[IA64] lazy_mmu_prot_update needs to be aware of huge pages

Function lazy_mmu_prot_update is also used on huge pages when it is called
by set_huge_ptep_writable, but it isn't aware of huge pages.
Signed-off-by: Zhang Yanmin <yanmin.zhang@intel.com>
Acked-by: Ken Chen <kenneth.w.chen@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

arch/ia64/mm/init.c

@@ -109,6 +109,7 @@ lazy_mmu_prot_update (pte_t pte)
 {
 	unsigned long addr;
 	struct page *page;
+	unsigned long order;
 
 	if (!pte_exec(pte))
 		return;				/* not an executable page... */
@@ -119,6 +120,11 @@ lazy_mmu_prot_update (pte_t pte)
 	if (test_bit(PG_arch_1, &page->flags))
 		return;				/* i-cache is already coherent with d-cache */
 
+	if (PageCompound(page)) {
+		order = (unsigned long) (page[1].lru.prev);
+		flush_icache_range(addr, addr + (1UL << order << PAGE_SHIFT));
+	}
+	else
 		flush_icache_range(addr, addr + PAGE_SIZE);
 	set_bit(PG_arch_1, &page->flags);	/* mark page as clean */
 }