kvm/ppc/mpic: in-kernel MPIC emulation

Hook the MPIC code up to the KVM interfaces, add locking, etc.

Signed-off-by: Scott Wood <scottwood@freescale.com>
[agraf: add stub function for kvmppc_mpic_set_epr, non-booke, 64bit]
Signed-off-by: Alexander Graf <agraf@suse.de>

Documentation/virtual/kvm/devices/mpic.txt

@@ -0,0 +1,37 @@
+MPIC interrupt controller
+=========================
+
+Device types supported:
+  KVM_DEV_TYPE_FSL_MPIC_20     Freescale MPIC v2.0
+  KVM_DEV_TYPE_FSL_MPIC_42     Freescale MPIC v4.2
+
+Only one MPIC instance, of any type, may be instantiated.  The created
+MPIC will act as the system interrupt controller, connecting to each
+vcpu's interrupt inputs.
+
+Groups:
+  KVM_DEV_MPIC_GRP_MISC
+  Attributes:
+    KVM_DEV_MPIC_BASE_ADDR (rw, 64-bit)
+      Base address of the 256 KiB MPIC register space.  Must be
+      naturally aligned.  A value of zero disables the mapping.
+      Reset value is zero.
+
+  KVM_DEV_MPIC_GRP_REGISTER (rw, 32-bit)
+    Access an MPIC register, as if the access were made from the guest.
+    "attr" is the byte offset into the MPIC register space.  Accesses
+    must be 4-byte aligned.
+
+    MSIs may be signaled by using this attribute group to write
+    to the relevant MSIIR.
+
+  KVM_DEV_MPIC_GRP_IRQ_ACTIVE (rw, 32-bit)
+    IRQ input line for each standard openpic source.  0 is inactive and 1
+    is active, regardless of interrupt sense.
+
+    For edge-triggered interrupts:  Writing 1 is considered an activating
+    edge, and writing 0 is ignored.  Reading returns 1 if a previously
+    signaled edge has not been acknowledged, and 0 otherwise.
+
+    "attr" is the IRQ number.  IRQ numbers for standard sources are the
+    byte offset of the relevant IVPR from EIVPR0, divided by 32.