The PPC476GTR SoC supports message signalled interrupts (MSI) by writing
to special addresses within the High Speed Transfer Assist (HSTA) module.

This patch adds support for PCI MSI with a new system device. The DMA
window is also updated to allow access to the entire 42-bit address range
to allow PCI devices write access to the HSTA module.
Signed-off-by: NAlistair Popple <alistair@popple.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

We currently have a user visible CONFIG_POWERNV_MSI option, but it
doesn't actually disable MSI for powernv. The MSI code is always built,
what it does disable is the inclusion of the MSI bitmap code, which
leads to a build error.

eg, with PPC_POWERNV=y and POWERNV_MSI=n we get:

  arch/powerpc/platforms/built-in.o: In function `.pnv_teardown_msi_irqs':
  pci.c:(.text+0x3558): undefined reference to `.msi_bitmap_free_hwirqs'

We don't really need a POWERNV_MSI symbol, just have the MSI bitmap code
depend directly on PPC_POWERNV.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Reviewed-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

As Michael Ellerman suggested, to add CONFIG_POWERNV_MSI for PowerNV
platform. That's similar to CONFIG_PSERIES_MSI for pSeries platform.
For now, we don't make it dependent on CONFIG_EEH since it's not ready
to enable that yet.

Apart from that, we also enable CONFIG_PPC_MSI_BITMAP on selecting
CONFIG_POWERNV_MSI.
Signed-off-by: NGavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

We need PPC_MSI_BITMAP support
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Move the GE PIC drivers to allow these to be used by non-86xx boards.
Signed-off-by: NMartyn Welch <martyn.welch@ge.com>
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

This patch adds MSI support for 440SPe, 460Ex, 460Sx and 405Ex.
Signed-off-by: NRupjyoti Sarmah <rsarmah@apm.com>
Signed-off-by: NTirumala R Marri <tmarri@apm.com>
Acked-by: NJosh Boyer <jwboyer@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

SCOM is a side-band configuration bus implemented on some processors.
This code provides a way for code to map and operate on devices via
SCOM, while the details of how that is implemented is left up to a
SCOM "controller" in the platform code.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This is a significant rework of the XICS driver, too significant to
conveniently break it up into a series of smaller patches to be honest.

The driver is moved to a more generic location to allow new platforms
to use it, and is broken up into separate ICP and ICS "backends". For
now we have the native and "hypervisor" ICP backends and one common
RTAS ICS backend.

The driver supports one ICP backend instanciation, and many ICS ones,
in order to accomodate future platforms with multiple possibly different
interrupt "sources" mechanisms.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The initial patch had the option at the top level which wasn't
quite right.  Moving under the platform options is a bit better.
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

Structured similar to the existing QE GPIO support.
Signed-off-by: NPeter Korsgaard <jacmet@sunsite.dk>
Acked-by: NAnton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: NKumar Gala <galak@kernel.crashing.org>

There are now two almost identical implementations of an MSI bitmap
allocator, one in mpic_msi.c and the other in fsl_msi.c.

Merge them together and put the result in msi_bitmap.c.  Some of the
MPIC bits will remain to provide a nicer interface for the MPIC users.

In the process we fix two buglets.  The first is that the allocation
routines, now msi_bitmap_alloc_hwirqs(), returned an unsigned result,
even though they use -1 to indicate allocation failure.  Although all
the callers were checking correctly, it is much better for the routine
to just return an int.  At least until someone wants > ~2 billion MSIs.

The second buglet is that the device tree reservation logic only
allowed power-of-two reservations.  AFAICT that didn't effect any
existing code but it's nicer if we can reserve arbitrary irqs from MSI
use.

We also add some selftests, which exposed the two buglets and now test
for them, as well as some basic sanity tests.  The tests are only built
when CONFIG_DEBUG_KERNEL=y.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

This adds to the previous 2 patches the support for the 4xx PCI Express
cells as found in the 440SPe revA, revB and 405EX.

Unfortunately, due to significant differences between these, and other
interesting "features" of those pieces of HW, the code isn't as simple
as it is for PCI and PCI-X and some of the functions differ significantly
between the 3 implementations. Thus, not only this code can only support
those 3 implementations for now and will refuse to operate on any other,
but there are added ifdef's to avoid the bloat of building a fairly large
amount of code on platforms that don't need it.

Also, this code currently only supports fully initializing root complex
nodes, not endpoint. Some more code will have to be lifted from the
arch/ppc implementation to add the endpoint support, though it's mostly
differences in memory mapping, and the question on how to represent
endpoint mode PCI in the device-tree is thus open.

Many thanks to Stefan Roese for testing & fixing up the 405EX bits !
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NStefan Roese <sr@denx.de>
Signed-off-by: NJosh Boyer <jwboyer@linux.vnet.ibm.com>