diff --git a/arch/arm/include/asm/arch_gicv3.h b/arch/arm/include/asm/arch_gicv3.h
index 7da5503c0591411f43df6bc767fb8c4eef314789..e08d151840567dcb6085271200601666836b0771 100644
--- a/arch/arm/include/asm/arch_gicv3.h
+++ b/arch/arm/include/asm/arch_gicv3.h
@@ -117,6 +117,7 @@ static inline u32 gic_read_iar(void)
 	u32 irqstat;
 
 	asm volatile("mrc " __stringify(ICC_IAR1) : "=r" (irqstat));
+	dsb(sy);
 	return irqstat;
 }
 
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 0a73632b28d573cfa450e4edf75dacfc8683ad86..43dfd15c1dd22e4e18b1dbb37e1b3da811b0ceaf 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -78,6 +78,9 @@ struct its_node {
 
 #define ITS_ITT_ALIGN		SZ_256
 
+/* Convert page order to size in bytes */
+#define PAGE_ORDER_TO_SIZE(o)	(PAGE_SIZE << (o))
+
 struct event_lpi_map {
 	unsigned long		*lpi_map;
 	u16			*col_map;
@@ -600,11 +603,6 @@ static void its_unmask_irq(struct irq_data *d)
 	lpi_set_config(d, true);
 }
 
-static void its_eoi_irq(struct irq_data *d)
-{
-	gic_write_eoir(d->hwirq);
-}
-
 static int its_set_affinity(struct irq_data *d, const struct cpumask *mask_val,
 			    bool force)
 {
@@ -641,7 +639,7 @@ static struct irq_chip its_irq_chip = {
 	.name			= "ITS",
 	.irq_mask		= its_mask_irq,
 	.irq_unmask		= its_unmask_irq,
-	.irq_eoi		= its_eoi_irq,
+	.irq_eoi		= irq_chip_eoi_parent,
 	.irq_set_affinity	= its_set_affinity,
 	.irq_compose_msi_msg	= its_irq_compose_msi_msg,
 };
@@ -846,7 +844,6 @@ static int its_alloc_tables(const char *node_name, struct its_node *its)
 		u64 type = GITS_BASER_TYPE(val);
 		u64 entry_size = GITS_BASER_ENTRY_SIZE(val);
 		int order = get_order(psz);
-		int alloc_size;
 		int alloc_pages;
 		u64 tmp;
 		void *base;
@@ -878,9 +875,8 @@ static int its_alloc_tables(const char *node_name, struct its_node *its)
 			}
 		}
 
-		alloc_size = (1 << order) * PAGE_SIZE;
 retry_alloc_baser:
-		alloc_pages = (alloc_size / psz);
+		alloc_pages = (PAGE_ORDER_TO_SIZE(order) / psz);
 		if (alloc_pages > GITS_BASER_PAGES_MAX) {
 			alloc_pages = GITS_BASER_PAGES_MAX;
 			order = get_order(GITS_BASER_PAGES_MAX * psz);
@@ -933,7 +929,7 @@ static int its_alloc_tables(const char *node_name, struct its_node *its)
 			shr = tmp & GITS_BASER_SHAREABILITY_MASK;
 			if (!shr) {
 				cache = GITS_BASER_nC;
-				__flush_dcache_area(base, alloc_size);
+				__flush_dcache_area(base, PAGE_ORDER_TO_SIZE(order));
 			}
 			goto retry_baser;
 		}
@@ -966,7 +962,7 @@ static int its_alloc_tables(const char *node_name, struct its_node *its)
 		}
 
 		pr_info("ITS: allocated %d %s @%lx (psz %dK, shr %d)\n",
-			(int)(alloc_size / entry_size),
+			(int)(PAGE_ORDER_TO_SIZE(order) / entry_size),
 			its_base_type_string[type],
 			(unsigned long)virt_to_phys(base),
 			psz / SZ_1K, (int)shr >> GITS_BASER_SHAREABILITY_SHIFT);