x86: fix: do not run code in amd_bus.c on non-AMD CPUs

Jan Beulich wrote:

> Even worse - this would even try to access the MSR on non-AMD CPUs
> (currently probably prevented just by the fact that only AMD ones use
> family values of 0x10 or higher).

This patch adds cpu vendor check to the postcore_initcalls.

Reported-by: Jan Beulich <[e-mail]>
Signed-off-by: Robert Richter <[e-mail]>
Signed-off-by: Ingo Molnar <[e-mail]>

arch/x86/pci/amd_bus.c

···
 	return 0;
 }
 
-postcore_initcall(early_fill_mp_bus_info);
+#else  /* !CONFIG_X86_64 */
 
-#endif
+static int __init early_fill_mp_bus_info(void) { return 0; }
+
+#endif /* !CONFIG_X86_64 */
 
 /* common 32/64 bit code */
 
···
 	return 0;
 }
 
-postcore_initcall(enable_pci_io_ecs);
+static int __init amd_postcore_init(void)
+{
+	if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
+		return 0;
+
+	early_fill_mp_bus_info();
+	enable_pci_io_ecs();
+
+	return 0;
+}
+
+postcore_initcall(amd_postcore_init);