irqchip/gic-v3: Add EPPI range support

Expand the pre-existing PPI support to be able to deal with the
Extended PPI range (EPPI). This includes obtaining the number of PPIs
from each individual redistributor, and compute the minimum set
(just in case someone builds something really clever...).

Signed-off-by: Marc Zyngier <maz@kernel.org>

include/linux/irqchip/arm-gic-v3.h

@@ -124,6 +124,18 @@
 
 #define GICR_TYPER_CPU_NUMBER(r)	(((r) >> 8) & 0xffff)
 
+#define EPPI_BASE_INTID			1056
+
+#define GICR_TYPER_NR_PPIS(r)						\
+	({								\
+		unsigned int __ppinum = ((r) >> 27) & 0x1f;		\
+		unsigned int __nr_ppis = 16;				\
+		if (__ppinum == 1 || __ppinum == 2)			\
+			__nr_ppis +=  __ppinum * 32;			\
+									\
+		__nr_ppis;						\
+	 })
+
 #define GICR_WAKER_ProcessorSleep	(1U << 1)
 #define GICR_WAKER_ChildrenAsleep	(1U << 2)