x86: add table_top check for alloc_low_page in 64 bit

that range is from find_e820_area, so don't try to use end_pfn to see
if out of boundary...use table_top instead to avoid possible strange
result while cross the boundary...

also change early_printk to printk, because init_memory_mapping is after
early param parsing, and console=uart8250 already working at that time.
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

arch/x86/mm/init_64.c

@@ -227,6 +227,7 @@ void __init cleanup_highmap(void)
 
 static unsigned long __initdata table_start;
 static unsigned long __meminitdata table_end;
+static unsigned long __meminitdata table_top;
 
 static __meminit void *alloc_low_page(unsigned long *phys)
 {
@@ -240,7 +241,7 @@ static __meminit void *alloc_low_page(unsigned long *phys)
 		return adr;
 	}
 
-	if (pfn >= end_pfn)
+	if (pfn >= table_top)
 		panic("alloc_low_page: ran out of memory");
 
 	adr = early_ioremap(pfn * PAGE_SIZE, PAGE_SIZE);
@@ -372,10 +373,10 @@ static void __init find_early_table_space(unsigned long end)
 
 	table_start >>= PAGE_SHIFT;
 	table_end = table_start;
+	table_top = table_start + (tables >> PAGE_SHIFT);
 
-	early_printk("kernel direct mapping tables up to %lx @ %lx-%lx\n",
-		end, table_start << PAGE_SHIFT,
-		(table_start << PAGE_SHIFT) + tables);
+	printk(KERN_DEBUG "kernel direct mapping tables up to %lx @ %lx-%lx\n",
+		end, table_start << PAGE_SHIFT, table_top << PAGE_SHIFT);
 }
 
 static void __init init_gbpages(void)