3 files changed, 40 insertions, 0 deletions

diff --git a/arch/arm/include/asm/virt.h b/arch/arm/include/asm/virt.h
index 0a99723edbf2..86164df86cb4 100644
--- a/arch/arm/include/asm/virt.h
+++ b/arch/arm/include/asm/virt.h
@@ -47,6 +47,23 @@ unsigned long __hyp_get_vectors(void);
 #define __boot_cpu_mode (SVC_MODE)
 #endif
 
+#ifndef ZIMAGE
+void hyp_mode_check(void);
+
+/* Reports the availability of HYP mode */
+static inline bool is_hyp_mode_available(void)
+{
+        return ((__boot_cpu_mode & MODE_MASK) == HYP_MODE &&
+                !(__boot_cpu_mode & BOOT_CPU_MODE_MISMATCH));
+}
+
+/* Check if the bootloader has booted CPUs in different modes */
+static inline bool is_hyp_mode_mismatched(void)
+{
+        return !!(__boot_cpu_mode & BOOT_CPU_MODE_MISMATCH);
+}
+#endif
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* ! VIRT_H */
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index a81dcecc7343..04fd01feea86 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -55,6 +55,7 @@
 #include <asm/traps.h>
 #include <asm/unwind.h>
 #include <asm/memblock.h>
+#include <asm/virt.h>
 
 #if defined(CONFIG_DEPRECATED_PARAM_STRUCT)
 #include "compat.h"
@@ -937,6 +938,21 @@ static int __init meminfo_cmp(const void *_a, const void *_b)
         return cmp < 0 ? -1 : cmp > 0 ? 1 : 0;
 }
 
+void __init hyp_mode_check(void)
+{
+#ifdef CONFIG_ARM_VIRT_EXT
+        if (is_hyp_mode_available()) {
+                pr_info("CPU: All CPU(s) started in HYP mode.\n");
+                pr_info("CPU: Virtualization extensions available.\n");
+        } else if (is_hyp_mode_mismatched()) {
+                pr_warn("CPU: WARNING: CPU(s) started in wrong/inconsistent modes (primary CPU mode 0x%x)\n",
+                        __boot_cpu_mode & MODE_MASK);
+                pr_warn("CPU: This may indicate a broken bootloader or firmware.\n");
+        } else
+                pr_info("CPU: All CPU(s) started in SVC mode.\n");
+#endif
+}
+
 void __init setup_arch(char **cmdline_p)
 {
         struct machine_desc *mdesc;
@@ -980,6 +996,10 @@ void __init setup_arch(char **cmdline_p)
         if (is_smp())
                 smp_init_cpus();
 #endif
+
+        if (!is_smp())
+                hyp_mode_check();
+
         reserve_crashkernel();
 
         tcm_init();
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index ebd8ad274d76..adf226e718d2 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -42,6 +42,7 @@
 #include <asm/ptrace.h>
 #include <asm/localtimer.h>
 #include <asm/smp_plat.h>
+#include <asm/virt.h>
 
 /*
  * as from 2.5, kernels no longer have an init_tasks structure
@@ -287,6 +288,8 @@ void __init smp_cpus_done(unsigned int max_cpus)
                num_online_cpus(),
                bogosum / (500000/HZ),
                (bogosum / (5000/HZ)) % 100);
+
+        hyp_mode_check();
 }
 
 void __init smp_prepare_boot_cpu(void)