[PATCH] ARM: pm: fix HYP/SVC mode mismatch when MCPM is used

[Marek Szyprowski]

MCPM does a soft reset of the CPUs and uses common cpu_resume() routine to
perform low-level platform initialization. This results in a try to install
HYP stubs for the second time for each CPU and results in false HYP/SVC
mode mismatch detection. The HYP stubs are already installed at the
beginning of the kernel initialization on the boot CPU (head.S) or in the
secondary_startup() for other CPUs. To fix this issue MCPM code should use
a cpu_resume() routine without HYP stubs installation.

This change fixes HYP/SVC mode mismatch on Samsung Exynos5422-based Odroid
XU3/XU4/HC1 boards.

Fixes: 3721924c8154 ("ARM: 8081/1: MCPM: provide infrastructure to allow for 
MCPM loopback")
Signed-off-by: Marek Szyprowski <m.szyprow...@samsung.com>
---
 arch/arm/common/mcpm_entry.c   |  2 +-
 arch/arm/include/asm/suspend.h |  1 +
 arch/arm/kernel/sleep.S        | 11 +++++++++++
 3 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/arch/arm/common/mcpm_entry.c b/arch/arm/common/mcpm_entry.c
index ad574d20415c..1b1b82b37ce0 100644
--- a/arch/arm/common/mcpm_entry.c
+++ b/arch/arm/common/mcpm_entry.c
@@ -381,7 +381,7 @@ static int __init nocache_trampoline(unsigned long _arg)
        unsigned int cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
        phys_reset_t phys_reset;
 
-       mcpm_set_entry_vector(cpu, cluster, cpu_resume);
+       mcpm_set_entry_vector(cpu, cluster, cpu_resume_no_hyp);
        setup_mm_for_reboot();
 
        __mcpm_cpu_going_down(cpu, cluster);
diff --git a/arch/arm/include/asm/suspend.h b/arch/arm/include/asm/suspend.h
index 452bbdcbcc83..506314265c6f 100644
--- a/arch/arm/include/asm/suspend.h
+++ b/arch/arm/include/asm/suspend.h
@@ -10,6 +10,7 @@ struct sleep_save_sp {
 };
 
 extern void cpu_resume(void);
+extern void cpu_resume_no_hyp(void);
 extern void cpu_resume_arm(void);
 extern int cpu_suspend(unsigned long, int (*)(unsigned long));
 
diff --git a/arch/arm/kernel/sleep.S b/arch/arm/kernel/sleep.S
index a8257fc9cf2a..b856d183691e 100644
--- a/arch/arm/kernel/sleep.S
+++ b/arch/arm/kernel/sleep.S
@@ -122,6 +122,11 @@ ENDPROC(cpu_resume_after_mmu)
 
 #ifdef CONFIG_MMU
        .arm
+#ifdef CONFIG_MCPM
+ENTRY(cpu_resume_no_hyp)
+ARM_BE8(setend be)                     @ ensure we are in BE mode
+       b       0f
+#endif
 ENTRY(cpu_resume_arm)
  THUMB(        badr    r9, 1f          )       @ Kernel is entered in ARM.
  THUMB(        bx      r9              )       @ If this is a Thumb-2 kernel,
@@ -135,6 +140,9 @@ ARM_BE8(setend be)                  @ ensure we are in BE 
mode
        bl      __hyp_stub_install_secondary
 #endif
        safe_svcmode_maskall r1
+#ifdef CONFIG_MCPM
+0:
+#endif
        mov     r1, #0
        ALT_SMP(mrc p15, 0, r0, c0, c0, 5)
        ALT_UP_B(1f)
@@ -163,6 +171,9 @@ ENDPROC(cpu_resume)
 
 #ifdef CONFIG_MMU
 ENDPROC(cpu_resume_arm)
+#endif
+#ifdef CONFIG_MCPM
+ENDPROC(cpu_resume_no_hyp)
 #endif
 
        .align 2
-- 
2.17.1