x86, e820: remove end_user_pfn

end_user_pfn used to modify the meaning of the e820 maps.

Now that all e820 operations are cleaned up, unified, tightened up,
the e820 map always get updated to reality, we don't need to keep
this secondary mechanism anymore.

If you hit this commit in bisection it means something slipped through.
Signed-off-by: NYinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

arch/x86/kernel/e820.c

@@ -1048,11 +1048,6 @@ u64 __init early_reserve_e820(u64 startt, u64 sizet, u64 align)
 # define MAX_ARCH_PFN MAXMEM>>PAGE_SHIFT
 #endif
 
-/*
- * Last pfn which the user wants to use.
- */
-unsigned long __initdata end_user_pfn = MAX_ARCH_PFN;
-
 /*
  * Find the highest page frame number we have available
  */
@@ -1085,8 +1080,6 @@ static unsigned long __init e820_end_pfn(unsigned long limit_pfn, unsigned type)
 
 	if (last_pfn > max_arch_pfn)
 		last_pfn = max_arch_pfn;
-	if (last_pfn > end_user_pfn)
-		last_pfn = end_user_pfn;
 
 	printk(KERN_INFO "last_pfn = %#lx max_arch_pfn = %#lx\n",
 			 last_pfn, max_arch_pfn);
@@ -1131,12 +1124,6 @@ int __init e820_find_active_region(const struct e820entry *ei,
 	if (*ei_endpfn > last_pfn)
 		*ei_endpfn = last_pfn;
 
-	/* Obey end_user_pfn to save on memmap */
-	if (*ei_startpfn >= end_user_pfn)
-		return 0;
-	if (*ei_endpfn > end_user_pfn)
-		*ei_endpfn = end_user_pfn;
-
 	return 1;
 }
 
@@ -1201,7 +1188,6 @@ static int __init parse_memopt(char *p)
 
 	userdef = 1;
 	mem_size = memparse(p, &p);
-	end_user_pfn = mem_size>>PAGE_SHIFT;
 	e820_remove_range(mem_size, ULLONG_MAX - mem_size, E820_RAM, 1);
 
 	return 0;
@@ -1245,10 +1231,9 @@ static int __init parse_memmap_opt(char *p)
 	} else if (*p == '$') {
 		start_at = memparse(p+1, &p);
 		e820_add_region(start_at, mem_size, E820_RESERVED);
-	} else {
-		end_user_pfn = (mem_size >> PAGE_SHIFT);
+	} else
 		e820_remove_range(mem_size, ULLONG_MAX - mem_size, E820_RAM, 1);
-	}
+
 	return *p == '\0' ? 0 : -EINVAL;
 }
 early_param("memmap", parse_memmap_opt);