No longer call init_mtrrs() if there are no MTRRs, also made generic_init_mtrrs()

no longer try to access any MSRs when there are no MTRRs. Got it? :-)


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@17574 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/add-ons/kernel/cpu/x86/generic_x86.cpp

@@ -60,6 +60,9 @@ generic_count_mtrrs(void)
 void
 generic_init_mtrrs(uint32 count)
 {
+	if (count == 0)
+		return;
+
 	// disable and clear all MTRRs
 	// (we leave the fixed MTRRs as is)
 	// TODO: check if the fixed MTRRs are set on all CPUs identically?

src/system/kernel/arch/x86/arch_cpu.c

@@ -358,11 +358,9 @@ arch_cpu_init_post_modules(kernel_args *args)
 
 	close_module_list(cookie);
 
-	if (sCpuModule == NULL)
-		return B_OK;
-
-	// initialize MTRRs
-	call_all_cpus(&init_mtrrs, NULL);
+	// initialize MTRRs if available
+	if (x86_count_mtrrs > 0)
+		call_all_cpus(&init_mtrrs, NULL);
 
 	return B_OK;
 }