1 files changed, 27 insertions, 2 deletions

diff --git a/arch/powerpc/kernel/security.c b/arch/powerpc/kernel/security.c
index f6f469fc4073..9b8631533e02 100644
--- a/arch/powerpc/kernel/security.c
+++ b/arch/powerpc/kernel/security.c
@@ -4,6 +4,7 @@
 //
 // Copyright 2018, Michael Ellerman, IBM Corporation.
 
+#include <linux/cpu.h>
 #include <linux/kernel.h>
 #include <linux/device.h>
 #include <linux/seq_buf.h>
@@ -22,10 +23,14 @@ enum count_cache_flush_type {
         COUNT_CACHE_FLUSH_SW    = 0x2,
         COUNT_CACHE_FLUSH_HW    = 0x4,
 };
-static enum count_cache_flush_type count_cache_flush_type;
+static enum count_cache_flush_type count_cache_flush_type = COUNT_CACHE_FLUSH_NONE;
 
 bool barrier_nospec_enabled;
 static bool no_nospec;
+static bool btb_flush_enabled;
+#ifdef CONFIG_PPC_FSL_BOOK3E
+static bool no_spectrev2;
+#endif
 
 static void enable_barrier_nospec(bool enable)
 {
@@ -101,6 +106,23 @@ static __init int barrier_nospec_debugfs_init(void)
 device_initcall(barrier_nospec_debugfs_init);
 #endif /* CONFIG_DEBUG_FS */
 
+#ifdef CONFIG_PPC_FSL_BOOK3E
+static int __init handle_nospectre_v2(char *p)
+{
+        no_spectrev2 = true;
+
+        return 0;
+}
+early_param("nospectre_v2", handle_nospectre_v2);
+void setup_spectre_v2(void)
+{
+        if (no_spectrev2)
+                do_btb_flush_fixups();
+        else
+                btb_flush_enabled = true;
+}
+#endif /* CONFIG_PPC_FSL_BOOK3E */
+
 #ifdef CONFIG_PPC_BOOK3S_64
 ssize_t cpu_show_meltdown(struct device *dev, struct device_attribute *attr, char *buf)
 {
@@ -191,8 +213,11 @@ ssize_t cpu_show_spectre_v2(struct device *dev, struct device_attribute *attr, c
 
                 if (count_cache_flush_type == COUNT_CACHE_FLUSH_HW)
                         seq_buf_printf(&s, "(hardware accelerated)");
-        } else
+        } else if (btb_flush_enabled) {
+                seq_buf_printf(&s, "Mitigation: Branch predictor state flush");
+        } else {
                 seq_buf_printf(&s, "Vulnerable");
+        }
 
         seq_buf_printf(&s, "\n");