[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, 7 insertions, 5 deletions

diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c
index fc0428aea0c0..4fd2bec89916 100644
--- a/arch/powerpc/sysdev/mpic.c
+++ b/arch/powerpc/sysdev/mpic.c
@@ -618,7 +618,7 @@ static irqreturn_t mpic_ipi_action(int irq, void *dev_id)
  */
 
 
-static void mpic_unmask_irq(unsigned int irq)
+void mpic_unmask_irq(unsigned int irq)
 {
         unsigned int loops = 100000;
         struct mpic *mpic = mpic_from_irq(irq);
@@ -638,7 +638,7 @@ static void mpic_unmask_irq(unsigned int irq)
         } while(mpic_irq_read(src, MPIC_INFO(IRQ_VECTOR_PRI)) & MPIC_VECPRI_MASK);
 }
 
-static void mpic_mask_irq(unsigned int irq)
+void mpic_mask_irq(unsigned int irq)
 {
         unsigned int loops = 100000;
         struct mpic *mpic = mpic_from_irq(irq);
@@ -659,7 +659,7 @@ static void mpic_mask_irq(unsigned int irq)
         } while(!(mpic_irq_read(src, MPIC_INFO(IRQ_VECTOR_PRI)) & MPIC_VECPRI_MASK));
 }
 
-static void mpic_end_irq(unsigned int irq)
+void mpic_end_irq(unsigned int irq)
 {
         struct mpic *mpic = mpic_from_irq(irq);
 
@@ -792,7 +792,7 @@ static unsigned int mpic_type_to_vecpri(struct mpic *mpic, unsigned int type)
         }
 }
 
-static int mpic_set_irq_type(unsigned int virq, unsigned int flow_type)
+int mpic_set_irq_type(unsigned int virq, unsigned int flow_type)
 {
         struct mpic *mpic = mpic_from_irq(virq);
         unsigned int src = mpic_irq_to_hw(virq);
@@ -1203,8 +1203,10 @@ void __init mpic_init(struct mpic *mpic)
 
         /* Do the HT PIC fixups on U3 broken mpic */
         DBG("MPIC flags: %x\n", mpic->flags);
-        if ((mpic->flags & MPIC_U3_HT_IRQS) && (mpic->flags & MPIC_PRIMARY))
+        if ((mpic->flags & MPIC_U3_HT_IRQS) && (mpic->flags & MPIC_PRIMARY)) {
                 mpic_scan_ht_pics(mpic);
+                mpic_u3msi_init(mpic);
+        }
 
         for (i = 0; i < mpic->num_sources; i++) {
                 /* start with vector = source number, and masked */