Make irq_domain_ops pointer a constant to make it safer for multiple
instances to share the same ops pointer and change the irq_domain code
so that it does not modify the ops.

v4: Fix mismatched type reference in powerpc code
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Milton Miller <miltonm@bga.com>
Tested-by: NOlof Johansson <olof@lixom.net>

This patch drops the powerpc-specific irq_host structures and uses the common
irq_domain strucutres defined in linux/irqdomain.h.  It also fixes all
the users to use the new structure names.

Renaming irq_host to irq_domain has been discussed for a long time, and this
patch is a step in the process of generalizing the powerpc virq code to be
usable by all architecture.

An astute reader will notice that this patch actually removes the irq_host
structure instead of renaming it.  This is because the irq_domain structure
already exists in include/linux/irqdomain.h and has the needed data members.
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Milton Miller <miltonm@bga.com>
Tested-by: NOlof Johansson <olof@lixom.net>

On machines using the Apple U4 bridge (AKA IBM CPC945) PCIe interface such
as the latest generation G5 machines x16 slot or the x16 slot of the
PowerStation, MSIs are currently broken (and will oops when enabling).

This fixes the oops and implements proper support for those. Instead of
using the PCIe <-> HT bridge conversion, on such slots we need to use
a bunch of magic registers in the bridge as the MSI target, encoding
the interrupt number in the low bits of the address itself
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This affects the U3 MSI code as well as the PASEMI MSI code.  We keep
some of the MPIC routines as helpers, and also the U3 best-guess
reservation logic.  The rest is replaced by the generic code.

And a few printk format changes due to hwirq type change.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Some of the routines defined in mpic_msi.c are declared mpic.h,
so the former should include the latter.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

Create a helper function (alloc_maybe_bootmem) that is marked __init_refok
to limit the chances of mistakenly referring to other __init routines.

WARNING: vmlinux.o(.text+0x2a9c4): Section mismatch: reference to .init.text:.__alloc_bootmem (between '.update_dn_pci_info' and '.pci_dn_reconfig_notifier')
WARNING: vmlinux.o(.text+0x36430): Section mismatch: reference to .init.text:.__alloc_bootmem (between '.mpic_msi_init_allocator' and '.find_ht_magic_addr')
WARNING: vmlinux.o(.text+0x5e804): Section mismatch: reference to .init.text:.__alloc_bootmem (between '.celleb_setup_phb' and '.celleb_fake_pci_write_config')
WARNING: vmlinux.o(.text+0x5e8e8): Section mismatch: reference to .init.text:.__alloc_bootmem (between '.celleb_setup_phb' and '.celleb_fake_pci_write_config')
WARNING: vmlinux.o(.text+0x5e968): Section mismatch: reference to .init.text:.__alloc_bootmem (between '.celleb_setup_phb' and '.celleb_fake_pci_write_config')
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

The majority of irq_host implementations (3 out of 4) are associated
with a device_node, and need to stash it somewhere. Rather than having
it somewhere different for each host, add an optional device_node pointer
to the irq_host structure.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NPaul 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: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>