[PATCH] powerpc/mpic: Fix mapping of "DCR" based MPIC variants

[Benjamin Herrenschmidt]

Commit 31207dab7d2e63795eb15823947bd2f7025b08e2
"Fix incorrect allocation of interrupt rev-map"
introduced a regression crashing on boot on machines using
a "DCR" based MPIC, such as the Cell blades.

The reason is that the irq host data structure is initialized
much later as a result of that patch, causing our calls to
mpic_map() do be done before we have a host setup.

Unfortunately, this breaks _mpic_map_dcr() which uses the
mpic->irqhost to get to the device node.

This fixes it by, instead, passing the device node explicitely
to mpic_map().

Signed-off-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
---

 arch/powerpc/sysdev/mpic.c |   29 ++++++++++++++++-------------
 1 file changed, 16 insertions(+), 13 deletions(-)

--- linux-work.orig/arch/powerpc/sysdev/mpic.c	2009-06-23 11:30:14.000000000 +1000
+++ linux-work/arch/powerpc/sysdev/mpic.c	2009-06-23 11:45:17.000000000 +1000
@@ -279,28 +279,29 @@ static void _mpic_map_mmio(struct mpic *
 }
 
 #ifdef CONFIG_PPC_DCR
-static void _mpic_map_dcr(struct mpic *mpic, struct mpic_reg_bank *rb,
+static void _mpic_map_dcr(struct mpic *mpic, struct device_node *node,
+			  struct mpic_reg_bank *rb,
 			  unsigned int offset, unsigned int size)
 {
 	const u32 *dbasep;
 
-	dbasep = of_get_property(mpic->irqhost->of_node, "dcr-reg", NULL);
+	dbasep = of_get_property(node, "dcr-reg", NULL);
 
-	rb->dhost = dcr_map(mpic->irqhost->of_node, *dbasep + offset, size);
+	rb->dhost = dcr_map(node, *dbasep + offset, size);
 	BUG_ON(!DCR_MAP_OK(rb->dhost));
 }
 
-static inline void mpic_map(struct mpic *mpic, phys_addr_t phys_addr,
-			    struct mpic_reg_bank *rb, unsigned int offset,
-			    unsigned int size)
+static inline void mpic_map(struct mpic *mpic, struct device_node *node,
+			    phys_addr_t phys_addr, struct mpic_reg_bank *rb,
+			    unsigned int offset, unsigned int size)
 {
 	if (mpic->flags & MPIC_USES_DCR)
-		_mpic_map_dcr(mpic, rb, offset, size);
+		_mpic_map_dcr(mpic, node, rb, offset, size);
 	else
 		_mpic_map_mmio(mpic, phys_addr, rb, offset, size);
 }
 #else /* CONFIG_PPC_DCR */
-#define mpic_map(m,p,b,o,s)	_mpic_map_mmio(m,p,b,o,s)
+#define mpic_map(m,n,p,b,o,s)	_mpic_map_mmio(m,p,b,o,s)
 #endif /* !CONFIG_PPC_DCR */
 
 
@@ -1152,8 +1153,8 @@ struct mpic * __init mpic_alloc(struct d
 	}
 
 	/* Map the global registers */
-	mpic_map(mpic, paddr, &mpic->gregs, MPIC_INFO(GREG_BASE), 0x1000);
-	mpic_map(mpic, paddr, &mpic->tmregs, MPIC_INFO(TIMER_BASE), 0x1000);
+	mpic_map(mpic, node, paddr, &mpic->gregs, MPIC_INFO(GREG_BASE), 0x1000);
+	mpic_map(mpic, node, paddr, &mpic->tmregs, MPIC_INFO(TIMER_BASE), 0x1000);
 
 	/* Reset */
 	if (flags & MPIC_WANTS_RESET) {
@@ -1194,7 +1195,7 @@ struct mpic * __init mpic_alloc(struct d
 
 	/* Map the per-CPU registers */
 	for (i = 0; i < mpic->num_cpus; i++) {
-		mpic_map(mpic, paddr, &mpic->cpuregs[i],
+		mpic_map(mpic, node, paddr, &mpic->cpuregs[i],
 			 MPIC_INFO(CPU_BASE) + i * MPIC_INFO(CPU_STRIDE),
 			 0x1000);
 	}
@@ -1202,7 +1203,7 @@ struct mpic * __init mpic_alloc(struct d
 	/* Initialize main ISU if none provided */
 	if (mpic->isu_size == 0) {
 		mpic->isu_size = mpic->num_sources;
-		mpic_map(mpic, paddr, &mpic->isus[0],
+		mpic_map(mpic, node, paddr, &mpic->isus[0],
 			 MPIC_INFO(IRQ_BASE), MPIC_INFO(IRQ_STRIDE) * mpic->isu_size);
 	}
 	mpic->isu_shift = 1 + __ilog2(mpic->isu_size - 1);
@@ -1256,8 +1257,10 @@ void __init mpic_assign_isu(struct mpic 
 
 	BUG_ON(isu_num >= MPIC_MAX_ISU);
 
-	mpic_map(mpic, paddr, &mpic->isus[isu_num], 0,
+	mpic_map(mpic, mpic->irqhost->of_node,
+		 paddr, &mpic->isus[isu_num], 0,
 		 MPIC_INFO(IRQ_STRIDE) * mpic->isu_size);
+
 	if ((isu_first + mpic->isu_size) > mpic->num_sources)
 		mpic->num_sources = isu_first + mpic->isu_size;
 }