEMI-OPIC".
Signed-off-by: Olof Johansson <olof@lixom.net>
Acked-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Hook up affinity-setting for U3/U4 MSI interrupt sources.
Tested on Quad G5 with myri10ge.
Signed-off-by: Olof Johansson <olof@lixom.net>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
MPIC U3/U4 MSI backend. Based on code from Segher, heavily hacked by me.
This only deals with MSI on U3/U4 MPICs, aka. CPC 9x5.
If we find a U3/U4 then we enable this backend, ie. take over the ppc_md
MSI hooks. We might need more elaborate logic in future to decide which
backend is enabled.
We need our own irq_chip so that we can do MSI masking/unmasking on
the device itself. We also need to mask explicitly on shutdown to make
sure we don't get bitten by lazy-disable semantics.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
To support MSI on MPIC we need a way to reserve and allocate hardware irq
numbers, this patch implements an allocator for that purpose.
New firmware platforms must define a "msi-available-ranges" property on their
MPIC node for MSI to work. For U3/U4 we do a best-guess setup.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
