Revert "UBUNTU: SAUCE: rfi-flush: Add no_rfi_flush and nopti comandline options"

This reverts commit 2d8d8a24.

CVE-2017-5754

BugLink: http://bugs.launchpad.net/bugs/1756121

The functionality of this commit will be provided by the following
upstream patch series:
  * powerpc/64s: Allow control of RFI flush via debugfs
  * powerpc/64s: Wire up cpu_show_meltdown()
  * powerpc/powernv: Check device-tree for RFI flush settings
  * powerpc/pseries: Query hypervisor for RFI flush settings
  * powerpc/64s: Support disabling RFI flush with no_rfi_flush and nopti
  * powerpc/64s: Add support for RFI flush of L1-D cache
  * powerpc/64s: Convert slb_miss_common to use RFI_TO_USER/KERNEL
  * powerpc/64: Convert the syscall exit path to use RFI_TO_USER/KERNEL
  * powerpc/64: Convert fast_exception_return to use RFI_TO_USER/KERNEL
  * powerpc/64s: Simple RFI macro conversions
  * powerpc/64: Add macros for annotating the destination of rfid/hrfid
  * powerpc/pseries: Add H_GET_CPU_CHARACTERISTICS flags & wrapper
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

arch/powerpc/kernel/setup_64.c

@@ -835,29 +835,8 @@ early_initcall(disable_hardlockup_detector);
 #ifdef CONFIG_PPC_BOOK3S_64
 static enum l1d_flush_type enabled_flush_types;
 static void *l1d_flush_fallback_area;
-static bool no_rfi_flush;
 bool rfi_flush;
 
-static int __init handle_no_rfi_flush(char *p)
-{
-	pr_info("rfi-flush: disabled on command line.");
-	no_rfi_flush = true;
-	return 0;
-}
-early_param("no_rfi_flush", handle_no_rfi_flush);
-
-/*
- * The RFI flush is not KPTI, but because users will see doco that says to use
- * nopti we hijack that option here to also disable the RFI flush.
- */
-static int __init handle_no_pti(char *p)
-{
-	pr_info("rfi-flush: disabling due to 'nopti' on command line.\n");
-	handle_no_rfi_flush(NULL);
-	return 0;
-}
-early_param("nopti", handle_no_pti);
-
 static void do_nothing(void *unused)
 {
 	/*
@@ -923,8 +902,6 @@ void __init setup_rfi_flush(enum l1d_flush_type types, bool enable)
 		pr_info("rfi-fixups: Using mttrig type flush\n");
 
 	enabled_flush_types = types;
-
-	if (!no_rfi_flush)
-		rfi_flush_enable(enable);
+	rfi_flush_enable(enable);
 }
 #endif /* CONFIG_PPC_BOOK3S_64 */