x86/power/32: Move SYSENTER MSR restoration to fix_processor_context()

x86_64 restores system call MSRs in fix_processor_context(), and
x86_32 restored them along with segment registers.  The 64-bit
variant makes more sense, so move the 32-bit code to match the
64-bit code.

No side effects are expected to runtime behavior.

Tested-by: Jarkko Nikula <[email protected]>
Signed-off-by: Andy Lutomirski <[email protected]>
Acked-by: Rafael J. Wysocki <[email protected]>
Acked-by: Thomas Gleixner <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Josh Poimboeuf <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Pavel Machek <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Rafael J. Wysocki <[email protected]>
Cc: Zhang Rui <[email protected]>
Link: http://lkml.kernel.org/r/65158f8d7ee64dd6bbc6c1c83b3b34aaa854e3ae.1513286253.git.luto@kernel.org
Signed-off-by: Ingo Molnar <[email protected]>

Author: amluto

arch/x86/power/cpu.c

@@ -174,6 +174,9 @@ static void fix_processor_context(void)
 	write_gdt_entry(desc, GDT_ENTRY_TSS, &tss, DESC_TSS);
 
 	syscall_init();				/* This sets MSR_*STAR and related */
+#else
+	if (boot_cpu_has(X86_FEATURE_SEP))
+		enable_sep_cpu();
 #endif
 	load_TR_desc();				/* This does ltr */
 	load_mm_ldt(current->active_mm);	/* This does lldt */
@@ -237,12 +240,6 @@ static void notrace __restore_processor_state(struct saved_context *ctxt)
 	loadsegment(fs, ctxt->fs);
 	loadsegment(gs, ctxt->gs);
 	loadsegment(ss, ctxt->ss);
-
-	/*
-	 * sysenter MSRs
-	 */
-	if (boot_cpu_has(X86_FEATURE_SEP))
-		enable_sep_cpu();
 #else
 /* CONFIG_X86_64 */
 	asm volatile ("movw %0, %%ds" :: "r" (ctxt->ds));