[POWERPC] pasemi: Implement NMI support

Some PWRficient-based boards have a NMI button that's wired up to a GPIO
as interrupt source. By configuring the openpic accordingly, these get
delivered as a machine check with high priority, instead of as an external
interrupt.

The device tree contains a property "nmi-source" in the openpic node
for these systems, and it's the (hwirq) source for the input.

Also, for these interrupts, the IACK is read from another register than
the regular (MCACK instead), but they are EOI'd as usual. So implement
said function for the mpic driver.

Finally, move a couple of external function defines to include/ instead
of local under sysdev. Being able to mask/unmask and eoi directly saves
us from setting up a dummy irq handler that will never be called.

Signed-off-by: Olof Johansson <olof@lixom.net>

1 files changed, 27 insertions, 3 deletions

diff --git a/arch/powerpc/platforms/pasemi/setup.c b/arch/powerpc/platforms/pasemi/setup.c
index b5dfd4252110..eb271fded876 100644
--- a/arch/powerpc/platforms/pasemi/setup.c
+++ b/arch/powerpc/platforms/pasemi/setup.c
@@ -61,6 +61,7 @@ struct mce_regs {
 
 static struct mce_regs mce_regs[MAX_MCE_REGS];
 static int num_mce_regs;
+static int nmi_virq = NO_IRQ;
 
 
 static void pas_restart(char *cmd)
@@ -189,6 +190,8 @@ static __init void pas_init_IRQ(void)
         unsigned long openpic_addr;
         const unsigned int *opprop;
         int naddr, opplen;
+        int mpic_flags;
+        const unsigned int *nmiprop;
         struct mpic *mpic;
 
         mpic_node = NULL;
@@ -221,13 +224,26 @@ static __init void pas_init_IRQ(void)
         openpic_addr = of_read_number(opprop, naddr);
         printk(KERN_DEBUG "OpenPIC addr: %lx\n", openpic_addr);
 
+        mpic_flags = MPIC_PRIMARY | MPIC_LARGE_VECTORS;
+
+        nmiprop = of_get_property(mpic_node, "nmi-source", NULL);
+        if (nmiprop)
+                mpic_flags |= MPIC_ENABLE_MCK;
+
         mpic = mpic_alloc(mpic_node, openpic_addr,
-                          MPIC_PRIMARY|MPIC_LARGE_VECTORS,
-                          0, 0, "PASEMI-OPIC");
+                          mpic_flags, 0, 0, "PASEMI-OPIC");
         BUG_ON(!mpic);
 
         mpic_assign_isu(mpic, 0, openpic_addr + 0x10000);
         mpic_init(mpic);
+        /* The NMI/MCK source needs to be prio 15 */
+        if (nmiprop) {
+                nmi_virq = irq_create_mapping(NULL, *nmiprop);
+                mpic_irq_set_priority(nmi_virq, 15);
+                set_irq_type(nmi_virq, IRQ_TYPE_EDGE_RISING);
+                mpic_unmask_irq(nmi_virq);
+        }
+
         of_node_put(mpic_node);
         of_node_put(root);
 }
@@ -247,6 +263,14 @@ static int pas_machine_check_handler(struct pt_regs *regs)
 
         srr0 = regs->nip;
         srr1 = regs->msr;
+
+        if (mpic_get_mcirq() == nmi_virq) {
+                printk(KERN_ERR "NMI delivered\n");
+                debugger(regs);
+                mpic_end_irq(nmi_virq);
+                goto out;
+        }
+
         dsisr = mfspr(SPRN_DSISR);
         printk(KERN_ERR "Machine Check on CPU %d\n", cpu);
         printk(KERN_ERR "SRR0  0x%016lx SRR1 0x%016lx\n", srr0, srr1);
@@ -310,7 +334,7 @@ static int pas_machine_check_handler(struct pt_regs *regs)
                 }
         }
 
-
+out:
         /* SRR1[62] is from MSR[62] if recoverable, so pass that back */
         return !!(srr1 & 0x2);
 }