x86, e820: Clean up sanitize_e820_map() users

The argument 3 of sanitize_e820_map() will only be updated upon a
successful sanitization. Some of the callers have extra conditionals
for the same purpose. Clean them up.

default_machine_specific_memory_setup() must keep the extra
conditional because boot_params.e820_entries is an u8 and not an u32,
so the direct update would overwrite other fields in boot_params.

[ tglx: Massaged changelog ]

Signed-off-by: WANG Chao <chaowang@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Lee Chun-Yi <joeyli.kernel@gmail.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Link: http://lkml.kernel.org/r/1420601859-18439-1-git-send-email-chaowang@redhat.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

arch/x86/kernel/e820.c

@@ -184,9 +184,9 @@ void __init e820_print_map(char *who)
  * overwritten in the same location, starting at biosmap.
  *
  * The integer pointed to by pnr_map must be valid on entry (the
- * current number of valid entries located at biosmap) and will
- * be updated on return, with the new number of valid entries
- * (something no more than max_nr_map.)
+ * current number of valid entries located at biosmap). If the
+ * sanitizing succeeds the *pnr_map will be updated with the new
+ * number of valid entries (something no more than max_nr_map).
  *
  * The return value from sanitize_e820_map() is zero if it
  * successfully 'sanitized' the map entries passed in, and is -1
@@ -561,23 +561,15 @@ u64 __init e820_remove_range(u64 start, u64 size, unsigned old_type,
 
 void __init update_e820(void)
 {
-	u32 nr_map;
-
-	nr_map = e820.nr_map;
-	if (sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &nr_map))
+	if (sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map))
 		return;
-	e820.nr_map = nr_map;
 	printk(KERN_INFO "e820: modified physical RAM map:\n");
 	e820_print_map("modified");
 }
 static void __init update_e820_saved(void)
 {
-	u32 nr_map;
-
-	nr_map = e820_saved.nr_map;
-	if (sanitize_e820_map(e820_saved.map, ARRAY_SIZE(e820_saved.map), &nr_map))
-		return;
-	e820_saved.nr_map = nr_map;
+	sanitize_e820_map(e820_saved.map, ARRAY_SIZE(e820_saved.map),
+				&e820_saved.nr_map);
 }
 #define MAX_GAP_END 0x100000000ull
 /*
@@ -898,11 +890,9 @@ early_param("memmap", parse_memmap_opt);
 void __init finish_e820_parsing(void)
 {
 	if (userdef) {
-		u32 nr = e820.nr_map;
-
-		if (sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &nr) < 0)
+		if (sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map),
+					&e820.nr_map) < 0)
 			early_panic("Invalid user supplied memory map");
-		e820.nr_map = nr;
 
 		printk(KERN_INFO "e820: user-defined physical RAM map:\n");
 		e820_print_map("user");