ARM: exynos: Fix imprecise abort during Exynos5422 suspend to RAM

Suspend to RAM on Odroid XU3/XU4/HC1 family (Exynos5422) causes
imprecise abort:

	PM: Syncing filesystems ... done.
	Freezing user space processes ... (elapsed 0.003 seconds) done.
	OOM killer disabled.
	Freezing remaining freezable tasks ... (elapsed 0.003 seconds) done.
	wake enabled for irq 139
	Disabling non-boot CPUs ...
	IRQ51 no longer affine to CPU1
	IRQ52 no longer affine to CPU2
	IRQ53 no longer affine to CPU3
	IRQ54 no longer affine to CPU4
	IRQ55 no longer affine to CPU5
	IRQ56 no longer affine to CPU6
	cpu cpu4: Dropping the link to regulator.40
	IRQ57 no longer affine to CPU7
	Unhandled fault: external abort on non-linefetch (0x1008) at 0xf081a028
	Internal error: : 1008 [#1] PREEMPT SMP ARM

with last call trace in exynos_suspend_enter().

The abort is caused by writing to register in secure part of sysram.
Boards booted under secure firmware (e.g. Hardkernel Odroid boards)
should access non-secure sysram.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>

1 files changed, 13 insertions, 3 deletions

diff --git a/arch/arm/mach-exynos/suspend.c b/arch/arm/mach-exynos/suspend.c
index 700d8d91ea93..bb8e3985acdb 100644
--- a/arch/arm/mach-exynos/suspend.c
+++ b/arch/arm/mach-exynos/suspend.c
@@ -63,6 +63,7 @@ struct exynos_pm_data {
 struct exynos_pm_state {
 	int cpu_state;
 	unsigned int pmu_spare3;
+	void __iomem *sysram_base;
 };
 
 static const struct exynos_pm_data *pm_data __ro_after_init;
@@ -261,7 +262,7 @@ static int exynos5420_cpu_suspend(unsigned long arg)
 	unsigned int cluster = MPIDR_AFFINITY_LEVEL(mpidr, 1);
 	unsigned int cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
 
-	writel_relaxed(0x0, sysram_base_addr + EXYNOS5420_CPU_STATE);
+	writel_relaxed(0x0, pm_state.sysram_base + EXYNOS5420_CPU_STATE);
 
 	if (IS_ENABLED(CONFIG_EXYNOS5420_MCPM)) {
 		mcpm_set_entry_vector(cpu, cluster, exynos_cpu_resume);
@@ -333,7 +334,7 @@ static void exynos5420_pm_prepare(void)
 	 * needs to restore it back in case, the primary cpu fails to
 	 * suspend for any reason.
 	 */
-	pm_state.cpu_state = readl_relaxed(sysram_base_addr +
+	pm_state.cpu_state = readl_relaxed(pm_state.sysram_base +
 					   EXYNOS5420_CPU_STATE);
 
 	exynos_pm_enter_sleep_mode();
@@ -453,7 +454,7 @@ static void exynos5420_pm_resume(void)
 
 	/* Restore the sysram cpu state register */
 	writel_relaxed(pm_state.cpu_state,
-		       sysram_base_addr + EXYNOS5420_CPU_STATE);
+		       pm_state.sysram_base + EXYNOS5420_CPU_STATE);
 
 	pmu_raw_writel(EXYNOS5420_USE_STANDBY_WFI_ALL,
 			S5P_CENTRAL_SEQ_OPTION);
@@ -658,4 +659,13 @@ void __init exynos_pm_init(void)
 
 	register_syscore_ops(&exynos_pm_syscore_ops);
 	suspend_set_ops(&exynos_suspend_ops);
+
+	/*
+	 * Applicable as of now only to Exynos542x. If booted under secure
+	 * firmware, the non-secure region of sysram should be used.
+	 */
+	if (exynos_secure_firmware_available())
+		pm_state.sysram_base = sysram_ns_base_addr;
+	else
+		pm_state.sysram_base = sysram_base_addr;
 }