[PATCH AUTOSEL 4.9 088/251] ARM: 8847/1: pm: fix HYP/SVC mode mismatch when MCPM is used

Sasha Levin
2020-01-16T18:09:30Z

From: Marek Szyprowski <m.szyprowski@samsung.com>

[ Upstream commit ca70ea43f80c98582f5ffbbd1e6f4da2742da0c4 ]

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.szyprowski@samsung.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Tested-by: Anand Moon <linux.amoon@gmail.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/arm/common/mcpm_entry.c | 2 +-
arch/arm/include/asm/suspend.h | 1 +
arch/arm/kernel/sleep.S | 12 ++++++++++++
3 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/arch/arm/common/mcpm_entry.c b/arch/arm/common/mcpm_entry.c
index a923524d1040..8617323eb273 100644
--- a/arch/arm/common/mcpm_entry.c
+++ b/arch/arm/common/mcpm_entry.c
@@ -379,7 +379,7 @@ 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 6c7182f32cef..e6c2f426f8c8 100644
--- a/arch/arm/include/asm/suspend.h
+++ b/arch/arm/include/asm/suspend.h
@@ -7,6 +7,7 @@ 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 0f6c1000582c..c8569390e7e7 100644
--- a/arch/arm/kernel/sleep.S
+++ b/arch/arm/kernel/sleep.S
@@ -119,6 +119,14 @@ ENDPROC(cpu_resume_after_mmu)
.text
.align

+#ifdef CONFIG_MCPM
+ .arm
+THUMB( .thumb )
+ENTRY(cpu_resume_no_hyp)
+ARM_BE8(setend be) @ ensure we are in BE mode
+ b no_hyp
+#endif
+
#ifdef CONFIG_MMU
.arm
ENTRY(cpu_resume_arm)
@@ -134,6 +142,7 @@ ARM_BE8(setend be) @ ensure we are in BE mode
bl __hyp_stub_install_secondary
#endif
safe_svcmode_maskall r1
+no_hyp:
mov r1, #0
ALT_SMP(mrc p15, 0, r0, c0, c0, 5)
ALT_UP_B(1f)
@@ -162,6 +171,9 @@ ENDPROC(cpu_resume)

#ifdef CONFIG_MMU
ENDPROC(cpu_resume_arm)
+#endif
+#ifdef CONFIG_MCPM
+ENDPROC(cpu_resume_no_hyp)
#endif

.align 2
--
2.20.1