[POWERPC] MPIC U3/U4 MSI backend

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>

1 files changed, 11 insertions, 0 deletions

diff --git a/arch/powerpc/sysdev/mpic.h b/arch/powerpc/sysdev/mpic.h
index 87cb2aea2fb..3a1c3d2c594 100644
--- a/arch/powerpc/sysdev/mpic.h
+++ b/arch/powerpc/sysdev/mpic.h
@@ -16,12 +16,23 @@ extern void mpic_msi_reserve_hwirq(struct mpic *mpic, irq_hw_number_t hwirq);
 extern int mpic_msi_init_allocator(struct mpic *mpic);
 extern irq_hw_number_t mpic_msi_alloc_hwirqs(struct mpic *mpic, int num);
 extern void mpic_msi_free_hwirqs(struct mpic *mpic, int offset, int num);
+extern int mpic_u3msi_init(struct mpic *mpic);
 #else
 static inline void mpic_msi_reserve_hwirq(struct mpic *mpic,
                                           irq_hw_number_t hwirq)
 {
         return;
 }
+
+static inline int mpic_u3msi_init(struct mpic *mpic)
+{
+        return -1;
+}
 #endif
 
+extern int mpic_set_irq_type(unsigned int virq, unsigned int flow_type);
+extern void mpic_end_irq(unsigned int irq);
+extern void mpic_mask_irq(unsigned int irq);
+extern void mpic_unmask_irq(unsigned int irq);
+
 #endif /* _POWERPC_SYSDEV_MPIC_H */