x86/mm/cpa: Factor common code between cpa_flush_*()

The start of cpa_flush_range() and cpa_flush_array() is the same, use
a common function.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Cc: Bin Yang <bin.yang@intel.com>
Cc: Mark Gross <mark.gross@intel.com>
Link: https://lkml.kernel.org/r/20180919085948.138859183@infradead.org

arch/x86/mm/pageattr.c

@@ -285,22 +285,28 @@ static void cpa_flush_all(unsigned long cache)
 	on_each_cpu(__cpa_flush_all, (void *) cache, 1);
 }
 
-static void cpa_flush_range(unsigned long start, int numpages, int cache)
+static bool __cpa_flush_range(unsigned long start, int numpages, int cache)
 {
-	unsigned int i, level;
-	unsigned long addr;
-
 	BUG_ON(irqs_disabled() && !early_boot_irqs_disabled);
+
 	WARN_ON(PAGE_ALIGN(start) != start);
 
 	if (!static_cpu_has(X86_FEATURE_CLFLUSH)) {
 		cpa_flush_all(cache);
-		return;
+		return true;
 	}
 
 	flush_tlb_kernel_range(start, start + PAGE_SIZE * numpages);
 
-	if (!cache)
+	return !cache;
+}
+
+static void cpa_flush_range(unsigned long start, int numpages, int cache)
+{
+	unsigned int i, level;
+	unsigned long addr;
+
+	if (__cpa_flush_range(start, numpages, cache))
 		return;
 
 	/*
@@ -326,16 +332,7 @@ static void cpa_flush_array(unsigned long baddr, unsigned long *start,
 {
 	unsigned int i, level;
 
-	BUG_ON(irqs_disabled() && !early_boot_irqs_disabled);
-
-	if (!static_cpu_has(X86_FEATURE_CLFLUSH)) {
-		cpa_flush_all(cache);
-		return;
-	}
-
-	flush_tlb_kernel_range(baddr, baddr + PAGE_SIZE * numpages);
-
-	if (!cache)
+	if (__cpa_flush_range(baddr, numpages, cache))
 		return;
 
 	/*